relative_humidity_wet_psychrometric

metpy.calc.relative_humidity_wet_psychrometric(pressure, dry_bulb_temperature, wet_bulb_temperature, **kwargs)

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:

• pressure (pint.Quantity) – Total atmospheric pressure

• dry_bulb_temperature (pint.Quantity) – Dry bulb temperature

• wet_bulb_temperature (pint.Quantity) – Wet bulb temperature

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')>

See also

psychrometric_vapor_pressure_wet, saturation_vapor_pressure

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)