<?xml version="1.0"?>
<standard_name_table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="CFStandardNameTable-1.1.xsd">
  <version_number>12</version_number>
  <last_modified>2009-07-06T12:05:02Z</last_modified>
  <institution>Program for Climate Model Diagnosis and Intercomparison</institution>
  <contact>webmaster@pcmdi.llnl.gov</contact>
  <entry id="age_of_stratospheric_air">
    <canonical_units>s</canonical_units>
    <description>&quot;Age of stratospheric air&quot; means an estimate of the time since a parcel of stratospheric air was last in contact with the troposphere.</description>
  </entry>
  <entry id="air_density">
    <canonical_units>kg m-3</canonical_units>
    <description></description>
  </entry>
  <entry id="air_potential_temperature">
    <canonical_units>K</canonical_units>
    <grib>13</grib>
    <amip>theta</amip>
    <description>Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure.</description>
  </entry>
  <entry id="air_pressure">
    <canonical_units>Pa</canonical_units>
    <grib>1</grib>
    <amip>plev</amip>
    <description></description>
  </entry>
  <entry id="air_pressure_anomaly">
    <canonical_units>Pa</canonical_units>
    <grib>26</grib>
    <description>&quot;anomaly&quot; means difference from climatology.</description>
  </entry>
  <entry id="air_pressure_at_cloud_base">
    <canonical_units>Pa</canonical_units>
    <description>cloud_base refers to the base of the lowest cloud.</description>
  </entry>
  <entry id="air_pressure_at_cloud_top">
    <canonical_units>Pa</canonical_units>
    <description>cloud_top refers to the top of the highest cloud.</description>
  </entry>
  <entry id="air_pressure_at_convective_cloud_base">
    <canonical_units>Pa</canonical_units>
    <description>cloud_base refers to the base of the lowest cloud. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="air_pressure_at_convective_cloud_top">
    <canonical_units>Pa</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="air_pressure_at_freezing_level">
    <canonical_units>Pa</canonical_units>
    <description></description>
  </entry>
  <entry id="air_pressure_at_sea_level">
    <canonical_units>Pa</canonical_units>
    <grib>2 E151</grib>
    <amip>psl</amip>
    <description>sea_level means mean sea level, which is close to the geoid in sea areas. Air pressure at sea level is the quantity often abbreviated as MSLP or PMSL.</description>
  </entry>
  <entry id="air_temperature">
    <canonical_units>K</canonical_units>
    <grib>11 E130</grib>
    <amip>ta</amip>
    <description>Air temperature is the bulk temperature of the air, not the surface (skin) temperature.</description>
  </entry>
  <entry id="air_temperature_anomaly">
    <canonical_units>K</canonical_units>
    <grib>25</grib>
    <description>&quot;anomaly&quot; means difference from climatology. Air temperature is the bulk temperature of the air, not the surface (skin) temperature.</description>
  </entry>
  <entry id="air_temperature_at_cloud_top">
    <canonical_units>K</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Air temperature is the bulk temperature of the air, not the surface (skin) temperature.</description>
  </entry>
  <entry id="air_temperature_lapse_rate">
    <canonical_units>K m-1</canonical_units>
    <grib>19</grib>
    <description>Air temperature is the bulk temperature of the air, not the surface (skin) temperature. A lapse rate is the negative derivative of a quantity with respect to increasing height above the surface, or the (positive) derivative with respect to increasing depth.</description>
  </entry>
  <entry id="air_temperature_threshold">
    <canonical_units>K</canonical_units>
    <description>Air temperature is the bulk temperature of the air, not the surface (skin) temperature. Air temperature excess and deficit are calculated relative to the air temperature threshold.</description>
  </entry>
  <entry id="altimeter_range">
    <canonical_units>m</canonical_units>
    <description>An altimeter operates by sending out a short pulse of radiation and measuring the time required for the pulse to return from the sea surface; this measurement is used to calculate the distance between the instrument and the sea surface.  That measurement is called the &quot;altimeter range&quot; and does not include any range corrections.</description>
  </entry>
  <entry id="altimeter_range_correction_due_to_dry_troposphere">
    <canonical_units>m</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase.   To apply the altimeter range correction it must be added to the quantity with standard name altimeter_range.  &quot;Correction_due_to_dry_troposphere&quot; means a correction for dry gases in the troposphere, i.e. excluding the effect of liquid water.  Additional altimeter range corrections are given by the quantities with standard names altimeter_range_correction_due_to_wet_troposphere, altimeter_range_correction_due_to_ionosphere, sea_surface_height_correction_due_to_air_pressure_at_low_frequency and sea_surface_height_correction_due_to_air_pressure_and_wind_at_high_frequency.</description>
  </entry>
  <entry id="altimeter_range_correction_due_to_ionosphere">
    <canonical_units>m</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase.   To apply the altimeter range correction it must be added to the quantity with standard name altimeter_range.  &quot;Correction_due_to_ionosphere&quot; means a correction for the atmosphere's electron content in the ionosphere. Additional altimeter range corrections are given by the quantities with standard names altimeter_range_correction_due_to_wet_troposphere, altimeter_range_correction_due_to_dry_troposphere, sea_surface_height_correction_due_to_air_pressure_at_low_frequency and sea_surface_height_correction_due_to_air_pressure_and_wind_at_high_frequency.</description>
  </entry>
  <entry id="altimeter_range_correction_due_to_wet_troposphere">
    <canonical_units>m</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase.   To apply the altimeter range correction it must be added to the quantity with standard name altimeter_range.  &quot;Correction_due_to_wet_troposphere&quot; means a correction for the effect of liquid water in the troposphere.  Additional altimeter range corrections are given by the quantities with standard names altimeter_range_correction_due_to_dry_troposphere, altimeter_range_correction_due_to_ionosphere, sea_surface_height_correction_due_to_air_pressure_at_low_frequency and sea_surface_height_correction_due_to_air_pressure_and_wind_at_high_frequency.</description>
  </entry>
  <entry id="altitude">
    <canonical_units>m</canonical_units>
    <grib>8</grib>
    <description>Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level.</description>
  </entry>
  <entry id="altitude_at_top_of_dry_convection">
    <canonical_units>m</canonical_units>
    <description>Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level.</description>
  </entry>
  <entry id="angle_of_rotation_from_east_to_x">
    <canonical_units>degree</canonical_units>
    <description>The quantity with standard name angle_of_rotation_from_east_to_x is the angle, anticlockwise reckoned positive, between due East and (dr/di)jk, where r(i,j,k) is the vector 3D position of the point with coordinate indices (i,j,k).  It could be used for rotating vector fields between model space and latitude-longitude space.</description>
  </entry>
  <entry id="angle_of_rotation_from_east_to_y">
  <canonical_units>degree</canonical_units>
  <description>The quantity with standard name angle_of_rotation_from_east_to_y is the angle, anticlockwise reckoned positive, between due East and (dr/dj)ik, where r(i,j,k) is the vector 3D position of the point with coordinate indices (i,j,k).  It could be used for rotating vector fields between model space and latitude-longitude space.</description>
  </entry>
  <entry id="angstrom_exponent_of_ambient_aerosol_in_air">
  <canonical_units>1</canonical_units>
  <description> &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. The &quot;Angstrom exponent&quot; appears in the formula relating aerosol optical thickness to the wavelength of incident radiation: T(lambda) = T(lambda0) * [lambda/lambda0] ** (-1 * alpha) where alpha is the Angstrom exponent, lambda is the wavelength of incident radiation, lambda0 is a reference wavelength, T(lambda) and T(lambda0) are the values of aerosol optical thickness at wavelengths lambda and lambda0, respectively.</description>
  </entry>
  <entry id="area_fraction">
    <canonical_units>1</canonical_units>
    <description>&quot;Area fraction&quot; means the fraction of horizontal area. To specify which area is quantified by a variable of area_fraction, provide a coordinate variable or scalar coordinate variable of land_cover or surface_cover. Alternatively, if one is defined, use a more specific standard name of &quot;X_area_fraction&quot; for the fraction of horizontal area occupied by X.</description>
  </entry>
  <entry id="area_fraction_below_surface">
    <canonical_units>1</canonical_units>
    <amip>psbg</amip>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. The fraction of horizontal area where the surface specified by the axes other than horizontal axes, for instance an isobaric surface, is below the (ground or sea) surface.</description>
  </entry>
  <entry id="area_type">
    <canonical_units>1</canonical_units>
    <description>A variable with the standard name of area_type contains strings which indicate the nature of the surface e.g. land, sea, sea_ice. These strings are standardised.  Values must be taken from the area_type table.</description>
  </entry>
  <entry id="atmosphere_absolute_vorticity">
    <canonical_units>s-1</canonical_units>
    <grib>41</grib>
    <description>Absolute vorticity is the sum of relative vorticity and the upward component of vorticity due to the Earth's rotation.</description>
  </entry>
  <entry id="atmosphere_boundary_layer_thickness">
    <canonical_units>m</canonical_units>
    <amip>zmla</amip>
    <description>The atmosphere boundary layer thickness is the &quot;depth&quot; or &quot;height&quot; of the (atmosphere) planetary boundary layer.</description>
  </entry>
  <entry id="atmosphere_cloud_condensed_water_content">
    <canonical_units>kg m-2</canonical_units>
    <grib>76</grib>
    <amip>clwvi</amip>
    <description>&quot;condensed_water&quot; means liquid and ice. &quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_cloud_ice_content">
    <canonical_units>kg m-2</canonical_units>
    <grib>58</grib>
    <amip>clivi</amip>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_cloud_liquid_water_content">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_convective_cloud_condensed_water_content">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;condensed_water&quot; means liquid and ice. Convective cloud is that produced by the convection schemes in an atmosphere model. &quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_convective_cloud_liquid_water_content">
    <canonical_units>kg m-2</canonical_units>
    <description>Convective cloud is that produced by the convection schemes in an atmosphere model.  &quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_convective_mass_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics. The atmosphere convective mass flux is the vertical transport of mass for a field of cumulus clouds or thermals, given by the product of air density and vertical velocity. For an area-average, cell_methods should specify whether the average is over all the area or the area of updrafts only.</description>
  </entry>
  <entry id="atmosphere_dry_energy_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Dry energy is the sum of dry static energy and kinetic energy. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="atmosphere_dry_static_energy_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="atmosphere_eastward_stress_due_to_gravity_wave_drag">
    <canonical_units>Pa</canonical_units>
    <amip>tauugwd</amip>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Atmosphere_Xward_stress is a stress which tends to accelerate the atmosphere in direction X.</description>
  </entry>
  <entry id="atmosphere_energy_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. &quot;Atmosphere energy content&quot; has not yet been precisely defined! Please express your views on this quantity on the CF email list.</description>
  </entry>
  <entry id="atmosphere_enthalpy_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="atmosphere_heat_diffusivity">
    <canonical_units>m2 s-1</canonical_units>
    <description></description>
  </entry>
  <entry id="atmosphere_horizontal_streamfunction">
    <canonical_units>m2 s-1</canonical_units>
    <grib>35</grib>
    <description>&quot;Horizontal&quot; indicates that the streamfunction applies to a horizontal velocity field on a particular vertical level.</description>
  </entry>
  <entry id="atmosphere_horizontal_velocity_potential">
    <canonical_units>m2 s-1</canonical_units>
    <grib>36</grib>
    <description>A velocity is a vector quantity. &quot;Horizontal&quot; indicates that the velocity potential applies to a horizontal velocity field on a particular vertical level.</description>
  </entry>
  <entry id="atmosphere_hybrid_height_coordinate">
    <canonical_units>m</canonical_units>
    <description>See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="atmosphere_hybrid_sigma_pressure_coordinate">
    <canonical_units>1</canonical_units>
    <description>See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="atmosphere_kinetic_energy_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_ln_pressure_coordinate">
    <canonical_units>1</canonical_units>
    <description>&quot;ln_X&quot; means natural logarithm of X. X must be dimensionless. See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_acetic_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_aceto_nitrile">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for aceto-nitrile is CH3CN. The IUPAC name for aceto-nitrile is ethanenitrile.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_alkanes">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  Alkanes are saturated hydrocarbons, i.e. they do not contain any chemical double bonds.  Alkanes contain only hydrogen and carbon combined in the general proportions C(n)H(2n+2); &quot;alkanes&quot; is the term used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual alkane species, e.g., methane and ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_alkenes">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  Alkenes are unsaturated hydrocarbons as they contain chemical double bonds between adjacent carbon atoms.  Alkenes contain only hydrogen and carbon combined in the general proportions C(n)H(2n); &quot;alkenes&quot; is the term used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual alkene species, e.g., ethene and propene.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_alpha_hexachlorocyclohexane">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for alpha_hexachlorocyclohexane is C6H6Cl6.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_alpha_pinene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for alpha_pinene is C10H16. The IUPAC name for alpha-pinene is (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ammonia">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for ammonia is NH3.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ammonium_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The chemical formula for ammonium is NH4.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_anthropogenic_nmvoc_expressed_as_carbon">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Anthropogenic&quot; means influenced, caused, or created by human activity. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_aromatic_compounds">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  Aromatic compounds in organic chemistry are compounds that contain at least one benzene ring of six carbon atoms joined by alternating single and double covalent bonds.  The simplest aromatic compound is benzene itself.  In standard names &quot;aromatic_compounds&quot; is the term used to describe the group of aromatic chemical species that  are represented within a given model.  The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.  Standard names exist for some individual aromatic species, e.g. benzene and xylene.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_atomic_bromine">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical symbol for atomic bromine is Br.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_atomic_chlorine">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical symbol for atomic chlorine is Cl.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_atomic_nitrogen">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical symbol for atomic nitrogen is N.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_benzene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for benzene is C6H6.  Benzene is the simplest aromatic hydrocarbon and has a ring structure consisting of six carbon atoms joined by alternating single and double chemical bonds. Each carbon atom is additionally bonded to one hydrogen atom. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_beta_pinene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for beta_pinene is C10H16.  The IUPAC name for beta-pinene is (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_biogenic_nmvoc_expressed_as_carbon">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Biogenic&quot; means influenced, caused, or created by natural processes.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_black_carbon_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_bromine_chloride">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for bromine chloride is BrCl.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_bromine_monoxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for bromine monoxide is BrO.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_bromine_nitrate">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for bromine nitrate is BrONO2. The chemical formula for the nitrate anion is NO3-.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_brox_expressed_as_bromine">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Brox&quot;  describes a family of chemical species consisting of inorganic bromine compounds with the exception of  hydrogen bromide (HBr) and bromine nitrate (BrONO2). &quot;Brox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols.  Standard names that use the term &quot;inorganic_bromine&quot; are used for quantities that contain all inorganic bromine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_butane">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_carbon_dioxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for carbon dioxide is CO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_carbon_monoxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula of carbon monoxide is CO.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_carbon_tetrachloride">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula of carbon tetrachloride is CCl4.</description>
  </entry>
 <entry id="atmosphere_mass_content_of_cfc11">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula of CFC11 is CFCl3. The IUPAC name fof CFC11 is trichloro-fluoro-methane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_cfc113">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula of CFC113 is CCl2FCClF2. The IUPAC name for CFC113 is 1,1,2-trichloro-1,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_cfc113a">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. The chemical formula of CFC113a CCl3CF3.  The IUPAC name for CFC113a is 1,1,1-trichloro-2,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_cfc114">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula of CFC114 is CClF2CClF2. The IUPAC name for CFC114 is 1,2-dichloro-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_cfc115">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula of CFC115 is CClF2CF3. The IUPAC name for CFC115 is 1-chloro-1,1,2,2,2-pentafluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_cfc12">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for CFC12 is CF2Cl2.  The IUPAC name for CFC12 is dichloro-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_chlorine_dioxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for chlorine dioxide is OClO.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_chlorine_monoxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for chlorine monoxide is ClO.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_chlorine_nitrate">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for chlorine nitrate is ClONO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_clox_expressed_as_chlorine">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Clox&quot; describes a family of chemical species consisting of inorganic chlorine compounds with the exception of  hydrogen chloride (HCl) and chlorine nitrate (ClONO2). &quot;Clox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols.   Standard names that use the term &quot;inorganic_chlorine&quot; are used for quantities that contain all inorganic chlorine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_dichlorine_peroxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for dichlorine peroxide is Cl2O2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_dimethyl_sulfide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for dimethyl sulfide is (CH3)2S.  Dimethyl sulfide is sometimes referred to as DMS.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_dinitrogen_pentoxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for dinitrogen pentoxide is N2O5.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_dust_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ethane">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for ethane is C2H6. Ethane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ethanol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for ethanol is C2H5OH.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ethene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for ethene is C2H4. Ethene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ethyne">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for ethyne is HC2H.  Ethyne is the IUPAC name for this species, which is also commonly known as acetylene.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_formaldehyde">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for formaldehyde is CH2O. The IUPAC name for formaldehyde is methanal.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_formic_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for formic acid is HCOOH.  The IUPAC name for formic acid is methanoic acid.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_gaseous_divalent_mercury">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Divalent mercury&quot; means all compounds in which the mercury has two binding sites to other ion(s) in a salt or to other atom(s) in a molecule.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_gaseous_elemental_mercury">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical symbol for mercury is Hg.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_halon1202">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for halon1202 is CBr2F2. The IUPAC name for halon1202 is dibromo-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_halon1211">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for halon1211 is CBrClF2. The IUPAC name for halon1211 is bromo-chloro-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_halon1301">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for halon1301 is CBrF3. The IUPAC name for halon1301 is bromo-trifluoro-methane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_halon2402">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for halo2402 is C2Br2F4. The IUPAC name for halon2402 is 1,2-dibromo-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hcc140a">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hcc140a is CH3CCl3. The IUPAC name for hcc140a is 1,1,1-trichloro-ethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hcfc141b">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for HCFC141b is CH3CCl2F. The IUPAC name for HCFC141b is 1,1-dichloro-1-fluoroethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hcfc142b">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for HCFC142b is CH3CClF2. The IUPAC name for HCFC142b is 1-chloro-1,1-difluoroethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hcfc22">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for HCFC22 is CHClF2.  The IUPAC name for HCFC22 is chloro-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hexachlorobiphenyl">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hexachlorobiphenyl is C12H4Cl6.  This structure of this species consists of two linked benzene rings, each of which is additionally bonded to three chlorine atoms.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hox_expressed_as_hydrogen">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;HOx&quot; means a combination of two radical species containing hydrogen and oxygen: OH and HO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hydrogen_bromide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hydrogen bromide is HBr.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hydrogen_chloride">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hydrogen chloride is HCl.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hydrogen_cyanide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hydrogen cyanide is HCN.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hydrogen_peroxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hydrogen peroxide is H2O2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hydroperoxyl_radical">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for the hydroperoxyl radical is HO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hydroxyl_radical">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for the hydroxyl radical is OH. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hypobromous_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hypobromous acid is HOBr.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_hypochlorous_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for hypochlorous acid is HOCl.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_inorganic_bromine">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols. &quot;Inorganic bromine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;brox&quot; are used for quantities that contain all inorganic bromine species except HBr and BrONO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_inorganic_chlorine">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols. &quot;Inorganic chlorine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;clox&quot; are used for quantities that contain all inorganic chlorine species except HCl and ClONO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_isoprene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for isoprene is CH2=C(CH3)CH=CH2. The IUPAC name for isoprene is 2-methyl-buta-1,3-diene. Isoprene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_limonene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for limonene is C10H16. The IUPAC name for limonene is 1-methyl-4-prop-1-en-2-yl-cyclohexene. Limonene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_mercury_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_methane">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for methane is CH4. Methane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_methanol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. The chemical formula for methanol is CH3OH.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_methyl_bromide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for methyl bromide is CH3Br. The IUPAC name for methyl bromide is bromomethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_methyl_chloride">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for methyl chloride is CH3Cl. The IUPAC name for methyl chloride is chloromethane.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_methyl_hydroperoxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for methyl hydroperoxide is CH3OOH.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_methyl_peroxy_radical">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for methyl_peroxy_radical is CH3O2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_molecular_hydrogen">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for molecular hydrogen is H2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitrate_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The chemical formula for the nitrate anion is NO3-.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitrate_radical">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for nitrate is NO3. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitric_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for nitric acid is HNO3.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitric_acid_trihydrate_ambient_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. Nitric acid trihydrate, sometimes referred to as NAT, is a stable crystalline substance consisting of three molecules of water to one molecule of nitric acid. The chemical formula for nitric acid is HNO3.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitrogen_monoxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for nitrogen monoxide is NO.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitrous_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for nitrous acid is HNO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nitrous_oxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for nitrous oxide is N2O.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nmvoc_expressed_as_carbon">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;nmvoc&quot; means non methane volatile organic compounds. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_nox_expressed_as_nitrogen">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Nox&quot; means a combination of two radical species containing nitrogen and oxygen: NO+NO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_noy_expressed_as_nitrogen">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Noy&quot; describes a family of chemical species. The family usually includes atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), peroxynitric acid (HNO4), bromine nitrate (BrONO2) , chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)). The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_oxygenated_hydrocarbons">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.   &quot;Oxygenated&quot; means containing oxygen. &quot;Hydrocarbon&quot; means a compound containing hydrogen and carbon.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_ozone">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for ozone is O3.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_particulate_organic_matter_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The term &quot;particulate_organic_matter_dry_aerosol&quot; means all particulate organic matter dry aerosol except black carbon. It is the sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_peroxy_radicals">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The term &quot;peroxy_radicals&quot; means all organic and inorganic peroxy radicals. This includes HO2 and all organic peroxy radicals, sometimes referred to as RO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_peroxyacetyl_nitrate">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. The chemical formula for peroxyacetyl nitrate, sometimes referred to as PAN, is CH3COO2NO2.  The IUPAC name for peroxyacetyl_nitrate is nitroethaneperoxoate.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_peroxynitric_acid">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for peroxynitric acid, sometimes referred to as PNA, is HO2NO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_primary_particulate_organic_matter_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. &quot;Primary particulate organic matter &quot; means all organic matter emitted directly to the atmosphere as particles except black carbon. The sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol is particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_propane">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for propane is C3H8. Propane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_propene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for propene is C3H6. Propene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_radon">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical symbol for radon is Rn.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_seasalt_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_secondary_particulate_organic_matter_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. &quot;Secondary particulate organic matter &quot; means particulate organic matter formed within the atmosphere from gaseous precursors. The sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol is particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_sulfate_ambient_aerosol">
