relative_humidity2vmr

typhon.physics.relative_humidity2vmr(RH, p, T, e_eq=None)

Convert relative humidity into water vapor VMR.

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

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:

• RH (float or ndarray) – Relative humidity.

• p (float or ndarray) – Pressue [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:

Volume mixing ratio [unitless].

Return type:

float or ndarray

See also

vmr2relative_humidity()

Complement function (returns RH for given VMR).

e_eq_water_mk()

Used to calculate the equilibrium water vapor pressure.

Examples

>>> relative_humidity2vmr(0.75, 101300, 300)
0.026185323887350429