Potential Temperature

Performs a variable conversion from temperature and pressure to potential temperature.

Transform: PotentialTFromT

obs filters:
- filter: Variable Transforms
  Transform: PotentialTFromT

Observation parameters needed (JEDI name)

• airTemperature ($T$)

• pressure ($P$)

The potential temperature ($\theta$) is calculated as follows:

$$\theta =(P_F/P{)}^{\kappa }\times T$$

where

$$\kappa =R_d/C_p$$

and $P_F$ is the reference surface pressure.

Note: the error on $\theta$ is set to the error on $T$ scaled by the conversion factor $(P_F/P{)}^{\kappa }$.

Filter optional parameters

This filter allows the user to set specified names for input and output variables (defaults are IODA naming conventions):

• pressure variable (default: pressure)

• temperature variable (default: airTemperature)

• potential temperature variable (default: potentialTemperature)