Brian Eaton et. al. Controlled vocabualry use in the NetCDF Climate and Forecast (CF) Metadata Convention More information: http://www.cgd.ucar.edu/cms/eaton/cf-metadata/standard_name.xmlhttp://www.cgd.ucar.edu/cms/eaton/cf-metadata/standard_name.xml 2005-08-01T11:25:26 Luis Bermudez MMI Parameters version 2005-08-01 NetCDF CF - Standard Name table Canonical Units Standard Name GRIB Description Standard Name AMIP kg m-2 76 "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. clwvi atmosphere_cloud_condensed_water_content atmosphere_cloud_condensed_water_content W m-2 Pa tauucorr "Eastward" indicates a vector component which is positive increasing 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. eastward_momentum_flux_correction eastward_momentum_flux_correction s-1 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. "tendency_of_X" means derivative of X with respect to time. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). tendency_of_mass_fraction_of_cloud_ice_in_air_due_to_advection tendency_of_mass_fraction_of_cloud_ice_in_air_due_to_advection surface_upwelling_longwave_flux_in_air_assuming_clear_sky The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "longwave" means longwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". 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. surface_upwelling_longwave_flux_in_air_assuming_clear_sky m-1 s-1 tendency_of_air_temperature_due_to_advection tendency_of_air_temperature_due_to_advection 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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. K s-1 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. W m-2 m-1 downwelling_spectral_radiative_flux_in_sea_water downwelling_spectral_radiative_flux_in_sea_water kg m-2 s-1 litter_carbon_flux litter_carbon_flux "Litter carbon" is dead inorganic material in or above the soil quantified as the mass of carbon which it contains. The litter carbon flux is the rate of production of litter. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Northward" indicates a vector component which is positive increasing northward (negative southward). Northward transport by the ocean gyre is geometrically defined as being the part due to the vertical integral of the product of deviations of velocity and tracer from their zonal means. The velocity does not include "bolus" or Gent-McWilliams velocity. sltovgyre northward_ocean_salt_transport_due_to_gyre kg s-1 northward_ocean_salt_transport_due_to_gyre land_ice_temperature land_ice_temperature "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. K equivalent_temperature equivalent_temperature Water vapor saturation deficit is the difference between the saturation water vapor pressure and the actual water vapor pressure. 56 water_vapor_saturation_deficit water_vapor_saturation_deficit m "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. lwe_thickness_of_convective_snowfall_amount lwe_thickness_of_convective_snowfall_amount "shortwave" means shortwave radiation. "toa" means top of atmosphere. The TOA outgoing shortwave flux is the reflected and scattered solar radiative flux i.e. the "upwelling" TOA shortwave flux, sometimes called the "outgoing shortwave radiation" or "OSR". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_outgoing_shortwave_flux rsut toa_outgoing_shortwave_flux northward_ocean_heat_transport_due_to_gyre htovgyre W northward_ocean_heat_transport_due_to_gyre 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 increasing northward (negative southward). Northward transport by the ocean gyre is geometrically defined as being the part due to the vertical integral of the product of deviations of velocity and tracer from their zonal means. The velocity does not include "bolus" or Gent-McWilliams velocity. m s-2 "product_of_X_and_Y" means X*Y. "Northward" indicates a vector component which is positive increasing 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.) "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. product_of_northward_wind_and_omega Pa m s-2 product_of_northward_wind_and_omega 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. "tendency_of_X" means derivative of X with respect to time. "Eastward" indicates a vector component which is positive increasing 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.) tendency_of_eastward_wind_due_to_gravity_wave_drag tendency_of_eastward_wind_due_to_gravity_wave_drag tnmmugwd surface_downwelling_photosynthetic_spherical_irradiance_in_sea_water surface_downwelling_photosynthetic_spherical_irradiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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". "square_of_X" means X*X. "Eastward" indicates a vector component which is positive increasing 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.) m2 s-2 square_of_eastward_wind mpuua square_of_eastward_wind "Northward" indicates a vector component which is positive increasing northward (negative southward). "Downward" indicates a vector component which is positive increasing 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. downward_northward_momentum_flux_in_air 125 downward_northward_momentum_flux_in_air 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. "tendency_of_X" means derivative of X with respect to time. "Northward" indicates a vector component which is positive increasing 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.) tendency_of_northward_wind_due_to_diffusion tendency_of_northward_wind_due_to_diffusion mass_fraction_of_sulfur_dioxide_in_air Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). mass_fraction_of_sulfur_dioxide_in_air 1 wind_speed_shear N136 Speed is the magnitude of velocity. 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.) The wind speed is the magnitude of the wind velocity. Wind speed shear is the derivative of wind speed with respect to height. wind_speed_shear downward_heat_flux_in_air downward_heat_flux_in_air "Downward" indicates a vector component which is positive increasing 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. A velocity is a vector quantity. "Horizontal" indicates that the velocity potential applies to a horizontal velocity field on a particular vertical level. atmosphere_horizontal_velocity_potential atmosphere_horizontal_velocity_potential 36 m2 s-1 tntsw tendency_of_air_temperature_due_to_shortwave_heating 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. "tendency_of_X" means derivative of X with respect to time. "shortwave" means shortwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_shortwave_heating Upwelling radiation is radiation from below. It does not mean "net upward". "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 towards which it is going 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. W m-2 m-1 sr-1 upwelling_spectral_radiance_in_air upwelling_spectral_radiance_in_air moisture_content_of_soil_layer "moisture" means water in all phases contained in soil. "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). mrsos moisture_content_of_soil_layer surface_downward_northward_stress The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Northward" indicates a vector component which is positive increasing northward (negative southward). "Downward" indicates a vector component which is positive increasing 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. The surface downward stress is the windstress on the surface. tauv E181 surface_downward_northward_stress land_binary_mask E172 land_binary_mask X_binary_mask has 1 where condition X is met, 0 elsewhere. 1 = land, 0 = sea. net_upward_longwave_flux_in_air_assuming_clear_sky net_upward_longwave_flux_in_air_assuming_clear_sky A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "longwave" means longwave radiation. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. rlntpcs kg m-3 s-1 downwelling_photosynthetic_radiative_flux_in_sea_water downwelling_photosynthetic_radiative_flux_in_sea_water 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. northward_ocean_freshwater_transport_due_to_gyre 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 increasing northward (negative southward). Northward transport by the ocean gyre is geometrically defined as being the part due to the vertical integral of the product of deviations of velocity and tracer from their zonal means. The velocity does not include "bolus" or Gent-McWilliams velocity. northward_ocean_freshwater_transport_due_to_gyre wet_bulb_temperature wet_bulb_temperature eastward_wind_shear "Eastward" indicates a vector component which is positive increasing 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. 45 eastward_wind_shear Height is the vertical distance above the surface. "Canopy" means the vegetation canopy. canopy_height canopy_height product_of_northward_wind_and_specific_humidity product_of_northward_wind_and_specific_humidity mpvhusa "product_of_X_and_Y" means X*Y. "specific" means per unit mass. "Northward" indicates a vector component which is positive increasing northward (negative southward). Specific humidity is the mass fraction of water vapor in (moist) air. 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.) m s-1 "Thickness" means the vertical extent of a layer. 92 sit sea_ice_thickness sea_ice_thickness "product_of_X_and_Y" means X*Y. "specific" means per unit mass. "Northward" indicates a vector component which is positive increasing 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.) product_of_northward_wind_and_specific_humdity product_of_northward_wind_and_specific_humdity 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. "tendency_of_X" means derivative of X with respect to time. Speed is the magnitude of velocity. 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.) The wind speed is the magnitude of the wind velocity. tendency_of_wind_speed_due_to_convection tendency_of_wind_speed_due_to_convection surface_snow_area_fraction snc The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "X_area_fraction" means the fraction of horizontal area occupied by X. surface_snow_area_fraction upward_sea_water_velocity A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). upward_sea_water_velocity kg surface_downwelling_photosynthetic_radiance_in_sea_water W m-2 sr-1 surface_downwelling_photosynthetic_radiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. toa_outgoing_shortwave_flux_assuming_clear_sky toa_outgoing_shortwave_flux_assuming_clear_sky A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. "toa" means top of atmosphere. The TOA outgoing shortwave flux is the reflected and scattered solar radiative flux i.e. the "upwelling" TOA shortwave flux, sometimes called the "outgoing shortwave radiation" or "OSR". In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. rsutcs large_scale_precipitation_amount "Amount" means mass per unit area. 62 large_scale_precipitation_amount "lwe" means liquid water equivalent. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. Specific mass balance means the net rate at which ice is added per unit area at the land ice surface. land_ice_lwe_surface_specific_mass_balance land_ice_lwe_surface_specific_mass_balance "Eastward" indicates a vector component which is positive increasing eastward (negative westward). "Downward" indicates a vector component which is positive increasing 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. downward_eastward_stress_at_sea_ice_base downward_eastward_stress_at_sea_ice_base divergence_of_sea_ice_velocity divergence_of_sea_ice_velocity 98 "[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. 83 E173 surface_roughness_length surface_roughness_length The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 25 air_temperature_anomaly air_temperature_anomaly "anomaly" means difference from climatology. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. m3 lwe_water_evaporation_rate lwe_water_evaporation_rate "lwe" means liquid water equivalent. "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_evaporation_flux_where_sea_ice water_evaporation_flux_where_sea_ice "lwe" means liquid water equivalent. lwe_snowfall_rate lwe_snowfall_rate atmosphere_northward_stress_due_to_gravity_wave_drag atmosphere_northward_stress_due_to_gravity_wave_drag tauvgwd 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 increasing northward (negative southward). Atmosphere_Xward_stress is a stress which tends to accelerate the atmosphere in direction X. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_spectral_radiative_flux_in_sea_water surface_downwelling_spectral_radiative_flux_in_sea_water "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_evaporation_flux_from_soil water_evaporation_flux_from_soil bedrock_altitude 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. bedrock_altitude time time s time sea_ice_draft Sea ice draft is the depth of the sea-ice lower surface below the water surface. sea_ice_draft product_of_eastward_sea_water_velocity_and_temperature product_of_eastward_sea_water_velocity_and_temperature "product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). K m s-1 surface_downwelling_spectral_radiative_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_spectral_radiative_flux_in_air soil_moisture_content_at_field_capacity soil_moisture_content_at_field_capacity mrsofc "moisture" means water in all phases contained in soil. "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including content_of_soil_layer are used. downwelling_photon_radiance_in_sea_water 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. mol m-2 s-1 sr-1 downwelling_photon_radiance_in_sea_water 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. "tendency_of_X" means derivative of X with respect to time. "longwave" means longwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_longwave_heating tntlw tendency_of_air_temperature_due_to_longwave_heating Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). mass_fraction_of_dimethyl_sulfide_in_air mass_fraction_of_dimethyl_sulfide_in_air mass_fraction_of_unfrozen_water_in_soil_moisture "moisture" means water in all phases contained in soil. "unfrozen_water" means liquid and vapour. