Term: apparent_air_temperature

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The quantity with standard name apparent_air_temperature is the perceived air temperature derived from either a combination of temperature and wind (which has standard name wind_chill_of_air_temperature) or temperature and humidity (which has standard name heat_index_of_air_temperature) for the hour indicated by the time coordinate variable. When the air temperature falls to 283.15 K or below, wind chill is used for the apparent_air_temperature. When the air temperature rises above 299.817 K, the heat index is used for apparent_air_temperature. For temperatures above 283.15 and below 299.817K, the apparent_air_temperature is the ambient air temperature (which has standard name air_temperature). References: https://digital.weather.gov/staticpages/definitions.php; WMO codes registry entry http://codes.wmo.int/grib2/codeflag/4.2/_0-0-21.

Term: apparent_air_temperature

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The quantity with standard name apparent_air_temperature is the perceived air temperature derived from either a combination of temperature and wind (which has standard name wind_chill_of_air_temperature) or temperature and humidity (which has standard name heat_index_of_air_temperature) for the hour indicated by the time coordinate variable. When the air temperature falls to 283.15 K or below, wind chill is used for the apparent_air_temperature. When the air temperature rises above 299.817 K, the heat index is used for apparent_air_temperature. For temperatures above 283.15 and below 299.817K, the apparent_air_temperature is the ambient air temperature (which has standard name air_temperature). References: https://digital.weather.gov/staticpages/definitions.php; WMO codes registry entry http://codes.wmo.int/grib2/codeflag/4.2/_0-0-21. It is strongly recommended to include a units_metadata attribute.

Term: apparent_air_temperature

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The quantity with standard name apparent_air_temperature is the perceived air temperature derived from either a combination of temperature and wind (which has standard name wind_chill_of_air_temperature) or temperature and humidity (which has standard name heat_index_of_air_temperature) for the hour indicated by the time coordinate variable. When the air temperature falls to 283.15 K or below, wind chill is used for the apparent_air_temperature. When the air temperature rises above 299.817 K, the heat index is used for apparent_air_temperature. For temperatures above 283.15 and below 299.817K, the apparent_air_temperature is the ambient air temperature (which has standard name air_temperature). References: https://digital.weather.gov/staticpages/definitions.php; WMO codes registry entry http://codes.wmo.int/grib2/codeflag/4.2/_0-0-21. In order to convert the units correctly, it is essential to know whether a temperature is on-scale or a difference. Therefore this standard strongly recommends that any variable whose units involve a temperature unit should also have a units_metadata attribute to make the distinction. It is strongly recommended to include the attribute units_metadata.

Term: apparent_air_temperature

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The quantity with standard name apparent_air_temperature is the perceived air temperature derived from either a combination of temperature and wind (which has standard name wind_chill_of_air_temperature) or temperature and humidity (which has standard name heat_index_of_air_temperature) for the hour indicated by the time coordinate variable. When the air temperature falls to 283.15 K or below, wind chill is used for the apparent_air_temperature. When the air temperature rises above 299.817 K, the heat index is used for apparent_air_temperature. For temperatures above 283.15 and below 299.817K, the apparent_air_temperature is the ambient air temperature (which has standard name air_temperature). References: https://digital.weather.gov/staticpages/definitions.php; WMO codes registry entry http://codes.wmo.int/grib2/codeflag/4.2/_0-0-21. It is strongly recommended that a variable with this standard name should have a units_metadata attribute, with one of the values "on-scale" or "difference", whichever is appropriate for the data, because it is essential to know whether the temperature is on-scale (meaning relative to the origin of the scale indicated by the units) or refers to temperature differences (implying that the origin of the temperature scale is irrevelant), in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).