relative_humidity_from_mixing_ratio

metpy.calc.relative_humidity_from_mixing_ratio(pressure, temperature, mixing_ratio)

Calculate the relative humidity from mixing ratio, temperature, and pressure.

Parameters

• pressure (pint.Quantity) – Total atmospheric pressure

• temperature (pint.Quantity) – Air temperature

• mixing_ratio (pint.Quantity) – Dimensionless mass mixing ratio

Returns

pint.Quantity – Relative humidity

Examples

>>> from metpy.calc import relative_humidity_from_mixing_ratio
>>> from metpy.units import units
>>> relative_humidity_from_mixing_ratio(1013.25 * units.hPa,
...                                     30 * units.degC, 18/1000).to('percent')
<Quantity(66.1763544, 'percent')>

See also

mixing_ratio_from_relative_humidity, saturation_mixing_ratio

Notes

Formula based on that from [Hobbs1977] pg. 74.

\[rh = \frac{w}{w_s}\]

• \(rh\) is relative humidity as a unitless ratio

• \(w\) is mixing ratio

• \(w_s\) is the saturation mixing ratio

Changed in version 1.0: Changed signature from (mixing_ratio, temperature, pressure)

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