Term: temperature_difference_between_ambient_air_and_air_lifted_adiabatically_from_the_surface

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

This quantity is defined as the temperature difference between a parcel of air lifted adiabatically from the surface to a finishing air pressure in the troposphere and the ambient air temperature at the finishing air pressure in the troposphere. It is often called the lifted index (LI) and provides a measure of the instability of the atmosphere. The air parcel is "lifted" by moving the air parcel from the surface to the Lifting Condensation Level (dry adiabatically) and then from the Lifting Condensation Level to the finishing air pressure (wet adiabatically). Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The term "surface" means the lower boundary of the atmosphere. A coordinate variable of final_air_pressure_of_lifted_parcel should be specified to indicate the specific air pressure that the temperature difference is calculated at.

Term: temperature_difference_between_ambient_air_and_air_lifted_adiabatically_from_the_surface

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

This quantity is defined as the temperature difference between a parcel of air lifted adiabatically from the surface to a finishing air pressure in the troposphere and the ambient air temperature at the finishing air pressure in the troposphere. It is often called the lifted index (LI) and provides a measure of the instability of the atmosphere. The air parcel is "lifted" by moving the air parcel from the surface to the Lifting Condensation Level (dry adiabatically) and then from the Lifting Condensation Level to the finishing air pressure (wet adiabatically). Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The term "surface" means the lower boundary of the atmosphere. A coordinate variable of final_air_pressure_of_lifted_parcel should be specified to indicate the specific air pressure that the temperature difference is calculated at. It is strongly recommended to include a units_metadata attribute.

Term: temperature_difference_between_ambient_air_and_air_lifted_adiabatically_from_the_surface

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

This quantity is defined as the temperature difference between a parcel of air lifted adiabatically from the surface to a finishing air pressure in the troposphere and the ambient air temperature at the finishing air pressure in the troposphere. It is often called the lifted index (LI) and provides a measure of the instability of the atmosphere. The air parcel is "lifted" by moving the air parcel from the surface to the Lifting Condensation Level (dry adiabatically) and then from the Lifting Condensation Level to the finishing air pressure (wet adiabatically). Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The term "surface" means the lower boundary of the atmosphere. A coordinate variable of final_air_pressure_of_lifted_parcel should be specified to indicate the specific air pressure that the temperature difference is calculated at. 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. units_metadata="temperature: difference" means that the temperature quantity is the difference between two temperatures, so the origin of the scale is irrelevant, and only the unit of measure matters. It is strongly recommended to include the attribute units_metadata="temperature: difference".

Term: temperature_difference_between_ambient_air_and_air_lifted_adiabatically_from_the_surface

Unit: K

Unit ref: UPKA

AMIP:

GRIB:

This quantity is defined as the temperature difference between a parcel of air lifted adiabatically from the surface to a finishing air pressure in the troposphere and the ambient air temperature at the finishing air pressure in the troposphere. It is often called the lifted index (LI) and provides a measure of the instability of the atmosphere. The air parcel is "lifted" by moving the air parcel from the surface to the Lifting Condensation Level (dry adiabatically) and then from the Lifting Condensation Level to the finishing air pressure (wet adiabatically). Air temperature is the bulk temperature of the air, not the surface (skin) temperature. The term "surface" means the lower boundary of the atmosphere. A coordinate variable of final_air_pressure_of_lifted_parcel should be specified to indicate the specific air pressure that the temperature difference is calculated at. It is strongly recommended that a variable with this standard name should have the attribute units_metadata="temperature: difference", meaning that it refers to temperature differences and implying that the origin of the temperature scale is irrelevant, because it is essential to know whether a temperature is on-scale or a difference in order to convert the units correctly (cf. https://cfconventions.org/cf-conventions/cf-conventions.html#temperature-units).