  <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  <amip>trsult</amip>
  </entry>
  <entry id="atmosphere_mass_content_of_sulfate_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The chemical formula for the sulfate anion is SO4(2-).</description>
  </entry>
  <entry id="atmosphere_mass_content_of_sulfate_expressed_as_sulfur_dry_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_sulfur_dioxide">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for sulfur dioxide is SO2.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_terpenes">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  Terpenes are hydrocarbons, that is, they contain only hydrogen and carbon combined in the general proportions (C5H8)n where n is an integer greater than on equal to one. The term &quot;terpenes&quot; is used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.  Standard names exist for some individual terpene species, e.g., isoprene and limonene.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_toluene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for toluene is C6H5CH3.  Toluene has the same structure as benzene, except that one of the hydrogen atoms is replaced by a methyl group.  The systematic name for toluene is methylbenzene.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_water_in_ambient_aerosol">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Water&quot; means water in all phases.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="atmosphere_mass_content_of_water_vapor">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. </description>
  </entry>
  <entry id="atmosphere_mass_content_of_xylene">
    <canonical_units> kg m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  The chemical formula for xylene is C6H4C2H6. In chemistry, xylene is a generic term for a group of three isomers of dimethylbenzene. The IUPAC names for the isomers are 1,2-dimethylbenzene, 1,3-dimethylbenzene and 1,4-dimethylbenzene. Xylene is an aromatic hydrocarbon. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
<entry id="atmosphere_mass_of_air_per_unit_area">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Mass_of_air&quot; means the mass due solely to the gaseous constituents of the atmosphere.  The standard name for the mass including precipitation and aerosol particles is atmosphere_mass_per_unit_area.</description>
  </entry>
  <entry id="atmosphere_mass_per_unit_area">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;X_area&quot; means the horizontal area occupied by X within the grid cell.</description>
  </entry>
  <entry id="atmosphere_moles_of_acetic_acid ">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid.</description>
  </entry>
  <entry id="atmosphere_moles_of_aceto_nitrile">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for aceto-nitrile is CH3CN. The IUPAC name for aceto-nitrile is ethanenitrile.</description>
  </entry>
  <entry id="atmosphere_moles_of_alpha_hexachlorocyclohexane ">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for alpha_hexachlorocyclohexane is C6H6Cl6.</description>
  </entry>
  <entry id="atmosphere_moles_of_alpha_pinene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for alpha_pinene is C10H16. The IUPAC name for alpha-pinene is (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene.</description>
  </entry>
  <entry id="atmosphere_moles_of_ammonia">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for ammonia is NH3.</description>
  </entry>
  <entry id="atmosphere_moles_of_anthropogenic_nmvoc_expressed_as_carbon">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Anthropogenic&quot; means influenced, caused, or created by human activity.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_atomic_bromine">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical symbol for atomic bromine is Br.</description>
  </entry>
  <entry id="atmosphere_moles_of_atomic_chlorine">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical symbol for atomic chlorine is Cl.</description>
  </entry>
  <entry id="atmosphere_moles_of_atomic_nitrogen">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical symbol for atomic nitrogen is N.</description>
  </entry>
  <entry id="atmosphere_moles_of_benzene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for benzene is C6H6.  Benzene is the simplest aromatic hydrocarbon and has a ring structure consisting of six carbon atoms joined by alternating single and double chemical bonds. Each carbon atom is additionally bonded to one hydrogen atom. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_beta_pinene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for beta_pinene is C10H16.  The IUPAC name for beta-pinene is (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane.</description>
  </entry>
  <entry id="atmosphere_moles_of_biogenic_nmvoc_expressed_as_carbon">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Biogenic&quot; means influenced, caused, or created by natural processes.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_bromine_chloride">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for bromine chloride is BrCl.</description>
  </entry>
  <entry id="atmosphere_moles_of_bromine_monoxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for bromine monoxide is BrO.</description>
  </entry>
  <entry id="atmosphere_moles_of_bromine_nitrate">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for bromine nitrate is BrONO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_brox_expressed_as_bromine">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Brox&quot;  describes a family of chemical species consisting of inorganic bromine compounds with the exception of  hydrogen bromide (HBr) and bromine nitrate (BrONO2). &quot;Brox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols.  Standard names that use the term &quot;inorganic_bromine&quot; are used for quantities that contain all inorganic bromine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_butane">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_carbon_dioxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for carbon dioxide is CO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_carbon_monoxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for carbon monoxide is CO.</description>
  </entry>
  <entry id="atmosphere_moles_of_carbon_tetrachloride">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for carbon tetrachloride is CCl4.</description>
  </entry>
  <entry id="atmosphere_moles_of_cfc11">
    <canonical_units> mol</canonical_units>
    <description>The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula of CFC11 is CFCl3. The IUPAC name fof CFC11 is trichloro-fluoro-methane.</description>
  </entry>
  <entry id="atmosphere_moles_of_cfc113">
    <canonical_units> mol</canonical_units>
    <description>The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula of CFC113 is CCl2FCClF2. The IUPAC name for CFC113 is 1,1,2-trichloro-1,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_cfc113a">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula of CFC113a CCl3CF3.  The IUPAC name for CFC113a is 1,1,1-trichloro-2,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_cfc114">
    <canonical_units> mol</canonical_units>
    <description>The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula of CFC114 is CClF2CClF2. The IUPAC name for CFC114 is 1,2-dichloro-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_cfc115">
    <canonical_units> mol</canonical_units>
    <description>The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula of CFC115 is CClF2CF3. The IUPAC name for CFC115 is 1-chloro-1,1,2,2,2-pentafluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_cfc12">
    <canonical_units> mol</canonical_units>
    <description>The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for CFC12 is CF2Cl2.  The IUPAC name for CFC12 is dichloro-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_moles_of_chlorine_dioxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for chlorine dioxide is OClO.</description>
  </entry>
  <entry id="atmosphere_moles_of_chlorine_monoxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for chlorine monoxide is ClO.</description>
  </entry>
  <entry id="atmosphere_moles_of_chlorine_nitrate">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for chlorine nitrate is ClONO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_clox_expressed_as_chlorine">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Clox&quot; describes a family of chemical species consisting of inorganic chlorine compounds with the exception of  hydrogen chloride (HCl) and chlorine nitrate (ClONO2). &quot;Clox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols.   Standard names that use the term &quot;inorganic_chlorine&quot; are used for quantities that contain all inorganic chlorine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_dichlorine_peroxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for dichlorine peroxide is Cl2O2.</description>
  </entry>
  <entry id="atmosphere_moles_of_dimethyl_sulfide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for dimethyl sulfide is (CH3)2S.  Dimethyl sulfide is sometimes referred to as DMS.</description>
  </entry>
  <entry id="atmosphere_moles_of_dinitrogen_pentoxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for dinitrogen pentoxide is N2O5.</description>
  </entry>
  <entry id="atmosphere_moles_of_ethane">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for ethane is C2H6. Ethane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_ethanol">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for ethanol is C2H5OH.</description>
  </entry>
  <entry id="atmosphere_moles_of_ethene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for ethene is C2H4. Ethene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_ethyne">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for ethyne is HC2H.  Ethyne is the IUPAC name for this species, which is also commonly known as acetylene.</description>
  </entry>
  <entry id="atmosphere_moles_of_formaldehyde">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for formaldehyde is CH2O. The IUPAC name for formaldehyde is methanal.</description>
  </entry>
  <entry id="atmosphere_moles_of_formic_acid">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for formic acid is HCOOH.  The IUPAC name for formic acid is methanoic acid.</description>
  </entry>
  <entry id="atmosphere_moles_of_gaseous_divalent_mercury">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Divalent mercury&quot; means all compounds in which the mercury has two binding sites to other ion(s) in a salt or to other atom(s) in a molecule.</description>
  </entry>
  <entry id="atmosphere_moles_of_gaseous_elemental_mercury">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical symbol for mercury is Hg.</description>
  </entry>
  <entry id="atmosphere_moles_of_halon1202">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for halon1202 is CBr2F2. The IUPAC name for halon1202 is dibromo-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_moles_of_halon1211">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for halon1211 is CBrClF2. The IUPAC name for halon1211 is bromo-chloro-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_moles_of_halon1301">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for halon1301 is CBrF3. The IUPAC name for halon1301 is bromo-trifluoro-methane.</description>
  </entry>
  <entry id="atmosphere_moles_of_halon2402">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for halo2402 is C2Br2F4. The IUPAC name for halon2402 is 1,2-dibromo-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_hcc140a">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hcc140a is CH3CCl3. The IUPAC name for hcc140a is 1,1,1-trichloro-ethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_hcfc141b">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for HCFC141b is CH3CCl2F. The IUPAC name for HCFC141b is 1,1-dichloro-1-fluoroethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_hcfc142b">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for HCFC142b is CH3CClF2. The IUPAC name for HCFC142b is 1-chloro-1,1-difluoroethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_hcfc22">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for HCFC22 is CHClF2.  The IUPAC name for HCFC22 is chloro-difluoro-methane.</description>
  </entry>
  <entry id="atmosphere_moles_of_hexachlorobiphenyl">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hexachlorobiphenyl is C12H4Cl6.  This structure of this species consists of two linked benzene rings, each of which is additionally bonded to three chlorine atoms.</description>
  </entry>
  <entry id="atmosphere_moles_of_hox_expressed_as_hydrogen">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;HOx&quot; means a combination of two radical species containing hydrogen and oxygen: OH and HO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_hydrogen_bromide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hydrogen bromide is HBr.</description>
  </entry>
  <entry id="atmosphere_moles_of_hydrogen_chloride">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hydrogen chloride is HCl.</description>
  </entry>
  <entry id="atmosphere_moles_of_hydrogen_cyanide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hydrogen cyanide is HCN.</description>
  </entry>
  <entry id="atmosphere_moles_of_hydrogen_peroxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hydrogen peroxide is H2O2.</description>
  </entry>
  <entry id="atmosphere_moles_of_hydroperoxyl_radical">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for the hydroperoxyl radical is HO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_moles_of_hydroxyl_radical">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for the hydroxyl radical is OH. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_moles_of_hypobromous_acid">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hypobromous acid is HOBr.</description>
  </entry>
  <entry id="atmosphere_moles_of_hypochlorous_acid">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for hypochlorous acid is HOCl.</description>
  </entry>
  <entry id="atmosphere_moles_of_inorganic_bromine">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols. &quot;Inorganic bromine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;brox&quot; are used for quantities that contain all inorganic bromine species except HBr and BrONO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_inorganic_chlorine">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols. &quot;Inorganic chlorine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;clox&quot; are used for quantities that contain all inorganic chlorine species except HCl and ClONO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_isoprene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for isoprene is CH2=C(CH3)CH=CH2. The IUPAC name for isoprene is 2-methyl-buta-1,3-diene. Isoprene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_limonene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for limonene is C10H16. The IUPAC name for limonene is 1-methyl-4-prop-1-en-2-yl-cyclohexene. Limonene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_methane">
    <canonical_units> mol</canonical_units>
    <description>The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for methane is CH4. Methane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_methanol">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for methanol is CH3OH.</description>
  </entry>
  <entry id="atmosphere_moles_of_methyl_bromide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for methyl bromide is CH3Br. The IUPAC name for methyl bromide is bromomethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_methyl_chloride">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for methyl chloride is CH3Cl. The IUPAC name for methyl chloride is chloromethane.</description>
  </entry>
  <entry id="atmosphere_moles_of_methyl_hydroperoxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for methyl hydroperoxide is CH3OOH.</description>
  </entry>
  <entry id="atmosphere_moles_of_methyl_peroxy_radical">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for methyl_peroxy_radical is CH3O2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_moles_of_molecular_hydrogen">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for molecular hydrogen is H2.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitrate_radical">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitric_acid">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for nitric acid is HNO3.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitric_acid_trihydrate_ambient_aerosol">
    <canonical_units> mol</canonical_units>
    <description> &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for nitric acid is HNO3. Nitric acid trihydrate, sometimes referred to as NAT, is a stable crystalline substance consisting of three molecules of water to one molecule of nitric acid.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitrogen_dioxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for nitrogen dioxide is NO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitrogen_monoxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for nitrogen monoxide is NO.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitrous_acid">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for nitrous acid is HNO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_nitrous_oxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for nitrous oxide is N2O.</description>
  </entry>
  <entry id="atmosphere_moles_of_nmvoc_expressed_as_carbon">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;nmvoc&quot; means non methane volatile organic compounds. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_nox_expressed_as_nitrogen">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Nox&quot; means a combination of two radical species containing nitrogen and oxygen: NO+NO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_noy_expressed_as_nitrogen">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. &quot;Noy&quot; describes a family of chemical species. The family usually includes atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), peroxynitric acid (HNO4), bromine nitrate (BrONO2) , chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)). The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="atmosphere_moles_of_ozone">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for ozone is O3.</description>
  </entry>
  <entry id="atmosphere_moles_of_peroxyacetyl_nitrate">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for peroxyacetyl nitrate, sometimes referred to as PAN, is CH3COO2NO2.  The IUPAC name for peroxyacetyl_nitrate is nitroethaneperoxoate.</description>
  </entry>
  <entry id="atmosphere_moles_of_peroxynitric_acid">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for peroxynitric acid, sometimes referred to as PNA, is HO2NO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_propane">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for propane is C3H8. Propane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_propene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for propene is C3H6. Propene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="atmosphere_moles_of_radon">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical symbol for radon is Rn.</description>
  </entry>
  <entry id="atmosphere_moles_of_sulfur_dioxide">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for sulfur dioxide is SO2.</description>
  </entry>
  <entry id="atmosphere_moles_of_toluene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for toluene is C6H5CH3.  Toluene has the same structure as benzene, except that one of the hydrogen atoms is replaced by a methyl group.  The systematic name for toluene is methylbenzene.</description>
  </entry>
  <entry id="atmosphere_moles_of_water_vapor">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe.</description>
  </entry>
  <entry id="atmosphere_moles_of_xylene">
    <canonical_units> mol</canonical_units>
    <description> The construction &quot;atmosphere_moles_of_X&quot; means the total number of moles of X in the entire atmosphere, i.e. summed over the atmospheric column and over the entire globe. The chemical formula for xylene is C6H4C2H6. In chemistry, xylene is a generic term for a group of three isomers of dimethylbenzene. The IUPAC names for the isomers are 1,2-dimethylbenzene, 1,3-dimethylbenzene and 1,4-dimethylbenzene. Xylene is an aromatic hydrocarbon. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="atmosphere_momentum_diffusivity">
    <canonical_units>m2 s-1</canonical_units>
    <description></description>
  </entry>
  <entry id="atmosphere_net_rate_of_absorption_of_longwave_energy">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;longwave&quot; means longwave radiation. Net absorbed radiation is the difference between absorbed and emitted radiation.</description>
  </entry>
  <entry id="atmosphere_net_rate_of_absorption_of_shortwave_energy">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;shortwave&quot; means shortwave radiation. Net absorbed radiation is the difference between absorbed and emitted radiation.</description>
  </entry>
  <entry id="atmosphere_northward_stress_due_to_gravity_wave_drag">
    <canonical_units>Pa</canonical_units>
    <amip>tauvgwd</amip>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward). Atmosphere_Xward_stress is a stress which tends to accelerate the atmosphere in direction X.</description>
  </entry>
  <entry id="atmosphere_number_content_of_aerosol_particles">
    <canonical_units> m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets). </description>
  </entry>
  <entry id="atmosphere_number_content_of_cloud_droplets">
    <canonical_units> m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. </description>
  </entry>
  <entry id="atmosphere_number_content_of_ice_crystals">
    <canonical_units> m-2</canonical_units>
    <description> &quot;Content&quot; indicates a quantity per unit area.  The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. </description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_black_carbon_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.  Black carbon aerosol is composed of elemental carbon.  It is strongly light absorbing.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_cloud">
    <canonical_units> 1 </canonical_units>
    <description> The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path.  A coordinate variable of radiation_wavelength or radiation_frequency can be specified to indicate that the optical thickness applies at specific wavelengths or frequencies. The atmosphere optical thickness applies to radiation passing through the entire atmosphere.  The specification of a physical process by the phrase due_to_process means that the quantity named is a  single term in a sum of terms which together compose the general quantity  named by omitting the phrase. </description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_convective_cloud">
    <canonical_units> 1 </canonical_units>
    <description> The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path.  A coordinate variable of radiation_wavelength or radiation_frequency can be specified to indicate that the optical thickness applies at specific wavelengths or frequencies. The atmosphere optical thickness applies to radiation passing through the entire atmosphere.  Convective cloud is that produced by the convection schemes in an atmosphere model.  The specification of a physical process by the phrase due_to_process means that the quantity named is a  single term in a sum of terms which together compose the general quantity  named by omitting the phrase. </description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_dust_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_particulate_organic_matter_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_pm10_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.  &quot;Pm10 aerosol&quot; is an air pollutant with an aerodynamic diameter of less than or equal to 10 micrometers.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_pm1_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.  &quot;Pm1 aerosol&quot; is an air pollutant with an aerodynamic diameter of less than or equal to 1 micrometer.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_pm2p5_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.  &quot;Pm2p5 aerosol&quot; is an air pollutant with an aerodynamic diameter of less than or equal to 2.5 micrometers.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_seasalt_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth.  The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_stratiform_cloud">
    <canonical_units> 1 </canonical_units>
    <description> The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path.  A coordinate variable of radiation_wavelength or radiation_frequency can be specified to indicate that the optical thickness applies at specific wavelengths or frequencies. The atmosphere optical thickness applies to radiation passing through the entire atmosphere.  In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes).  The specification of a physical process by the phrase due_to_process means that the quantity named is a  single term in a sum of terms which together compose the general quantity  named by omitting the phrase. </description>
