bigleaf (version 0.7.0)

isothermal.Rn: Isothermal Net Radiation

Description

Calculates the isothermal net radiation, i.e. the net radiation that the surface would receive if it had the same temperature than the air.

Usage

isothermal.Rn(data, Rn = "Rn", Tair = "Tair", Tsurf = "Tsurf",
  emissivity, constants = bigleaf.constants())

Arguments

data

Data.frame or matrix containing all required variables

Rn

Net radiation (W m-2)

Tair

Air temperature (degC)

Tsurf

Surface temperature (degC)

emissivity

Emissivity of the surface (-)

constants

sigma - Stefan-Boltzmann constant (W m-2 K-4) Kelvin - conversion degree Celsius to Kelvin

Value

Rni -

isothermal net radiation (W m-2)

Details

The isothermal net radiation (Rni) is given by:

$$Rni = Rn + \epsilon * \sigma * (Tsurf^4 - Tair^4)$$

where \(\epsilon\) is the emissivity of the surface. Tsurf and Tair are in Kelvin.

References

Jones, H. 2014: Plants and Microclimate. 3rd edition, Cambridge University Press.

Examples

# NOT RUN {
# calculate isothermal net radiation of a surface that is 2degC warmer than the air.
isothermal.Rn(Rn=400,Tair=25,Tsurf=27,emissivity=0.98) 

# }