earthkit.meteo.thermo.fieldlist.saturation_specific_humidity_slope

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

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

Parameters:

  • t (FieldList|Field) – Temperature (K).

  • p (FieldList|Field|Iterable[float]|float|None) – Pressure (Pa). If None, inferred from the field metadata of t. Otherwise, if t is a FieldList p must be a FieldList or an array-like of the same length as t. If t is a Field, p must be a single Field or a float.

  • es (FieldList|Field|None, optional) – saturation_vapour_pressure() pre-computed for the given phase (Pa). When specified, it is used in the computation instead of being computed from t and phase using saturation_vapour_pressure().

  • es_slope (FieldList|Field|None, optional) – saturation_vapour_pressure_slope() pre-computed for the given phase (Pa/K). When specified, it is used in the computation instead of being computed from t and phase using saturation_vapour_pressure_slope().

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

  • eps (float, optional) – Where p - es < eps nan is returned.

Returns:

Slope of saturation specific humidity (kg kg-1 K-1). The result has the same type as the input t (FieldList or Field).

Return type:

FieldList|Field

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