  </entry>
  <entry id="atmosphere_optical_thickness_due_to_water_in_ambient_aerosol">
    <canonical_units>1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The optical thickness is the integral along the path of radiation of a volume scattering/absorption/attenuation coefficient. The radiative flux is reduced by a factor exp(-optical_thickness) on traversing the path. The atmosphere optical thickness applies to radiation passing through the entire atmosphere. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets). &quot;atmosphere_optical_thickness_due_to_water_in_ambient_aerosol&quot; refers to the optical thickness due to the water that is associated with aerosol particles due to hygroscopic growth in ambient air, affecting the particle's radius and refractive index.  It corresponds to the difference between the total dry aerosol optical thickness and the total ambient aerosol optical thickness.</description>
  </entry>
  <entry id="atmosphere_potential_energy_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Potential energy is the sum of the gravitational potential energy relative to the geoid and the centripetal potential energy. (The geopotential is the specific potential energy.)</description>
  </entry>
  <entry id="atmosphere_relative_vorticity">
    <canonical_units>s-1</canonical_units>
    <grib>43 E138</grib>
    <description>Relative vorticity is the upward component of the vorticity vector i.e. the component which arises from horizontal velocity.</description>
  </entry>
  <entry id="atmosphere_sigma_coordinate">
    <canonical_units>1</canonical_units>
    <description>See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="atmosphere_sleve_coordinate">
    <canonical_units>1</canonical_units>
    <description>See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="atmosphere_specific_convective_available_potential_energy">
    <canonical_units>J kg-1</canonical_units>
    <description>&quot;specific&quot; means per unit mass. Potential energy is the sum of the gravitational potential energy relative to the geoid and the centripetal potential energy. (The geopotential is the specific potential energy.) Convective(ly) available potential energy is often abbreviated as &quot;CAPE&quot;.</description>
  </entry>
  <entry id="atmosphere_sulfate_content">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used.</description>
  </entry>
  <entry id="atmosphere_water_content">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. &quot;Water&quot; means water in all phases.</description>
  </entry>
  <entry id="atmosphere_water_vapor_content">
    <canonical_units>kg m-2</canonical_units>
    <grib>54</grib>
    <amip>prw</amip>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Atmosphere water vapor content is sometimes referred to as &quot;precipitable water&quot;, although this term does not imply the water could all be precipitated.</description>
  </entry>
  <entry id="backscattering_ratio">
    <canonical_units> 1 </canonical_units>
    <description> Scattering of radiation is its deflection from its incident path without loss of energy.  Backwards scattering refers to the sum of scattering into all backward angles i.e. scattering_angle exceeding pi/2 radians. A scattering_angle should not be specified with this quantity.  &quot;Backscattering ratio&quot; is the ratio of the  quantity with standard name volume_attenuated_backwards_scattering_function_in_air to the quantity with standard name volume_attenuated_backwards_scattering_function_in_air_assuming_no_aerosol_or_cloud.</description>
  </entry>
  <entry id="baroclinic_eastward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward).</description>
  </entry>
  <entry id="baroclinic_northward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward).</description>
  </entry>
  <entry id="barotropic_eastward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward).</description>
  </entry>
  <entry id="barotropic_northward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward).</description>
  </entry>
  <entry id="barotropic_sea_water_x_velocity">
    <canonical_units> m s-1</canonical_units>
    <description> A velocity is a vector quantity.  &quot;x&quot; indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. </description>
  </entry>
  <entry id="barotropic_sea_water_y_velocity">
    <canonical_units> m s-1</canonical_units>
    <description> A velocity is a vector quantity.  &quot;y&quot; indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. </description>
  </entry>
  <entry id="baseflow_amount">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Baseflow&quot; is subsurface runoff which takes place below the level of the water table. Runoff is the liquid water which drains from land. &quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="beaufort_wind_force">
    <canonical_units>1</canonical_units>
    <description>&quot;Beaufort wind force&quot; is an index assigned on the Beaufort wind force scale and relates a qualitative description of the degree of disturbance or destruction caused by wind to the speed of the wind.  The Beaufort wind scale varies between 0 (qualitatively described as calm, smoke rises vertically, sea appears glassy) (wind speeds in the range 0 - 0.2 m s-1) and 12 (hurricane, wave heights in excess of 14 m) (wind speeds in excess of 32.7 m s-1).</description>
  </entry>
  <entry id="bedrock_altitude">
    <canonical_units>m</canonical_units>
    <description>Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. &quot;Bedrock&quot; is the solid Earth surface beneath land ice or ocean water.</description>
  </entry>
  <entry id="bedrock_altitude_change_due_to_isostatic_adjustment">
    <canonical_units>m</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. &quot;Bedrock&quot; is the solid Earth surface beneath land ice or ocean water. The zero of bedrock altitude change is arbitrary. Isostatic adjustment is the vertical movement of the lithosphere due to changing surface ice and water loads.</description>
  </entry>
  <entry id="bioluminescent_photon_rate_in_sea_water">
    <canonical_units>s-1 m-3</canonical_units>
    <description></description>
  </entry>
  <entry id="biomass_burning_carbon_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Biomass burning carbon&quot; refers to the rate at which biomass is burned by forest fires etc., expressed as the mass of carbon which it contains. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="bolus_eastward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>Bolus velocity in an ocean model means the velocity due to a scheme representing eddy-induced effects which are not resolved on the grid scale of the model.  &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward).</description>
  </entry>
  <entry id="bolus_northward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>Bolus velocity in an ocean model means the velocity due to a scheme representing eddy-induced effects which are not resolved on the grid scale of the model.  &quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward).</description>
  </entry>
  <entry id="bolus_sea_water_x_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;x&quot; indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. Bolus velocity in an ocean model means the velocity due to a scheme representing eddy-induced effects which are not resolved on the grid scale of the model.  bolus_sea_water_x_velocity is used in some parameterisations of lateral diffusion in the ocean. </description>
  </entry>
  <entry id="bolus_sea_water_y_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;y&quot; indicates a vector component along the grid y-axis, when this is not true longitude, positive with increasing y. Bolus velocity in an ocean model means the velocity due to a scheme representing eddy-induced effects which are not resolved on the grid scale of the model. bolus_sea_water_y_velocity is used in some parameterisations of lateral diffusion in the ocean.</description>
  </entry>
  <entry id="bolus_upward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>Bolus velocity in an ocean model means the velocity due to a scheme representing eddy-induced effects which are not resolved on the grid scale of the model.  &quot;Upward&quot; indicates a vector component which is positive when directed upward (negative downward).</description>
  </entry>
  <entry id="brightness_temperature">
    <canonical_units>K</canonical_units>
    <grib>118</grib>
    <description>The brightness temperature of a body is the temperature of a black body which radiates the same power per unit solid angle per unit area.</description>
  </entry>
  <entry id="brunt_vaisala_frequency_in_air">
    <canonical_units>s-1</canonical_units>
    <description>Frequency is the number of oscillations of a wave per unit time.</description>
  </entry>
  <entry id="canopy_and_surface_water_amount">
    <canonical_units>kg m-2</canonical_units>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;Amount&quot; means mass per unit area. &quot;Water&quot; means water in all phases, including frozen i.e. ice and snow. &quot;Canopy&quot; means the plant or vegetation canopy. &quot;Canopy and surface water&quot; means the sum of water on the ground and on the canopy.</description>
  </entry>
  <entry id="canopy_height">
    <canonical_units>m</canonical_units>
    <description>Height is the vertical distance above the surface. &quot;Canopy&quot; means the plant or vegetation canopy.</description>
  </entry>
  <entry id="canopy_temperature">
    <canonical_units>K</canonical_units>
    <description>&quot;Canopy&quot; means the plant or vegetation canopy.  &quot;Canopy_temperature&quot; is the bulk temperature of the canopy, not the surface (skin) temperature.
</description>
  </entry>
  <entry id="canopy_throughfall_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Canopy&quot; means the plant or vegetation canopy.  &quot;Throughfall&quot; is the part of the precipitation flux that reaches the ground directly through the vegetative canopy, through intershrub spaces in the canopy, and as drip from the leaves, twigs, and stems (but not including snowmelt).  In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="canopy_water_amount">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Amount&quot; means mass per unit area. &quot;Water&quot; means water in all phases, including frozen i.e. ice and snow. &quot;Canopy&quot; means the plant or vegetation canopy. The canopy water is the water on the canopy.</description>
  </entry>
  <entry id="cell_area">
    <canonical_units>m2</canonical_units>
    <description>&quot;Cell_area&quot; is the horizontal area of a gridcell.</description>
  </entry>
  <entry id="cell_thickness">
    <canonical_units> m</canonical_units>
    <description> &quot;Thickness&quot; means the vertical extent of a layer. &quot;Cell&quot; refers to a model grid-cell.</description>
  </entry>
  <entry id="change_in_atmosphere_energy_content_due_to_change_in_sigma_coordinate_wrt_surface_pressure">
    <canonical_units>J m-2</canonical_units>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;wrt&quot; means with respect to. &quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. &quot;Atmosphere energy content&quot; has not yet been precisely defined! Please express your views on this quantity on the CF email list. See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="change_in_energy_content_of_atmosphere_layer_due_to_change_in_sigma_coordinate_wrt_surface_pressure">
    <canonical_units>J m-2</canonical_units>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;wrt&quot; means with respect to. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="change_over_time_in_atmospheric_water_content_due_to_advection">
    <canonical_units>kg m-2</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;change_over_time_in_X&quot; means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. &quot;Content&quot; indicates a quantity per unit area. &quot;Water&quot; means water in all phases.</description>
  </entry>
  <entry id="change_over_time_in_surface_snow_amount">
    <canonical_units>kg m-2</canonical_units>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;change_over_time_in_X&quot; means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. &quot;Amount&quot; means mass per unit area. Surface amount refers to the amount on the ground, excluding that on the plant or vegetation canopy.</description>
  </entry>
  <entry id="cloud_albedo">
    <canonical_units> 1 </canonical_units>
    <description>The albedo of cloud.</description>
  </entry>
  <entry id="cloud_area_fraction">
    <canonical_units>1</canonical_units>
    <grib>71 E164</grib>
    <amip>clt</amip>
    <description>&quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called &quot;cloud amount&quot; and &quot;cloud cover&quot;. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. The cloud area fraction in a layer of the atmosphere has the standard name cloud_area_fraction_in_atmosphere_layer.</description>
  </entry>
  <entry id="cloud_area_fraction_in_atmosphere_layer">
    <canonical_units>1</canonical_units>
    <amip>cl</amip>
    <description>&quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. &quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called &quot;cloud amount&quot; and &quot;cloud cover&quot;.</description>
  </entry>
  <entry id="cloud_base_altitude">
    <canonical_units>m</canonical_units>
    <description>cloud_base refers to the base of the lowest cloud. Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level.</description>
  </entry>
  <entry id="cloud_condensed_water_content_of_atmosphere_layer">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;condensed_water&quot; means liquid and ice. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well.</description>
  </entry>
  <entry id="cloud_ice_content_of_atmosphere_layer">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well.</description>
  </entry>
  <entry id="cloud_ice_mixing_ratio">
    <canonical_units>1</canonical_units>
    <description>Cloud ice mixing ratio of a parcel of air is the ratio of the mass of ice to the mass of dry air.</description>
  </entry>
  <entry id="cloud_liquid_water_content_of_atmosphere_layer">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well.</description>
  </entry>
  <entry id="cloud_liquid_water_mixing_ratio">
    <canonical_units>1</canonical_units>
    <description>Cloud liquid water mixing ratio of a parcel of air is the ratio of the mass of liquid water to the mass of dry air.</description>
  </entry>
  <entry id="convective_cloud_longwave_emissivity">
    <canonical_units> 1 </canonical_units>
    <description> Emissivity is the ratio of the power emitted by an object to the power that would be emitted by a perfect black body having the same temperature as the object. The emissivity is assumed to be an integral over all wavelengths, unless a coordinate of radiation_wavelength or radiation_frequency is included to specify either the wavelength or frequency. Convective cloud is that produced by the convection schemes in an atmosphere model.  &quot;longwave&quot; means longwave radiation. </description>
  </entry>
  <entry id="cloud_top_altitude">
    <canonical_units>m</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level.</description>
  </entry>
  <entry id="convective_cloud_area_fraction">
    <canonical_units>1</canonical_units>
    <grib>72 E185</grib>
    <description>&quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called &quot;cloud amount&quot; and &quot;cloud cover&quot;. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. The cloud area fraction in a layer of the atmosphere has the standard name cloud_area_fraction_in_atmosphere_layer. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="convective_cloud_area_fraction_in_atmosphere_layer">
    <canonical_units>1</canonical_units>
    <description>&quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. &quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called &quot;cloud amount&quot; and &quot;cloud cover&quot;. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="convective_cloud_base_altitude">
    <canonical_units>m</canonical_units>
    <description>cloud_base refers to the base of the lowest cloud. Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="convective_cloud_base_height">
    <canonical_units>m</canonical_units>
    <description>cloud_base refers to the base of the lowest cloud. Height is the vertical distance above the surface. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="convective_cloud_top_altitude">
    <canonical_units>m</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="convective_cloud_top_height">
    <canonical_units>m</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Height is the vertical distance above the surface. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="convective_precipitation_amount">
    <canonical_units>kg m-2</canonical_units>
    <grib>63</grib>
    <description>&quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="convective_precipitation_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <amip>prc</amip>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="convective_precipitation_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Precipitation rate&quot; means the depth or thickness of the layer formed by precipitation per unit time.</description>
  </entry>
  <entry id="convective_rainfall_amount">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="convective_rainfall_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="convective_rainfall_rate">
    <canonical_units>m s-1</canonical_units>
    <description></description>
  </entry>
  <entry id="convective_snowfall_amount">
    <canonical_units>kg m-2</canonical_units>
    <grib>78</grib>
    <description>&quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="convective_snowfall_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="coriolis_parameter">
    <canonical_units>s-1</canonical_units>
    <description>The Coriolis parameter is twice the component of the earth's angular velocity about the local vertical i.e. 2 W sin L, where L is latitude and W the angular speed of the earth.</description>
  </entry>
  <entry id="correction_for_model_negative_specific_humidity">
    <canonical_units>1</canonical_units>
    <description>A numerical correction which is added to modelled negative specific humidities in order to obtain a value of zero.</description>
  </entry>
  <entry id="depth">
    <canonical_units>m</canonical_units>
    <description>Depth is the vertical distance below the surface.</description>
  </entry>
  <entry id="depth_at_maximum_upward_derivative_of_sea_water_potential_temperature">
    <canonical_units>m</canonical_units>
    <description>This quantity, often used to indicate the &quot;thermocline depth&quot;, is the depth of the maximum vertical gradient of sea water potential temperature.  Depth is the vertical distance below the surface. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure.</description>
  </entry>
  <entry id="depth_of_isosurface_of_sea_water_potential_temperature">
    <canonical_units>m</canonical_units>
    <description>This quantity, sometimes called the &quot;isotherm depth&quot;, is the depth (if it exists) at which the sea water potential temperature equals some specified value. This value should be specified in a scalar coordinate variable. Depth is the vertical distance below the surface. Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure.</description>
  </entry>
  <entry id="dew_point_depression">
    <canonical_units>K</canonical_units>
    <grib>18</grib>
    <description>Dew point depression is also called dew point deficit. It is the amount by which the air temperature exceeds its dew point temperature. Dew point temperature is the temperature at which a parcel of air reaches saturation upon being cooled at constant pressure and specific humidity.</description>
  </entry>
  <entry id="dew_point_temperature">
    <canonical_units>K</canonical_units>
    <grib>17</grib>
    <description>Dew point temperature is the temperature at which a parcel of air reaches saturation upon being cooled at constant pressure and specific humidity.</description>
  </entry>
  <entry id="difference_of_air_pressure_from_model_reference">
    <canonical_units>Pa</canonical_units>
    <description>In some atmosphere models, the difference of air pressure from model reference is a prognostic variable, instead of the air pressure itself. The model reference air pressure is a model-dependent constant.</description>
  </entry>
  <entry id="dimensionless_exner_function">
    <canonical_units>1</canonical_units>
    <description>The term &quot;Exner function&quot; is applied to various quantities in the literature. &quot;Dimensionless Exner function&quot; is the standard name of (p/p0)^(R/Cp), where p is pressure, p0 a reference pressure, R the gas constant and Cp the specific heat at constant pressure. This quantity is also the ratio of in-situ to potential temperature. Standard names for other variants can be defined on request.</description>
  </entry>
  <entry id="direction_of_sea_ice_velocity">
    <canonical_units>degree</canonical_units>
    <grib>93</grib>
    <description>&quot;direction_of_X&quot; means direction of a vector, a bearing. A velocity is a vector quantity. Sea ice velocity is defined as a two-dimensional vector, with no vertical component.</description>
  </entry>
  <entry id="direction_of_sea_water_velocity">
    <canonical_units>degree</canonical_units>
    <grib>47</grib>
    <description>&quot;direction_of_X&quot; means direction of a vector, a bearing. A velocity is a vector quantity.</description>
  </entry>
  <entry id="dissipation_in_atmosphere_boundary_layer">
    <canonical_units>W m-2</canonical_units>
    <grib>E145</grib>
    <description></description>
  </entry>
  <entry id="divergence_of_sea_ice_velocity">
    <canonical_units>s-1</canonical_units>
    <grib>98</grib>
    <description>&quot;[horizontal_]divergence_of_X&quot; means [horizontal] divergence of a vector X; if X does not have a vertical component then &quot;horizontal&quot; should be omitted. A velocity is a vector quantity. Sea ice velocity is defined as a two-dimensional vector, with no vertical component.</description>
  </entry>
  <entry id="divergence_of_wind">
    <canonical_units>s-1</canonical_units>
    <grib>44 E155</grib>
    <description>&quot;[horizontal_]divergence_of_X&quot; means [horizontal] divergence of a vector X; if X does not have a vertical component then &quot;horizontal&quot; should be omitted. Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.)</description>
  </entry>
  <entry id="downward_dry_static_energy_flux_due_to_diffusion">
    <canonical_units>W m-2</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_eastward_momentum_flux_in_air">
    <canonical_units>Pa</canonical_units>
    <grib>124</grib>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). &quot;Downward eastward&quot; indicates the ZX component of a tensor. Momentum flux is dimensionally equivalent to stress and pressure. It is a tensor quantity. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_eastward_stress_at_sea_ice_base">
    <canonical_units>Pa</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). &quot;Downward eastward&quot; indicates the ZX component of a tensor. A downward eastward stress is a downward flux of eastward momentum, which accelerates the lower medium eastward and the upper medium westward.</description>
  </entry>
  <entry id="downward_heat_flux_at_ground_level_in_snow">
    <canonical_units>W m-2</canonical_units>
    <description>ground_level means the land surface (beneath the snow and surface water, if any). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_heat_flux_at_ground_level_in_soil">
    <canonical_units>W m-2</canonical_units>
    <description>ground_level means the land surface (beneath the snow and surface water, if any). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_heat_flux_in_air">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). The vertical heat flux in air is the sum of all heat fluxes i.e. radiative, latent and sensible. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_heat_flux_in_floating_ice">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.  &quot;Floating ice&quot; means any ice that is floating on water, e.g. on a sea or lake surface.</description>
  </entry>
  <entry id="downward_heat_flux_in_sea_ice">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_heat_flux_in_soil">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_northward_momentum_flux_in_air">
    <canonical_units>Pa</canonical_units>
    <grib>125</grib>
    <description>&quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). &quot;Downward northward&quot; indicates the ZY component of a tensor. Momentum flux is dimensionally equivalent to stress and pressure. It is a tensor quantity. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_northward_stress_at_sea_ice_base">
    <canonical_units>Pa</canonical_units>
    <description>&quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). &quot;Downward northward&quot; indicates the ZY component of a tensor. A downward northward stress is a downward flux of northward momentum, which accelerates the lower medium northward and the upper medium southward.</description>
  </entry>
  <entry id="downward_sea_ice_basal_salt_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_water_vapor_flux_in_air_due_to_diffusion">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downward_x_stress_at_sea_ice_base">
    <canonical_units>Pa</canonical_units>
    <description>&quot;x&quot; indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward).</description>
  </entry>
  <entry id="downward_y_stress_at_sea_ice_base">
    <canonical_units>Pa</canonical_units>
    <description>&quot;y&quot; indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward).</description>
  </entry>
  <entry id="downwelling_longwave_flux_in_air">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;longwave&quot; means longwave radiation. Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_longwave_radiance_in_air">
    <canonical_units>W m-2 sr-1</canonical_units>
    <description>&quot;longwave&quot; means longwave radiation. Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead.</description>
  </entry>
  <entry id="downwelling_photon_flux_in_sea_water">
    <canonical_units>mol m-2 s-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. A photon flux is specified in terms of numbers of photons expressed in moles. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_photon_radiance_in_sea_water">
    <canonical_units>mol m-2 s-1 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Photon radiance is the photon flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead. A photon flux is specified in terms of numbers of photons expressed in moles.</description>
  </entry>
  <entry id="downwelling_photon_spherical_irradiance_in_sea_water">
    <canonical_units>mol m-2 s-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Photon spherical irradiance is the photon flux incident on unit area of a hemispherical (or &quot;2-pi&quot;) collector. A photon flux is specified in terms of numbers of photons expressed in moles.</description>
  </entry>
  <entry id="downwelling_photosynthetic_photon_flux_in_sea_water">
    <canonical_units>mol m-2 s-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;Photosynthetic&quot; radiation is the part of the spectrum which is used in photosynthesis e.g. 300-700 nm. The range of wavelengths could be specified precisely by the bounds of a coordinate of radiation_wavelength. A photon flux is specified in terms of numbers of photons expressed in moles. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_photosynthetic_photon_radiance_in_sea_water">
    <canonical_units>mol m-2 s-1 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Photon radiance is the photon flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead. &quot;Photosynthetic&quot; radiation is the part of the spectrum which is used in photosynthesis e.g. 300-700 nm. The range of wavelengths could be specified precisely by the bounds of a coordinate of radiation_wavelength. A photon flux is specified in terms of numbers of photons expressed in moles.</description>
  </entry>
  <entry id="downwelling_photosynthetic_photon_spherical_irradiance_in_sea_water">
    <canonical_units>mol m-2 s-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;Photosynthetic&quot; radiation is the part of the spectrum which is used in photosynthesis e.g. 300-700 nm. The range of wavelengths could be specified precisely by the bounds of a coordinate of radiation_wavelength. Photon spherical irradiance is the photon flux incident on unit area of a hemispherical (or &quot;2-pi&quot;) collector. A photon flux is specified in terms of numbers of photons expressed in moles.</description>
  </entry>
  <entry id="downwelling_photosynthetic_radiance_in_sea_water">
