Update for CF Version:86
global_average_sea_level_change_due_to_change_in_ocean_mass
Unit: m
Unit ref: ULAA
Global average mass volume sea level change is caused by water mass balance (evaporation – precipitation + runoff). This in turn results in a change in volume of the world ocean. Zero sea level change is an arbitrary 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. Because global average sea level change quantifies the change in volume of the world ocean, it is not calculated necessarily by considering local changes in mean sea level. This quantity is sometimes called "barystatic sea level rise" or "barystatic sea level change". It is the part of global-mean sea-level rise which is due to the addition to the ocean of water mass that formerly resided within the land area (as land water storage or land ice) or in the atmosphere (which contains a relatively tiny mass of water).
area_fraction_below_surface
Unit: 1
Unit ref: UUUU
AMIP: psbg
The quantity with standard name area_fraction_below_surface is the fraction of horizontal area where a given isobaric surface is below the (ground or sea) surface. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The surface called "surface" means the lower boundary of the atmosphere.
mass_concentration_of_pm10_magnesium_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the magnesium dication is Mg(2+).
mass_concentration_of_pm10_potassium_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the potassium cation is K+.
mass_concentration_of_pm10_calcium_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the calcium dication is Ca(2+).
mass_concentration_of_pm10_sodium_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the sodium cation is Na+.
mass_concentration_of_pm10_methanesulfonic_acid_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for methanesulfonic acid is CH3SO3H.
mass_concentration_of_pm10_bromide_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the bromide anion is Br-.
mass_concentration_of_pm10_oxalate_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the oxalate dianion is C2O4(2-).
mass_concentration_of_pm10_sulfate_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the sulfate anion is SO4(2-).
permafrost_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Permafrost is soil or rock that has remained at a temperature at or below zero degrees Celsius throughout the seasonal cycle for two or more years.
change_in_sea_floor_height_above_reference_ellipsoid_due_to_ocean_tide_loading
Unit: m
Unit ref: ULAA
Sea surface height is a time-varying quantity. A reference ellipsoid is a regular mathematical figure that approximates the irregular shape of the geoid. A number of reference ellipsoids are defined for use in the field of geodesy. 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. Tides are a significant contributor to the observed sea surface height. The load tidal component of sea surface height describes the variability of the sea surface due to the deformation of the Earth because of the weight of the water masses displaced by ocean tides.
acoustic_equivalent_area_in_sea_water
Unit: m
Unit ref: ULAA
Acoustic equivalent area is the squared area backscattering coefficient divided by the depth integral of squared volume backscattering coefficient. Area backscattering coefficient is the integral of the volume backscattering coefficient over a defined distance. Volume backscattering coefficient is the linear form of acoustic_volume_backscattering_strength_in_sea_water. The parameter is computed to provide a value that represents the area that would be occupied if all data cells contained the mean density and is the reciprocal of acoustic_index_of_aggregation_in_sea_water. For further details see Urmy et. al (2012) doi:10.1093/icesjms/fsr205 and Woillez et. al (2007) doi.org/10.1093/icesjms/fsm025.
acoustic_inertia_in_sea_water
Unit: m-2
Unit ref: PMSQ
Acoustic inertia is the sum of squared distances from the acoustic_centre_of_mass weighted by the volume backscattering coefficient at each distance and normalized by the total area backscattering coefficient. Volume backscattering coefficient is the linear form of acoustic_volume_backscattering_strength_in_sea_water. Area backscattering coefficient is the integral of the volume backscattering coefficient over a defined distance. For further details see Urmy et. al (2012) doi:10.1093/icesjms/fsr205 and Bez and Rivoirard (2001) doi:10.1016/S0165-7836(00)00241-1.
acoustic_index_of_aggregation_in_sea_water
Unit: m-1
Unit ref: UPRM
Acoustic index of aggregation is the depth integral of squared volume backscattering coefficient divided by the squared area backscattering coefficient. Volume backscattering coefficient is the linear form of acoustic_volume_backscattering_strength_in_sea_water. Area backscattering coefficient is the integral of the volume backscattering coefficient over a defined distance. The parameter is computed to provide a value that represents the patchiness of biomass in the water column in the field of fisheries acoustics - the value is high when small areas are much denser than the rest of the distribution. The parameter is also the reciprocal of acoustic_equivalent_area_in_sea_water. For further details see Urmy et. al (2012) doi:10.1093/icesjms/fsr205 and Woillez et. al (2007) doi.org/10.1093/icesjms/fsm025.
