bigleaf (version 0.8.2)

psychrometric.constant: Psychrometric Constant

Description

Calculates the psychrometric 'constant'.

Usage

psychrometric.constant(Tair, pressure, constants = bigleaf.constants())

Value

\(\gamma\) - the psychrometric constant (kPa K-1)

Arguments

Tair

Air temperature (deg C)

pressure

Atmospheric pressure (kPa)

constants

cp - specific heat of air for constant pressure (J K-1 kg-1)
eps - ratio of the molecular weight of water vapor to dry air (-)

Details

The psychrometric constant (\(\gamma\)) is given as:

$$\gamma = cp * pressure / (eps * \lambda)$$

where \(\lambda\) is the latent heat of vaporization (J kg-1), as calculated from latent.heat.vaporization.

References

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

Examples

psychrometric.constant(seq(5,45,5),100)