    <canonical_units>W m-2 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead. &quot;Photosynthetic&quot; radiation is the part of the spectrum which is used in photosynthesis e.g. 300-700 nm. The range of wavelengths could be specified precisely by the bounds of a coordinate of radiation_wavelength.</description>
  </entry>
  <entry id="downwelling_photosynthetic_radiative_flux_in_sea_water">
    <canonical_units>W m-2</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Radiative flux is the sum of shortwave and longwave radiative fluxes. &quot;Photosynthetic&quot; radiation is the part of the spectrum which is used in photosynthesis e.g. 300-700 nm. The range of wavelengths could be specified precisely by the bounds of a coordinate of radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_photosynthetic_spherical_irradiance_in_sea_water">
    <canonical_units>W m-2</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;Photosynthetic&quot; radiation is the part of the spectrum which is used in photosynthesis e.g. 300-700 nm. The range of wavelengths could be specified precisely by the bounds of a coordinate of radiation_wavelength. Spherical irradiance is the radiation incident on unit area of a hemispherical (or &quot;2-pi&quot;) collector. It is sometimes called &quot;scalar irradiance&quot;. The direction (up/downwelling) is specified. Radiation incident on a 4-pi collector has standard names of &quot;omnidirectional spherical irradiance&quot;.</description>
  </entry>
  <entry id="downwelling_radiance_in_sea_water">
    <canonical_units>W m-2 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead.</description>
  </entry>
  <entry id="downwelling_radiative_flux_in_sea_water">
    <canonical_units>W m-2</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Radiative flux is the sum of shortwave and longwave radiative fluxes. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_shortwave_flux_in_air">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;shortwave&quot; means shortwave radiation. Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_shortwave_flux_in_sea_water">
    <canonical_units> W m-2</canonical_units>
    <description> Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;.  When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;.  In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;.  In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.  &quot;shortwave&quot; means shortwave radiation.  </description>
  </entry>
  <entry id="downwelling_shortwave_radiance_in_air">
    <canonical_units>W m-2 sr-1</canonical_units>
    <description>&quot;shortwave&quot; means shortwave radiation. Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead.</description>
  </entry>
  <entry id="downwelling_spectral_photon_flux_in_sea_water">
    <canonical_units>mol m-2 s-1 m-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. A photon flux is specified in terms of numbers of photons expressed in moles. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_spectral_photon_radiance_in_sea_water">
    <canonical_units>mol m-2 s-1 m-1 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Photon radiance is the photon flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead. A photon flux is specified in terms of numbers of photons expressed in moles.</description>
  </entry>
  <entry id="downwelling_spectral_photon_spherical_irradiance_in_sea_water">
    <canonical_units>mol m-2 s-1 m-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. Photon spherical irradiance is the photon flux incident on unit area of a hemispherical (or &quot;2-pi&quot;) collector. A photon flux is specified in terms of numbers of photons expressed in moles.</description>
  </entry>
  <entry id="downwelling_spectral_radiance_in_air">
    <canonical_units>W m-2 m-1 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead.</description>
  </entry>
  <entry id="downwelling_spectral_radiance_in_sea_water">
    <canonical_units>W m-2 m-1 sr-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction from which it is coming must be specified, for instance with a coordinate of zenith_angle. If the radiation does not depend on direction, a standard name of isotropic radiance should be chosen instead.</description>
  </entry>
  <entry id="downwelling_spectral_radiative_flux_in_air">
    <canonical_units>W m-2 m-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_spectral_radiative_flux_in_sea_water">
    <canonical_units>W m-2 m-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="downwelling_spectral_spherical_irradiance_in_sea_water">
    <canonical_units>W m-2 m-1</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. &quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. Spherical irradiance is the radiation incident on unit area of a hemispherical (or &quot;2-pi&quot;) collector. It is sometimes called &quot;scalar irradiance&quot;. The direction (up/downwelling) is specified. Radiation incident on a 4-pi collector has standard names of &quot;omnidirectional spherical irradiance&quot;.</description>
  </entry>
  <entry id="downwelling_spherical_irradiance_in_sea_water">
    <canonical_units>W m-2</canonical_units>
    <description>Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Spherical irradiance is the radiation incident on unit area of a hemispherical (or &quot;2-pi&quot;) collector. It is sometimes called &quot;scalar irradiance&quot;. The direction (up/downwelling) is specified. Radiation incident on a 4-pi collector has standard names of &quot;omnidirectional spherical irradiance&quot;.</description>
  </entry>
  <entry id="dry_energy_content_of_atmosphere_layer">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Dry energy is the sum of dry static energy and kinetic energy. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="dry_static_energy_content_of_atmosphere_layer">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="duration_of_sunshine">
    <canonical_units>s</canonical_units>
    <description>The WMO definition of sunshine is that the surface incident radiative flux from the solar beam (i.e. excluding diffuse skylight) exceeds 120 W m-2. &quot;Duration&quot; is the length of time for which a condition holds.</description>
  </entry>
  <entry id="dynamic_tropopause_potential_temperature">
    <canonical_units>K</canonical_units>
    <description>The dynamical tropopause used in interpreting the dynamics of the upper troposphere and lower stratosphere.  There are various definitions of dynamical tropopause in the scientific literature.</description>
  </entry>
<entry id="eastward_atmosphere_dry_static_energy_transport_across_unit_distance">
    <canonical_units>W m-1</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="eastward_atmosphere_water_transport_across_unit_distance">
    <canonical_units>kg s-1 m-1</canonical_units>
    <description>&quot;Water&quot; means water in all phases. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport.</description>
  </entry>
  <entry id="eastward_atmosphere_water_vapor_transport_across_unit_distance">
    <canonical_units>kg m-1 s-1</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport.</description>
  </entry>
  <entry id="eastward_mass_flux_of_air">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="eastward_momentum_flux_correction">
    <canonical_units>Pa</canonical_units>
    <amip>tauucorr</amip>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Momentum flux is dimensionally equivalent to stress and pressure. It is a tensor quantity. Flux correction is also called &quot;flux adjustment&quot;. A positive flux correction is downward i.e. added to the ocean. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="eastward_sea_ice_velocity">
    <canonical_units>m s-1</canonical_units>
    <grib>95</grib>
    <description>A velocity is a vector quantity. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Sea ice velocity is defined as a two-dimensional vector, with no vertical component.</description>
  </entry>
  <entry id="eastward_sea_water_velocity">
    <canonical_units>m s-1</canonical_units>
    <grib>49</grib>
    <description>A velocity is a vector quantity. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward).</description>
  </entry>
  <entry id="eastward_transformed_eulerian_mean_air_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward).</description>
  </entry>
  <entry id="eastward_water_vapor_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="eastward_water_vapor_transport_across_unit_distance_in_atmosphere_layer">
    <canonical_units>kg m-1 s-1</canonical_units>
    <description>&quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport.</description>
  </entry>
  <entry id="eastward_wind">
    <canonical_units>m s-1</canonical_units>
    <grib>33 E131</grib>
    <amip>ua</amip>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.)</description>
  </entry>
  <entry id="eastward_wind_shear">
    <canonical_units>s-1</canonical_units>
    <grib>45</grib>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.) Wind shear is the derivative of wind with respect to height.</description>
  </entry>
  <entry id="effective_radius_of_convective_cloud_ice_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. Convective cloud is that produced by the convection schemes in an atmosphere model. </description>
  </entry>
  <entry id="effective_radius_of_convective_cloud_liquid_water_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. Convective cloud is that produced by the convection schemes in an atmosphere model. </description>
  </entry>
  <entry id="effective_radius_of_convective_cloud_rain_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. Convective cloud is that produced by the convection schemes in an atmosphere model. </description>
  </entry>
  <entry id="effective_radius_of_convective_cloud_snow_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. Convective cloud is that produced by the convection schemes in an atmosphere model. </description>
  </entry>
  <entry id="effective_radius_of_stratiform_cloud_graupel_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes).  </description>
  </entry>
  <entry id="effective_radius_of_stratiform_cloud_ice_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). </description>
  </entry>
  <entry id="effective_radius_of_stratiform_cloud_liquid_water_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). </description>
  </entry>
  <entry id="effective_radius_of_stratiform_cloud_rain_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). </description>
  </entry>
  <entry id="effective_radius_of_stratiform_cloud_snow_particle">
    <canonical_units> m</canonical_units>
    <description> The effective radius of a size distribution of particles, such as aerosols, cloud droplets or ice crystals, is the area weighted mean radius of particle size. It is calculated as the ratio of the third to the second moment of the particle size distribution. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). </description>
  </entry>
  <entry id="enthalpy_content_of_atmosphere_layer">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="equilibrium_line_altitude">
    <canonical_units>m</canonical_units>
    <description>Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. The equilibrium line is the locus of points on a land ice surface at which ice accumulation balances ice ablation over the year.</description>
  </entry>
  <entry id="equivalent_potential_temperature">
    <canonical_units>K</canonical_units>
    <description>Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure.</description>
  </entry>
  <entry id="equivalent_pressure_of_atmosphere_ozone_content">
    <canonical_units>Pa</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. The equivalent pressure of a particular constituent of the atmosphere is the surface pressure exerted by the weight of that constituent alone.</description>
  </entry>
  <entry id="equivalent_reflectivity_factor">
    <canonical_units> dBZ</canonical_units>
    <description> &quot;Equivalent relectivity factor&quot;  is the radar reflectivity factor that is calculated from the measured radar return power assuming the target is composed of liquid water droplets whose diameter is less than one tenth of the radar wavelength, i.e., treating the droplets as Rayleigh scatterers.  The actual radar reflectivity factor would depend on the size distribution and composition of the particles within the target volume and these are  often unknown.</description>
  </entry>
  <entry id="equivalent_temperature">
    <canonical_units>K</canonical_units>
    <description></description>
  </entry>
  <entry id="equivalent_thickness_at_stp_of_atmosphere_ozone_content">
    <canonical_units>m</canonical_units>
    <grib>10</grib>
    <description>&quot;stp&quot; means standard temperature (0 degC) and pressure (101325 Pa). &quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. The equivalent thickness at STP of a particular constituent of the atmosphere is the thickness of the layer that the gas would occupy if it was separated from the other constituents and gathered together at STP.</description>
  </entry>
  <entry id="ertel_potential_vorticity">
    <canonical_units>K m2 kg-1 s-1</canonical_units>
    <amip>vorpot</amip>
    <description></description>
  </entry>
  <entry id="floating_ice_thickness">
    <canonical_units>m</canonical_units>
    <description>&quot;Floating ice&quot; means any ice that is floating on water, e.g. on a sea or lake surface.  &quot;Thickness&quot; means the vertical extent of the ice.</description>
  </entry>
  <entry id="forecast_period">
    <canonical_units>s</canonical_units>
    <description>Forecast period is the time interval between the forecast reference time and the validity time. A period is an interval of time, or the time-period of an oscillation.</description>
  </entry>
  <entry id="forecast_reference_time">
    <canonical_units>s</canonical_units>
    <description>The forecast reference time in NWP is the &quot;data time&quot;, the time of the analysis from which the forecast was made. It is not the time for which the forecast is valid; the standard name of time should be used for that time.</description>
  </entry>
  <entry id="fractional_saturation_of_oxygen_in_sea_water">
    <canonical_units>1</canonical_units>
    <description>Fractional saturation is the ratio of some measure of concentration to the saturated value of the same quantity.</description>
  </entry>
  <entry id="freezing_level_altitude">
    <canonical_units>m</canonical_units>
    <description>Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level.</description>
  </entry>
  <entry id="freezing_temperature_of_sea_water">
    <canonical_units>K</canonical_units>
    <description></description>
  </entry>
  <entry id="frozen_water_content_of_soil_layer">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;frozen_water&quot; means ice. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s).</description>
  </entry>
  <entry id="geoid_height_above_reference_ellipsoid">
    <canonical_units>m</canonical_units>
    <description>The geoid is a surface of constant geopotential with which mean sea level would coincide if the ocean were at rest. (The volume enclosed between the geoid and the sea floor equals the mean volume of water in the ocean.) In an ocean GCM the geoid is the surface of zero depth, or the rigid lid if the model uses that approximation.  A reference ellipsoid is a regular mathematical figure that approximates the irregular shape of the geoid. A number of reference ellipsoids are defined for use in the field of geodesy.</description>
  </entry>
  <entry id="geopotential">
    <canonical_units>m2 s-2</canonical_units>
    <grib>6 E129</grib>
    <description>Geopotential is the sum of the specific gravitational potential energy relative to the geoid and the specific centripetal potential energy.</description>
  </entry>
  <entry id="geopotential_height">
    <canonical_units>m</canonical_units>
    <grib>7 E156</grib>
    <amip>zg</amip>
    <description>Geopotential is the sum of the specific gravitational potential energy relative to the geoid and the specific centripetal potential energy. Geopotential height is the geopotential divided by the standard acceleration due to gravity. It is numerically similar to the altitude (or geometric height) and not to the quantity with standard name height, which is relative to the surface.</description>
  </entry>
  <entry id="geopotential_height_anomaly">
    <canonical_units>m</canonical_units>
    <grib>27</grib>
    <description>&quot;anomaly&quot; means difference from climatology. Geopotential is the sum of the specific gravitational potential energy relative to the geoid and the specific centripetal potential energy. Geopotential height is the geopotential divided by the standard acceleration due to gravity. It is numerically similar to the altitude (or geometric height) and not to the quantity with standard name height, which is relative to the surface.</description>
  </entry>
  <entry id="geostrophic_eastward_wind">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.)</description>
  </entry>
  <entry id="geostrophic_northward_wind">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward). Wind is defined as a two-dimensional (horizontal) air velocity vector, with no vertical component. (Vertical motion in the atmosphere has the standard name upward_air_velocity.)</description>
  </entry>
  <entry id="global_average_sea_level_change">
    <canonical_units>m</canonical_units>
    <description>Global average sea level change is due to change in volume of the water in the ocean, caused by mass and/or density change, or to change in the volume of the ocean basins, caused by tectonics etc. It is sometimes called &quot;eustatic&quot;, which is a term that also has other definitions. It differs from the change in the global average sea surface height relative to the centre of the Earth by the global average vertical movement of the ocean floor. Zero sea level change is an arbitrary level.</description>
  </entry>
  <entry id="global_average_steric_sea_level_change">
    <canonical_units> m</canonical_units>
    <description> Global average steric sea level change is caused by changes in sea water density due to changes in temperature (thermosteric) and salinity (halosteric). Zero sea level change is an arbitrary level. </description>
  </entry>
  <entry id="global_average_thermosteric_sea_level_change">
    <canonical_units>m</canonical_units>
    <description>Global average thermosteric sea level change is the part caused by change in density due to change in temperature i.e. thermal expansion. Zero sea level change is an arbitrary level.</description>
  </entry>
  <entry id="grid_latitude">
    <canonical_units>degree</canonical_units>
    <description>Latitude is positive northward; its units of degree_north (or equivalent) indicate this explicitly. In a latitude-longitude system defined with respect to a rotated North Pole, the standard name of grid_latitude should be used instead of latitude. Grid latitude is positive in the grid-northward direction, but its units should be plain degree.</description>
  </entry>
  <entry id="grid_longitude">
    <canonical_units>degree</canonical_units>
    <description>Longitude is positive eastward; its units of degree_east (or equivalent) indicate this explicitly. In a latitude-longitude system defined with respect to a rotated North Pole, the standard name of grid_longitude should be used instead of longitude. Grid longitude is positive in the grid-eastward direction, but its units should be plain degree.</description>
  </entry>
  <entry id="gross_primary_productivity_of_carbon">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>Gross primary productivity is the rate of synthesis of biomass per unit area from inorganic precursors by autotrophs, especially by photosynthesising plants using sunlight for energy. The producers also respire some of this biomass and the difference is net_primary_producivity. &quot;Productivity of carbon&quot; refers to the production of biomass expressed as the mass of carbon which it contains.</description>
  </entry>
  <entry id="heat_flux_correction">
    <canonical_units>W m-2</canonical_units>
    <amip>hfcorr</amip>
    <description>Flux correction is also called &quot;flux adjustment&quot;. A positive flux correction is downward i.e. added to the ocean. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="heat_flux_into_sea_water_due_to_iceberg_thermodynamics">
    <canonical_units> W m-2</canonical_units>
    <description> In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.  The specification of a physical process by the phrase due_to_process means that the quantity named is a  single term in a sum of terms which together compose the general quantity  named by omitting the phrase.  &quot; Iceberg thermodynamics&quot; refers to the addition or subtraction of mass due to surface and basal fluxes, i.e., due to melting, sublimation and fusion.</description>
  </entry>
  <entry id="heat_flux_into_sea_water_due_to_newtonian_relaxation">
    <canonical_units>W m-2</canonical_units>
    <description>The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase.  The heat_flux_into_sea_water_due_to_newtonian_relaxation is the heat flux resulting from the Newtonian relaxation of the sea surface temperature. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="heat_flux_into_sea_water_due_to_sea_ice_thermodynamics">
    <canonical_units> W m-2</canonical_units>
    <description> In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.  The specification of a physical process by the phrase due_to_process means that the quantity named is a  single term in a sum of terms which together compose the general quantity  named by omitting the phrase.  &quot;Sea ice thermodynamics&quot; refers to the addition or subtraction of mass due to surface and basal fluxes, i.e., due to melting, sublimation and fusion.</description>
  </entry>
  <entry id="heat_flux_into_sea_water_due_to_snow_thermodynamics">
    <canonical_units> W m-2</canonical_units>
    <description> In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.  The specification of a physical process by the phrase due_to_process means that the quantity named is a  single term in a sum of terms which together compose the general quantity  named by omitting the phrase.  &quot;Snow thermodynamics&quot; refers to the addition or subtraction of mass due to surface and basal fluxes, i.e., due to melting, sublimation and fusion.</description>
  </entry>
  <entry id="height">
    <canonical_units>m</canonical_units>
    <amip>zh</amip>
    <description>Height is the vertical distance above the surface.</description>
  </entry>
  <entry id="height_above_reference_ellipsoid">
    <canonical_units>m</canonical_units>
    <description>Height is the vertical distance above a surface. A reference ellipsoid is a mathematical figure that approximates the geoid. The geoid is a surface of constant geopotential with which mean sea level would coincide if the ocean were at rest. The ellipsoid is an approximation because the geoid is an irregular shape. A number of reference ellipsoids are defined for use in the field of geodesy.</description>
  </entry>
  <entry id="height_above_sea_floor">
    <canonical_units>m</canonical_units>
    <description></description>
  </entry>
  <entry id="height_at_cloud_top">
    <canonical_units>m</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Height is the vertical distance above the surface.</description>
  </entry>
  <entry id="heterotrophic_respiration_carbon_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Respiration carbon&quot; refers to the rate at which biomass is respired expressed as the mass of carbon which it contains. Heterotrophic respiration is respiration by heterotrophs (&quot;consumers&quot;), which are organisms (including animals and decomposers) that consume other organisms or dead organic material, rather than synthesising organic material from inorganic precursors using energy from the environment (especially sunlight) as autotrophs (&quot;producers&quot;) do. Heterotrophic respiration goes on both above and within the soil. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="histogram_of_backscattering_ratio_over_height_above_reference_ellipsoid">
    <canonical_units> 1 </canonical_units>
    <description> Scattering of radiation is its deflection from its incident path without loss of energy.  Backwards scattering refers to the sum of scattering into all backward angles i.e. scattering_angle exceeding pi/2 radians. A scattering_angle should not be specified with this quantity.  &quot;Backscattering ratio&quot; is the ratio of the  quantity with standard name volume_attenuated_backwards_scattering_function_in_air to the quantity with standard name volume_attenuated_backwards_scattering_function_in_air_assuming_no_aerosol_or_cloud. &quot;histogram_of_X[_over_Z]&quot; means histogram (i.e. number of counts for each  range of X) of variations (over Z) of X.   The data variable should have an  axis for X. </description>
  </entry>
  <entry id="histogram_of_equivalent_reflectivity_factor_over_height_above_reference_ellipsoid">
    <canonical_units> 1 </canonical_units>
    <description> &quot;Equivalent relectivity factor&quot;  is the radar reflectivity factor that is calculated from the measured radar return power assuming the target is composed of liquid water droplets whose diameter is less than one tenth of the radar wavelength, i.e., treating the droplets as Rayleigh scatterers.  The actual radar reflectivity factor would depend on the size distribution and composition of the particles within the target volume and these are  often unknown. &quot;histogram_of_X[_over_Z]&quot; means histogram (i.e. number of counts for each  range of X) of variations (over Z) of X.   The data variable should have an  axis for X. </description>
  </entry>
  <entry id="horizontal_atmosphere_dry_energy_transport">
    <canonical_units>W m-2</canonical_units>
    <description>Dry energy is the sum of dry static energy and kinetic energy. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="horizontal_dry_energy_transport_in_atmosphere_layer">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Dry energy is the sum of dry static energy and kinetic energy. Dry static energy is the sum of enthalpy and potential energy (itself the sum of gravitational and centripetal potential energy). Enthalpy can be written either as (1) CpT, where Cp is heat capacity at constant pressure, T is absolute temperature, or (2) U+pV, where U is internal energy, p is pressure and V is volume.</description>
  </entry>
  <entry id="humidity_mixing_ratio">
    <canonical_units>1</canonical_units>
    <grib>53</grib>
    <description>Humidity mixing ratio of a parcel of moist air is the ratio of the mass of water vapor to the mass of dry air.</description>
  </entry>
  <entry id="integral_of_air_temperature_deficit_wrt_time">
    <canonical_units>K s</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The air temperature deficit is the air temperature threshold minus the air temperature. Its integral with respect to time is often called after its units of &quot;degree-days&quot;.</description>
  </entry>
  <entry id="integral_of_air_temperature_excess_wrt_time">
    <canonical_units>K s</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The air temperature excess is the air temperature minus the air temperature threshold. Its integral with respect to time is often called after its units of &quot;degree-days&quot;.</description>
  </entry>
  <entry id="integral_of_sea_water_potential_temperature_wrt_depth_expressed_as_heat_content">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds.  &quot;wrt&quot; means with respect to. &quot;expressed_as_heat_content&quot; means that this quantity is calculated as the (assumed constant) specific heat capacity times density of sea water multiplied by the integral, over the specified layer of the ocean, of the sea water potential temperature wrt depth.</description>
  </entry>
  <entry id="integral_of_sea_water_temperature_wrt_depth_in_ocean_layer">
    <canonical_units>K m</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface.</description>
  </entry>
  <entry id="integral_of_surface_downward_eastward_stress_wrt_time">
    <canonical_units>Pa s</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;Eastward&quot; indicates a vector component which is positive when directed eastward (negative westward). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). &quot;Downward eastward&quot; indicates the ZX component of a tensor. A downward eastward stress is a downward flux of eastward momentum, which accelerates the lower medium eastward and the upper medium westward. The surface downward stress is the windstress on the surface.</description>
  </entry>
  <entry id="integral_of_surface_downward_latent_heat_flux_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to.  The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). The surface latent heat flux is the exchange of heat between the surface and the air on account of evaporation (including sublimation). In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_surface_downward_northward_stress_wrt_time">