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). mass_fraction_of_unfrozen_water_in_soil_moisture "product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. product_of_air_temperature_and_omega product_of_air_temperature_and_omega K Pa s-1 water_potential_evaporation_flux "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) Potential evaporation is the rate at which evaporation would take place under unaltered ambient conditions (temperature, relative humidity, wind, etc.) if the supply of water were unlimited, as if from an open water surface. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_potential_evaporation_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Thickness" means the vertical extent of a layer. surface_snow_thickness 66 surface_snow_thickness snd thickness_of_rainfall_amount "Amount" means mass per unit area. The construction thickness_of_[X_]rainfall_amount means the accumulated "depth" of rainfall i.e. the thickness of a layer of liquid water having the same mass per unit area as the rainfall amount. thickness_of_rainfall_amount longitude longitude degree_east longitude 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. 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. bedrock_altitude_change_due_to_isostatic_adjustment bedrock_altitude_change_due_to_isostatic_adjustment Pa s-1 tendency_of_specific_humidity_due_to_diffusion 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. "tendency_of_X" means derivative of X with respect to time. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. tendency_of_specific_humidity_due_to_diffusion lwe_large_scale_precipitation_rate lwe_large_scale_precipitation_rate "lwe" means liquid water equivalent. Height is the vertical distance above the surface. Wind waves are waves on the ocean surface. significant_height_of_swell_waves significant_height_of_swell_waves 105 "tendency_of_X" means derivative of X with respect to time. "Northward" indicates a vector component which is positive increasing 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.) tnmmvtot tendency_of_northward_wind tendency_of_northward_wind The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. mol m-2 s-1 m-1 surface_downwelling_spectral_photon_spherical_irradiance_in_sea_water surface_downwelling_spectral_photon_spherical_irradiance_in_sea_water surface_northward_sea_water_velocity The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). surface_northward_sea_water_velocity "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. land_ice_basal_melt_rate land_ice_basal_melt_rate hfls surface_upward_latent_heat_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Upward" indicates a vector component which is positive increasing upward (negative downward). 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. 121 E147 surface_upward_latent_heat_flux Humidity mixing ratio of a parcel of moist air is the ratio of the mass of water vapor to the mass of dry air. 53 humidity_mixing_ratio humidity_mixing_ratio 118 brightness_temperature brightness_temperature 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. land_ice_calving_rate land_ice_calving_rate "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. The land ice calving rate is the rate at which ice is lost per unit area through calving into the ocean. 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. "tendency_of_X" means derivative of X with respect to time. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. tendency_of_specific_humidity_due_to_advection tendency_of_specific_humidity_due_to_advection "longwave" means longwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction towards which it is going 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. upwelling_longwave_radiance_in_air upwelling_longwave_radiance_in_air "wrt" means with respect to. Depth is the vertical distance below the surface. ocean_integral_of_sea_water_temperature_wrt_depth K m ocean_integral_of_sea_water_temperature_wrt_depth "X_area_fraction" means the fraction of horizontal area occupied by X. sea_area_fraction sea_area_fraction cloud_area_fraction 71 E164 cloud_area_fraction "X_area_fraction" means the fraction of horizontal area occupied by X. 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. clt surface_downward_water_flux surface_downward_water_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Water" means water in all phases. "Downward" indicates a vector component which is positive increasing downward (negative upward). The surface water flux is the result of precipitation and evaporation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_moist_convection tendency_of_air_temperature_due_to_moist_convection tntmc soil_respiration_carbon_flux soil_respiration_carbon_flux "Respiration carbon" refers to the rate at which biomass is respired expressed as the mass of carbon which it contains. Soil respiration is the sum of respiration in the soil by animals and decomposers of litter (heterotrophs or "consumers"), which have not produced the biomass they respire, and respiration by the roots of plants (autotrophs or "producers"), which have themselves produced the biomass they respire. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. orog surface_altitude surface_altitude air_pressure_at_freezing_level air_pressure_at_freezing_level Upwelling radiation is radiation from below. It does not mean "net upward". "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. upwelling_spectral_radiative_flux_in_sea_water upwelling_spectral_radiative_flux_in_sea_water 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. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "tendency_of_X" means derivative of X with respect to time. "shortwave" means shortwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_shortwave_heating_assuming_clear_sky tendency_of_air_temperature_due_to_shortwave_heating_assuming_clear_sky K2 prc convective_precipitation_flux convective_precipitation_flux In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "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. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). cloud_condensed_water_content_of_atmosphere_layer cloud_condensed_water_content_of_atmosphere_layer atmosphere_surface_drag_coefficient atmosphere_surface_drag_coefficient The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. land_ice_y_velocity land_ice_y_velocity 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. subsurface_runoff_flux Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. subsurface_runoff_flux 63 "Amount" means mass per unit area. convective_precipitation_amount convective_precipitation_amount mol m-2 s-1 downwelling_photon_flux_in_sea_water 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. downwelling_photon_flux_in_sea_water surface_albedo The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 84 E174 surface_albedo relative_humidity relative_humidity 52 E157 hur toa_instantaneous_longwave_forcing toa_instantaneous_longwave_forcing "longwave" means longwave radiation. "toa" means top of atmosphere. Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.). land_ice_basal_x_velocity land_ice_basal_x_velocity 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. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_runoff_flux surface_runoff_flux mrros atmosphere_hybrid_height_coordinate atmosphere_hybrid_height_coordinate See Appendix D of the CF convention for information about dimensionless vertical coordinates. snow_temperature Snow temperature is the bulk temperature of the snow, not the surface (skin) temperature. snow_temperature dew_point_depression dew_point_depression 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. 18 "X_area_fraction" means the fraction of horizontal area occupied by X. 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). isccp_cloud_area_fraction clisccp isccp_cloud_area_fraction product_of_northward_wind_and_geopotential_height mpvzga "product_of_X_and_Y" means X*Y. Geopotential is 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. "Northward" indicates a vector component which is positive increasing 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.) product_of_northward_wind_and_geopotential_height sea_ice_volume sea_ice_volume thickness_of_snowfall_amount "Amount" means mass per unit area. The construction thickness_of_[X_]snowfall_amount means the accumulated "depth" of snow which fell i.e. the thickness of the layer of snow at its own density. There are corresponding standard names for liquid water equivalent (lwe) thickness. thickness_of_snowfall_amount sea_surface_temperature Sea surface temperature is usually abbreviated as "SST". It is the temperature of sea water near the surface (including the part under sea-ice, if any), and not the skin temperature, whose standard name is surface_temperature. For the temperature of sea water at a particular depth or layer, a data variable of sea_water_temperature with a vertical coordinate axis should be used. sea_surface_temperature surface_downwelling_spherical_irradiance_in_sea_water surface_downwelling_spherical_irradiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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". tendency_of_air_density tendency_of_air_density "tendency_of_X" means derivative of X with respect to time. net_downward_shortwave_flux_in_air "shortwave" means shortwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. net_downward_shortwave_flux_in_air "[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.) divergence_of_wind divergence_of_wind 44 E155 "shortwave" means shortwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". Radiance is the radiative flux in a particular direction, per unit of solid angle. The direction towards which it is going 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. upwelling_shortwave_radiance_in_air upwelling_shortwave_radiance_in_air soil_carbon_content soil_carbon_content "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including content_of_soil_layer are used. "tendency_of_X" means derivative of X with respect to time. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. tendency_of_specific_humidity tendency_of_specific_humidity Soil temperature is the bulk temperature of the soil, not the surface (skin) temperature. 85 soil_temperature soil_temperature precipitation_flux In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. precipitation_flux 59 pr upward_heat_flux_in_air "Upward" indicates a vector component which is positive increasing upward (negative downward). 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. upward_heat_flux_in_air downwelling_shortwave_radiance_in_air downwelling_shortwave_radiance_in_air "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. chlorophyll_concentration_in_sea_water chlorophyll_concentration_in_sea_water kg m-3 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. forecast_reference_time forecast_reference_time net_downward_shortwave_flux_in_air_assuming_clear_sky rsntpcs net_downward_shortwave_flux_in_air_assuming_clear_sky A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_dry_convection tntdc tendency_of_air_temperature_due_to_dry_convection 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. downwelling_spectral_radiance_in_air downwelling_spectral_radiance_in_air air_pressure_at_sea_level psl 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. 2 E151 air_pressure_at_sea_level The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. surface_albedo_assuming_deep_snow surface_albedo_assuming_deep_snow "tendency_of_X" means derivative of X with respect to time. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). tendency_of_mass_fraction_of_cloud_liquid_water_in_air tendency_of_mass_fraction_of_cloud_liquid_water_in_air surface_downward_heat_flux_in_air surface_downward_heat_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Downward" indicates a vector component which is positive increasing 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. hfns land_ice_thickness "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. "Thickness" means the vertical extent of a layer. land_ice_thickness sea_ice_mass sea_ice_mass lwe_precipitation_rate "lwe" means liquid water equivalent. lwe_precipitation_rate S m-1 lwe_thickness_of_large_scale_snowfall_amount lwe_thickness_of_large_scale_snowfall_amount "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. toa_net_upward_longwave_flux "longwave" means longwave radiation. "toa" means top of atmosphere. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_net_upward_longwave_flux northward_ocean_salt_transport northward_ocean_salt_transport "Northward" indicates a vector component which is positive increasing northward (negative southward). Ocean transport means transport by all processes, both sea water and sea ice. 