geocat.comp.meteorology._relhum_water

geocat.comp.meteorology._relhum_water(t, w, p)

Calculates relative humidity with respect to water, given temperature, mixing ratio, and pressure.

Definition of mixing ratio if:

• es - is the saturation mixing ratio

• ep - is the ratio of the molecular weights of water vapor to dry air

• p - is the atmospheric pressure

• rh - is the relative humidity (given as a percent)

\[rh = 100* q / ( (ep*es)/(p-es) )\]

Notes and Correspondence: “Improved Magnus Form Approximation of Saturation Vapor Pressure” Oleg A. Alduchov and Robert E. Eskridge https://doi.org/10.1175/1520-0450(1996)035%3C0601:IMFAOS%3E2.0.CO;2

“On the Computation of Saturation Vapor Pressure” F. W. Murray https://doi.org/10.1175/1520-0450(1967)006%3C0203:OTCOSV%3E2.0.CO;2

Parameters:

• t (xarray.DataArray, numpy.ndarray, list, float) – Temperature in Kelvin

• w (xarray.DataArray, numpy.ndarray, list, float) – Mixing ratio in kg/kg. Must have the same dimensions as temperature

• p (xarray.DataArray, numpy.ndarray, list, float) – Pressure in Pa. Must have the same dimensions as temperature

Returns:

rh (xarray.DataArray, numpy.ndarray) – Relative humidity. Will have the same dimensions as temperature

See also

Related GeoCAT Functions: relhum() relhum_ice() relhum_water() _xrelhum()

Related NCL Functions: relhum, relhum_ttd, relhum_ice, relhum_water