    <canonical_units>Pa s</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;Northward&quot; indicates a vector component which is positive when directed northward (negative southward). &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). &quot;Downward northward&quot; indicates the ZY component of a tensor. A downward northward stress is a downward flux of northward momentum, which accelerates the lower medium northward and the upper medium southward. The surface downward stress is the windstress on the surface.</description>
  </entry>
  <entry id="integral_of_surface_downward_sensible_heat_flux_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to.  The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward).  The surface sensible heat flux, also called &quot;turbulent&quot; heat flux, is the exchange of heat between the surface and the air by motion of air. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_surface_downwelling_longwave_flux_in_air_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;longwave&quot; means longwave radiation. Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_surface_downwelling_shortwave_flux_in_air_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to. The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;shortwave&quot; means shortwave radiation. Downwelling radiation is radiation from above. It does not mean &quot;net downward&quot;. Surface downwelling shortwave is the sum of direct and diffuse solar radiation incident on the surface, and is sometimes called &quot;global radiation&quot;. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_surface_net_downward_longwave_flux_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to.  The surface called &quot;surface&quot; means the lower boundary of the atmosphere.  &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). &quot;Longwave&quot; means longwave radiation.  In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_surface_net_downward_shortwave_flux_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to.  The surface called &quot;surface&quot; means the lower boundary of the atmosphere.  &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). &quot;Shortwave&quot; means shortwave radiation.  In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_toa_net_downward_shortwave_flux_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to.  &quot;toa&quot; means top of atmosphere. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling).  &quot;Shortwave&quot; means shortwave radiation.  In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="integral_of_toa_outgoing_longwave_flux_wrt_time">
    <canonical_units>W s m-2</canonical_units>
    <description>&quot;integral_of_Y_wrt_X&quot; means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. &quot;wrt&quot; means with respect to.  &quot;toa&quot; means top of atmosphere.  &quot;Longwave&quot; means longwave radiation.  The TOA outgoing longwave flux is the upwelling thermal radiative flux, often called the &quot;outgoing longwave radiation&quot; or &quot;OLR&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="isccp_cloud_area_fraction">
    <canonical_units>1</canonical_units>
    <amip>clisccp</amip>
    <description>&quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called &quot;cloud amount&quot; and &quot;cloud cover&quot;. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. The cloud area fraction in a layer of the atmosphere has the standard name cloud_area_fraction_in_atmosphere_layer. The ISCCP cloud area fraction is diagnosed from atmosphere model output by the ISCCP simulator software in such a way as to be comparable with the observational diagnostics of ISCCP (the International Satellite Cloud Climatology Project).</description>
  </entry>
  <entry id="isotropic_longwave_radiance_in_air">
    <canonical_units>W m-2 sr-1</canonical_units>
    <description>&quot;longwave&quot; means longwave radiation. Radiance is the radiative flux in a particular direction, per unit of solid angle. If radiation is isotropic, the radiance is independent of direction, so the direction should not be specified. If the radiation is directionally dependent, a standard name of upwelling or downwelling radiance should be chosen instead.</description>
  </entry>
  <entry id="isotropic_shortwave_radiance_in_air">
    <canonical_units>W m-2 sr-1</canonical_units>
    <description>&quot;shortwave&quot; means shortwave radiation. Radiance is the radiative flux in a particular direction, per unit of solid angle. If radiation is isotropic, the radiance is independent of direction, so the direction should not be specified. If the radiation is directionally dependent, a standard name of upwelling or downwelling radiance should be chosen instead.</description>
  </entry>
  <entry id="isotropic_spectral_radiance_in_air">
    <canonical_units>W m-2 m-1 sr-1</canonical_units>
    <description>&quot;spectral&quot; means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called &quot;monochromatic&quot;. Radiation wavelength has standard name radiation_wavelength. Radiance is the radiative flux in a particular direction, per unit of solid angle. If radiation is isotropic, the radiance is independent of direction, so the direction should not be specified. If the radiation is directionally dependent, a standard name of upwelling or downwelling radiance should be chosen instead.</description>
  </entry>
  <entry id="kinetic_energy_content_of_atmosphere_layer">
    <canonical_units>J m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well.</description>
  </entry>
  <entry id="lagrangian_tendency_of_air_pressure">
    <canonical_units>Pa s-1</canonical_units>
    <grib>39 E135</grib>
    <amip>wap</amip>
    <description>&quot;tendency_of_X&quot; means derivative of X with respect to time. The Lagrangian tendency of a quantity is its rate of change following the motion of the fluid, also called the &quot;material derivative&quot; or &quot;convective derivative&quot;. The Lagrangian tendency of air pressure, often called &quot;omega&quot;, plays the role of the upward component of air velocity when air pressure is being used as the vertical coordinate. If the vertical air velocity is upwards, it is negative when expressed as a tendency of air pressure; downwards is positive.</description>
  </entry>
  <entry id="lagrangian_tendency_of_atmosphere_sigma_coordinate">
    <canonical_units>s-1</canonical_units>
    <grib>38</grib>
    <description>&quot;tendency_of_X&quot; means derivative of X with respect to time. The Lagrangian tendency of a quantity is its rate of change following the motion of the fluid, also called the &quot;material derivative&quot; or &quot;convective derivative&quot;. The Lagrangian tendency of sigma plays the role of the upward component of air velocity when the atmosphere sigma coordinate (a dimensionless atmosphere vertical coordinate) is being used as the vertical coordinate. If the vertical air velocity is upwards, it is negative when expressed as a tendency of sigma; downwards is positive. See Appendix D of the CF convention for information about dimensionless vertical coordinates.</description>
  </entry>
  <entry id="land_area_fraction">
    <canonical_units>1</canonical_units>
    <grib>81</grib>
    <amip>sftlf</amip>
    <description>&quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell.</description>
  </entry>
  <entry id="land_binary_mask">
    <canonical_units>1</canonical_units>
    <grib>E172</grib>
    <description>X_binary_mask has 1 where condition X is met, 0 elsewhere. 1 = land, 0 = sea.</description>
  </entry>
  <entry id="land_ice_area_fraction">
    <canonical_units>1</canonical_units>
    <amip>sftgif</amip>
    <description>&quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_basal_melt_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. The land ice basal melt rate is the rate at which ice is lost per unit area at the base of the ice.</description>
  </entry>
  <entry id="land_ice_basal_x_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;x&quot; indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_basal_y_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;y&quot; indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_calving_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. The land ice calving rate is the rate at which ice is lost per unit area through calving into the ocean.</description>
  </entry>
  <entry id="land_ice_lwe_basal_melt_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. The land ice basal melt rate is the rate at which ice is lost per unit area at the base of the ice.</description>
  </entry>
  <entry id="land_ice_lwe_calving_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. The land ice calving rate is the rate at which ice is lost per unit area through calving into the ocean.</description>
  </entry>
  <entry id="land_ice_lwe_surface_specific_mass_balance">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. Specific mass balance means the net rate at which ice is added per unit area at the land ice surface.</description>
  </entry>
  <entry id="land_ice_sigma_coordinate">
    <canonical_units>1</canonical_units>
    <description>&quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_surface_specific_mass_balance">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. Specific mass balance means the net rate at which ice is added per unit area at the land ice surface.</description>
  </entry>
  <entry id="land_ice_temperature">
    <canonical_units>K</canonical_units>
    <description>&quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_thickness">
    <canonical_units>m</canonical_units>
    <description>&quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_vertical_mean_x_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;x&quot; indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. The vertical mean land ice velocity is the average from the bedrock to the surface of the ice.</description>
  </entry>
  <entry id="land_ice_vertical_mean_y_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;y&quot; indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock. The vertical mean land ice velocity is the average from the bedrock to the surface of the ice.</description>
  </entry>
  <entry id="land_ice_x_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;x&quot; indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="land_ice_y_velocity">
    <canonical_units>m s-1</canonical_units>
    <description>A velocity is a vector quantity. &quot;y&quot; indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. &quot;Land ice&quot; means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
  </entry>
  <entry id="large_scale_cloud_area_fraction">
    <canonical_units>1</canonical_units>
    <description>&quot;X_area_fraction&quot; means the fraction of horizontal area occupied by X. &quot;X_area&quot; means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called &quot;cloud amount&quot; and &quot;cloud cover&quot;. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. The cloud area fraction in a layer of the atmosphere has the standard name cloud_area_fraction_in_atmosphere_layer.</description>
  </entry>
  <entry id="large_scale_graupel_flux">
    <canonical_units> kg m-2 s-1</canonical_units>
    <description> In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.  In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics. </description>
  </entry>
  <entry id="large_scale_precipitation_amount">
    <canonical_units>kg m-2</canonical_units>
    <grib>62</grib>
    <description>&quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="large_scale_precipitation_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="large_scale_rainfall_amount">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="large_scale_rainfall_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="large_scale_rainfall_rate">
    <canonical_units>m s-1</canonical_units>
    <description></description>
  </entry>
  <entry id="large_scale_snowfall_amount">
    <canonical_units>kg m-2</canonical_units>
    <grib>79</grib>
    <description>&quot;Amount&quot; means mass per unit area.</description>
  </entry>
  <entry id="large_scale_snowfall_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="latitude">
    <canonical_units>degree_north</canonical_units>
    <amip>latitude</amip>
    <description>Latitude is positive northward; its units of degree_north (or equivalent) indicate this explicitly. In a latitude-longitude system defined with respect to a rotated North Pole, the standard name of grid_latitude should be used instead of latitude. Grid latitude is positive in the grid-northward direction, but its units should be plain degree.</description>
  </entry>
  <entry id="leaf_area_index">
    <canonical_units>1</canonical_units>
    <description>&quot;X_area&quot; means the horizontal area occupied by X within the grid cell.</description>
  </entry>
  <entry id="liquid_water_content_of_snow_layer">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area.</description>
  </entry>
  <entry id="liquid_water_content_of_soil_layer">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s).</description>
  </entry>
  <entry id="litter_carbon_content">
    <canonical_units>kg m-2</canonical_units>
    <description>&quot;Content&quot; indicates a quantity per unit area. &quot;Litter carbon&quot; is dead inorganic material in or above the soil quantified as the mass of carbon which it contains.</description>
  </entry>
  <entry id="litter_carbon_flux">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>&quot;Litter carbon&quot; is dead inorganic material in or above the soil quantified as the mass of carbon which it contains. The litter carbon flux is the rate of production of litter. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="longitude">
    <canonical_units>degree_east</canonical_units>
    <amip>longitude</amip>
    <description>Longitude is positive eastward; its units of degree_east (or equivalent) indicate this explicitly. In a latitude-longitude system defined with respect to a rotated North Pole, the standard name of grid_longitude should be used instead of longitude. Grid longitude is positive in the grid-eastward direction, but its units should be plain degree.</description>
  </entry>
  <entry id="lwe_convective_precipitation_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent.</description>
  </entry>
  <entry id="lwe_convective_snowfall_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent.</description>
  </entry>
  <entry id="lwe_large_scale_precipitation_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent.</description>
  </entry>
  <entry id="lwe_large_scale_snowfall_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent.</description>
  </entry>
  <entry id="lwe_precipitation_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent.</description>
  </entry>
  <entry id="lwe_snowfall_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent.</description>
  </entry>
  <entry id="lwe_thickness_of_atmosphere_water_vapor_content">
    <canonical_units>m</canonical_units>
    <grib>E137</grib>
    <description>&quot;lwe&quot; means liquid water equivalent. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. &quot;Content&quot; indicates a quantity per unit area. The &quot;atmosphere content&quot; of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including content_of_atmosphere_layer are used. Atmosphere water vapor content is sometimes referred to as &quot;precipitable water&quot;, although this term does not imply the water could all be precipitated.</description>
  </entry>
  <entry id="lwe_thickness_of_canopy_water_amount">
    <canonical_units>m</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. &quot;Water&quot; means water in all phases, including frozen i.e. ice and snow. &quot;Canopy&quot; means the plant or vegetation canopy. The canopy water is the water on the canopy.</description>
  </entry>
  <entry id="lwe_thickness_of_convective_precipitation_amount">
    <canonical_units>m</canonical_units>
    <grib>E143</grib>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area.</description>
  </entry>
  <entry id="lwe_thickness_of_convective_snowfall_amount">
    <canonical_units>m</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area.</description>
  </entry>
  <entry id="lwe_thickness_of_frozen_water_content_of_soil_layer">
    <canonical_units>m</canonical_units>
    <description>&quot;frozen_water&quot; means ice. &quot;lwe&quot; means liquid water equivalent. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s).</description>
  </entry>
  <entry id="lwe_thickness_of_large_scale_precipitation_amount">
    <canonical_units>m</canonical_units>
    <grib>E142</grib>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area.</description>
  </entry>
  <entry id="lwe_thickness_of_large_scale_snowfall_amount">
    <canonical_units>m</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area.</description>
  </entry>
  <entry id="lwe_thickness_of_moisture_content_of_soil_layer">
    <canonical_units>m</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;moisture&quot; means water in all phases contained in soil. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s).</description>
  </entry>
  <entry id="lwe_thickness_of_precipitation_amount">
    <canonical_units>m</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area.</description>
  </entry>
  <entry id="lwe_thickness_of_snowfall_amount">
    <canonical_units>m</canonical_units>
    <grib>E144</grib>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area.</description>
  </entry>
  <entry id="lwe_thickness_of_soil_moisture_content">
    <canonical_units>m</canonical_units>
    <grib>E140</grib>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;moisture&quot; means water in all phases contained in soil. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. &quot;Content&quot; indicates a quantity per unit area. The &quot;soil content&quot; of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including content_of_soil_layer are used.</description>
  </entry>
  <entry id="lwe_thickness_of_surface_snow_amount">
    <canonical_units>m</canonical_units>
    <grib>E141</grib>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. Surface amount refers to the amount on the ground, excluding that on the plant or vegetation canopy.</description>
  </entry>
  <entry id="lwe_thickness_of_water_evaporation_amount">
    <canonical_units>m</canonical_units>
    <grib>E182</grib>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Amount&quot; means mass per unit area. The construction lwe_thickness_of_X_amount or _content means the vertical extent of a layer of liquid water having the same mass per unit area. &quot;Water&quot; means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called &quot;sublimation&quot;.)</description>
  </entry>
  <entry id="lwe_water_evaporation_rate">
    <canonical_units>m s-1</canonical_units>
    <description>&quot;lwe&quot; means liquid water equivalent. &quot;Water&quot; means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called &quot;sublimation&quot;.)</description>
  </entry>
  <entry id="magnitude_of_derivative_of_position_wrt_model_level_number">
    <canonical_units>m</canonical_units>
    <description>The quantity with standard name magnitude_of_derivative_of_position_wrt_model_level_number (known in differential geometry as a &quot;scale factor&quot;) is | (dr/dk)ij|, where r(i,j,k) is the vector 3D position of the point with coordinate indices (i,j,k). It is a measure of the gridblock spacing in the z-direction.</description>
  </entry>
  <entry id="magnitude_of_derivative_of_position_wrt_x_coordinate_index">
    <canonical_units>m</canonical_units>
    <description>The quantity with standard name magnitude_of_derivative_of_position_wrt_x_coordinate_index (known in differential geometry as a &quot;scale factor&quot;) is | (dr/di)jk|, where r(i,j,k) is the vector 3D position of the point with coordinate indices (i,j,k). It is a measure of the gridblock spacing in the x-direction.</description>
  </entry>
  <entry id="magnitude_of_derivative_of_position_wrt_y_coordinate_index">
    <canonical_units>m</canonical_units>
    <description>The quantity with standard name magnitude_of_derivative_of_position_wrt_y_coordinate_index (known in differential geometry as a &quot;scale factor&quot;) is | (dr/dj)ik|, where r(i,j,k) is the vector 3D position of the point with coordinate indices (i,j,k). It is a measure of the gridblock spacing in the y-direction.</description>
  </entry>
  <entry id="magnitude_of_surface_downward_stress">
    <canonical_units>Pa</canonical_units>
    <description>The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;magnitude_of_X&quot; means magnitude of a vector X. &quot;Downward&quot; indicates a vector component which is positive when directed downward (negative upward).</description>
  </entry>
  <entry id="mass_concentration_of_acetic_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid.</description>
  </entry>
  <entry id="mass_concentration_of_aceto_nitrile_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for aceto-nitrile is CH3CN. The IUPAC name for aceto-nitrile is ethanenitrile.</description>
  </entry>
  <entry id="mass_concentration_of_alkanes_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Alkanes are saturated hydrocarbons, i.e. they do not contain any chemical double bonds.  Alkanes contain only hydrogen and carbon combined in the general proportions C(n)H(2n+2); &quot;alkanes&quot; is the term used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual alkane species, e.g., methane and ethane.</description>
  </entry>
  <entry id="mass_concentration_of_alkenes_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Alkenes are unsaturated hydrocarbons as they contain chemical double bonds between adjacent carbon atoms.  Alkenes contain only hydrogen and carbon combined in the general proportions C(n)H(2n); &quot;alkenes&quot; is the term used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual alkene species, e.g., ethene and propene.</description>
  </entry>
  <entry id="mass_concentration_of_alpha_hexachlorocyclohexane_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for alpha_hexachlorocyclohexane is C6H6Cl6.</description>
  </entry>
  <entry id="mass_concentration_of_alpha_pinene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for alpha_pinene is C10H16. The IUPAC name for alpha-pinene is (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene.</description>
  </entry>
  <entry id="mass_concentration_of_ammonia_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ammonia is NH3.</description>
  </entry>
  <entry id="mass_concentration_of_ammonium_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The chemical formula for ammonium is NH4.</description>
  </entry>
  <entry id="mass_concentration_of_anthropogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Anthropogenic&quot; means influenced, caused, or created by human activity.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. </description>
  </entry>
  <entry id="mass_concentration_of_aromatic_compounds_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Aromatic compounds in organic chemistry are compounds that contain at least one benzene ring of six carbon atoms joined by alternating single and double covalent bonds.  The simplest aromatic compound is benzene itself.  In standard names &quot;aromatic_compounds&quot; is the term used to describe the group of aromatic chemical species that  are represented within a given model.  The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.  Standard names exist for some individual aromatic species, e.g. benzene and xylene.</description>
  </entry>
  <entry id="mass_concentration_of_atomic_bromine_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic bromine is Br.</description>
  </entry>
  <entry id="mass_concentration_of_atomic_chlorine_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic chlorine is Cl.</description>
  </entry>
  <entry id="mass_concentration_of_atomic_nitrogen_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic nitrogen is N.</description>
  </entry>
  <entry id="mass_concentration_of_benzene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for benzene is C6H6.  Benzene is the simplest aromatic hydrocarbon and has a ring structure consisting of six carbon atoms joined by alternating single and double chemical bonds. Each carbon atom is additionally bonded to one hydrogen atom. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="mass_concentration_of_beta_pinene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for beta_pinene is C10H16.  The IUPAC name for beta-pinene is (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane.</description>
  </entry>
  <entry id="mass_concentration_of_biogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Biogenic&quot; means influenced, caused, or created by natural processes.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_black_carbon_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_concentration_of_bromine_chloride_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine chloride is BrCl.</description>
  </entry>
  <entry id="mass_concentration_of_bromine_monoxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine monoxide is BrO.</description>
  </entry>
  <entry id="mass_concentration_of_bromine_nitrate_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine nitrate is BrONO2.</description>
  </entry>
  <entry id="mass_concentration_of_brox_expressed_as_bromine_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Brox&quot;  describes a family of chemical species consisting of inorganic bromine compounds with the exception of  hydrogen bromide (HBr) and bromine nitrate (BrONO2). &quot;Brox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols.  Standard names that use the term &quot;inorganic_bromine&quot; are used for quantities that contain all inorganic bromine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_butane_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_carbon_dioxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for carbon dioxide is CO2.</description>
  </entry>
  <entry id="mass_concentration_of_carbon_monoxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of carbon monoxide is CO.</description>
  </entry>
  <entry id="mass_concentration_of_carbon_tetrachloride_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of carbon tetrachloride is CCl4.</description>
  </entry>
  <entry id="mass_concentration_of_cfc11_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC11 is CFCl3. The IUPAC name fof CFC11 is trichloro-fluoro-methane.</description>
  </entry>
  <entry id="mass_concentration_of_cfc113_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC113 is CCl2FCClF2. The IUPAC name for CFC113 is 1,1,2-trichloro-1,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mass_concentration_of_cfc113a_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC113a CCl3CF3.  The IUPAC name for CFC113a is 1,1,1-trichloro-2,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mass_concentration_of_cfc114_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC114 is CClF2CClF2. The IUPAC name for CFC114 is 1,2-dichloro-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mass_concentration_of_cfc115_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC115 is CClF2CF3. The IUPAC name for CFC115 is 1-chloro-1,1,2,2,2-pentafluoro-ethane.</description>
  </entry>
  <entry id="mass_concentration_of_cfc12_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for CFC12 is CF2Cl2.  The IUPAC name for CFC12 is dichloro-difluoro-methane.</description>
  </entry>
  <entry id="mass_concentration_of_chlorine_dioxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine dioxide is OClO.</description>
  </entry>
  <entry id="mass_concentration_of_chlorine_monoxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine monoxide is ClO.</description>
  </entry>
  <entry id="mass_concentration_of_chlorine_nitrate_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine nitrate is ClONO2. </description>
  </entry>
  <entry id="mass_concentration_of_chlorophyll_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Chlorophyll is the green pigment found in most plants, algae and cyanobacteria.  The presence of chlorophyll is essential for photosynthesis to take place.  There are five different forms of chlorophyll that occur naturally.  All contain a chlorin ring (chemical formula C20H16N4) which gives the green pigment and a side chain whose structure varies.  The naturally occurring forms of chlorophyll contain between 35 and 55 carbon atoms.</description>
  </entry>
  <entry id="mass_concentration_of_clox_expressed_as_chlorine_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Clox&quot; describes a family of chemical species consisting of inorganic chlorine compounds with the exception of  hydrogen chloride (HCl) and chlorine nitrate (ClONO2). &quot;Clox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols.   Standard names that use the term &quot;inorganic_chlorine&quot; are used for quantities that contain all inorganic chlorine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_condensed_water_in_soil">
    <canonical_units>kg m-3</canonical_units>
    <description>Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  Condensed water means liquid and ice.
