bigleaf (version 0.7.0)

virtual.temp: Virtual Temperature

Description

Virtual temperature, defined as the temperature at which dry air would have the same density as moist air at its actual temperature.

Usage

virtual.temp(Tair, pressure, VPD, Esat.formula = c("Sonntag_1990",
  "Alduchov_1996", "Allen_1998"), constants = bigleaf.constants())

Arguments

Tair

Air temperature (deg C)

pressure

Atmospheric pressure (kPa)

VPD

Vapor pressure deficit (kPa)

Esat.formula

Optional: formula to be used for the calculation of esat and the slope of esat. One of "Sonntag_1990" (Default), "Alduchov_1996", or "Allen_1998". See Esat.slope.

constants

Kelvin - conversion degree Celsius to Kelvin eps - ratio of the molecular weight of water vapor to dry air (-)

Value

Tv -

virtual temperature (deg C)

Details

the virtual temperature is given by:

$$Tv = Tair / (1 - (1 - eps) e/pressure)$$

where Tair is in Kelvin (converted internally). Likewise, VPD is converted to actual vapor pressure (e in kPa) with VPD.to.e internally.

References

Monteith J.L., Unsworth M.H., 2008: Principles of Environmental Physics. 3rd edition. Academic Press, London.

Examples

# NOT RUN {
virtual.temp(25,100,1.5)                        
              
# }