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()
)Value
- Tv -
virtual temperature (deg C)
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.
References
Monteith J.L., Unsworth M.H., 2008: Principles of Environmental Physics.
3rd edition. Academic Press, London.