virtual.temp {bigleaf}

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 (-)

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.

Value

Tv -

virtual temperature (deg C)

References

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

Examples

virtual.temp(25,100,1.5)