virtual_temperature#

metpy.calc.virtual_temperature(temperature, mixing_ratio, molecular_weight_ratio=0.6219569100577033)#

Calculate virtual temperature.

This calculation must be given an air parcel’s temperature and mixing ratio. The implementation uses the formula outlined in [Hobbs2006] pg.80.

Parameters:

  • temperature (pint.Quantity) – Air temperature

  • mixing_ratio (pint.Quantity) – Mass mixing ratio (dimensionless)

  • 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. (\(\epsilon\approx0.622\))

Returns:

pint.Quantity – Corresponding virtual temperature of the parcel

Examples

>>> from metpy.calc import virtual_temperature
>>> from metpy.units import units
>>> virtual_temperature(283 * units.K, 12 * units('g/kg'))
<Quantity(285.039709, 'kelvin')>

Notes

\[T_v = T \frac{\text{w} + \epsilon}{\epsilon\,(1 + \text{w})}\]

Changed in version 1.0: Renamed mixing parameter to mixing_ratio