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cf-standard-name-table.xml
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cf-standard-name-table.xml
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<?xml version="1.0"?>
<standard_name_table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="CFStandardNameTable-1.1.xsd">
<version_number>9</version_number>
<last_modified>2008-06-10T12:24:13Z</last_modified>
<institution>Centre for Environmental Data Analysis</institution>
<contact>[email protected]</contact>
<entry id="aerosol_angstrom_exponent">
<canonical_units>1</canonical_units>
<description>"Aerosol" means the suspended liquid or solid particles in air (except cloud droplets).</description>
</entry>
<entry id="age_of_stratospheric_air">
<canonical_units>s</canonical_units>
<description>"Age of stratospheric air" 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>"anomaly" 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>"anomaly" 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="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="area_fraction">
<canonical_units>1</canonical_units>
<description>"Area fraction" 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 "X_area_fraction" 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 "surface" 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="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 "depth" or "height" 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>"condensed_water" means liquid and ice. "Content" indicates a quantity per unit area. The "atmosphere content" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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_content_of_sulfate_aerosol">
<canonical_units>kg m-2</canonical_units>
<amip>trsult</amip>
<description>"Content" indicates a quantity per unit area. "Aerosol" means the suspended liquid or solid particles in air (except cloud droplets).</description>
</entry>
<entry id="atmosphere_convective_cloud_condensed_water_content">
<canonical_units>kg m-2</canonical_units>
<description>"condensed_water" means liquid and ice. Convective cloud is that produced by the convection schemes in an atmosphere model. "Content" indicates a quantity per unit area. The "atmosphere content" 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. "Content" indicates a quantity per unit area. The "atmosphere content" 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, "flux" implies per unit area, called "flux density" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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. "Eastward" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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 energy content" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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>"Horizontal" 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. "Horizontal" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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>"ln_X" 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_of_air_per_unit_area">
<canonical_units>kg m-2</canonical_units>
<description>"Mass_of_air" 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>"X_area" means the horizontal area occupied by X within the grid cell.</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>"longwave" 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>"shortwave" 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. "Northward" 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_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. "Aerosol" 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. "Aerosol" 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. Black carbon aerosol is composed of elemental carbon. It is strongly light absorbing.</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. "Aerosol" 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="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. "Aerosol" 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="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. "Aerosol" 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. "Pm10 aerosol" 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. "Aerosol" 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. "Pm1 aerosol" 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. "Aerosol" 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. "Pm2p5 aerosol" 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. "Aerosol" 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="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. "Aerosol" means the suspended liquid or solid particles in air (except cloud droplets). "atmosphere_optical_thickness_due_to_water_in_ambient_aerosol" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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>"specific" 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 "CAPE".</description>
</entry>
<entry id="atmosphere_sulfate_content">
<canonical_units>kg m-2</canonical_units>
<description>"Content" indicates a quantity per unit area. The "atmosphere content" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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. "Water" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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 "precipitable water", although this term does not imply the water could all be precipitated.</description>
</entry>
<entry id="baroclinic_eastward_sea_water_velocity">
<canonical_units>m s-1</canonical_units>
<description>A velocity is a vector quantity. "Eastward" 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. "Northward" 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. "Eastward" 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. "Northward" indicates a vector component which is positive when directed northward (negative southward).</description>
</entry>
<entry id="baseflow_amount">
<canonical_units>kg m-2</canonical_units>
<description>"Baseflow" is subsurface runoff which takes place below the level of the water table. Runoff is the liquid water which drains from land. "Amount" means mass per unit area.</description>
</entry>
<entry id="beaufort_wind_force">
<canonical_units>1</canonical_units>
<description>"Beaufort wind force" 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. "Bedrock" 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. "Bedrock" 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>"Biomass burning carbon" 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, "flux" implies per unit area, called "flux density" 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. "Eastward" 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. "Northward" indicates a vector component which is positive when directed northward (negative southward).</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. "Upward" 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 "surface" means the lower boundary of the atmosphere. "Amount" means mass per unit area. "Water" means water in all phases, including frozen i.e. ice and snow. "Canopy" means the plant or vegetation canopy. "Canopy and surface water" 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. "Canopy" means the plant or vegetation canopy.</description>
