relative_humidity_wet_psychrometric#

metpy.calc.relative_humidity_wet_psychrometric(pressure, dry_bulb_temperature, wet_bulb_temperature, **kwargs)[source]#

Calculate the relative humidity with wet bulb and dry bulb temperatures.

This uses a psychrometric relationship as outlined in [WMO8], with coefficients from [Fan1987].

Parameters:
Returns:

pint.Quantity – Relative humidity

Examples

>>> from metpy.calc import relative_humidity_wet_psychrometric
>>> from metpy.units import units
>>> relative_humidity_wet_psychrometric(1000 * units.hPa, 19 * units.degC,
...                                     10 * units.degC).to('percent')
<Quantity(30.4311332, 'percent')>

Notes

\[RH = \frac{e}{e_s}\]
  • \(RH\) is relative humidity as a unitless ratio

  • \(e\) is vapor pressure from the wet psychrometric calculation

  • \(e_s\) is the saturation vapor pressure

Changed in version 1.0: Changed signature from (dry_bulb_temperature, web_bulb_temperature, pressure, **kwargs)