earthkit.meteo.thermo.xarray.saturation_specific_humidity_slope

earthkit.meteo.thermo.xarray.saturation_specific_humidity_slope(t, p, es=None, es_slope=None, phase='mixed', eps=0.0001)

Compute the slope of saturation specific humidity with respect to temperature.

Parameters:

  • t (xarray.DataArray) – Temperature (K)

  • p (xarray.DataArray) – Pressure (Pa)

  • es (xarray.DataArray or None, optional) – saturation_vapour_pressure() pre-computed for the given phase (Pa)

  • es_slope (xarray.DataArray or None, optional) – saturation_vapour_pressure_slope() pre-computed for the given phase (Pa/K)

  • phase (str, optional) – Define the phase with respect to the computation will be performed. It is either “water”, “ice” or “mixed”. See saturation_vapour_pressure()

  • eps (number) – Where p - es < eps nan is returned.

Returns:

Slope of saturation specific humidity (\(kg kg^{-1} K^{-1}\))

Return type:

xarray.DataArray

The computation is based on the following formula:

\[\frac{\partial q_{s}}{\partial t} = \frac{\epsilon p}{(p+e_{s}(\epsilon - 1))^{2}} \frac{d e_{s}}{d t}\]

where