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 increasing northward (negative southward). Northward transport by (meridional) overturning is geometrically defined as being the part due to the vertical integral of the product of zonal means of velocity and tracer. The velocity does not include "bolus" or Gent-McWilliams velocity. northward_ocean_freshwater_transport_due_to_overturning northward_ocean_freshwater_transport_due_to_overturning area_fraction_below_surface psbg The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "X_area_fraction" means the fraction of horizontal area occupied by X. 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. area_fraction_below_surface cli mass_fraction_of_cloud_ice_in_air Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). mass_fraction_of_cloud_ice_in_air 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. 19 air_temperature_lapse_rate air_temperature_lapse_rate K m-1 The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Amount" means mass per unit area. Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage. surface_runoff_amount 90 surface_runoff_amount northward_ocean_heat_transport_due_to_bolus_advection 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 increasing northward (negative southward). Northward transport by bolus advection in an ocean model means the part due to a scheme representing eddy-induced effects not included in the velocity field. northward_ocean_heat_transport_due_to_bolus_advection surface_net_downward_shortwave_flux_assuming_clear_sky surface_net_downward_shortwave_flux_assuming_clear_sky The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. visibility_in_air The visibility is the distance at which something can be seen. 20 visibility_in_air "direction_of_X" means direction of a vector, a bearing. A velocity is a vector quantity. 104 degree direction_of_swell_wave_velocity direction_of_swell_wave_velocity dbar downwelling_spectral_radiance_in_sea_water downwelling_spectral_radiance_in_sea_water 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. "tendency_of_X" means derivative of X with respect to time. "Eastward" indicates a vector component which is positive increasing 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.) tnmmutot tendency_of_eastward_wind tendency_of_eastward_wind surface_downward_latent_heat_flux surface_downward_latent_heat_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Downward" indicates a vector component which is positive increasing 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. rainfall_amount rainfall_amount "Amount" means mass per unit area. The unit of salinity is PSU, which is dimensionless. The units attribute should be given as 1e-3 or 0.001 i.e. parts per thousand if salinity is in PSU. sea_water_salinity sea_water_salinity so 1e-3 88 surface_upward_water_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Water" means water in all phases. "Upward" indicates a vector component which is positive increasing upward (negative downward). The surface water flux is the result of precipitation and evaporation. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_upward_water_flux sea_water_potential_temperature Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. sea_water_potential_temperature sea_water_speed Speed is the magnitude of velocity. sea_water_speed 48 sea_water_potential_density sea_water_potential_density Potential density is the density a parcel of air or sea water would have if moved adiabatically to a reference pressure, by default assumed to be sea level pressure. For sea water potential density, if 1000 kg m-3 is subtracted, the standard name sea_water_sigma_theta should be chosen instead. "X_area_fraction" means the fraction of horizontal area occupied by X. 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_area_fraction 72 E185 convective_cloud_area_fraction potential_vorticity_of_atmosphere_layer Pa-1 s-1 potential_vorticity_of_atmosphere_layer "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). Atmosphere potential vorticity is the vertically averaged absolute vorticity of a layer of the atmosphere divided by the pressure difference from the bottom to the top of the layer. "tendency_of_X" means derivative of X with respect to time. tendency_of_ocean_barotropic_streamfunction tendency_of_ocean_barotropic_streamfunction m3 s-2 tendency_of_land_ice_thickness "tendency_of_X" means derivative of X with respect to time. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. "Thickness" means the vertical extent of a layer. tendency_of_land_ice_thickness ertel_potential_vorticity ertel_potential_vorticity K m2 kg-1 s-1 vorpot "Amount" means mass per unit area. large_scale_rainfall_amount large_scale_rainfall_amount sftlf land_area_fraction land_area_fraction "X_area_fraction" means the fraction of horizontal area occupied by X. 81 W m-1 eastward_atmosphere_dry_static_energy_transport_across_unit_distance "Eastward" indicates a vector component which is positive increasing 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 (CpT+gz, where Cp is heat capacity at constant pressure, T is absolute temperature, g is acceleration due to gravity and z is altitude) and kinetic energy. eastward_atmosphere_dry_static_energy_transport_across_unit_distance "tendency_of_X" means derivative of X with respect to time. tendency_of_air_pressure tendency_of_air_pressure 3 "specific" means per unit mass. specific_gravitational_potential_energy J kg-1 specific_gravitational_potential_energy surface_downwelling_radiative_flux_in_sea_water surface_downwelling_radiative_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. tendency_of_eastward_wind_due_to_convection 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. "tendency_of_X" means derivative of X with respect to time. "Eastward" indicates a vector component which is positive increasing 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.) tendency_of_eastward_wind_due_to_convection tnmmuc product_of_eastward_wind_and_specific_humidity product_of_eastward_wind_and_specific_humidity "product_of_X_and_Y" means X*Y. "specific" means per unit mass. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). Specific humidity is the mass fraction of water vapor in (moist) air. 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.) 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. gross_primary_productivity_of_carbon gross_primary_productivity_of_carbon Geopotential is sum of the specific gravitational potential energy relative to the geoid and the specific centripetal potential energy. 6 E129 geopotential geopotential tropopause_air_pressure tropopause_air_pressure radiation_wavelength radiation_wavelength The radiation wavelength can refer to any electromagnetic wave, such as light, heat radiation and radio waves. litter_carbon_content litter_carbon_content "Content" indicates a quantity per unit area. "Litter carbon" is dead inorganic material in or above the soil quantified as the mass of carbon which it contains. 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 increasing northward (negative southward). Northward transport by (meridional) overturning is geometrically defined as being the part due to the vertical integral of the product of zonal means of velocity and tracer. The velocity does not include "bolus" or Gent-McWilliams velocity. northward_ocean_salt_transport_due_to_overturning northward_ocean_salt_transport_due_to_overturning sltovovrt "Downward" indicates a vector component which is positive increasing downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. downward_heat_flux_in_sea_ice downward_heat_flux_in_sea_ice tendency_of_mass_fraction_of_cloud_ice_in_air "tendency_of_X" means derivative of X with respect to time. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). tendency_of_mass_fraction_of_cloud_ice_in_air upwelling_spectral_radiative_flux_in_air Upwelling radiation is radiation from below. It does not mean "net upward". "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. upwelling_spectral_radiative_flux_in_air cloud_top_altitude 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. cloud_top_altitude "Amount" means mass per unit area. 61 precipitation_amount precipitation_amount sea_water_sigma_theta Sigma-theta of sea water is the potential density (i.e. the density when moved adiabatically to a reference pressure) of water having the same temperature and salinity, minus 1000 kg m-3. Note that sea water sigma is not the same quantity as the dimensionless ocean sigma coordinate (see Appendix D of the CF convention), for which there is another standard name. sea_water_sigma_theta 43 E138 atmosphere_relative_vorticity Relative vorticity is the upward component of the vorticity vector i.e. the component which arises from horizontal velocity. atmosphere_relative_vorticity land_ice_lwe_basal_melt_rate "lwe" means liquid water equivalent. "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. land_ice_lwe_basal_melt_rate surface_downwelling_spectral_radiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_spectral_radiance_in_sea_water water_evaporation_flux_from_canopy "Water" means water in all phases. "Canopy" means the vegetation canopy. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_evaporation_flux_from_canopy atmosphere_specific_convective_available_potential_energy "specific" means per unit mass. Convective(ly) available potential energy is often abbreviated as "CAPE". atmosphere_specific_convective_available_potential_energy cloud_base refers to the base of the lowest cloud. air_pressure_at_cloud_base air_pressure_at_cloud_base 122 E146 surface_upward_sensible_heat_flux surface_upward_sensible_heat_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Upward" indicates a vector component which is positive increasing upward (negative downward). 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. hfss Pa2 s-2 lwe_thickness_of_convective_precipitation_amount lwe_thickness_of_convective_precipitation_amount "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. E143 prveg precipitation_flux_onto_canopy_where_land precipitation_flux_onto_canopy_where_land Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. "Canopy" means the vegetation canopy. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. swell_wave_period 106 swell_wave_period A period is an interval of time, or the time-period of an oscillation. height zh height Height is the vertical distance above the surface. E140 lwe_thickness_of_soil_moisture_content "lwe" means liquid water equivalent. "moisture" means water in all phases contained in soil. "Content" indicates a quantity per unit area. "Thickness" means the vertical extent of a layer. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including content_of_soil_layer are used. lwe_thickness_of_soil_moisture_content "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. lwe_thickness_of_snowfall_amount lwe_thickness_of_snowfall_amount E144 E141 lwe_thickness_of_surface_snow_amount The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. Surface snow amount refers to the amount on the ground, excluding that on the vegetation canopy. lwe_thickness_of_surface_snow_amount "tendency_of_X" means derivative of X with respect to time. A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). Upward air velocity is the vertical component of the 3D air velocity vector. tendency_of_upward_air_velocity tendency_of_upward_air_velocity air_temperature ta Air temperature is the bulk temperature of the air, not the surface (skin) temperature. 11 E130 air_temperature geopotential_height_anomaly "anomaly" means difference from climatology. Geopotential is 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. 27 geopotential_height_anomaly surface_upward_heat_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Upward" indicates a vector component which is positive increasing upward (negative downward). 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. surface_upward_heat_flux_in_air mass_fraction_of_ozone_in_air mass_fraction_of_ozone_in_air Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). "Amount" means mass per unit area. The construction thickness_of_[X_]rainfall_amount means the accumulated "depth" of rainfall i.e. the thickness of a layer of liquid water having the same mass per unit area as the rainfall amount. thickness_of_large_scale_rainfall_amount thickness_of_large_scale_rainfall_amount J m-2 atmosphere_kinetic_energy_content "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_kinetic_energy_content freezing_level_altitude freezing_level_altitude Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. 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. global_average_sea_level_change global_average_sea_level_change rainfall_flux In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. rainfall_flux land_ice_vertical_mean_y_velocity land_ice_vertical_mean_y_velocity 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. The vertical mean land ice velocity is the average from the bedrock to the surface of the ice. "square_of_X" means X*X. "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. square_of_lagrangian_tendency_of_air_pressure square_of_lagrangian_tendency_of_air_pressure tendency_of_air_temperature_due_to_diffusion 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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_diffusion "shortwave" means shortwave radiation. "toa" means top of atmosphere. Adjusted forcing is the radiative flux change caused by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.) after allowance for stratospheric temperature adjustment. toa_adjusted_shortwave_forcing toa_adjusted_shortwave_forcing tropopause_net_downward_longwave_flux tropopause_net_downward_longwave_flux "longwave" means longwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. square_of_geopotential_height m2 "square_of_X" means X*X. Geopotential is 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. square_of_geopotential_height "tendency_of_X" means derivative of X with respect to time. 