</entry>
<entry id="canopy_temperature">
<canonical_units>K</canonical_units>
<description>"Canopy" means the plant or vegetation canopy. "Canopy_temperature" 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>"Canopy" means the plant or vegetation canopy. "Throughfall" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="canopy_water_amount">
<canonical_units>kg m-2</canonical_units>
<description>"Amount" means mass per unit area. "Water" means water in all phases, including frozen i.e. ice and snow. "Canopy" means the plant or vegetation canopy. The canopy water is the water on the canopy.</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 "surface" 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. "wrt" means with respect to. "Content" indicates a quantity per unit area. The "atmosphere content" 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 energy content" 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 "surface" 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. "wrt" means with respect to. "Content" indicates a quantity per unit area. "Layer" 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. "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Content" indicates a quantity per unit area. "Water" 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 "surface" means the lower boundary of the atmosphere. "change_over_time_in_X" means change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate. "Amount" 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_area_fraction">
<canonical_units>1</canonical_units>
<grib>71 E164</grib>
<amip>clt</amip>
<description>"X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called "cloud amount" and "cloud cover". 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>"Layer" 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. "X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called "cloud amount" and "cloud cover".</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>"condensed_water" means liquid and ice. "Content" indicates a quantity per unit area. "Layer" 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>"Content" indicates a quantity per unit area. "Layer" 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_content_of_atmosphere_layer">
<canonical_units>kg m-2</canonical_units>
<description>"Content" indicates a quantity per unit area. "Layer" 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_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="concentration_of_chlorophyll_in_sea_water">
<canonical_units>kg m-3</canonical_units>
<description></description>
</entry>
<entry id="concentration_of_suspended_matter_in_sea_water">
<canonical_units>kg m-3</canonical_units>
<description></description>
</entry>
<entry id="convective_cloud_area_fraction">
<canonical_units>1</canonical_units>
<grib>72 E185</grib>
<description>"X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called "cloud amount" and "cloud cover". 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>"Layer" 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. "X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called "cloud amount" and "cloud cover". 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>"Amount" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="convective_rainfall_amount">
<canonical_units>kg m-2</canonical_units>
<description>"Amount" 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, "flux" implies per unit area, called "flux density" 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>"Amount" 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, "flux" implies per unit area, called "flux density" 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="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 "Exner function" is applied to various quantities in the literature. "Dimensionless Exner function" 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>"direction_of_X" 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>"direction_of_X" 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>"[horizontal_]divergence_of_X" means [horizontal] divergence of a vector X; if X does not have a vertical component then "horizontal" 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>"[horizontal_]divergence_of_X" means [horizontal] divergence of a vector X; if X does not have a vertical component then "horizontal" 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. "Downward" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_eastward_momentum_flux_in_air">
<canonical_units>Pa</canonical_units>
<grib>124</grib>
<description>"Eastward" indicates a vector component which is positive when directed eastward (negative westward). "Downward" indicates a vector component which is positive when directed downward (negative upward). "Downward eastward" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_eastward_stress_at_sea_ice_base">
<canonical_units>Pa</canonical_units>
<description>"Eastward" indicates a vector component which is positive when directed eastward (negative westward). "Downward" indicates a vector component which is positive when directed downward (negative upward). "Downward eastward" 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). "Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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). "Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_heat_flux_in_air">
<canonical_units>W m-2</canonical_units>
<description>"Downward" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_heat_flux_in_sea_ice">
<canonical_units>W m-2</canonical_units>
<description>"Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_heat_flux_in_soil">
<canonical_units>W m-2</canonical_units>
<description>"Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_northward_momentum_flux_in_air">
<canonical_units>Pa</canonical_units>
<grib>125</grib>
<description>"Northward" indicates a vector component which is positive when directed northward (negative southward). "Downward" indicates a vector component which is positive when directed downward (negative upward). "Downward northward" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_northward_stress_at_sea_ice_base">
<canonical_units>Pa</canonical_units>
<description>"Northward" indicates a vector component which is positive when directed northward (negative southward). "Downward" indicates a vector component which is positive when directed downward (negative upward). "Downward northward" 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>"Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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. "Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downward_x_stress_at_sea_ice_base">
