vmr2relative_humidity

typhon.physics.vmr2relative_humidity(vmr, p, T, e_eq=None)

Convert water vapor VMR into relative humidity.

$$\mathrm{RH}=\frac{x\cdot p}{e_s(T)}$$

Note

By default, the relative humidity is calculated with respect to saturation over liquid water in accordance to the WMO standard for radiosonde observations. You can use e_eq_mixed_mk() to calculate relative humidity with respect to saturation over the mixed-phase following the IFS model documentation.

Parameters:

• vmr (float or ndarray) – Volume mixing ratio,

• p (float or ndarray) – Pressure [Pa].

• T (float or ndarray) – Temperature [K].

• e_eq (callable) – Function to calculate the equilibrium vapor pressure of water in Pa. The function must implement the signature e_eq = f(T) where T is temperature in Kelvin. If None the function e_eq_water_mk() is used.

Returns:

Relative humidity [unitless].

Return type:

float or ndarray

See also

relative_humidity2vmr()

Complement function (returns VMR for given RH).

e_eq_water_mk()

Used to calculate the equilibrium water vapor pressure.

Examples

>>> vmr2relative_humidity(0.025, 1013e2, 300)
0.71604995533615401