earthkit.meteo.thermo.fieldlist.specific_humidity_from_relative_humidity

earthkit.meteo.thermo.fieldlist.specific_humidity_from_relative_humidity(t, r, p=None)

Compute the specific humidity from relative humidity.

Parameters:

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

  • r (FieldList|Field) – Relative humidity (%).

  • p (FieldList|Field|Iterable[float]|float|None) – Pressure (Pa). If None, inferred from the field metadata.

Returns:

Specific humidity (kg/kg). The result has the same type as the input t and r (FieldList or Field).

Return type:

FieldList|Field

The computation starts with determining the vapour pressure:

\[e(q, p) = r \frac{e_{msat}(t)}{100}\]

where:

  • \(e\) is the vapour pressure (see vapour_pressure())

  • \(e_{msat}\) is the saturation_vapour_pressure() based on the “mixed” phase

  • \(q\) is the specific humidity

Then \(q\) is computed from \(e\) using specific_humidity_from_vapour_pressure().