vaporpressure: Vapor pressure

In meteor: Meteorological Data Manipulation

Vapor pressure

Description

Functions to compute the saturated vapor pressure (SVP), actual vapor pressure (VP), and vapor pressure deficit (VPD) in Pascal or the dew-point temperature in C.

For temperature < 0C the saturation vapour pressure equation for ice is used according to Goff and Gratch (1946), whereas for temperature >=0C that of Goff (1957) is used.

Usage

SVP(temp)
VP(temp, relh)
VPD(temp, relh)
tDew(temp, relh)

Arguments

temp	numeric. Temperature in degrees C
relh	relative humidity (percent)

Value

numeric vector (Pascal).

Author(s)

Robert Hijmans, partly based on Python meteolib by Maarten J. Waterloo and J. Delsman http://python.hydrology-amsterdam.nl/

References

Goff, J.A.,and S. Gratch, 1946. Low-pressure properties of water from -160 to 212 F. Transactions of the American society of heating and ventilating engineers, p. 95-122, presented at the 52nd annual meeting of the American society of heating and ventilating engineers, New York, USA.

Goff, J. A. 1957. Saturation pressure of water on the new Kelvin temperature scale, Transactions of the American society of heating and ventilating engineers, pp 347-354, presented at the semi-annual meeting of the American society of heating and ventilating engineers, Murray Bay, Quebec, Canada.

Examples

temperature <- seq(-10,30,10)
SVP(temperature)
VP(temperature, 60)
VPD(temperature, 60)
tDew(temperature, 60)

meteor documentation built on July 26, 2023, 5:16 p.m.