product_of_wind_speed_and_water_vapor_saturation_deficit_in_air
Unit: Pa m s-1
Unit ref: PAMS
The product of windspeed and vapor pressure deficit is referred to as the Hot-Dry-Windy Index (HDW) for interpreting fire weather. It is a fire weather index that indicates the influence that the atmosphere has on a fire through wind, heat, and moisture (cf. https://www.bia.gov/sites/default/files/dup/assets/public/pdf/idc-020513.pdf). The units of HDW do not have an established physical significance for fire processes. As a fire weather index, it should be expressed in units of hPa m s-1.
nfdrs_1_hour_fuel_moisture
Unit: %
Unit ref: UPCT
1 hour fuel moisture (FM1) represents the modeled moisture content of dead fuels consisting of herbaceous plants or roundwood less than one-quarter inch in diameter. It also includes the uppermost layer of litter on the forest floor. The 1-hour timelag fuel moisture is a function of length of day (as influenced by latitude and calendar date), daily downwelling shortwave radiation, daily maximum temperature and minimum relative humidity, and daily precipitation values. It is a component in the US National Fire Danger Rating System (cf. https://www.bia.gov/sites/default/files/dup/assets/public/pdf/idc-020513.pdf). The US National Fire Danger Rating System comprises several numeric indexes that rate the potential over a large area for wildland fires to ignite, spread, and require action to suppress or manage. It was designed for use in the continental United States, and all its components are relative, not absolute .
surface_upwelling_longwave_flux_in_air_assuming_clear_sky_and_reference_mole_fraction_of_ozone_in_air
Unit: W/m2
Unit ref: UFAA
The surface called "surface" means the lower boundary of the atmosphere. The term "longwave" means longwave radiation. Upwelling radiation is radiation from below. It does not mean "net upward". The sign convention is that "upwelling" is positive upwards and "downwelling" is positive downwards. 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. 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. "Clear sky" means in the absence of clouds. The 3D ozone field acts as a reference ozone field in a diagnostic call to the model's radiation scheme. It is expressed in terms of mole fraction of ozone in air. It may be observation-based or model-derived. It may be from any time period. By using the same ozone reference in the diagnostic radiation call in two model simulations and calculating differences between the radiative flux diagnostics from the prognostic call to the radiation scheme and the diagnostic call to the radiation scheme with the ozone reference, an instantaneous radiative forcing for ozone can be calculated.
modis_cloud_area_fraction
Unit: 1
Unit ref: UUUU
The MODIS cloud area fraction is diagnosed from atmosphere model output by the MODIS simulator software in such a way as to be comparable with the observational diagnostics of MODIS (Moderate Resolution Imaging Spectroradiometer). Cloud area fraction is also called “cloud amount” and “cloud cover.” As seen from above, mean fraction of grid column occupied by cloud of optical depths and heights specified by the tau and pressure intervals given above. Dimensions of the histogram are cloud top pressure and cloud optical depth. To distinguish that these are cloud area fractions as seen by a specific satellite instrument simulator, not the same as cloud area fractions diagnosed by the native model, the prefix format of satellite name_ is employed. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion.
modis_liquid_topped_cloud_area_fraction
Unit: 1
Unit ref: UUUU
Liquid means liquid-topped clouds, as seen by the MODIS simulator. To distinguish that these are cloud area fractions as seen by a specific satellite instrument simulator, not the same as cloud area fractions diagnosed by the native model, the prefix format of satellite name_ is employed. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion.
spectral_width_of_radio_wave_in_air_scattered_by_air
Unit: Hz
Unit ref: UTHZ
Frequency width of the radio wave, that was transmitted by an instrument and propagates in the air where it's scattered by the air due to which its properties change, and it is received by an instrument. The "instrument" (examples are radar and lidar) is the device used to make the observation. The "scatterers" are what causes the transmitted signal to be returned to the instrument (examples are aerosols, hydrometeors and refractive index irregularities in the air). A standard name referring to frequency spectra width of the signal received at the instrument.
ocean_dynamic_sea_level
Unit: m
Unit ref: ULAA
Ocean dynamic sea level is the contribution to sea surface height variability made by processes other than astronomic forcing of the ocean and shallow water resonance of tidal components, or variations in air pressure. Sea surface height is a time-varying quantity.
change_in_sea_surface_height_due_to_change_in_air_pressure
Unit: m
Unit ref: ULAA
Sea surface height is a time-varying quantity. 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.
modis_ice_topped_cloud_area_fraction
Unit: 1
Unit ref: UUUU
Ice means ice-topped clouds, as seen by the MODIS simulator. To distinguish that these are cloud area fractions as seen by a specific satellite instrument simulator, not the same as cloud area fractions diagnosed by the native model, the prefix format of satellite name_ is employed. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion.
