Thermimage (version 2.1)

Lu: Estimates upward facing ground radiation (W/m2)

Description

Estimates upward facing ground radiation (W/m2), from the Stephan Boltzmann relationship and ground temperature

Usage

Lu(Tg = 20, Eground = 0.97)

Arguments

Tg

Ground temperature (degrees celsius)

Eground

Emissivity of soil or ground. Default value is 0.97.

Value

• A value, vector of length one, corresponding to the longwave radiation from the ground, units: W/m2.

Details

Calculates ground radiation facing upward. Assumes ground emissivity = 0.97. Terrain emissivities vary from 0.89 (sand, snow) to 0.97 (moist soil) - Blaxter, 1986

References

Blaxter, 1986. Energy metabolism in animals and man. Cambridge University Press, Cambridge, UK, 340 pp.

See Also

Ld

Examples

## The function is currently defined as
function (Tg = 20, Eground = 0.97) 
{
    GT <- Tg + 273.15
    Lu <- Eground * StephBoltz() * (GT)^4
    Lu
  }

# Estimates ground generated longwave radiation rising up.  Units W/m2.
# Example calculation:
Tg<-30
Eground<-0.97
Lu(Tg, Eground)