rafthetae − computes equivalent potential temperature using Emanuel formula as well as saturation mixing ratio
rafthetae −d|q pressure temperature dewpoint|mixing_ratio equiv_pot_temp sat_mixing_ratio [liq_water]
Rafthetae computes equivalent potential temperature (K) from the pressure (mb), temperature (C), either dewpoint (C) or water vapor mixing ratio (g/kg), and optionally, the liquid water content (g/m^3). The flag -d indicates dewpoint is expected, while -q indicates that mixing ratio is expected. The first three command line arguments, and optionally the last, indicate the names of the respective variable fields in the Candis file expected on the standard input. The result is written to the standard output with the equivalent potential temperature named in the fifth command line argument and the saturation mixing ratio in the sixth argument. The formula for equivalent potential temperature is due to Kerry Emanuel of MIT.
The effect of liquid water content is generally small.
The dewpoint is not allowed to exceed the temperature and the mixing ratio is not allowed to exceed the saturation mixing ratio. Some would consider this to be a feature.
The new fields have the same size and shape as the pressure field. The program checks the temperature, mixing ratio, and liquid water content fields only for compatible size with the pressure field, not for compatible shape.