acoustic_centre_of_mass_in_sea_water
Unit: m
Unit ref: ULAA
Acoustic centre of mass is the average of all sampled depths weighted by their volume backscattering coefficient. Volume backscattering coefficient is the linear form of acoustic_volume_backscattering_strength_in_sea_water. For further details see Urmy et. al (2012) doi:10.1093/icesjms/fsr205.
acoustic_proportion_occupied_in_sea_water
Unit: 1
Unit ref: UUUU
Acoustic proportion occupied is occupied volume divided by the volume sampled. Occupied volume is the integral of the ratio of acoustic_volume_backscattering_strength_in_sea_water above -90 dB to the reference value, 1 m2 m-2. For further details see Urmy et. al (2012) doi:10.1093/icesjms/fsr205.
change_in_mean_sea_level_wrt_solid_surface
Unit: m
Unit ref: ULAA
The change in local mean sea level relative to the local solid surface, i.e. sea floor. The abbreviation "wrt" means "with respect to". A positive value means sea level rise.
mass_concentration_of_pm10_ammonium_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for ammonium is NH4+.
mass_concentration_of_pm10_chloride_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for chloride is Cl-.
upward_heat_flux_at_base_of_grounded_ice_sheet
Unit: W m-2
Unit ref: UFAA
In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Upward" indicates a vector component which is positive when directed upward (negative downward). "Grounded ice sheet" indicates where the ice sheet rests over bedrock and is thus grounded. It excludes ice-caps, glaciers and floating ice shelves. The quantity with standard name upward_heat_flux_at_base_of_grounded_ice_sheet is the upward heat flux at the interface between the ice and bedrock. It does not include any heat flux from the ocean into an ice shelf.
area_fraction_of_day_defined_by_solar_zenith_angle
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. A coordinate variable of solar_zenith_angle indicating the day extent should be specified. Solar zenith angle is the the angle between the line of sight to the sun and the local vertical.
sea_water_volume_fraction
Unit: 1
Unit ref: UUUU
"X_volume_fraction" means the fraction of volume occupied by X. It is evaluated as the volume of interest divided by the grid cell volume. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. A data variable with standard name sea_water_volume_fraction is used to store the fraction of a grid cell underlying sea-water, for example, where part of the grid cell is occupied by land or to record ocean volume on a model's native grid following a regridding operation.
grounded_ice_sheet_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Grounded ice sheet" indicates where the ice sheet rests over bedrock and is thus grounded. It excludes ice-caps, glaciers and floating ice shelves.
burned_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Burned area" means the area of burned vegetation.
gross_rate_of_increase_in_area_fraction
Unit: s-1
Unit ref: PRSC
The "rate of increase in area fraction" is the fraction of a grid cell that transitions to a given area type per unit time, for example, as a result of land use changes. The quantity described by this standard name is a gross increase because it includes only land where the use transitions to the given area type and excludes land that transitions away from that area type during the same period. The area type should be specified using a coordinate or scalar coordinate variable with standard name area_type. There is also a standard name for gross_rate_of_decrease_in_area_fraction. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction.
clear_sky_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The clear_sky area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. "Clear sky" means in the absence of clouds.
convective_cloud_area_fraction
Unit: 1
Unit ref: UUUU
GRIB: 72 E185
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names also exist for high, medium and low cloud types. Convective cloud is that produced by the convection schemes in an atmosphere model. Cloud area fraction is also called "cloud amount" and "cloud cover".
convective_cloud_area_fraction_in_atmosphere_layer
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Standard names also exist for high, medium and low cloud types. Convective cloud is that produced by the convection schemes in an atmosphere model. Cloud area fraction is also called "cloud amount" and "cloud cover".
fog_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Fog means water droplets or minute ice crystals close to the surface which reduce visibility in air to less than 1000m.
fraction_of_time_with_sea_ice_area_fraction_above_threshold
Unit: 1
Unit ref: UUUU
"Fraction of time" is the fraction of a time period defined by the bounds of the time coordinate variable for which a characteristic of interest exists. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. The area threshold value must be specified by supplying a coordinate variable or scalar coordinate variable with the standard name of sea_ice_area_fraction. "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs.
floating_ice_shelf_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. A "floating ice shelf", sometimes called a "floating ice sheet", indicates where an ice sheet extending from a land area flows over sea water.