<canonical_units>Pa</canonical_units>
<description>"x" indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. "Downward" 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>"y" indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. "Downward" 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>"longwave" means longwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downwelling_longwave_radiance_in_air">
<canonical_units>W m-2 sr-1</canonical_units>
<description>"longwave" means longwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". 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 "net downward". A photon flux is specified in terms of numbers of photons expressed in moles. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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 "net downward". 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 "net downward". Photon spherical irradiance is the photon flux incident on unit area of a hemispherical (or "2-pi") 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 "net downward". "Photosynthetic" 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, "flux" implies per unit area, called "flux density" 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 "net downward". 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. "Photosynthetic" 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 "net downward". "Photosynthetic" 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 "2-pi") 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 "net downward". 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. "Photosynthetic" 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 "net downward". Radiative flux is the sum of shortwave and longwave radiative fluxes. "Photosynthetic" 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 "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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 "net downward". "Photosynthetic" 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 "2-pi") collector. It is sometimes called "scalar irradiance". The direction (up/downwelling) is specified. Radiation incident on a 4-pi collector has standard names of "omnidirectional spherical irradiance".</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 "net downward". 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 "net downward". 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 "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downwelling_shortwave_flux_in_air">
<canonical_units>W m-2</canonical_units>
<description>"shortwave" means shortwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="downwelling_shortwave_radiance_in_air">
<canonical_units>W m-2 sr-1</canonical_units>
<description>"shortwave" means shortwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". 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 "net downward". A photon flux is specified in terms of numbers of photons expressed in moles. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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 "net downward". 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 "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. Photon spherical irradiance is the photon flux incident on unit area of a hemispherical (or "2-pi") 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 "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". 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 "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". 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 "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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 "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. When thought of as being incident on a surface, a radiative flux is sometimes called "irradiance". In addition, it is identical with the quantity measured by a cosine-collector light-meter and sometimes called "vector irradiance". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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 "net downward". "spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". Radiation wavelength has standard name radiation_wavelength. Spherical irradiance is the radiation incident on unit area of a hemispherical (or "2-pi") collector. It is sometimes called "scalar irradiance". The direction (up/downwelling) is specified. Radiation incident on a 4-pi collector has standard names of "omnidirectional spherical irradiance".</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 "net downward". Spherical irradiance is the radiation incident on unit area of a hemispherical (or "2-pi") collector. It is sometimes called "scalar irradiance". The direction (up/downwelling) is specified. Radiation incident on a 4-pi collector has standard names of "omnidirectional spherical irradiance".</description>
</entry>
<entry id="dry_energy_content_of_atmosphere_layer">
<canonical_units>J m-2</canonical_units>
<description>"Content" indicates a quantity per unit area. "Layer" 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>"Content" indicates a quantity per unit area. "Layer" 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. "Duration" 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>"Eastward" 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>"Water" means water in all phases. "Eastward" 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>"Eastward" 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>"Eastward" indicates a vector component which is positive when directed eastward (negative westward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="eastward_momentum_flux_correction">
<canonical_units>Pa</canonical_units>
<amip>tauucorr</amip>
<description>"Eastward" 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 "flux adjustment". A positive flux correction is downward i.e. added to the ocean. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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. "Eastward" 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. "Eastward" 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>"Eastward" 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>"Eastward" indicates a vector component which is positive when directed eastward (negative westward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" 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>"Layer" 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. "Eastward" 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>"Eastward" 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>"Eastward" 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="enthalpy_content_of_atmosphere_layer">
