Estimate Incoming longwave radiation.

Estimate Incoming longwave radiation. Not included in FAO56 paper but added for convinience.

cal_Rli(
  temp,
  ea = NULL,
  s = 1,
  method = c("MAR", "SWI", "IJ", "BRU", "SAT", "KON")
)

Arguments

temp

Near surface air temperature [deg Celsius].

ea

Near surface actual vapour pressure [kPa].

s

Cloud air emissivity, the ratio between acutal incomming shortwave radiation and clear sky incoming shortwave radiation.

method

The method to esteimate the air emissivity. Must be one of 'MAR', 'SWI', 'IJ', 'BRU', 'T', and 'KON'.

Value

Incomming longwave radiation [W /m2].

References

1. Satterlund, D. R. (1979), An improved equation for estimating long-wave radiation from the atmosphere, Water Resour. Res., 15( 6), 1649– 1650, doi:10.1029/WR015i006p01649.

2. Sedlar, J., & Hock, R. (2009). Testing longwave radiation parameterizations under clear and overcast skies at Storglaciären, Sweden. The Cryosphere, 3(1), 75-84.