long.wave.radiation.balance: estimate long wave radiation balance for snow
In RHydro: Classes and methods for hydrological modelling and analysis

Description Usage Arguments Details Value Author(s) References Examples

estimate long wave radiation balance for snow

1	long.wave.radiation.balance(t.air, t.atm = t.air, t.snow = NULL, sigma = 4.9 * 10^-9, vap.pres, cloud.cover = 0, sky.view = 0, emiss.snow = 1)

`t.air`	zoo-object of air temperatures.
`t.atm`	zoo-object of atmosphere temperatures.
`t.snow`	zoo-object of snow temperatures.
`sigma`	Boltzman constant in MJ * 1/m^21/day1/K^4
`vap.pres`	zoo object of vapour pressure in kPa
`cloud.cover`	fraction of cloud cover (no unit)
`sky.view`	fraction of sky covered by forest (no unit)
`emiss.snow`	emissivity of snow (no unit)

All temperatures in degree C. If t.snow is set to zero, it is estimated as min(t.air - 2.5 , 0)

`L`	zoo.object of long wave radiation in MJ * 1/m^2 * 1/day
`L.in`	incoming radiation
`L.out`	from snow cover emitted radiation
`e.at`	estimated emissivity of the atmosphere

Dominik Reusser

Dingman, S. L. (2002): Physical hydrology,Waveland Press, Long Grove, Ill.

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#Example 5-7 from Dingman
long.wave.radiation.balance(t.air=4, vap.pres=0.651, sky.view=0.8, cloud.cover=0.5)
#Dingman reports 0.27 MJ * 1/m^2 * 1/day