gross_rate_of_decrease_in_area_fraction
Unit: s-1
Unit ref: PRSC
The "gross rate of decrease in area fraction" is the fraction of a grid cell that transitions from a given area type per unit time, for example, as a result of land use changes. The quantity described by this standard name is a gross decrease because it includes only land where the use transitions away from the given area type and excludes land that transitions to that area type during the same period. The area type should be specified using a coordinate of scalar coordinate variable with standard name area_type. There is also a standard name for gross_rate_of_increase_in_area_fraction. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction.
high_type_cloud_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. High type clouds are: Cirrus, Cirrostratus, Cirrocumulus. X_type_cloud_area_fraction is generally determined on the basis of cloud type, though Numerical Weather Prediction (NWP) models often calculate them based on the vertical location of the cloud. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Cloud area fraction is also called "cloud amount" and "cloud cover".
surface_snow_area_fraction
Unit: 1
Unit ref: UUUU
AMIP: snc
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Surface snow refers to the snow on the solid ground or on surface ice cover, but excludes, for example, falling snowflakes and snow on plants.
tendency_of_sea_ice_area_fraction_due_to_ridging
Unit: s-1
Unit ref: PRSC
The phrase "tendency_of_X" means derivative of X with respect to time. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called "sea ice concentration". "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. 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. Sea ice "ridging" occurs in rough sea conditions. The motion of the sea surface can cause areas of sea ice to deform and fold resulting in ridged upper and lower surfaces. The ridges can be as much as twenty metres thick if thick ice is deformed.
ice_cloud_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names also exist for high, medium and low cloud types. Cloud area fraction is also called "cloud amount" and "cloud cover".
cloud_area_fraction
Unit: 1
Unit ref: UUUU
AMIP: clt
GRIB: 71 E164
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names also exist for high, medium and low cloud types. Cloud area fraction is also called "cloud amount" and "cloud cover".
ice_cloud_area_fraction_in_atmosphere_layer
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be "model_level_number", but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Standard names also exist for high, medium and low cloud types. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Cloud area fraction is also called "cloud amount" and "cloud cover".
cloud_area_fraction_in_atmosphere_layer
Unit: 1
Unit ref: UUUU
AMIP: cl
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Standard names also exist for high, medium and low cloud types. Cloud area fraction is also called "cloud amount" and "cloud cover".
isccp_cloud_area_fraction
Unit: 1
Unit ref: UUUU
AMIP: clisccp
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names also exist for high, medium and low cloud types. 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). Cloud area fraction is also called "cloud amount" and "cloud cover".
land_area_fraction
Unit: 1
Unit ref: UUUU
AMIP: sftlf
GRIB: 81
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction.
land_ice_area_fraction
Unit: 1
Unit ref: UUUU
AMIP: sftgif
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Land ice" means glaciers, ice-caps and ice-sheets resting on bedrock and also includes ice-shelves.
liquid_water_cloud_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names also exist for high, medium and low cloud types. "Cloud area fraction is also called "cloud amount" and "cloud cover".
liquid_water_cloud_area_fraction_in_atmosphere_layer
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be "model_level_number", but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Standard names also exist for high, medium and low cloud types. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Cloud area fraction is also called "cloud amount" and "cloud cover".
low_type_cloud_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Low type clouds are: Stratus, Stratocumulus, Cumulus, Cumulonimbus. X_type_cloud_area_fraction is generally determined on the basis of cloud type, though Numerical Weather Prediction (NWP) models often calculate them based on the vertical location of the cloud. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Cloud area fraction is also called "cloud amount" and "cloud cover".
medium_type_cloud_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Middle type clouds are: Altostratus, Altocumulus, Nimbostratus. X_type_cloud_area_fraction is generally determined on the basis of cloud type, though Numerical Weather Prediction (NWP) models often calculate them based on the vertical location of the cloud. For the cloud area fraction between specified levels in the atmosphere, standard names including "cloud_area_fraction_in_atmosphere_layer" are used. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. Cloud area fraction is also called "cloud amount" and "cloud cover".
received_power_of_radio_wave_scattered_by_air
Unit: W
Unit ref: WATT
The "instrument" (examples are radar and lidar) is the device used to make the observation. 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. A standard name referring to the recieved power of the signal at the instrument.
spectral_width_of_radio_wave_scattered_by_air
Unit: Hz
Unit ref: UTHZ
The "instrument" (examples are radar and lidar) is the device used to make the observation. 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. A standard name referring to frequency width of the received signal.
radio_signal_roundtrip_travel_time_in_air
Unit: s
Unit ref: UTBB/
The "instrument" (examples are radar and lidar) is the device used to make the observation. 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. A standard name referring to time taken for a signal to propagate from the emitting instrument to a reflecting volume and back again to the instrument.