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. tendency_of_bedrock_altitude tendency_of_bedrock_altitude atmosphere_sulfate_content atmosphere_sulfate_content "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 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. dimensionless_exner_function dimensionless_exner_function A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). barotropic_northward_sea_water_velocity barotropic_northward_sea_water_velocity land_ice_lwe_calving_rate "lwe" means liquid water equivalent. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. The land ice calving rate is the rate at which ice is lost per unit area through calving into the ocean. land_ice_lwe_calving_rate sea_water_y_velocity sea_water_y_velocity 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. The unit of salinity is PSU, which is dimensionless. The units attribute should be given as 1e-3 or 0.001 i.e. parts per thousand if salinity is in PSU. Sea surface salinity is often abbreviated as "SSS". For the salinity of sea water at a particular depth or layer, a data variable of sea_water_salinity with a vertical coordinate axis should be used. sea_surface_salinity sea_surface_salinity "anomaly" means difference from climatology. 26 air_pressure_anomaly air_pressure_anomaly product_of_air_temperature_and_specific_humidity product_of_air_temperature_and_specific_humidity "product_of_X_and_Y" means X*Y. "specific" means per unit mass. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. Specific humidity is the mass fraction of water vapor in (moist) air. sltovdiff northward_ocean_salt_transport_due_to_diffusion northward_ocean_salt_transport_due_to_diffusion 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 increasing northward (negative southward). Northward transport by diffusion means the part due to horizontal or isopyncal diffusion schemes in an ocean model, but not including the "bolus" or Gent-McWilliams velocity. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "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. surface_downwelling_longwave_flux_in_air surface_downwelling_longwave_flux_in_air rlds projection_x_coordinate "x" indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. Projection coordinates are distances in the x- and y-directions on a plane onto which the surface of the Earth has been projected according to a map projection. The relationship between the projection coordinates and latitude and longitude is described by the grid_mapping. projection_x_coordinate 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 increasing northward (negative southward). Northward transport by bolus advection in an ocean model means the part due to a scheme representing eddy-induced effects not included in the velocity field. northward_ocean_salt_transport_due_to_bolus_advection northward_ocean_salt_transport_due_to_bolus_advection tendency_of_mass_fraction_of_cloud_ice_in_air_due_to_diffusion 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. "tendency_of_X" means derivative of X with respect to time. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). tendency_of_mass_fraction_of_cloud_ice_in_air_due_to_diffusion sea_ice_speed Speed is the magnitude of velocity. 94 sea_ice_speed projection_y_coordinate projection_y_coordinate "y" indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. Projection coordinates are distances in the x- and y-directions on a plane onto which the surface of the Earth has been projected according to a map projection. The relationship between the projection coordinates and latitude and longitude is described by the grid_mapping. downwelling_spectral_spherical_irradiance_in_sea_water downwelling_spectral_spherical_irradiance_in_sea_water 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". downward_sea_ice_basal_salt_flux downward_sea_ice_basal_salt_flux "Downward" indicates a vector component which is positive increasing downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. 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. The vertical mean land ice velocity is the average from the bedrock to the surface of the ice. land_ice_vertical_mean_x_velocity land_ice_vertical_mean_x_velocity subsurface_runoff_amount subsurface_runoff_amount "Amount" means mass per unit area. Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage. convective_snowfall_amount convective_snowfall_amount "Amount" means mass per unit area. 78 "Downward" indicates a vector component which is positive increasing downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. downward_heat_flux_in_soil downward_heat_flux_in_soil evspsblveg water_evaporation_flux_from_canopy_where_land water_evaporation_flux_from_canopy_where_land Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. "Water" means water in all phases. "Canopy" means the vegetation canopy. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. 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. downwelling_spectral_photon_flux_in_sea_water downwelling_spectral_photon_flux_in_sea_water 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. dew_point_temperature 17 downwelling_radiative_flux_in_sea_water downwelling_radiative_flux_in_sea_water 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. water_content_of_atmosphere_layer "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). "Water" means water in all phases. water_content_of_atmosphere_layer Sea water density is the in-situ density (not the potential density). If 1000 kg m-3 is subtracted, the standard name sea_water_sigma_t should be chosen instead. sea_water_density sea_water_density surface_downwelling_shortwave_flux_in_air_assuming_clear_sky surface_downwelling_shortwave_flux_in_air_assuming_clear_sky rsdscs The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". Surface downwelling shortwave is the sum of direct and diffuse solar radiation incident on the surface, and is sometimes called "global radiation". 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. "shortwave" means shortwave radiation. "toa" means top of atmosphere. Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.). toa_instantaneous_shortwave_forcing toa_instantaneous_shortwave_forcing frozen_water_content_of_soil_layer "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. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). frozen_water_content_of_soil_layer grid_latitude grid_latitude 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. product_of_eastward_wind_and_northward_wind "product_of_X_and_Y" means X*Y. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). "Northward" indicates a vector component which is positive increasing 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.) mpuva product_of_eastward_wind_and_northward_wind downwelling_photosynthetic_spherical_irradiance_in_sea_water downwelling_photosynthetic_spherical_irradiance_in_sea_water 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". tropopause_instantaneous_longwave_forcing tropopause_instantaneous_longwave_forcing "longwave" means longwave radiation. Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.). surface_upwelling_shortwave_flux_in_air_assuming_clear_sky The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". 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. rsuscs surface_upwelling_shortwave_flux_in_air_assuming_clear_sky degree_north northward_atmosphere_water_transport_across_unit_distance northward_atmosphere_water_transport_across_unit_distance "Water" means water in all phases. "Northward" indicates a vector component which is positive increasing northward (negative southward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport. kg s-1 m-1 sea_ice_transport_across_line Transport across_line means that which crosses a particular line on the Earth's surface; formally this means the integral along the line of the normal component of the transport. sea_ice_transport_across_line Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. The surface temperature is the (skin) temperature at the interface, not the bulk temperature of the medium above or below. surface_temperature_where_land surface_temperature_where_land land_ice_sigma_coordinate land_ice_sigma_coordinate "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. mol m-2 s-1 m-1 sr-1 surface_net_upward_longwave_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "longwave" means longwave radiation. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_net_upward_longwave_flux 112 E177 "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. clivi atmosphere_cloud_ice_content atmosphere_cloud_ice_content 58 "X_area_fraction" means the fraction of horizontal area occupied by X. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. land_ice_area_fraction land_ice_area_fraction sftgif thickness_of_convective_snowfall_amount "Amount" means mass per unit area. The construction thickness_of_[X_]snowfall_amount means the accumulated "depth" of snow which fell i.e. the thickness of the layer of snow at its own density. There are corresponding standard names for liquid water equivalent (lwe) thickness. thickness_of_convective_snowfall_amount square_of_brunt_vaisala_frequency_in_air "square_of_X" means X*X. s-2 square_of_brunt_vaisala_frequency_in_air N138 surface_snow_thickness_where_sea_ice The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. "Thickness" means the vertical extent of a layer. surface_snow_thickness_where_sea_ice The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "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. rldscs surface_downwelling_longwave_flux_in_air_assuming_clear_sky surface_downwelling_longwave_flux_in_air_assuming_clear_sky The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_spectral_photon_radiance_in_sea_water surface_downwelling_spectral_photon_radiance_in_sea_water tendency_of_air_temperature_due_to_large_scale_precipitation 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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tntlsp tendency_of_air_temperature_due_to_large_scale_precipitation "product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. "Northward" indicates a vector component which is positive increasing 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.) mpvta product_of_northward_wind_and_air_temperature product_of_northward_wind_and_air_temperature toa_adjusted_longwave_forcing "longwave" means longwave radiation. "toa" means top of atmosphere. Adjusted forcing is the radiative flux change caused by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.) after allowance for stratospheric temperature adjustment. toa_adjusted_longwave_forcing to sea_water_temperature sea_water_temperature 80 equilibrium_line_altitude equilibrium_line_altitude 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. "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. isotropic_spectral_radiance_in_air isotropic_spectral_radiance_in_air sea_ice_freeboard sea_ice_freeboard Sea ice freeboard is the height of the sea-ice upper surface above the water surface. eastward_atmosphere_water_transport_across_unit_distance "Water" means water in all phases. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport. eastward_atmosphere_water_transport_across_unit_distance "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. direction_of_sea_ice_velocity 93 direction_of_sea_ice_velocity heterotrophic_respiration_carbon_flux heterotrophic_respiration_carbon_flux "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. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. net_upward_shortwave_flux_in_air_assuming_clear_sky net_upward_shortwave_flux_in_air_assuming_clear_sky geopotential_height Geopotential is 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. 7 E156 geopotential_height zg 96 northward_sea_ice_velocity northward_sea_ice_velocity A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). Sea ice velocity is defined as a two-dimensional vector, with no vertical component. northward_ocean_freshwater_transport_due_to_bolus_advection 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 increasing northward (negative southward). Northward transport by bolus advection in an ocean model means the part due to a scheme representing eddy-induced effects not included in the velocity field. northward_ocean_freshwater_transport_due_to_bolus_advection sea_surface_height_above_geoid The geoid is a surface of constant geopotential with which mean sea level would coincide if the ocean were at rest. (The volume enclosed between the geoid and the sea floor equals the mean volume of water in the ocean.) In an ocean GCM the geoid is the surface of zero depth, or the rigid lid if the model uses that approximation. "Sea surface height" is a time-varying quantity. By definition of the geoid, the global average of the time-mean sea surface height (i.e. mean sea level) above the geoid must be zero. The standard name for the height of the sea surface above mean sea level is sea_surface_height_above_sea_level. sea_surface_height_above_geoid upward_eastward_stress_at_sea_ice_base "Eastward" indicates a vector component which is positive increasing eastward (negative westward). "Upward" indicates a vector component which is positive increasing upward (negative downward). "Upward eastward" indicates the ZX component of a tensor. An upward eastward stress is an upward flux of eastward momentum, which accelerates the upper medium eastward and the lower medium westward. upward_eastward_stress_at_sea_ice_base 10 equivalent_thickness_at_stp_of_atmosphere_ozone_content "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. "Thickness" means the vertical extent of a layer. 