ExAtRa {ClimClass} | R Documentation |
Extra-Atmospheric Radiation
Description
Calculates Extra-Atmospheric Radiation. Called by function arid
for Thornthwaite's index.
Usage
ExAtRa(DOY, latitude, Gsc = 0.082, unit = "mm", T = 12)
Arguments
DOY |
day of the year. |
latitude |
latitude in degrees (negative for S emishpere). |
Gsc |
solar constant in MJ m-2 min-1 (default: 0.0820). |
unit |
unit for solar radiation. Accepted values are "mm" and "MJ". |
T |
temperature in degrees C. Default is 12. |
Details
If unit
= "mm", the calculated value represents the water height evaporated by solar radiation, calculated by the latent heat for vaporization. Otherwise (unit
= "MJ") output is the solar radiation energy in MJ.
Temperature T
is used only for the assessment of latent heat of vaporization, when unit
= "mm".
Value
The daily extra-atmospheric solar radiation energy, espressed either in MJ or in mm of evaporated water.
Author(s)
Emanuele Eccel
See Also
Examples
data(Trent_climate)
# creates a vector with middle days for every month in a year
quinci <- paste(15,"/",1:12,"/",2014,sep="")
posixlt <- strptime(quinci, format="%d/%m/%Y")
yDay <- posixlt$yday+1 # field yday starts from 0
latitude<-46
# generates 12 values, one for each month
coeff_rad<- ExAtRa(DOY=yDay,latitude=latitude, unit="mm")
[Package ClimClass version 2.1.0 Index]