nfdrs_10_hour_fuel_moisture
Unit: %
Unit ref: UPCT
10 hour fuel moisture (FM10) represents the modeled moisture content of dead fuels consisting of roundwood in the size range of one quarter to 1 inch in diameter and very roughly, the layer of litter extending from just below the surface to three-quarters of inch below the surface. The 10-hour timelag fuel moisture is a function of length of day (as influenced by latitude and calendar date), daily downwelling shortwave radiation, daily maximum temperature and minimum relative humidity, and daily precipitation values. It is a component in the US National Fire Danger Rating System (cf. https://www.bia.gov/sites/default/files/dup/assets/public/pdf/idc-020513.pdf). The US National Fire Danger Rating System comprises several numeric indexes that rate the potential over a large area for wildland fires to ignite, spread, and require action to suppress or manage. It was designed for use in the continental United States, and all its components are relative, not absolute.
mass_concentration_of_pm10_nitrate_dry_aerosol_particles_in_air
Unit: kg m-3
Unit ref: UKMC
"Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Aerosol" means the system of suspended liquid or solid particles in air (except cloud droplets) and their carrier gas, the air itself. Aerosol particles take up ambient water (a process known as hygroscopic growth) depending on the relative humidity and the composition of the particles. "Dry aerosol particles" means aerosol particles without any water uptake. "Pm10 aerosol" means atmospheric particulate compounds with an aerodynamic diameter of less than or equal to 10 micrometers. The chemical formula for the nitrate anion is NO3-.
sea_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction.
snow_area_fraction_viewable_from_above
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Snow "viewable from above" refers to the snow on objects or the ground as viewed from above, which excludes, for example, falling snow flakes and snow obscured by a canopy, vegetative cover, or other features resting on the surface.
tendency_of_sea_ice_area_fraction_due_to_thermodynamics
Unit: s-1
Unit ref: PRSC
The phrase "tendency_of_X" means derivative of X with respect to time. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called "sea ice concentration". "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. 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. "Sea ice thermodynamics" refers to the addition or subtraction of mass due to surface and basal fluxes.
vegetation_area_fraction
Unit: 1
Unit ref: UUUU
GRIB: 87
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Vegetation" means any plants e.g. trees, shrubs, grass. The term "plants" refers to the kingdom of plants in the modern classification which excludes fungi. Plants are autotrophs i.e. "producers" of biomass using carbon obtained from carbon dioxide.
sea_ice_area_fraction
Unit: 1
Unit ref: UUUU
AMIP: sic
GRIB: 91
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called "sea ice concentration". "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs.
stratiform_cloud_area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. To specify which area is quantified by a variable with standard name area_fraction, provide a coordinate variable or scalar coordinate variable with standard name area_type. Alternatively, if one is defined, use a more specific standard name of X_area_fraction for the fraction of horizontal area occupied by X. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). Cloud area fraction is also called "cloud amount" and "cloud cover".
stratiform_cloud_area_fraction_in_atmosphere_layer
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Standard names also exist for high, medium and low cloud types. Standard names referring only to "cloud_area_fraction" should be used for quantities for the whole atmosphere column. In an atmosphere model, stratiform cloud is that produced by large-scale convergence (not the convection schemes). Cloud area fraction is also called "cloud amount" and "cloud cover".
tendency_of_sea_ice_area_fraction_due_to_dynamics
Unit: s-1
Unit ref: PRSC
The phrase "tendency_of_X" means derivative of X with respect to time. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. Sea ice area fraction is area of the sea surface occupied by sea ice. It is also called "sea ice concentration". "Sea ice" means all ice floating in the sea which has formed from freezing sea water, rather than by other processes such as calving of land ice to form icebergs. 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. "Sea ice dynamics" refers to the motion of sea ice.
area_fraction
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. To specify which area is quantified by a variable with standard name area_fraction, provide a coordinate variable or scalar coordinate variable with standard name area_type. Alternatively, if one is defined, use a more specific standard name of X_area_fraction for the fraction of horizontal area occupied by X.
area_fraction_of_night_defined_by_solar_zenith_angle
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. A coordinate variable of solar_zenith_angle indicating the day extent should be specified. Solar zenith angle is the the angle between the line of sight to the sun and the local vertical.
area_fraction_of_twilight_defined_by_solar_zenith_angle
Unit: 1
Unit ref: UUUU
"Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area, or if the cell_methods restricts the evaluation to some portion of that grid cell (e.g. "where sea_ice"), then it is the area of interest divided by the area of the identified portion. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. A coordinate variable of solar_zenith_angle indicating the day extent should be specified. Solar zenith angle is the the angle between the line of sight to the sun and the local vertical.