metpy.calc.
psychrometric_vapor_pressure_wet
Calculate the vapor pressure with wet bulb and dry bulb temperatures.
This uses a psychrometric relationship as outlined in [WMO8], with coefficients from [Fan1987].
pressure (pint.Quantity) – Total atmospheric pressure
pint.Quantity
dry_bulb_temperature (pint.Quantity) – Dry bulb temperature
wet_bulb_temperature (pint.Quantity) – Wet bulb temperature
psychrometer_coefficient (pint.Quantity, optional) – Psychrometer coefficient. Defaults to 6.21e-4 K^-1.
pint.Quantity – Vapor pressure
Notes
\(e'\) is vapor pressure
\(e'_w(T_w)\) is the saturation vapor pressure with respect to water at temperature \(T_w\)
\(p\) is the pressure of the wet bulb
\(T\) is the temperature of the dry bulb
\(T_w\) is the temperature of the wet bulb
\(A\) is the psychrometer coefficient
Psychrometer coefficient depends on the specific instrument being used and the ventilation of the instrument.
Changed in version 1.0: Changed signature from (dry_bulb_temperature, wet_bulb_temperature, pressure, psychrometer_coefficient)
(dry_bulb_temperature, wet_bulb_temperature, pressure, psychrometer_coefficient)
See also
saturation_vapor_pressure