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. equivalent_thickness_at_stp_of_atmosphere_ozone_content Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.). tropopause_instantaneous_radiative_forcing tropopause_instantaneous_radiative_forcing 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.) In meteorological reports, the direction of the wind vector is usually (but not always) given as the direction from which it is blowing (wind_from_direction) (westerly, northerly, etc.). In other contexts, such as atmospheric modelling, it is often natural to give the direction in the usual manner of vectors as the heading or the direction to which it is blowing (wind_to_direction) (eastward, southward, etc.) wind_to_direction wind_to_direction mole_fraction_of_ozone_in_air tro3 mole_fraction_of_ozone_in_air Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y. 13 air_potential_temperature air_potential_temperature Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. theta baroclinic_eastward_sea_water_velocity baroclinic_eastward_sea_water_velocity A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). large_scale_snowfall_amount large_scale_snowfall_amount "Amount" means mass per unit area. 79 string A variable with the standard name of region contains strings which indicate geographical regions. These strings must be chosen from the standard region list. region region "product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). product_of_northward_sea_water_velocity_and_temperature product_of_northward_sea_water_velocity_and_temperature 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. downwelling_photosynthetic_photon_flux_in_sea_water downwelling_photosynthetic_photon_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "longwave" means longwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". 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. rlus surface_upwelling_longwave_flux_in_air surface_upwelling_longwave_flux_in_air "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. isotropic_shortwave_radiance_in_air isotropic_shortwave_radiance_in_air "Northward" indicates a vector component which is positive increasing northward (negative southward). "Upward" indicates a vector component which is positive increasing upward (negative downward). "Upward northward" indicates the ZY component of a tensor. An upward northward stress is an upward flux of northward momentum, which accelerates the upper medium northward and the lower medium southward. upward_northward_stress_at_sea_ice_base upward_northward_stress_at_sea_ice_base clw mass_fraction_of_cloud_liquid_water_in_air Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). mass_fraction_of_cloud_liquid_water_in_air ocean_s_coordinate See Appendix D of the CF convention for information about dimensionless vertical coordinates. ocean_s_coordinate northward_ocean_freshwater_transport northward_ocean_freshwater_transport "Northward" indicates a vector component which is positive increasing northward (negative southward). Ocean transport means transport by all processes, both sea water and sea ice. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). "Downward" indicates a vector component which is positive increasing 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. The surface downward stress is the windstress on the surface. tauu surface_downward_eastward_stress E180 surface_downward_eastward_stress equivalent_potential_temperature Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. equivalent_potential_temperature water_evaporation_flux evspsbl water_evaporation_flux "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "shortwave" means shortwave radiation. "toa" means top of atmosphere. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_net_downward_shortwave_flux_assuming_clear_sky toa_net_downward_shortwave_flux_assuming_clear_sky tendency_of_air_temperature_due_to_diabatic_processes tnt tendency_of_air_temperature_due_to_diabatic_processes 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. "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_mass_fraction_of_cloud_liquid_water_in_air_due_to_advection 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. "tendency_of_X" means derivative of X with respect to time. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). tendency_of_mass_fraction_of_cloud_liquid_water_in_air_due_to_advection "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. dissipation_in_atmosphere_boundary_layer dissipation_in_atmosphere_boundary_layer E145 E139 The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. The surface temperature is the (skin) temperature at the interface, not the bulk temperature of the medium above or below. surface_temperature surface_temperature ts "longwave" means longwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. net_downward_longwave_flux_in_air net_downward_longwave_flux_in_air soil_albedo Soil albedo is the albedo of the soil surface assuming no snow. soil_albedo "lwe" means liquid water equivalent. "moisture" means water in all phases contained in soil. "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. "Thickness" means the vertical extent of a layer. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). lwe_thickness_of_moisture_content_of_soil_layer lwe_thickness_of_moisture_content_of_soil_layer thickness_of_convective_rainfall_amount "Amount" means mass per unit area. The construction thickness_of_[X_]rainfall_amount means the accumulated "depth" of rainfall i.e. the thickness of a layer of liquid water having the same mass per unit area as the rainfall amount. thickness_of_convective_rainfall_amount 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. hfcorr heat_flux_correction heat_flux_correction atmosphere_horizontal_streamfunction 35 atmosphere_horizontal_streamfunction "Horizontal" indicates that the streamfunction applies to a horizontal velocity field on a particular vertical level. pseudo_equivalent_temperature pseudo_equivalent_temperature 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. global_average_thermosteric_sea_level_change global_average_thermosteric_sea_level_change surface_downwelling_photon_radiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_photon_radiance_in_sea_water sea_ice_area sea_ice_area cloud_top refers to the top of the highest cloud. air_pressure_at_convective_cloud_top air_pressure_at_convective_cloud_top northward_ocean_freshwater_transport_due_to_diffusion 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 increasing northward (negative southward). Northward transport by diffusion means the part due to horizontal or isopyncal diffusion schemes in an ocean model, but not including the "bolus" or Gent-McWilliams velocity. northward_ocean_freshwater_transport_due_to_diffusion planetary_albedo planetary_albedo surface_downwelling_spectral_spherical_irradiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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". surface_downwelling_spectral_spherical_irradiance_in_sea_water lwe_thickness_of_canopy_water_amount "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. "Water" means water in all phases. "Canopy" means the vegetation canopy. The canopy water is the water on the vegetation canopy. lwe_thickness_of_canopy_water_amount toa_adjusted_radiative_forcing "toa" means top of atmosphere. Adjusted forcing is the radiative flux change caused by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.) after allowance for stratospheric temperature adjustment. toa_adjusted_radiative_forcing "frozen_water" means ice. "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including content_of_soil_layer are used. soil_frozen_water_content mrfso soil_frozen_water_content "Northward" indicates a vector component which is positive increasing northward (negative southward). "Downward" indicates a vector component which is positive increasing 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. downward_northward_stress_at_sea_ice_base downward_northward_stress_at_sea_ice_base northward_atmosphere_heat_transport "Northward" indicates a vector component which is positive increasing northward (negative southward). "Atmosphere heat transport" means total heat transport by the atmosphere by all processes. northward_atmosphere_heat_transport air_density air_density "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. "Thickness" means the vertical extent of a layer. ocean_isopycnal_layer_thickness_diffusivity ocean_isopycnal_layer_thickness_diffusivity height_at_cloud_top height_at_cloud_top cloud_top refers to the top of the highest cloud. Height is the vertical distance above the surface. "Northward" indicates a vector component which is positive increasing northward (negative southward). Ocean transport means transport by all processes, both sea water and sea ice. northward_ocean_heat_transport northward_ocean_heat_transport 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. land_ice_basal_y_velocity land_ice_basal_y_velocity Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. mass_concentration_of_sulfate_aerosol_in_air trsul mass_concentration_of_sulfate_aerosol_in_air E134 The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. ps surface_air_pressure surface_air_pressure Adjusted forcing is the radiative flux change caused by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.) after allowance for stratospheric temperature adjustment. tropopause_adjusted_radiative_forcing tropopause_adjusted_radiative_forcing direction_of_sea_water_velocity 47 direction_of_sea_water_velocity "direction_of_X" means direction of a vector, a bearing. A velocity is a vector quantity. product_of_upward_air_velocity_and_specific_humidity product_of_upward_air_velocity_and_specific_humidity "product_of_X_and_Y" means X*Y. "specific" means per unit mass. A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). Specific humidity is the mass fraction of water vapor in (moist) air. Upward air velocity is the vertical component of the 3D air velocity vector. "product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). Upward air velocity is the vertical component of the 3D air velocity vector. product_of_upward_air_velocity_and_air_temperature product_of_upward_air_velocity_and_air_temperature "Content" indicates a quantity per unit area. trsult atmosphere_content_of_sulfate_aerosol atmosphere_content_of_sulfate_aerosol tendency_of_sea_ice_thickness_due_to_thermodynamics 97 tendency_of_sea_ice_thickness_due_to_thermodynamics 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. "tendency_of_X" means derivative of X with respect to time. "Thickness" means the vertical extent of a layer. surface_net_upward_shortwave_flux surface_net_upward_shortwave_flux 111 E176 The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "shortwave" means shortwave radiation. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "lwe" means liquid water equivalent. lwe_large_scale_snowfall_rate lwe_large_scale_snowfall_rate "probability_of_X" means the chance that X is true or of at least one occurrence of X. Space and time coordinates must be used to indicate the area and time-interval to which a probability applies. thunderstorm_probability thunderstorm_probability 60 sea_level means mean sea level, which is close to the geoid in sea areas. sea_floor_depth_below_sea_level sea_floor_depth_below_sea_level 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. sea_water_x_velocity sea_water_x_velocity sea_water_sigma_t Sigma-t of sea water is the density of water at atmospheric pressure (i.e. the surface) having the same temperature and salinity, minus 1000 kg m-3. Note that sea water sigma is not the same quantity as the dimensionless ocean sigma coordinate (see Appendix D of the CF convention), for which there is another standard name. sea_water_sigma_t pseudo_equivalent_potential_temperature 14 Potential temperature is the temperature a parcel of air or sea water would have if moved adiabatically to sea level pressure. pseudo_equivalent_potential_temperature snow_soot_content "Content" indicates a quantity per unit area. snow_soot_content The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. "Upward" indicates a vector component which is positive increasing upward (negative downward). 