</description>
  </entry>
  <entry id="mass_concentration_of_diatoms_expressed_as_carbon_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Diatoms are single-celled phytoplankton with an external skeleton made of silica. Phytoplankton are autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis.</description>
  </entry>
  <entry id="mass_concentration_of_diatoms_expressed_as_nitrogen_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Diatoms are single-celled phytoplankton with an external skeleton made of silica. Phytoplankton are autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis.</description>
  </entry>
  <entry id="mass_concentration_of_dichlorine_peroxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dichlorine peroxide is Cl2O2.</description>
  </entry>
  <entry id="mass_concentration_of_dimethyl_sulfide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dimethyl sulfide is (CH3)2S.  Dimethyl sulfide is sometimes referred to as DMS.</description>
  </entry>
  <entry id="mass_concentration_of_dinitrogen_pentoxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dinitrogen pentoxide is N2O5.</description>
  </entry>
  <entry id="mass_concentration_of_dust_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_concentration_of_ethane_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethane is C2H6. Ethane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_ethanol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethanol is C2H5OH.</description>
  </entry>
  <entry id="mass_concentration_of_ethene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethene is C2H4. Ethene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_ethyne_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethyne is HC2H.  Ethyne is the IUPAC name for this species, which is also commonly known as acetylene.</description>
  </entry>
  <entry id="mass_concentration_of_formaldehyde_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for formaldehyde is CH2O. The IUPAC name for formaldehyde is methanal.</description>
  </entry>
  <entry id="mass_concentration_of_formic_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for formic acid is HCOOH.  The IUPAC name for formic acid is methanoic acid.</description>
  </entry>
  <entry id="mass_concentration_of_gaseous_divalent_mercury_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Divalent mercury&quot; means all compounds in which the mercury has two binding sites to other ion(s) in a salt or to other atom(s) in a molecule.</description>
  </entry>
  <entry id="mass_concentration_of_gaseous_elemental_mercury_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for mercury is Hg.</description>
  </entry>
  <entry id="mass_concentration_of_halon1202_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1202 is CBr2F2. The IUPAC name for halon1202 is dibromo-difluoro-methane.</description>
  </entry>
  <entry id="mass_concentration_of_halon1211_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1211 is CBrClF2. The IUPAC name for halon1211 is bromo-chloro-difluoro-methane.</description>
  </entry>
  <entry id="mass_concentration_of_halon1301_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1301 is CBrF3. The IUPAC name for halon1301 is bromo-trifluoro-methane.</description>
  </entry>
  <entry id="mass_concentration_of_halon2402_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halo2402 is C2Br2F4. The IUPAC name for halon2402 is 1,2-dibromo-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mass_concentration_of_hcc140a_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hcc140a is CH3CCl3. The IUPAC name for hcc140a is 1,1,1-trichloro-ethane.</description>
  </entry>
  <entry id="mass_concentration_of_hcfc141b_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC141b is CH3CCl2F. The IUPAC name for HCFC141b is 1,1-dichloro-1-fluoroethane.</description>
  </entry>
  <entry id="mass_concentration_of_hcfc142b_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC142b is CH3CClF2. The IUPAC name for HCFC142b is 1-chloro-1,1-difluoroethane.</description>
  </entry>
  <entry id="mass_concentration_of_hcfc22_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC22 is CHClF2.  The IUPAC name for HCFC22 is chloro-difluoro-methane.</description>
  </entry>
  <entry id="mass_concentration_of_hexachlorobiphenyl_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hexachlorobiphenyl is C12H4Cl6.  This structure of this species consists of two linked benzene rings, each of which is additionally bonded to three chlorine atoms.</description>
  </entry>
  <entry id="mass_concentration_of_hox_expressed_as_hydrogen_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;HOx&quot; means a combination of two radical species containing hydrogen and oxygen: OH and HO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_hydrogen_bromide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen bromide is HBr.</description>
  </entry>
  <entry id="mass_concentration_of_hydrogen_chloride_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen chloride is HCl.</description>
  </entry>
  <entry id="mass_concentration_of_hydrogen_cyanide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen cyanide is HCN.</description>
  </entry>
  <entry id="mass_concentration_of_hydrogen_peroxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen peroxide is H2O2.</description>
  </entry>
  <entry id="mass_concentration_of_hydroperoxyl_radical_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for the hydroperoxyl radical is HO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_concentration_of_hydroxyl_radical_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for the hydroxyl radical is OH. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_concentration_of_hypobromous_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hypobromous acid is HOBr.</description>
  </entry>
  <entry id="mass_concentration_of_hypochlorous_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hypochlorous acid is HOCl.</description>
  </entry>
  <entry id="mass_concentration_of_inorganic_bromine_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols. &quot;Inorganic bromine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;brox&quot; are used for quantities that contain all inorganic bromine species except HBr and BrONO2.</description>
  </entry>
  <entry id="mass_concentration_of_inorganic_chlorine_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols. &quot;Inorganic chlorine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;clox&quot; are used for quantities that contain all inorganic chlorine species except HCl and ClONO2.</description>
  </entry>
  <entry id="mass_concentration_of_isoprene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for isoprene is CH2=C(CH3)CH=CH2. The IUPAC name for isoprene is 2-methyl-buta-1,3-diene. Isoprene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_limonene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for limonene is C10H16. The IUPAC name for limonene is 1-methyl-4-prop-1-en-2-yl-cyclohexene. Limonene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_mercury_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_concentration_of_methane_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methane is CH4. Methane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_methanol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methanol is CH3OH.</description>
  </entry>
  <entry id="mass_concentration_of_methyl_bromide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl bromide is CH3Br. The IUPAC name for methyl bromide is bromomethane.</description>
  </entry>
  <entry id="mass_concentration_of_methyl_chloride_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl chloride is CH3Cl. The IUPAC name for methyl chloride is chloromethane.</description>
  </entry>
  <entry id="mass_concentration_of_methyl_hydroperoxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl hydroperoxide is CH3OOH.</description>
  </entry>
  <entry id="mass_concentration_of_methyl_peroxy_radical_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl_peroxy_radical is CH3O2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_concentration_of_molecular_hydrogen_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for molecular hydrogen is H2.</description>
  </entry>
  <entry id="mass_concentration_of_nitrate_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The chemical formula for the nitrate anion is NO3-.</description>
  </entry>
  <entry id="mass_concentration_of_nitrate_radical_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_concentration_of_nitric_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitric acid is HNO3.</description>
  </entry>
  <entry id="mass_concentration_of_nitric_acid_trihydrate_ambient_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. The chemical formula for nitric acid is HNO3. Nitric acid trihydrate, sometimes referred to as NAT, is a stable crystalline substance consisting of three molecules of water to one molecule of nitric acid.</description>
  </entry>
  <entry id="mass_concentration_of_nitrogen_dioxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrogen dioxide is NO2.</description>
  </entry>
  <entry id="mass_concentration_of_nitrogen_monoxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrogen monoxide is NO.</description>
  </entry>
  <entry id="mass_concentration_of_nitrous_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrous acid is HNO2.</description>
  </entry>
  <entry id="mass_concentration_of_nitrous_oxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrous oxide is N2O.</description>
  </entry>
  <entry id="mass_concentration_of_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_nox_expressed_as_nitrogen_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Nox&quot; means a combination of two radical species containing nitrogen and oxygen: NO+NO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_noy_expressed_as_nitrogen_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Noy&quot; describes a family of chemical species. The family usually includes atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), peroxynitric acid (HNO4), bromine nitrate (BrONO2) , chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)). The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_concentration_of_organic_detritus_expressed_as_carbon_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Organic detritus are particles of debris from decaying plants and animals.</description>
  </entry>
  <entry id="mass_concentration_of_organic_detritus_expressed_as_nitrogen_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Organic detritus are particles of debris from decaying plants and animals.</description>
  </entry>
  <entry id="mass_concentration_of_oxygen_in_sea_water">
    <canonical_units>kg m-3</canonical_units>
    <description>Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mass_concentration_of_oxygenated_hydrocarbons_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.  &quot;Oxygenated&quot; means containing oxygen. &quot;Hydrocarbon&quot; means a compound containing hydrogen and carbon.</description>
  </entry>
  <entry id="mass_concentration_of_ozone_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ozone is O3.</description>
  </entry>
  <entry id="mass_concentration_of_particulate_organic_matter_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The term &quot;particulate_organic_matter_dry_aerosol&quot; means all particulate organic matter dry aerosol except black carbon. It is the sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="mass_concentration_of_peroxy_radicals_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The term &quot;peroxy_radicals&quot; means all organic and inorganic peroxy radicals. This includes HO2 and all organic peroxy radicals, sometimes referred to as RO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_concentration_of_peroxyacetyl_nitrate_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for peroxyacetyl nitrate, sometimes referred to as PAN, is CH3COO2NO2.  The IUPAC name for peroxyacetyl_nitrate is nitroethaneperoxoate.</description>
  </entry>
  <entry id="mass_concentration_of_peroxynitric_acid_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for peroxynitric acid, sometimes referred to as PNA, is HO2NO2.</description>
  </entry>
  <entry id="mass_concentration_of_phosphate_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mass_concentration_of_phytoplankton_expressed_as_chlorophyll_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Phytoplankton are autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis. Chlorophyll is the green pigment found in most plants, algae and cyanobacteria.  The presence of chlorophyll is essential for photosynthesis to take place.  There are five different forms of chlorophyll that occur naturally.  All contain a chlorin ring (chemical formula C20H16N4) which gives the green pigment and a side chain whose structure varies.  The naturally occurring forms of chlorophyll contain between 35 and 55 carbon atoms.</description>
  </entry>
  <entry id="mass_concentration_of_primary_particulate_organic_matter_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. &quot;Primary particulate organic matter &quot; means all organic matter emitted directly to the atmosphere as particles except black carbon. The sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol is particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="mass_concentration_of_propane_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for propane is C3H8. Propane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_propene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for propene is C3H6. Propene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_concentration_of_radon_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for radon is Rn.</description>
  </entry>
  <entry id="mass_concentration_of_seasalt_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_concentration_of_secondary_particulate_organic_matter_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. &quot;Secondary particulate organic matter &quot; means particulate organic matter formed within the atmosphere from gaseous precursors. The sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol is particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="mass_concentration_of_silicate_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mass_concentration_of_sulfate_ambient_aerosol_in_air">
    <canonical_units>kg m-3</canonical_units>
    <amip>trsul</amip>
    <description>Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  "Ambient aerosol" is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="mass_concentration_of_sulfate_dry_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water. The chemical formula for the sulfate anion is SO4(2-).</description>
  </entry>
  <entry id="mass_concentration_of_sulfur_dioxide_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for sulfur dioxide is SO2.</description>
  </entry>
  <entry id="mass_concentration_of_suspended_matter_in_sea_water">
    <canonical_units> kg m-3</canonical_units>
    <description>Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mass_concentration_of_terpenes_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Terpenes are hydrocarbons, that is, they contain only hydrogen and carbon combined in the general proportions (C5H8)n where n is an integer greater than on equal to one. The term &quot;terpenes&quot; is used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.  Standard names exist for some individual terpene species, e.g., isoprene and limonene.</description>
  </entry>
  <entry id="mass_concentration_of_toluene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for toluene is C6H5CH3.  Toluene has the same structure as benzene, except that one of the hydrogen atoms is replaced by a methyl group.  The systematic name for toluene is methylbenzene.</description>
  </entry>
  <entry id="mass_concentration_of_water_in_ambient_aerosol_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> &quot;Water&quot; means water in all phases.  Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="mass_concentration_of_water_vapor_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mass_concentration_of_xylene_in_air">
    <canonical_units> kg m-3</canonical_units>
    <description> Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for xylene is C6H4C2H6. In chemistry, xylene is a generic term for a group of three isomers of dimethylbenzene. The IUPAC names for the isomers are 1,2-dimethylbenzene, 1,3-dimethylbenzene and 1,4-dimethylbenzene. Xylene is an aromatic hydrocarbon. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="mass_fraction_of_acetic_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid.</description>
  </entry>
  <entry id="mass_fraction_of_aceto_nitrile_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for aceto-nitrile is CH3CN. The IUPAC name for aceto-nitrile is ethanenitrile.</description>
  </entry>
  <entry id="mass_fraction_of_alkanes_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Alkanes are saturated hydrocarbons, i.e. they do not contain any chemical double bonds.  Alkanes contain only hydrogen and carbon combined in the general proportions C(n)H(2n+2); &quot;alkanes&quot; is the term used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual alkane species, e.g., methane and ethane.</description>
  </entry>
  <entry id="mass_fraction_of_alkenes_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Alkenes are unsaturated hydrocarbons as they contain chemical double bonds between adjacent carbon atoms.  Alkenes contain only hydrogen and carbon combined in the general proportions C(n)H(2n); &quot;alkenes&quot; is the term used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names exist for some individual alkene species, e.g., ethene and propene.</description>
  </entry>
  <entry id="mass_fraction_of_alpha_hexachlorocyclohexane_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for alpha_hexachlorocyclohexane is C6H6Cl6.</description>
  </entry>
  <entry id="mass_fraction_of_alpha_pinene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for alpha_pinene is C10H16. The IUPAC name for alpha-pinene is (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene.</description>
  </entry>
  <entry id="mass_fraction_of_ammonia_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ammonia is NH3.</description>
  </entry>
  <entry id="mass_fraction_of_ammonium_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Mass_fraction_of_ammonium&quot; means that the mass is expressed as mass of NH4.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_fraction_of_anthropogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Anthropogenic&quot; means influenced, caused, or created by human activity.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_aromatic_compounds_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Aromatic compounds in organic chemistry are compounds that contain at least one benzene ring of six carbon atoms joined by alternating single and double covalent bonds.  The simplest aromatic compound is benzene itself.  In standard names &quot;aromatic_compounds&quot; is the term used to describe the group of aromatic chemical species that  are represented within a given model.  The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.  Standard names exist for some individual aromatic species, e.g. benzene and xylene.</description>
  </entry>
  <entry id="mass_fraction_of_atomic_bromine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic bromine is Br.</description>
  </entry>
  <entry id="mass_fraction_of_atomic_chlorine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic chlorine is Cl.</description>
  </entry>
  <entry id="mass_fraction_of_atomic_nitrogen_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic nitrogen is N.</description>
  </entry>
  <entry id="mass_fraction_of_benzene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for benzene is C6H6.  Benzene is the simplest aromatic hydrocarbon and has a ring structure consisting of six carbon atoms joined by alternating single and double chemical bonds. Each carbon atom is additionally bonded to one hydrogen atom. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="mass_fraction_of_beta_pinene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for beta_pinene is C10H16.  The IUPAC name for beta-pinene is (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane.</description>
  </entry>
  <entry id="mass_fraction_of_biogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Biogenic&quot; means influenced, caused, or created by natural processes. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_black_carbon_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.  Black carbon aerosol is composed of elemental carbon.  It is strongly light absorbing.</description>
  </entry>
  <entry id="mass_fraction_of_bromine_chloride_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine chloride is BrCl.</description>
  </entry>
  <entry id="mass_fraction_of_bromine_monoxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine monoxide is BrO.</description>
  </entry>
  <entry id="mass_fraction_of_bromine_nitrate_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine nitrate is BrONO2.</description>
  </entry>
  <entry id="mass_fraction_of_brox_expressed_as_bromine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Brox&quot;  describes a family of chemical species consisting of inorganic bromine compounds with the exception of  hydrogen bromide (HBr) and bromine nitrate (BrONO2). &quot;Brox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompaniedby a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols.  Standard names that use the term &quot;inorganic_bromine&quot; are usedfor quantities that contain all inorganic bromine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_butane_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_carbon_dioxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for carbon dioxide is CO2.</description>
  </entry>
  <entry id="mass_fraction_of_carbon_monoxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of carbon monoxide is CO.</description>
  </entry>
 <entry id="mass_fraction_of_carbon_tetrachloride_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of carbon tetrachloride is CCl4.</description>
  </entry>
  <entry id="mass_fraction_of_cfc11_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC11 is CFCl3. The IUPAC name fof CFC11 is trichloro-fluoro-methane.</description>
  </entry>
  <entry id="mass_fraction_of_cfc113_in_air">
    <canonical_units> 1 </canonical_units>
<description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC113 is CCl2FCClF2. The IUPAC name for CFC113 is 1,1,2-trichloro-1,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mass_fraction_of_cfc113a_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC113a CCl3CF3.  The IUPAC name for CFC113a is 1,1,1-trichloro-2,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mass_fraction_of_cfc114_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC114 is CClF2CClF2. The IUPAC name for CFC114 is 1,2-dichloro-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mass_fraction_of_cfc115_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC115 is CClF2CF3. The IUPAC name for CFC115 is 1-chloro-1,1,2,2,2-pentafluoro-ethane.</description>
  </entry>
  <entry id="mass_fraction_of_cfc12_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for CFC12 is CF2Cl2.  The IUPAC name for CFC12 is dichloro-difluoro-methane.</description>
  </entry>
  <entry id="mass_fraction_of_chlorine_dioxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine dioxide is OClO.</description>
  </entry>
  <entry id="mass_fraction_of_chlorine_monoxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine monoxide is ClO.</description>
  </entry>
 <entry id="mass_fraction_of_chlorine_nitrate_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine nitrate is ClONO2.</description>
  </entry>
  <entry id="mass_fraction_of_cloud_condensed_water_in_air">
    <canonical_units>1</canonical_units>
    <description>&quot;condensed_water&quot; means liquid and ice. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_cloud_ice_in_air">
    <canonical_units>1</canonical_units>
    <amip>cli</amip>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_cloud_liquid_water_in_air">
    <canonical_units>1</canonical_units>
    <amip>clw</amip>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
 <entry id="mass_fraction_of_clox_expressed_as_chlorine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Clox&quot; describes a familyof chemical species consisting of inorganic chlorine compounds with the exception of  hydrogen chloride (HCl) and chlorine nitrate (ClONO2). &quot;Clox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols.   Standard names that use the term &quot;inorganic_chlorine&quot; are used for quantitiesthat contain all inorganic chlorine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A.It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_convective_cloud_condensed_water_in_air">
    <canonical_units>1</canonical_units>
    <description>&quot;condensed_water&quot; means liquid and ice. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_convective_cloud_ice_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="mass_fraction_of_convective_cloud_liquid_water_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
 <entry id="mass_fraction_of_dichlorine_peroxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dichlorineperoxide is Cl2O2.</description>
  </entry>