<canonical_units>J m-2</canonical_units>
<description>"Content" indicates a quantity per unit area. "Layer" 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>"Content" indicates a quantity per unit area. The "atmosphere content" 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_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>"stp" means standard temperature (0 degC) and pressure (101325 Pa). "Content" indicates a quantity per unit area. The "atmosphere content" 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="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 "data time", 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>"frozen_water" means ice. "Content" indicates a quantity per unit area. "Layer" 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="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>"anomaly" 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>"Eastward" 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>"Northward" 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 "eustatic", 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_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. "Productivity of carbon" 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 "flux adjustment". A positive flux correction is downward i.e. added to the ocean. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</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_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>"Respiration carbon" refers to the rate at which biomass is respired expressed as the mass of carbon which it contains. Heterotrophic respiration is respiration by heterotrophs ("consumers"), 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 ("producers") do. Heterotrophic respiration goes on both above and within the soil. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</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>"Layer" 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>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" 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 "degree-days".</description>
</entry>
<entry id="integral_of_air_temperature_excess_wrt_time">
<canonical_units>K s</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" 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 "degree-days".</description>
</entry>
<entry id="integral_of_sea_water_temperature_wrt_depth_in_ocean_layer">
<canonical_units>K m</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. "Layer" 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_latent_heat_flux_wrt_time">
<canonical_units>W s m-2</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. The surface called "surface" means the lower boundary of the atmosphere. "Downward" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="integral_of_surface_downward_sensible_heat_flux_wrt_time">
<canonical_units>W s m-2</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). The surface sensible heat flux, also called "turbulent" 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, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="integral_of_surface_net_downward_longwave_flux_wrt_time">
<canonical_units>W s m-2</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. The surface called "surface" means the lower boundary of the atmosphere. "Downward" 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). "Longwave" means longwave radiation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="integral_of_surface_net_downward_shortwave_flux_wrt_time">
<canonical_units>W s m-2</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. The surface called "surface" means the lower boundary of the atmosphere. "Downward" 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). "Shortwave" means shortwave radiation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="integral_of_toa_net_downward_shortwave_flux_wrt_time">
<canonical_units>W s m-2</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. "toa" means top of atmosphere. "Downward" 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). "Shortwave" means shortwave radiation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="integral_of_toa_outgoing_longwave_flux_wrt_time">
<canonical_units>W s m-2</canonical_units>
<description>"integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. "toa" means top of atmosphere. "Longwave" means longwave radiation. The TOA outgoing longwave flux is the upwelling thermal radiative flux, often called the "outgoing longwave radiation" or "OLR". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.</description>
</entry>
<entry id="isccp_cloud_area_fraction">
<canonical_units>1</canonical_units>
<amip>clisccp</amip>
<description>"X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. Cloud area fraction is also called "cloud amount" and "cloud cover". 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>"longwave" 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>"shortwave" 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>"spectral" means per unit wavelength or as a function of wavelength; spectral quantities are sometimes called "monochromatic". 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>"Content" indicates a quantity per unit area. "Layer" 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>"tendency_of_X" 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 "material derivative" or "convective derivative". The Lagrangian tendency of air pressure, often called "omega", 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>"tendency_of_X" 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 "material derivative" or "convective derivative". 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>"X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" 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_cover">
<canonical_units>1</canonical_units>
<description>A variable with the standard name of land_cover contains strings which indicate the nature of the anthropogenic land use or vegetation e.g. urban, grass, needleleaf trees, ice. These strings have not yet been standardised. The alternative standard name of surface_cover is a generalisation of land_cover. Alternatively, the data variable may contain integers which can be translated to strings using flag_values and flag_meanings attributes.</description>
</entry>
<entry id="land_ice_area_fraction">
<canonical_units>1</canonical_units>
<amip>sftgif</amip>
<description>"X_area_fraction" means the fraction of horizontal area occupied by X. "X_area" means the horizontal area occupied by X within the grid cell. "Land ice" 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>"Land ice" 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. "x" indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. "Land ice" 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. "y" indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock.</description>
</entry>