atmosphere_stability_showalter_index

complete
Created: Feb. 5, 2024
Proposer: Jonathan Gregory & Lars Barring
Proposed Date: 2024-01-10
#270
Change Date: Feb. 5, 2024, 2:53 p.m.
Term: atmosphere_stability_showalter_index
Unit: K
Unit ref: UPKA
AMIP:
GRIB:
The atmosphere_stability_showalter_index is an index used to determine convective and thunderstorm potential and is often referred to as simply the showalter index. The index is defined as the temperature difference between a parcel of air lifted from 850 to 500 hPa (wet adiabatically) and the ambient air temperature at 500 hPa.
Change Date: Feb. 5, 2024, 2:54 p.m.
Term: atmosphere_stability_showalter_index
Unit: K
Unit ref: UPKA
AMIP:
GRIB:
The atmosphere_stability_showalter_index is an index used to determine convective and thunderstorm potential and is often referred to as simply the showalter index. The index is defined as the temperature difference between a parcel of air lifted from 850 to 500 hPa (wet adiabatically) and the ambient air temperature at 500 hPa. It is strongly recommended to include a units_metadata attribute.
Change Date: Feb. 9, 2024, 3:46 p.m.
Term: atmosphere_stability_showalter_index
Unit: K
Unit ref: UPKA
AMIP:
GRIB:
The atmosphere_stability_showalter_index is an index used to determine convective and thunderstorm potential and is often referred to as simply the showalter index. The index is defined as the temperature difference between a parcel of air lifted from 850 to 500 hPa (wet adiabatically) and the ambient air temperature at 500 hPa. 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".
Change Date: Feb. 23, 2024, 4:20 p.m.
Term: atmosphere_stability_showalter_index
Unit: K
Unit ref: UPKA
AMIP:
GRIB:
The atmosphere_stability_showalter_index is an index used to determine convective and thunderstorm potential and is often referred to as simply the showalter index. The index is defined as the temperature difference between a parcel of air lifted from 850 to 500 hPa (wet adiabatically) and the ambient air temperature at 500 hPa. 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).