  <entry id="mass_fraction_of_dimethyl_sulfide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_dinitrogen_pentoxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dinitrogenpentoxide is N2O5.</description>
  </entry>
  <entry id="mass_fraction_of_dust_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_fraction_of_ethane_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethane is C2H6. Ethane is a member of the group of hydrocarbons known as alkanes.  There are standardnames for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_ethanol_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethanol isC2H5OH.</description>
  </entry>
  <entry id="mass_fraction_of_ethene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethene is C2H4. Ethene is a member of the group of hydrocarbons known as alkenes.  There are standardnames for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_ethyne_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethyne is HC2H.  Ethyne is the IUPAC name for this species, which is also commonly known as acetylene.</description>
  </entry>
  <entry id="mass_fraction_of_formaldehyde_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for formaldehyde is CH2O. The IUPAC name for formaldehyde is methanal.</description>
  </entry>
  <entry id="mass_fraction_of_formic_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for formic acid is HCOOH.  The IUPAC name for formic acid is methanoic acid.</description>
  </entry>
  <entry id="mass_fraction_of_frozen_water_in_soil_moisture">
    <canonical_units>1</canonical_units>
    <description>&quot;frozen_water&quot; means ice. &quot;moisture&quot; means water in all phases contained in soil. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_gaseous_divalent_mercury_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Divalent mercury&quot; means all compounds in which the mercury has two binding sites to other ion(s) in a salt or to other atom(s) in a molecule.</description>
  </entry>
  <entry id="mass_fraction_of_gaseous_elemental_mercury_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for mercury is Hg.</description>
  </entry>
  <entry id="mass_fraction_of_graupel_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_halon1202_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1202 is CBr2F2. The IUPAC name for halon1202 is dibromo-difluoro-methane.</description>
  </entry>
  <entry id="mass_fraction_of_halon1211_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1211 is CBrClF2. The IUPAC name for halon1211 is bromo-chloro-difluoro-methane.</description>
  </entry>
  <entry id="mass_fraction_of_halon1301_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1301 is CBrF3. The IUPAC name for halon1301 is bromo-trifluoro-methane.</description>
  </entry>
  <entry id="mass_fraction_of_halon2402_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halo2402 is C2Br2F4. The IUPAC name for halon2402 is 1,2-dibromo-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mass_fraction_of_hcc140a_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hcc140a isCH3CCl3. The IUPAC name for hcc140a is 1,1,1-trichloro-ethane.</description>
  </entry>
  <entry id="mass_fraction_of_hcfc141b_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC141b is CH3CCl2F. The IUPAC name for HCFC141b is 1,1-dichloro-1-fluoroethane.</description>
  </entry>
  <entry id="mass_fraction_of_hcfc142b_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC142b is CH3CClF2. The IUPAC name for HCFC142b is 1-chloro-1,1-difluoroethane.</description>
  </entry>
  <entry id="mass_fraction_of_hcfc22_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC22 is CHClF2.  The IUPAC name for HCFC22 is chloro-difluoro-methane.</description>
  </entry>
  <entry id="mass_fraction_of_hexachlorobiphenyl_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hexachlorobiphenyl is C12H4Cl6.  This structure of this species consists of two linked benzene rings,each of which is additionally bonded to three chlorine atoms.</description>
  </entry>
  <entry id="mass_fraction_of_hox_expressed_as_hydrogen_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;HOx&quot; means a combinationof two radical species containing hydrogen and oxygen: OH and HO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. Itmeans that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_hydrogen_bromide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen bromide is HBr.</description>
  </entry>
  <entry id="mass_fraction_of_hydrogen_chloride_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen chloride is HCl.</description>
  </entry>
  <entry id="mass_fraction_of_hydrogen_cyanide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen cyanide is HCN.</description>
  </entry>
  <entry id="mass_fraction_of_hydrogen_peroxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen peroxide is H2O2.</description>
  </entry>
  <entry id="mass_fraction_of_hydroperoxyl_radical_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for the hydroperoxyl radical is HO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_fraction_of_hydroxyl_radical_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for the hydroxyl radical is OH. In chemistry, a 'radical' is a highly reactive, and therefore shortlived,species.</description>
  </entry>
  <entry id="mass_fraction_of_hypobromous_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hypobromous acid is HOBr.</description>
  </entry>
  <entry id="mass_fraction_of_hypochlorous_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hypochlorous acid is HOCl.</description>
  </entry>
  <entry id="mass_fraction_of_inorganic_bromine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols. &quot;Inorganic bromine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;brox&quot; are used for quantities that contain all inorganic bromine species except HBr and BrONO2.</description>
  </entry>
 <entry id="mass_fraction_of_inorganic_chlorine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols. &quot;Inorganic chlorine&quot; is the termused in standard names for all species belonging to the family that are represented withina given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;clox&quot; are used for quantities that contain all inorganic chlorine species except HCl and ClONO2.</description>
  </entry>
  <entry id="mass_fraction_of_isoprene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for isoprene is CH2=C(CH3)CH=CH2. The IUPAC name for isoprene is 2-methyl-buta-1,3-diene. Isoprene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_limonene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for limonene is C10H16. The IUPAC name for limonene is 1-methyl-4-prop-1-en-2-yl-cyclohexene. Limonene isa member of the group of hydrocarbons known as terpenes.  There are standard names for theterpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_mercury_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_fraction_of_methane_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methane isCH4. Methane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_methanol_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethanol isC2H5OH. The chemical formula for methanol is CH3OH.</description>
  </entry>
  <entry id="mass_fraction_of_methyl_bromide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl bromide is CH3Br. The IUPAC name for methyl bromide is bromomethane.</description>
  </entry>
  <entry id="mass_fraction_of_methyl_chloride_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl chloride is CH3Cl. The IUPAC name for methyl chloride is chloromethane.</description>
  </entry>
  <entry id="mass_fraction_of_methyl_hydroperoxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl hydroperoxide is CH3OOH.</description>
  </entry>
  <entry id="mass_fraction_of_methyl_peroxy_radical_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl_peroxy_radical is CH3O2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
 <entry id="mass_fraction_of_molecular_hydrogen_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for molecular hydrogen is H2.</description>
  </entry>
  <entry id="mass_fraction_of_nitrate_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). &quot;Mass_fraction_of_nitrate&quot; means that the mass is expressed as mass of NO3.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_fraction_of_nitrate_radical_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_fraction_of_nitric_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitric acid is HNO3.</description>
  </entry>
  <entry id="mass_fraction_of_nitric_acid_trihydrate_ambient_aerosol_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot;is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. The chemical formula for nitric acid is HNO3. Nitric acid trihydrate, sometimes referred to as NAT,is a stable crystalline substance consisting of three molecules of water to one molecule of nitric acid.</description>
  </entry>
  <entry id="mass_fraction_of_nitrogen_dioxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrogen dioxide is NO2.</description>
  </entry>
  <entry id="mass_fraction_of_nitrogen_monoxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrogen monoxide is NO.</description>
  </entry>
  <entry id="mass_fraction_of_nitrous_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrous acid is HNO2.</description>
  </entry>
  <entry id="mass_fraction_of_nitrous_oxide_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrous oxide is N2O.</description>
  </entry>
  <entry id="mass_fraction_of_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methanevolatile organic compounds. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_nox_expressed_as_nitrogen_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Nox&quot; means a combinationof two radical species containing nitrogen and oxygen: NO+NO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_noy_expressed_as_nitrogen_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Noy&quot; describes a family of chemical species. The family usually includes atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), peroxynitric acid (HNO4), bromine nitrate (BrONO2) , chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)). The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mass_fraction_of_oxygenated_hydrocarbons_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.  &quot;Oxygenated&quot; means containing oxygen. &quot;Hydrocarbon&quot; means a compound containing hydrogen and carbon.</description>
  </entry>
  <entry id="mass_fraction_of_ozone_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_particulate_organic_matter_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.  &quot;particulate_organic_matter_dry_aerosol&quot; means all particulate organic matter dry aerosol except black carbon.  It is the sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="mass_fraction_of_peroxy_radicals_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The term &quot;peroxy_radicals&quot; means all organic and inorganic peroxy radicals. This includes HO2 and all organic peroxyradicals, sometimes referred to as RO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mass_fraction_of_peroxyacetyl_nitrate_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for peroxyacetyl nitrate, sometimes referred to as PAN, is CH3COO2NO2.  The IUPAC name for peroxyacetyl_nitrate is nitroethaneperoxoate.</description>
  </entry>
  <entry id="mass_fraction_of_peroxynitric_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for peroxynitric acid, sometimes referred to as PNA, is HO2NO2.</description>
  </entry>
  <entry id="mass_fraction_of_pm1_ambient_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquidor solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth dependson the relative humidity and the composition of the aerosol. &quot;Pm1 aerosol&quot; is an air pollutant with an aerodynamic diameter of less than or equal to 1 micrometer. To specify the relative humidity and temperature at which the particle size applies, provide scalar coordinate variables with the standard names of, respectively, &quot;relative_humidity&quot; and &quot;air_temperature&quot;.</description>
  </entry>
  <entry id="mass_fraction_of_pm10_ambient_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. &quot;Pm10 aerosol&quot; is an air pollutant with an aerodynamic diameter of less than or equal to 10 micrometers. To specify the relative humidity and temperature at which the particle size applies, provide scalar coordinate variables with the standard names of, respectively, &quot;relative_humidity&quot; and &quot;air_temperature.&quot;</description>
  </entry>
  <entry id="mass_fraction_of_pm2p5_ambient_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. &quot;Pm2p5 aerosol&quot; is an air pollutant with an aerodynamic diameter of less than or equal to 2.5 micrometers. To specify the relative humidity and temperature at which the particle size applies, provide scalar coordinate variables with the standard names of, respectively, &quot;relative_humidity&quot; and &quot;air_temperature&quot;.</description>
  </entry>
  <entry id="mass_fraction_of_precipitation_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_primary_particulate_organic_matter_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.  &quot;Primary particulate organic matter &quot; means all organic matter emitted directly to the atmosphere as particles except black carbon.  The sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol is particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="mass_fraction_of_propane_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for propane isC3H8. Propane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_propene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for propene isC3H6. Propene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mass_fraction_of_radon_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for radon is Rn.</description>
  </entry>
  <entry id="mass_fraction_of_rain_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_seasalt_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_fraction_of_secondary_particulate_organic_matter_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.  &quot;Secondary particulate organic matter &quot; means particulate organic matter formed within the atmosphere from gaseous precursors.  The sum of primary_particulate_organic_matter_dry_aerosol and secondary_particulate_organic_matter_dry_aerosol is particulate_organic_matter_dry_aerosol.</description>
  </entry>
  <entry id="mass_fraction_of_snow_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_stratiform_cloud_ice_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes).</description>
  </entry>
  <entry id="mass_fraction_of_stratiform_cloud_liquid_water_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes).</description>
  </entry>
  <entry id="mass_fraction_of_sulfate_dry_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Mass_fraction_of_sulfate&quot; means that the mass is expressed as mass of SO4.  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol. &quot;Dry aerosol&quot; means aerosol without water.</description>
  </entry>
  <entry id="mass_fraction_of_sulfuric_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mass_fraction_of_sulfur_dioxide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_terpenes_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Terpenes are hydrocarbons, that is,they contain only hydrogen and carbon combined in the general proportions (C5H8)n where n is an integer greater than on equal to one. The term &quot;terpenes&quot; is used in standard names to describe the group of chemical species having this common structure that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.  Standard names exist for some individual terpene species, e.g., isoprene and limonene.</description>
  </entry>
  <entry id="mass_fraction_of_toluene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for toluene isC6H5CH3.  Toluene has the same structure as benzene, except that one of the hydrogen atomsis replaced by a methyl group.  The systematic name for toluene is methylbenzene.</description>
  </entry>
  <entry id="mass_fraction_of_unfrozen_water_in_soil_moisture">
    <canonical_units>1</canonical_units>
    <description>&quot;moisture&quot; means water in all phases contained in soil. &quot;unfrozen_water&quot; means liquid and vapour. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_water_in_air">
    <canonical_units>1</canonical_units>
    <description>&quot;Water&quot; means water in all phases. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).</description>
  </entry>
  <entry id="mass_fraction_of_water_in_ambient_aerosol_in_air">
    <canonical_units>1</canonical_units>
    <description>Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  Aerosol takes up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the aerosol.</description>
  </entry>
  <entry id="mass_fraction_of_xylene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mass fraction is used in the construction mass_fraction_of_X_in_Y, whereX is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X).  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for xylene is C6H4C2H6. In chemistry, xylene is a generic term for a group of three isomers of dimethylbenzene. The IUPAC names for the isomers are 1,2-dimethylbenzene, 1,3-dimethylbenzene and 1,4-dimethylbenzene. Xylene is an aromatic hydrocarbon. There are standard names that refer toaromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="minus_one_times_surface_upwelling_longwave_flux_in_air">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Minus one times&quot; means that the quantity described takes the opposite sign convention  to that for the quantity which has the same standard name apart from this phrase, i.e. the two quantities differ from one another by a factor of -1. The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;longwave&quot; means longwave radiation. Upwelling radiation is radiation from below. It does not mean &quot;net upward&quot;. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="minus_one_times_surface_upwelling_shortwave_flux_in_air">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Minus one times&quot; means that the quantity described takes the opposite sign convention  to that for the quantity which has the same standard name apart from this phrase, i.e. the two quantities differ from one another by a factor of -1. The surface called &quot;surface&quot; means the lower boundary of the atmosphere. &quot;shortwave&quot; means shortwave radiation. Upwelling radiation is radiation from below. It does not mean &quot;net upward&quot;. When thought of as being incident on a surface, a radiative flux is sometimes called &quot;irradiance&quot;. In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called &quot;vector irradiance&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="minus_one_times_toa_outgoing_shortwave_flux">
    <canonical_units>W m-2</canonical_units>
    <description>&quot;Minus one times&quot; means that the quantity described takes the opposite sign convention  to that for the quantity which has the same standard name apart from this phrase, i.e. the two quantities differ from one another by a factor of -1.  Shortwave means shortwave radiation. &quot;toa&quot; means top of atmosphere. The TOA outgoing shortwave flux is the reflected and scattered solar radiative flux i.e. the &quot;upwelling&quot; TOA shortwave flux, sometimes called the &quot;outgoing shortwave radiation&quot; or &quot;OSR&quot;. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="minus_one_times_water_flux_into_sea_water_from_rivers">
    <canonical_units>kg m-2 s-1</canonical_units>
    <description>The quantity minus_one_times_water_flux_into_sea_water_from_rivers is the quantity with standard name water_flux_into_sea_water_from_rivers multiplied by -1. &quot;Water&quot; means water in all phases. The water flux or volume transport into sea water from rivers is the inflow to the ocean, often applied to the surface in ocean models. In accordance with common usage in geophysical disciplines, &quot;flux&quot; implies per unit area, called &quot;flux density&quot; in physics.</description>
  </entry>
  <entry id="model_level_number">
    <canonical_units>1</canonical_units>
    <amip>lev</amip>
    <description>Model level number should be understood as equivalent to layer number.</description>
  </entry>
  <entry id="model_level_number_at_base_of_ocean_mixed_layer_defined_by_sigma_theta">
    <canonical_units> 1 </canonical_units>
    <description>The ocean mixed layer is the upper part of the ocean, regarded as being well-mixed. The base of the mixed layer defined by temperature, sigma, sigma_theta or vertical diffusivity is the level at which the quantity indicated differs from its surface value by a certain amount. The amount by which the quantity differs can be specified by a scalar coordinate variable. The quantity model_level_number_at_base_of_ocean_mixed_layer_defined_by_sigma_theta is sometimes referred to as the &quot;bowl index&quot;.</description>
  </entry>
  <entry id="model_level_number_at_convective_cloud_base">
    <canonical_units>1</canonical_units>
    <description>cloud_base refers to the base of the lowest cloud. Model level number should be understood as equivalent to layer number. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="model_level_number_at_convective_cloud_top">
    <canonical_units>1</canonical_units>
    <description>cloud_top refers to the top of the highest cloud. Model level number should be understood as equivalent to layer number. Convective cloud is that produced by the convection schemes in an atmosphere model.</description>
  </entry>
  <entry id="model_level_number_at_sea_floor">
    <canonical_units> 1 </canonical_units>
    <description>The quantity with standard name model_level_number_at_sea_floor is the depth of the ocean expressed in model levels. This could be a non-integer value because some ocean models use partial cells close to the sea floor.  For example, if this field were 23.4 at some location, it would mean the water column at that point comprised 23 full model levels plus 40% occupancy of the lowest (24th) gridcell.</description>
  </entry>
  <entry id="model_level_number_at_top_of_atmosphere_boundary_layer">
    <canonical_units>1</canonical_units>
    <description>Model level number should be understood as equivalent to layer number.</description>
  </entry>
  <entry id="moisture_content_of_soil_layer">
    <canonical_units>kg m-2</canonical_units>
    <amip>mrsos</amip>
    <description>&quot;moisture&quot; means water in all phases contained in soil. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s).</description>
  </entry>
  <entry id="moisture_content_of_soil_layer_at_field_capacity">
    <canonical_units>kg m-2</canonical_units>
    <amip>mrsofcs</amip>
    <description>&quot;moisture&quot; means water in all phases contained in soil. &quot;Content&quot; indicates a quantity per unit area. &quot;Layer&quot; means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). The field capacity of soil is the maximum content of water it can retain against gravitational drainage.</description>
  </entry>
  <entry id="mole_concentration_of_acetic_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid.</description>
  </entry>
  <entry id="mole_concentration_of_aceto_nitrile_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for aceto-nitrile is CH3CN. The IUPAC name for aceto-nitrile is ethanenitrile.</description>
  </entry>
  <entry id="mole_concentration_of_alpha_hexachlorocyclohexane_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for alpha_hexachlorocyclohexane is C6H6Cl6.</description>
  </entry>
  <entry id="mole_concentration_of_alpha_pinene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for alpha_pinene is C10H16. The IUPAC name for alpha-pinene is (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene.</description>
  </entry>
  <entry id="mole_concentration_of_ammonia_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ammonia is NH3.</description>
  </entry>
  <entry id="mole_concentration_of_ammonium_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means moles (amount of substance) per unit volume and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_concentration_of_anthropogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Anthropogenic&quot; means influenced,caused, or created by human activity.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituentsof A.</description>
  </entry>
  <entry id="mole_concentration_of_atomic_bromine_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic bromine is Br.</description>
  </entry>
  <entry id="mole_concentration_of_atomic_chlorine_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic chlorine is Cl.</description>
  </entry>
  <entry id="mole_concentration_of_atomic_nitrogen_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for atomic nitrogen is N.</description>
  </entry>
 <entry id="mole_concentration_of_benzene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for benzene is C6H6.  Benzene is the simplest aromatic hydrocarbon and has a ring structure consisting of six carbon atoms joined by alternating single and double chemical bonds. Each carbon atom is additionally bonded to one hydrogen atom. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="mole_concentration_of_beta_pinene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for beta_pinene is C10H16.  The IUPAC name for beta-pinene is (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane.</description>
  </entry>
  <entry id="mole_concentration_of_biogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Biogenic&quot; means influenced, caused, or created by natural processes.
