Estimates downward facing longwave radiation (W/m2) using a relationship derived from Gabathuler et al 2001
Usage
Lw(Ta = 20, RH = 0.5, n = 0.5)
Arguments
Ta
Local air temperature (degrees Celsius), ~ 2 m above ground
RH
Local relative humidity (fractional value from 0 to 1)
n
Fractional cloud cover (fractional value from 0 to 1)
Value
A value, vector of length one, corresponding to the incoming longwave radiation, units: W/m2.
Details
An alternative to Ld() for estimating incoming radiation by determining an offset temperature to account for the influence of atmospheric transmission loss. The incoming infrared radiation is estimated using the Stephan-Boltzmann relationship:
emissivity*Stephan Boltzmann constant*T^4
References
Gabathuler et al 2001. Parameterization of incoming longwave radiation in high mountain environments. Physical Geography 22: 99-114