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. surface_upward_sensible_heat_flux_where_sea surface_upward_sensible_heat_flux_where_sea Pa m s-1 product_of_geopotential_height_and_omega "product_of_X_and_Y" means X*Y. Geopotential is 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. "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. product_of_geopotential_height_and_omega product_of_northward_sea_water_velocity_and_salinity "product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). The unit of salinity is PSU, which is dimensionless. The units attribute should be given as 1e-3 or 0.001 i.e. parts per thousand if salinity is in PSU. product_of_northward_sea_water_velocity_and_salinity surface_upwelling_shortwave_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "shortwave" means shortwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". 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. rsus surface_upwelling_shortwave_flux_in_air northward_atmosphere_dry_static_energy_transport_across_unit_distance "Northward" indicates a vector component which is positive increasing northward (negative southward). Transport across_unit_distance means expressed per unit distance normal to the direction of transport. Dry static energy is the sum of enthalpy (CpT+gz, where Cp is heat capacity at constant pressure, T is absolute temperature, g is acceleration due to gravity and z is altitude) and kinetic energy. northward_atmosphere_dry_static_energy_transport_across_unit_distance ocean_mixed_layer_thickness 67 "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. "Thickness" means the vertical extent of a layer. ocean_mixed_layer_thickness specific_humidity 51 E133 specific_humidity "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. hus lwe_thickness_of_atmosphere_water_vapor_content "lwe" means liquid water equivalent. "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. "Thickness" means the vertical extent of a layer. Atmosphere water vapor content is sometimes referred to as "precipitable water", although this term does not imply the water could all be precipitated. lwe_thickness_of_atmosphere_water_vapor_content E137 tendency_of_northward_wind_due_to_convection 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. "tendency_of_X" means derivative of X with respect to time. "Northward" indicates a vector component which is positive increasing 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.) tnmmvc tendency_of_northward_wind_due_to_convection atmosphere_cloud_liquid_water_content atmosphere_cloud_liquid_water_content "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. rainfall_rate rainfall_rate "Water" means water in all phases. The water flux or volume transport into the ocean from rivers is the inflow to the ocean, often applied to the surface in ocean models. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_flux_into_ocean_from_rivers water_flux_into_ocean_from_rivers net_downward_longwave_flux_in_air_assuming_clear_sky net_downward_longwave_flux_in_air_assuming_clear_sky A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "longwave" means longwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. atmosphere_hybrid_sigma_pressure_coordinate atmosphere_hybrid_sigma_pressure_coordinate See Appendix D of the CF convention for information about dimensionless vertical coordinates. "Amount" means mass per unit area. snowfall_amount snowfall_amount radial_velocity_of_scatterers_away_from_instrument A velocity is a vector quantity. "Radial velocity away from instrument" means the component of the velocity of the scatterers along the line of sight of the instrument where positive implies movement away from the instrument (i.e. outward). The "instrument" (examples are radar and lidar) is the device used to make the observation, and the "scatterers" are what causes the transmitted signal to be returned to the instrument (examples are aerosols, hydrometeors and refractive index irregularities), of whatever kind the instrument detects. radial_velocity_of_scatterers_away_from_instrument surface_net_downward_shortwave_flux surface_net_downward_shortwave_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "shortwave" means shortwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. rss cloud_liquid_water_content_of_atmosphere_layer cloud_liquid_water_content_of_atmosphere_layer "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). surface_downwelling_photon_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_photon_flux_in_sea_water htovovrt northward_ocean_heat_transport_due_to_overturning northward_ocean_heat_transport_due_to_overturning 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 increasing northward (negative southward). Northward transport by (meridional) overturning is geometrically defined as being the part due to the vertical integral of the product of zonal means of velocity and tracer. The velocity does not include "bolus" or Gent-McWilliams velocity. biomass_burning_carbon_flux "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. biomass_burning_carbon_flux "Water" means water in all phases. The water flux into the ocean is the freshwater entering the sea water as a result of precipitation, evaporation, river inflow, sea ice effects and water flux correction (if applied). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_flux_into_ocean water_flux_into_ocean wfo surface_downwelling_photosynthetic_photon_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_photosynthetic_photon_flux_in_sea_water atmosphere_sigma_coordinate See Appendix D of the CF convention for information about dimensionless vertical coordinates. atmosphere_sigma_coordinate "shortwave" means shortwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". 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. tropopause_upwelling_shortwave_flux tropopause_upwelling_shortwave_flux "Respiration carbon" refers to the rate at which biomass is respired expressed as the mass of carbon which it contains. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. plant_respiration_carbon_flux plant_respiration_carbon_flux A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "longwave" means longwave radiation. "toa" means top of atmosphere. 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. toa_outgoing_longwave_flux_assuming_clear_sky toa_outgoing_longwave_flux_assuming_clear_sky rlutcs square_of_northward_wind "square_of_X" means X*X. "Northward" indicates a vector component which is positive increasing 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.) mpvva square_of_northward_wind upward_sea_ice_basal_heat_flux "Upward" indicates a vector component which is positive increasing upward (negative downward). The sea ice basal heat flux is the vertical heat flux (apart from radiation i.e. "diffusive") in sea water at the base of the sea ice. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. upward_sea_ice_basal_heat_flux 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. downwelling_photosynthetic_photon_radiance_in_sea_water downwelling_photosynthetic_photon_radiance_in_sea_water 50 northward_sea_water_velocity A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). northward_sea_water_velocity "X_area_fraction" means the fraction of horizontal area occupied by X. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called "sea ice concentration". 91 sic sea_ice_area_fraction sea_ice_area_fraction product_of_northward_wind_and_upward_air_velocity product_of_northward_wind_and_upward_air_velocity "product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). "Upward" indicates a vector component which is positive increasing upward (negative downward). 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.) Upward air velocity is the vertical component of the 3D air velocity vector. toa_instantaneous_radiative_forcing "toa" means top of atmosphere. Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.). toa_instantaneous_radiative_forcing surface_upwelling_spectral_radiative_flux_in_sea_water surface_upwelling_spectral_radiative_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Upwelling radiation is radiation from below. It does not mean "net upward". "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. 114 E179 toa_outgoing_longwave_flux "longwave" means longwave radiation. "toa" means top of atmosphere. 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. rlut toa_outgoing_longwave_flux "product_of_X_and_Y" means X*Y. "Eastward" indicates a vector component which is positive increasing 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.) "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. product_of_eastward_wind_and_omega product_of_eastward_wind_and_omega downwelling_spherical_irradiance_in_sea_water 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". downwelling_spherical_irradiance_in_sea_water toa_net_downward_shortwave_flux "shortwave" means shortwave radiation. "toa" means top of atmosphere. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_net_downward_shortwave_flux rst soil_moisture_content "moisture" means water in all phases contained in soil. "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including content_of_soil_layer are used. 86 soil_moisture_content mrso surface_snow_melt_heat_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. The surface snow melt heat flux is the supply of latent heat which is melting snow at freezing point. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_snow_melt_heat_flux See Appendix D of the CF convention for information about dimensionless vertical coordinates. Note that the ocean sigma coordinate is not the same quantity as sea water sigma (excess of density over 1000 kg m-3), for which there are various other standard names. ocean_sigma_coordinate ocean_sigma_coordinate atmosphere_water_content atmosphere_water_content "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. lwe_thickness_of_water_evaporation_amount E182 "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) lwe_thickness_of_water_evaporation_amount northward_wind_shear "Northward" indicates a vector component which is positive increasing 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.) Wind shear is the derivative of wind with respect to height. 46 northward_wind_shear moisture_content_of_soil_layer_at_field_capacity moisture_content_of_soil_layer_at_field_capacity "moisture" means water in all phases contained in soil. "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). mrsofcs water_sublimation_flux "Water" means water in all phases. Sublimation is the conversion of solid into vapor. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. water_sublimation_flux tendency_of_mass_fraction_of_cloud_liquid_water_in_air_due_to_diffusion 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. "tendency_of_X" means derivative of X with respect to time. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). tendency_of_mass_fraction_of_cloud_liquid_water_in_air_due_to_diffusion tropopause_adjusted_longwave_forcing "longwave" means longwave radiation. Adjusted forcing is the radiative flux change caused by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.) after allowance for stratospheric temperature adjustment. tropopause_adjusted_longwave_forcing brunt_vaisala_frequency_in_air brunt_vaisala_frequency_in_air canopy_water_amount "Amount" means mass per unit area. "Water" means water in all phases. "Canopy" means the vegetation canopy. The canopy water is the water on the vegetation canopy. canopy_water_amount "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock. Specific mass balance means the net rate at which ice is added per unit area at the land ice surface. land_ice_surface_specific_mass_balance land_ice_surface_specific_mass_balance In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. convective_snowfall_flux convective_snowfall_flux model_level_number model_level_number lev Model level number should be understood as equivalent to layer number. vegetation_carbon_content "Content" indicates a quantity per unit area. vegetation_carbon_content surface_albedo_assuming_no_snow The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. surface_albedo_assuming_no_snow product_of_eastward_wind_and_air_temperature product_of_eastward_wind_and_air_temperature "product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. "Eastward" indicates a vector component which is positive increasing 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.) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. large_scale_snowfall_flux large_scale_snowfall_flux 103 wind_wave_period wind_wave_period A period is an interval of time, or the time-period of an oscillation. 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.) cloud_top refers to the top of the highest cloud. air_pressure_at_cloud_top air_pressure_at_cloud_top tropopause_air_temperature tropopause_air_temperature Air temperature is the bulk temperature of the air, not the surface (skin) temperature. downwelling_photon_spherical_irradiance_in_sea_water downwelling_photon_spherical_irradiance_in_sea_water 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. 1 plev air_pressure air_pressure water_evaporation_amount 57 water_evaporation_amount "Amount" means mass per unit area. "Water" means water in all phases. Evaporation is the conversion of liquid or solid into vapor. (The conversion of solid alone into vapor is called "sublimation".) "shortwave" means shortwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. tropopause_net_downward_shortwave_flux tropopause_net_downward_shortwave_flux rsdt toa_incoming_shortwave_flux toa_incoming_shortwave_flux "shortwave" means shortwave radiation. "toa" means top of atmosphere. The TOA incoming shortwave flux is the radiative flux from the sun i.e. the "downwelling" TOA shortwave flux. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. sea_water_pressure sea_water_pressure product_of_omega_and_air_temperature mpwapta product_of_omega_and_air_temperature "product_of_X_and_Y" means X*Y. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. 124 downward_eastward_momentum_flux_in_air "Eastward" indicates a vector component which is positive increasing eastward (negative westward). "Downward" indicates a vector component which is positive increasing 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. downward_eastward_momentum_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). surface_eastward_sea_water_velocity surface_eastward_sea_water_velocity 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 increasing northward (negative southward). Northward transport by diffusion means the part due to horizontal or isopyncal diffusion schemes in an ocean model, but not including the "bolus" or Gent-McWilliams velocity. htovdiff northward_ocean_heat_transport_due_to_diffusion northward_ocean_heat_transport_due_to_diffusion tnmmvgwd tendency_of_northward_wind_due_to_gravity_wave_drag 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. "tendency_of_X" means derivative of X with respect to time. "Northward" indicates a vector component which is positive increasing 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.) tendency_of_northward_wind_due_to_gravity_wave_drag stfbaro ocean_barotropic_streamfunction m3 s-1 ocean_barotropic_streamfunction surface_downwelling_photosynthetic_photon_radiance_in_sea_water surface_downwelling_photosynthetic_photon_radiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. "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. lagrangian_tendency_of_atmosphere_sigma_coordinate lagrangian_tendency_of_atmosphere_sigma_coordinate 38 depth Depth is the vertical distance below the surface. depth atmosphere_energy_content atmosphere_energy_content "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. 39 E135 "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. lagrangian_tendency_of_air_pressure wap lagrangian_tendency_of_air_pressure tendency_of_eastward_wind_due_to_advection tendency_of_eastward_wind_due_to_advection 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. "tendency_of_X" means derivative of X with respect to time. "Eastward" indicates a vector component which is positive increasing 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.) surface_downward_sensible_heat_flux surface_downward_sensible_heat_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Downward" indicates a vector component which is positive increasing 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. lwe_thickness_of_large_scale_precipitation_amount E142 lwe_thickness_of_large_scale_precipitation_amount "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. water_vapor_pressure water_vapor_pressure Vapor pressure is the partial pressure of a constituent of air, such as water, which exists as liquid or solid under "normal" conditions. "Water" is specified when the term is being applied to water. 55 sea_ice_amount sea_ice_amount "Amount" means mass per unit area. large_scale_rainfall_rate large_scale_rainfall_rate northward_momentum_flux_correction tauvcorr "Northward" indicates a vector component which is positive increasing northward (negative southward). 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. northward_momentum_flux_correction tendency_of_upward_air_velocity_due_to_advection 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. "tendency_of_X" means derivative of X with respect to time. A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). Upward air velocity is the vertical component of the 3D air velocity vector. tendency_of_upward_air_velocity_due_to_advection downwelling_radiance_in_sea_water 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. downwelling_radiance_in_sea_water Speed is the magnitude of velocity. 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.) The wind speed is the magnitude of the wind velocity. 32 wind_speed wind_speed E158 tendency_of_surface_air_pressure The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "tendency_of_X" means derivative of X with respect to time. tendency_of_surface_air_pressure ocean_meridional_overturning_streamfunction The ocean meridional overturning streamfunction should not include not include "bolus" or Gent-McWilliams velocity. ocean_meridional_overturning_streamfunction stfmmcgo 40 upward_air_velocity upward_air_velocity A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). Upward air velocity is the vertical component of the 3D air velocity vector. 117 surface_downwelling_shortwave_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "shortwave" means shortwave radiation. Downwelling radiation is radiation from above. It does not mean "net downward". Surface downwelling shortwave is the sum of direct and diffuse solar radiation incident on the surface, and is sometimes called "global radiation". 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. rsds surface_downwelling_shortwave_flux_in_air 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. cloud_base_altitude cloud_base_altitude Zenith angle is the angle to the local vertical; a value of zero is directly overhead. zenith_angle zenith_angle "toa" means top of atmosphere. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). Radiative flux is the sum of shortwave and longwave radiative fluxes. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_net_downward_radiative_flux toa_net_downward_radiative_flux "Amount" means mass per unit area. transpiration_amount transpiration_amount cloud_ice_content_of_atmosphere_layer cloud_ice_content_of_atmosphere_layer "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). mptta "square_of_X" means X*X. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. square_of_air_temperature square_of_air_temperature downwelling_spectral_photon_radiance_in_sea_water downwelling_spectral_photon_radiance_in_sea_water 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. product_of_omega_and_specific_humidity mpwhusa "product_of_X_and_Y" means X*Y. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. product_of_omega_and_specific_humidity significant_height_of_wind_and_swell_waves Height is the vertical distance above the surface. Wind waves are waves on the ocean surface. Wind waves and swell waves are waves on the ocean surface. 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.) 100 significant_height_of_wind_and_swell_waves downwelling_longwave_radiance_in_air "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. downwelling_longwave_radiance_in_air 82 sea_level means mean sea level, which is close to the geoid in sea areas. "Sea surface height" is a time-varying quantity. The standard name for the height of the sea surface above the geoid is sea_surface_height_above_geoid. sea_surface_height_above_sea_level sea_surface_height_above_sea_level tendency_of_air_temperature "tendency_of_X" means derivative of X with respect to time. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "anomaly" means difference from climatology. The surface temperature is the (skin) temperature at the interface, not the bulk temperature of the medium above or below. surface_temperature_anomaly surface_temperature_anomaly lwe_convective_precipitation_rate "lwe" means liquid water equivalent. lwe_convective_precipitation_rate "Amount" means mass per unit area. The construction thickness_of_[X_]snowfall_amount means the accumulated "depth" of snow which fell i.e. the thickness of the layer of snow at its own density. There are corresponding standard names for liquid water equivalent (lwe) thickness. thickness_of_large_scale_snowfall_amount thickness_of_large_scale_snowfall_amount mass_fraction_of_water_in_air mass_fraction_of_water_in_air "Water" means water in all phases. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). barotropic_eastward_sea_water_velocity A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). barotropic_eastward_sea_water_velocity 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. downwelling_spectral_radiative_flux_in_air downwelling_spectral_radiative_flux_in_air mass_fraction_of_convective_condensed_water_in_air mass_fraction_of_convective_condensed_water_in_air "condensed_water" means liquid and ice. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_photon_spherical_irradiance_in_sea_water surface_downwelling_photon_spherical_irradiance_in_sea_water downwelling_photosynthetic_photon_spherical_irradiance_in_sea_water 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. downwelling_photosynthetic_photon_spherical_irradiance_in_sea_water "product_of_X_and_Y" means X*Y. Geopotential is 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. "Eastward" indicates a vector component which is positive increasing 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.) product_of_eastward_wind_and_geopotential_height product_of_eastward_wind_and_geopotential_height mpuzga wind_from_direction 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.) In meteorological reports, the direction of the wind vector is usually (but not always) given as the direction from which it is blowing (wind_from_direction) (westerly, northerly, etc.). In other contexts, such as atmospheric modelling, it is often natural to give the direction in the usual manner of vectors as the heading or the direction to which it is blowing (wind_to_direction) (eastward, southward, etc.) wind_from_direction 31 lwe_convective_snowfall_rate "lwe" means liquid water equivalent. lwe_convective_snowfall_rate leaf_area_index leaf_area_index net_primary_productivity_of_carbon Net primary productivity is the excess of gross_primary_producivity (rate of synthesis of biomass per unit area from inorganic precursors by autotrophs, or "producers", especially by photosynthesising plants using sunlight for energy) over the rate at which they themselves respire some of this biomass (plant_respiration, assuming all producers to be plants). "Productivity of carbon" refers to the production of biomass expressed as the mass of carbon which it contains. net_primary_productivity_of_carbon water_vapor_content_of_atmosphere_layer water_vapor_content_of_atmosphere_layer "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). potential_vorticity_of_ocean_layer "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an ocean layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). Ocean potential vorticity is the vertically averaged absolute vorticity of a layer of the ocean divided by the thickness of the layer. potential_vorticity_of_ocean_layer "x" indicates a vector component along the grid x-axis, when this is not true longitude, positive with increasing x. 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.) x_wind x_wind 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. land_ice_x_velocity land_ice_x_velocity surface_downwelling_photosynthetic_radiative_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_photosynthetic_radiative_flux_in_sea_water tendency_of_air_temperature_due_to_longwave_heating_assuming_clear_sky 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. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "tendency_of_X" means derivative of X with respect to time. "longwave" means longwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature. tendency_of_air_temperature_due_to_longwave_heating_assuming_clear_sky In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. convective_rainfall_flux convective_rainfall_flux tropopause_downwelling_longwave_flux "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. tropopause_downwelling_longwave_flux surface_downward_heat_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Downward" indicates a vector component which is positive increasing downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_downward_heat_flux_in_sea_water forecast_period forecast_period 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. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "longwave" means longwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_net_downward_longwave_flux_assuming_clear_sky surface_net_downward_longwave_flux_assuming_clear_sky net_upward_shortwave_flux_in_air net_upward_shortwave_flux_in_air "shortwave" means shortwave radiation. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. 116 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. downwelling_spectral_photon_spherical_irradiance_in_sea_water downwelling_spectral_photon_spherical_irradiance_in_sea_water wind_mixing_energy_flux_into_ocean wind_mixing_energy_flux_into_ocean 126 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.) In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "longwave" means longwave radiation. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. surface_net_downward_longwave_flux surface_net_downward_longwave_flux rls tendency_of_eastward_wind_due_to_diffusion tendency_of_eastward_wind_due_to_diffusion 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. "tendency_of_X" means derivative of X with respect to time. "Eastward" indicates a vector component which is positive increasing 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.) 8 altitude altitude Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. 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. "tendency_of_X" means derivative of X with respect to time. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. tnmrc tendency_of_specific_humidity_due_to_convection tendency_of_specific_humidity_due_to_convection A phrase assuming_condition indicates that the named quantity is the value which would obtain if all aspects of the system were unaltered except for the assumption of the circumstances specified by the condition. "longwave" means longwave radiation. "toa" means top of atmosphere. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_net_upward_longwave_flux_assuming_clear_sky toa_net_upward_longwave_flux_assuming_clear_sky transpiration_flux In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. transpiration_flux "X_area_fraction" means the fraction of horizontal area occupied by X. 87 vegetation_area_fraction vegetation_area_fraction atmosphere_boundary_layer_thickness "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. "Thickness" means the vertical extent of a layer. The atmosphere boundary layer thickness is the "depth" or "height" of the (atmosphere) planetary boundary layer. atmosphere_boundary_layer_thickness zmla toa_net_upward_shortwave_flux "shortwave" means shortwave radiation. "toa" means top of atmosphere. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. toa_net_upward_shortwave_flux 113 E178 convective_rainfall_amount "Amount" means mass per unit area. convective_rainfall_amount sea_floor_depth_below_geoid The geoid is a surface of constant geopotential with which mean sea level would coincide if the ocean were at rest. (The volume enclosed between the geoid and the sea floor equals the mean volume of water in the ocean.) In an ocean GCM the geoid is the surface of zero depth, or the rigid lid if the model uses that approximation. zobt sea_floor_depth_below_geoid "X_area_fraction" means the fraction of horizontal area occupied by X. 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. large_scale_cloud_area_fraction large_scale_cloud_area_fraction air_pressure_at_convective_cloud_base air_pressure_at_convective_cloud_base cloud_base refers to the base of the lowest cloud. "product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). "Upward" indicates a vector component which is positive increasing upward (negative downward). 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.) Upward air velocity is the vertical component of the 3D air velocity vector. product_of_eastward_wind_and_upward_air_velocity product_of_eastward_wind_and_upward_air_velocity tnmrd 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. "tendency_of_X" means derivative of X with respect to time. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. tendency_of_specific_humidity_due_to_model_physics tendency_of_specific_humidity_due_to_model_physics tropopause_adjusted_shortwave_forcing "shortwave" means shortwave radiation. Adjusted forcing is the radiative flux change caused by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.) after allowance for stratospheric temperature adjustment. tropopause_adjusted_shortwave_forcing square_of_upward_air_velocity "square_of_X" means X*X. A velocity is a vector quantity. "Upward" indicates a vector component which is positive increasing upward (negative downward). Upward air velocity is the vertical component of the 3D air velocity vector. square_of_upward_air_velocity 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. downwelling_photosynthetic_radiance_in_sea_water downwelling_photosynthetic_radiance_in_sea_water atmosphere_eastward_stress_due_to_gravity_wave_drag 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 increasing eastward (negative westward). Atmosphere_Xward_stress is a stress which tends to accelerate the atmosphere in direction X. tauugwd atmosphere_eastward_stress_due_to_gravity_wave_drag virtual_temperature 12 The virtual temperature of air is the temperature at which the dry air constituent of a parcel of moist air would have the same density as the moist air at the same pressure. virtual_temperature "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. 54 atmosphere_water_vapor_content atmosphere_water_vapor_content prw surface_snow_amount 65 The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Amount" means mass per unit area. Surface snow amount refers to the amount on the ground, excluding that on the vegetation canopy. surface_snow_amount snw eastward_sea_ice_velocity eastward_sea_ice_velocity 95 A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). Sea ice velocity is defined as a two-dimensional vector, with no vertical component. root_depth Depth is the vertical distance below the surface. The root depth is maximum depth of soil reached by plant roots, from which they can extract moisture. root_depth "y" indicates a vector component along the grid y-axis, when this is not true latitude, positive with increasing y. 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.) y_wind y_wind eastward_wind eastward_wind ua "Eastward" indicates a vector component which is positive increasing 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.) 33 E131 snowfall_flux snowfall_flux 64 In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. prsn water_volume_transport_into_ocean_from_rivers water_volume_transport_into_ocean_from_rivers "Water" means water in all phases. The water flux or volume transport into the ocean from rivers is the inflow to the ocean, often applied to the surface in ocean models. freezing_temperature_of_sea_water freezing_temperature_of_sea_water "product_of_X_and_Y" means X*Y. "specific" means per unit mass. Specific humidity is the mass fraction of water vapor in (moist) air. "omegaX" is used for brevity to mean "lagrangian_tendency_of_air_pressure in standard names constructed as a combination of omega with some other quantity. product_of_specific_humidity_and_omega product_of_specific_humidity_and_omega surface_snow_melt_flux surface_snow_melt_flux The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. snm water_flux_correction water_flux_correction "Water" means water in all phases. 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. 41 atmosphere_absolute_vorticity atmosphere_absolute_vorticity Absolute vorticity is the sum of relative vorticity and the upward component of vorticity due to the Earth's rotation. lwe_thickness_of_precipitation_amount "lwe" means liquid water equivalent. "Amount" means mass per unit area. The construction lwe_thickness_of_X_amount means the vertical extent of a layer of liquid water having the same mass per unit area. lwe_thickness_of_precipitation_amount sea_water_electrical_conductivity sea_water_electrical_conductivity large_scale_precipitation_flux In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. large_scale_precipitation_flux 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. grid_longitude grid_longitude large_scale_rainfall_flux large_scale_rainfall_flux In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. 99 surface_snow_melt_amount The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. "Amount" means mass per unit area. surface_snow_melt_amount snow_grain_size snow_grain_size A velocity is a vector quantity. "Northward" indicates a vector component which is positive increasing northward (negative southward). baroclinic_northward_sea_water_velocity baroclinic_northward_sea_water_velocity sea_ice_extent sea_ice_extent direction_of_wind_wave_velocity "direction_of_X" means direction of a vector, a bearing. A velocity is a vector quantity. 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.) 101 direction_of_wind_wave_velocity convective_rainfall_rate convective_rainfall_rate surface_downwelling_spectral_photon_flux_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_spectral_photon_flux_in_sea_water 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. "tendency_of_X" means derivative of X with respect to time. Speed is the magnitude of velocity. 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.) The wind speed is the magnitude of the wind velocity. tendency_of_wind_speed_due_to_gravity_wave_drag tendency_of_wind_speed_due_to_gravity_wave_drag significant_height_of_wind_waves Height is the vertical distance above the surface. Wind waves are waves on the ocean surface. 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.) 102 significant_height_of_wind_waves net_downward_radiative_flux_at_top_of_atmosphere_model Fluxes at the top_of_atmosphere_model differ from TOA fluxes only if the model TOA fluxes make some allowance for the atmosphere above the top of the model; if not, it is usual to give standard names with toa to the fluxes at the top of the model atmosphere. "Downward" indicates a vector component which is positive increasing downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). Radiative flux is the sum of shortwave and longwave radiative fluxes. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. rtmt net_downward_radiative_flux_at_top_of_atmosphere_model isotropic_longwave_radiance_in_air isotropic_longwave_radiance_in_air "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. surface_upwelling_spectral_radiative_flux_in_air The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Upwelling radiation is radiation from below. It does not mean "net upward". "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. surface_upwelling_spectral_radiative_flux_in_air Altitude is the (geometric) height above the geoid, which is the reference geopotential surface. The geoid is similar to mean sea level. tropopause_altitude tropopause_altitude 115 net_upward_longwave_flux_in_air net_upward_longwave_flux_in_air "longwave" means longwave radiation. "Upward" indicates a vector component which is positive increasing upward (negative downward). Net upward radiation is the difference between radiation from below (upwelling) and radiation from above (downwelling). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. tropopause_instantaneous_shortwave_forcing "shortwave" means shortwave radiation. Instantaneous forcing is the radiative flux change caused instantaneously by an imposed change in radiative forcing agent (greenhouse gases, aerosol, solar radiation, etc.). tropopause_instantaneous_shortwave_forcing "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an atmosphere layer must have a vertical coordinate variable indicating the extent of the layer(s). "X_area_fraction" means the fraction of horizontal area occupied by X. Cloud area fraction is also called "cloud amount" and "cloud cover". cloud_area_fraction_in_atmosphere_layer cloud_area_fraction_in_atmosphere_layer cl runoff_flux Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. mrro runoff_flux surface_downwelling_radiance_in_sea_water The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_radiance_in_sea_water va 34 E132 northward_wind northward_wind "Northward" indicates a vector component which is positive increasing 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.) product_of_eastward_sea_water_velocity_and_salinity product_of_eastward_sea_water_velocity_and_salinity "product_of_X_and_Y" means X*Y. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). The unit of salinity is PSU, which is dimensionless. The units attribute should be given as 1e-3 or 0.001 i.e. parts per thousand if salinity is in PSU. The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. Unless indicated, a quantity is assumed to apply to the whole area of each horizontal grid box. The qualifier where_type specifies instead that the quantity applies only to the part of the grid box of the named type. The surface temperature is the (skin) temperature at the interface, not the bulk temperature of the medium above or below. surface_temperature_where_open_sea surface_temperature_where_open_sea 49 eastward_sea_water_velocity A velocity is a vector quantity. "Eastward" indicates a vector component which is positive increasing eastward (negative westward). eastward_sea_water_velocity integral_of_sea_water_temperature_wrt_depth_in_ocean_layer "wrt" means with respect to. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. It does not mean model layers unless specified by a vertical coordinate of model_level_number. Quantities defined for an ocean layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s). Depth is the vertical distance below the surface. integral_of_sea_water_temperature_wrt_depth_in_ocean_layer The surface called "surface" means the lower boundary of the atmosphere; over sea areas this is taken to be mean sea level. 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. surface_downwelling_photosynthetic_photon_spherical_irradiance_in_sea_water surface_downwelling_photosynthetic_photon_spherical_irradiance_in_sea_water tendency_of_northward_wind_due_to_advection tendency_of_northward_wind_due_to_advection 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. "tendency_of_X" means derivative of X with respect to time. "Northward" indicates a vector component which is positive increasing 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.) mass_fraction_of_frozen_water_in_soil_moisture mass_fraction_of_frozen_water_in_soil_moisture "frozen_water" means ice. "moisture" means water in all phases contained in soil. Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of Y to the mass of X (including Y). latitude latitude 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. latitude upward_water_vapor_flux_in_air "Upward" indicates a vector component which is positive increasing upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. upward_water_vapor_flux_in_air