 The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituentsof A.</description>
  </entry>
  <entry id="mole_concentration_of_bromine_chloride_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine chloride is BrCl.</description>
  </entry>
 <entry id="mole_concentration_of_bromine_monoxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine monoxide is BrO.</description>
  </entry>
  <entry id="mole_concentration_of_bromine_nitrate_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for bromine nitrate is BrONO2.</description>
  </entry>
 <entry id="mole_concentration_of_brox_expressed_as_bromine_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Brox&quot; describes a family of chemical species consisting of inorganic bromine compounds with theexception of  hydrogen bromide (HBr) and bromine nitrate (BrONO2). &quot;Brox&quot; is theterm used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols.  Standard names that use the term &quot;inorganic_bromine&quot; are used for quantities that contain all inorganic bromine species including HCland ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard nameis calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
 <entry id="mole_concentration_of_butane_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes. There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_carbon_dioxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for carbon dioxide is CO2.</description>
  </entry>
  <entry id="mole_concentration_of_carbon_monoxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of carbon monoxide is CO.</description>
  </entry>
  <entry id="mole_concentration_of_carbon_tetrachloride_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of carbon tetrachloride is CCl4.</description>
  </entry>
  <entry id="mole_concentration_of_cfc11_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC11 is CFCl3. The IUPAC name fof CFC11 is trichloro-fluoro-methane.</description>
  </entry>
  <entry id="mole_concentration_of_cfc113_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC113 is CCl2FCClF2. The IUPAC name for CFC113 is 1,1,2-trichloro-1,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mole_concentration_of_cfc113a_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC113a CCl3CF3.  The IUPAC name for CFC113a is 1,1,1-trichloro-2,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mole_concentration_of_cfc114_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC114 is CClF2CClF2. The IUPAC name for CFC114 is 1,2-dichloro-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mole_concentration_of_cfc115_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula of CFC115 is CClF2CF3. The IUPAC name for CFC115 is 1-chloro-1,1,2,2,2-pentafluoro-ethane.</description>
  </entry>
 <entry id="mole_concentration_of_cfc12_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for CFC12 is CF2Cl2.  The IUPAC name for CFC12 is dichloro-difluoro-methane.</description>
  </entry>
  <entry id="mole_concentration_of_chlorine_dioxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine dioxide is OClO.</description>
  </entry>
  <entry id="mole_concentration_of_chlorine_monoxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine monoxide is ClO.</description>
  </entry>
  <entry id="mole_concentration_of_chlorine_nitrate_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for chlorine nitrate is ClONO2.</description>
  </entry>
  <entry id="mole_concentration_of_clox_expressed_as_chlorine_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Clox&quot;describes a family of chemical species consisting of inorganic chlorine compounds with theexception of  hydrogen chloride (HCl) and chlorine nitrate (ClONO2). &quot;Clox&quot; is the term used in standard names for all species belonging to the family that are representedwithin a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, byusing a comment attribute. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasaltand other aerosols.   Standard names that use the term &quot;inorganic_chlorine&quot; are used for quantities that contain all inorganic chlorine species including HCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculatedsolely with respect to the B contained in A, neglecting all other chemical constituents ofA.</description>
  </entry>
  <entry id="mole_concentration_of_diatoms_expressed_as_nitrogen_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated in terms of B alone, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_dichlorine_peroxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dichlorine peroxide is Cl2O2.</description>
  </entry>
  <entry id="mole_concentration_of_dimethyl_sulfide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dimethyl sulfide is (CH3)2S.  Dimethyl sulfide is sometimes referred to as DMS.</description>
  </entry>
  <entry id="mole_concentration_of_dinitrogen_pentoxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for dinitrogen pentoxide is N2O5.</description>
  </entry>
  <entry id="mole_concentration_of_ethane_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethane is C2H6. Ethane is a member of the group of hydrocarbons known as alkanes.There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_ethanol_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethanol is C2H5OH.</description>
  </entry>
  <entry id="mole_concentration_of_ethene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethene is C2H4. Ethene is a member of the group of hydrocarbons known as alkenes.There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_ethyne_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ethyne is HC2H.  Ethyne is the IUPAC name for this species, which is also commonlyknown as acetylene.</description>
  </entry>
  <entry id="mole_concentration_of_formaldehyde_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for formaldehyde is CH2O. The IUPAC name for formaldehyde is methanal.</description>
  </entry>
  <entry id="mole_concentration_of_formic_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for formic acid is HCOOH.  The IUPAC name for formic acid is methanoic acid.</description>
  </entry>
  <entry id="mole_concentration_of_gaseous_divalent_mercury_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Divalent mercury&quot; means all compounds in which the mercury has two binding sites to other ion(s)in a salt or to other atom(s) in a molecule.</description>
  </entry>
  <entry id="mole_concentration_of_gaseous_elemental_mercury_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for mercury is Hg.</description>
  </entry>
  <entry id="mole_concentration_of_halon1202_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1202 is CBr2F2. The IUPAC name for halon1202 is dibromo-difluoro-methane.</description>
  </entry>
  <entry id="mole_concentration_of_halon1211_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1211 is CBrClF2. The IUPAC name for halon1211 is bromo-chloro-difluoro-methane.</description>
  </entry>
  <entry id="mole_concentration_of_halon1301_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halon1301 is CBrF3. The IUPAC name for halon1301 is bromo-trifluoro-methane.</description>
  </entry>
  <entry id="mole_concentration_of_halon2402_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for halo2402 is C2Br2F4. The IUPAC name for halon2402 is 1,2-dibromo-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mole_concentration_of_hcc140a_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hcc140a is CH3CCl3. The IUPAC name for hcc140a is 1,1,1-trichloro-ethane.</description>
  </entry>
  <entry id="mole_concentration_of_hcfc141b_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC141b is CH3CCl2F. The IUPAC name for HCFC141b is 1,1-dichloro-1-fluoroethane.</description>
  </entry>
  <entry id="mole_concentration_of_hcfc142b_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC142b is CH3CClF2. The IUPAC name for HCFC142b is 1-chloro-1,1-difluoroethane.</description>
  </entry>
  <entry id="mole_concentration_of_hcfc22_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for HCFC22 is CHClF2.  The IUPAC name for HCFC22 is chloro-difluoro-methane.</description>
  </entry>
  <entry id="mole_concentration_of_hexachlorobiphenyl_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hexachlorobiphenyl is C12H4Cl6.  This structure of this species consists of two linked benzene rings, each of which is additionally bonded to three chlorine atoms.</description>
  </entry>
  <entry id="mole_concentration_of_hox_expressed_as_hydrogen_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;HOx&quot; means a combination of two radical species containing hydrogen and oxygen: OH and HO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_hydrogen_bromide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen bromide is HBr.</description>
  </entry>
  <entry id="mole_concentration_of_hydrogen_chloride_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen chloride is HCl.</description>
  </entry>
  <entry id="mole_concentration_of_hydrogen_cyanide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen cyanide is HCN.</description>
  </entry>
  <entry id="mole_concentration_of_hydrogen_peroxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hydrogen peroxide is H2O2.</description>
  </entry>
  <entry id="mole_concentration_of_hydroperoxyl_radical_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for the hydroperoxyl radical is HO2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mole_concentration_of_hydroxyl_radical_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for the hydroxyl radical is OH. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mole_concentration_of_hypobromous_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hypobromous acid is HOBr.</description>
  </entry>
  <entry id="mole_concentration_of_hypochlorous_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for hypochlorous acid is HOCl.</description>
  </entry>
  <entry id="mole_concentration_of_inorganic_bromine_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols. &quot;Inorganic bromine&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;brox&quot; are used for quantities that contain all inorganic bromine species except HBr and BrONO2.</description>
  </entry>
  <entry id="mole_concentration_of_inorganic_chlorine_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gases containing chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols. &quot;Inorganic chlorine&quot; is the term used in standard names for all species belonging to the family that arerepresented within a given model. The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. Standard names that use the term &quot;clox&quot;are used for quantities that contain all inorganic chlorine species except HCl and ClONO2.</description>
  </entry>
  <entry id="mole_concentration_of_isoprene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for isoprene is CH2=C(CH3)CH=CH2. The IUPAC name for isoprene is 2-methyl-buta-1,3-diene. Isoprene is a member of the group of hydrocarbons known as terpenes.  There are standard names for the terpene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_limonene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl hydroperoxide is CH3OOH.</description>
  </entry>
  <entry id="mole_concentration_of_mesozooplankton_expressed_as_nitrogen_in_sea_water">
    <canonical_units> mol m-3</canonical_units>
    <description>Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated in terms of B alone, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_methane_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methane is CH4. Methane is a member of the group of hydrocarbons known as alkanes. There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_methanol_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methanol is CH3OH.</description>
  </entry>
  <entry id="mole_concentration_of_methyl_bromide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl bromide is CH3Br. The IUPAC name for methyl bromide is bromomethane.</description>
  </entry>
  <entry id="mole_concentration_of_methyl_chloride_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl chloride is CH3Cl. The IUPAC name for methyl chloride is chloromethane.</description>
  </entry>
  <entry id="mole_concentration_of_methyl_hydroperoxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl hydroperoxide is CH3OOH.</description>
  </entry>
  <entry id="mole_concentration_of_methyl_peroxy_radical_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for methyl_peroxy_radical is CH3O2. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mole_concentration_of_microzooplankton_expressed_as_nitrogen_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated in terms of B alone, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_molecular_hydrogen_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for molecular hydrogen is H2.</description>
  </entry>
  <entry id="mole_concentration_of_nitrate_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means moles (amount of substance) per unit volume and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_concentration_of_nitrate_radical_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. In chemistry, a 'radical' is a highly reactive, and therefore shortlived, species.</description>
  </entry>
  <entry id="mole_concentration_of_nitric_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitric acid is HNO3.</description>
  </entry>
  <entry id="mole_concentration_of_nitric_acid_trihydrate_ambient_aerosol_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Aerosol&quot; means the suspended liquid or solid particles in air (except cloud droplets).  &quot;Ambient aerosol&quot; is aerosol that has taken up ambient water through hygroscopic growth. The extent of hygroscopic growth depends on the relative humidity and the composition of the aerosol. The chemical formula for nitric acid is HNO3. Nitric acid trihydrate, sometimes referred to as NAT, is a stable crystalline substance consisting of three molecules of water to one molecule of nitric acid.</description>
  </entry>
  <entry id="mole_concentration_of_nitrogen_dioxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrogen dioxide is NO2.</description>
  </entry>
  <entry id="mole_concentration_of_nitrogen_monoxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrogen monoxide is NO.</description>
  </entry>
  <entry id="mole_concentration_of_nitrous_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrous acid is HNO2.</description>
  </entry>
  <entry id="mole_concentration_of_nitrous_oxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for nitrous oxide is N2O.</description>
  </entry>
  <entry id="mole_concentration_of_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained inA, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_nox_expressed_as_nitrogen_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Nox&quot; means a combination of two radical species containing nitrogen and oxygen: NO+NO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solelywith respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_noy_expressed_as_nitrogen_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Noy&quot; describes a family of chemical species. The family usually includes atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), peroxynitric acid (HNO4), bromine nitrate (BrONO2) , chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)). The list of individual species that are included in a quantity having a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name iscalculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_organic_detritus_expressed_as_nitrogen_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Organic detritus are particles of debris from decaying plants and animals.</description>
  </entry>
  <entry id="mole_concentration_of_organic_detritus_expressed_as_silicon_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. Organic detritus are particles of debris from decaying plants and animals.</description>
  </entry>
  <entry id="mole_concentration_of_ozone_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for ozone is O3.</description>
  </entry>
  <entry id="mole_concentration_of_peroxyacetyl_nitrate_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for peroxyacetyl nitrate, sometimes referred to as PAN, is CH3COO2NO2.  The IUPAC namefor peroxyacetyl_nitrate is nitroethaneperoxoate.</description>
  </entry>
  <entry id="mole_concentration_of_peroxynitric_acid_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for peroxynitric acid, sometimes referred to as PNA, is HO2NO2.</description>
  </entry>
  <entry id="mole_concentration_of_phosphate_in_sea_water">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mole_concentration_of_phytoplankton_expressed_as_nitrogen_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_concentration_of_propane_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for propane is C3H8. Propane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_propene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for propene is C3H6. Propene is a member of the group of hydrocarbons known as alkenes.  There are standard names for the alkene group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_concentration_of_radon_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical symbol for radon is Rn.</description>
  </entry>
  <entry id="mole_concentration_of_silicate_in_sea_water">
    <canonical_units>mol m-3</canonical_units>
    <description>Mole concentration means moles (amount of substance) per unit volume and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_concentration_of_sulfur_dioxide_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for sulfur dioxide is SO2.</description>
  </entry>
  <entry id="mole_concentration_of_toluene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for toluene is C6H5CH3.  Toluene has the same structure as benzene, except that one ofthe hydrogen atoms is replaced by a methyl group.  The systematic name for toluene is methylbenzene.</description>
  </entry>
  <entry id="mole_concentration_of_water_vapor_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'.</description>
  </entry>
  <entry id="mole_concentration_of_xylene_in_air">
    <canonical_units> mol m-3</canonical_units>
    <description> Mole concentration means number of moles per unit volume, also called &quot;molarity&quot;, and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for xylene is C6H4C2H6. In chemistry, xylene is a generic term for a group of three isomers of dimethylbenzene. The IUPAC names for the isomers are 1,2-dimethylbenzene, 1,3-dimethylbenzene and 1,4-dimethylbenzene. Xylene is an aromatic hydrocarbon. There are standard names that refer to aromatic_compounds as a group, as well as those for individual species.</description>
  </entry>
  <entry id="mole_fraction_of_acetic_acid_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemicalformula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid.</description>
  </entry>
  <entry id="mole_fraction_of_aceto_nitrile_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemicalformula for aceto-nitrile is CH3CN. The IUPAC name for aceto-nitrile is ethanenitrile.</description>
  </entry>
  <entry id="mole_fraction_of_alpha_hexachlorocyclohexane_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_fraction_of_alpha_pinene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemicalformula for alpha_pinene is C10H16. The IUPAC name for alpha-pinene is (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene.</description>
  </entry>
  <entry id="mole_fraction_of_ammonia_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemicalformula for ammonia is NH3.</description>
  </entry>
  <entry id="mole_fraction_of_anthropogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Anthropogenic&quot; means influenced, caused, or created by human activity. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_fraction_of_atomic_bromine_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical symbol of atomic bromine is Br.</description>
  </entry>
  <entry id="mole_fraction_of_atomic_chlorine_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical symbol of atomic chlorine is Cl.</description>
  </entry>
  <entry id="mole_fraction_of_atomic_nitrogen_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical symbol of atomic nitrogen is N.</description>
  </entry>
  <entry id="mole_fraction_of_benzene_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_fraction_of_beta_pinene_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemicalformula for beta_pinene is C10H16.  The IUPAC name for beta-pinene is (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane.</description>
  </entry>
  <entry id="mole_fraction_of_biogenic_nmvoc_expressed_as_carbon_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;nmvoc&quot; means non methane volatile organic compounds. &quot;Biogenic&quot; means influenced, caused, or created by natural processes. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_fraction_of_bromine_chloride_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of bromine chloride is BrCl.</description>
  </entry>
  <entry id="mole_fraction_of_bromine_monoxide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of bromine monoxide is BrO.</description>
  </entry>
  <entry id="mole_fraction_of_bromine_nitrate_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y. The chemical formula of bromine nitrate is BrONO2.</description>
  </entry>
  <entry id="mole_fraction_of_brox_expressed_as_bromine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Brox&quot;  describes a family of chemical species consisting of inorganic bromine compounds withthe exception of  hydrogen bromide (HBr) and bromine nitrate (BrONO2). &quot;Brox&quot; isthe term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic bromine&quot;, sometimes referred to as Bry, describes a family of chemical species which result from the degradation of source gases containing bromine (halons, methyl bromide, VSLS) and natural inorganic bromine sources such as volcanoes, seasalt and other aerosols.  Standard names that use the term &quot;inorganic_bromine&quot; are used for quantities that contain all inorganic bromine species includingHCl and ClONO2. The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.</description>
  </entry>
  <entry id="mole_fraction_of_butane_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemicalformula for butane is C4H10. Butane is a member of the group of hydrocarbons known as alkanes.  There are standard names for the alkane group as well as for some of the individual species.</description>
  </entry>
  <entry id="mole_fraction_of_carbon_dioxide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_fraction_of_carbon_monoxide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.</description>
  </entry>
  <entry id="mole_fraction_of_carbon_tetrachloride_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of carbon tetrachloride is CCl4.</description>
  </entry>
  <entry id="mole_fraction_of_cfc11_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of CFC11 is CFCl3.  The IUPAC name for CFC11 is trichloro-fluoro-methane.</description>
  </entry>
  <entry id="mole_fraction_of_cfc113_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of CFC113 is CCl2FCClF2.  The IUPAC name for CFC113 is 1,1,2-trichloro-1,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mole_fraction_of_cfc113a_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of CFC113a CCl3CF3.  The IUPAC name for CFC113a is 1,1,1-trichloro-2,2,2-trifluoro-ethane.</description>
  </entry>
  <entry id="mole_fraction_of_cfc114_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of CFC114 is CClF2CClF2.  The IUPAC name for CFC114 is 1,2-dichloro-1,1,2,2-tetrafluoro-ethane.</description>
  </entry>
  <entry id="mole_fraction_of_cfc115_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of CFC115 is CClF2CF3.  The IUPAC name for CFC115 is 1-chloro-1,1,2,2,2-pentafluoro-ethane.</description>
  </entry>
  <entry id="mole_fraction_of_cfc12_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of CFC12 is CF2Cl2.  The IUPAC name for CFC12 is dichloro-difluoro-methane.</description>
  </entry>
  <entry id="mole_fraction_of_chlorine_dioxide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of chlorine dioxide is OClO.</description>
  </entry>
  <entry id="mole_fraction_of_chlorine_monoxide_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of chlorine monoxide is ClO.</description>
  </entry>
  <entry id="mole_fraction_of_chlorine_nitrate_in_air">
    <canonical_units>1</canonical_units>
    <description>Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y.  The chemical formula of chlorine nitrate is ClONO2.</description>
  </entry>
  <entry id="mole_fraction_of_clox_expressed_as_chlorine_in_air">
    <canonical_units> 1 </canonical_units>
    <description> Mole fraction is used in the construction mole_fraction_of_X_in_Y, whereX is a material constituent of Y.  A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. &quot;Clox&quot; describes a family of chemical species consisting of inorganic chlorine compounds withthe exception of  hydrogen chloride (HCl) and chlorine nitrate (ClONO2). &quot;Clox&quot; is the term used in standard names for all species belonging to the family that are represented within a given model. The list of individual species that are included in a quantity with a group chemical standard name can vary between models.  Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. &quot;Inorganic chlorine&quot;, sometimes referred to as Cly, describes a family of chemical species which result from the degradation of source gasescontaining chlorine (CFCs, HCFCs, VSLS) and natural inorganic chlorine sources such as seasalt and other aerosols.   Standard names tha