metpy.calc.virtual_potential_temperature(pressure, temperature, mixing, molecular_weight_ratio=<Quantity(0.6219800858985514, 'dimensionless')>)[source]

Calculate virtual potential temperature.

This calculation must be given an air parcel’s pressure, temperature, and mixing ratio. The implementation uses the formula outlined in [Markowski2010] pg.13.

  • pressure (pint.Quantity) – Total atmospheric pressure
  • temperature (pint.Quantity) – The temperature
  • mixing (pint.Quantity) – dimensionless mass mixing ratio
  • molecular_weight_ratio (pint.Quantity or float, optional) – The ratio of the molecular weight of the constituent gas to that assumed for air. Defaults to the ratio for water vapor to dry air. (\(\epsilon\approx0.622\)).

pint.Quantity – The corresponding virtual potential temperature of the parcel


\[\Theta_v = \Theta \frac{\text{w} + \epsilon}{\epsilon\,(1 + \text{w})}\]