metpy.calc.wet_bulb_potential_temperature(pressure, temperature, dewpoint)[source]#

Calculate wet-bulb potential temperature.

This calculation must be given an air parcel’s pressure, temperature, and dewpoint. The implementation uses the formula outlined in [DaviesJones2008]. First, theta-e is calculated then use the formula from [DaviesJones2008]

\[\theta_w = \theta_e - exp(\frac{a_0 + a_1 x + a_2 x^2 + a_3 x^3 + a_4 x^4} {1 + b_1 x + b_2 x^2 + b_3 x^3 + b_4 x^4})\]

where \(x = \theta_e / 273.15 K\).

When \(\theta_e <= -173.15 K\) then \(\theta_w = \theta_e\).


pint.Quantity – wet-bulb potential temperature of the parcel