subroutine albedo !! ~ ~ ~ PURPOSE ~ ~ ~ !! this subroutine calculates albedo in the HRU for the day !! use hru_module, only : hru, ihru, albday use soil_module use plant_module use organic_mineral_mass_module implicit none real :: cej = 0. !none |constant real :: eaj = 0. !none |soil cover index integer :: j = 0 ! none |HRU number real :: cover = 0. !kg/ha |soil cover j = ihru !! calculate albedo cej = -5.e-5 cover = pl_mass(j)%ab_gr_com%m + rsd1(j)%tot_com%m eaj = Exp(cej * (cover + .1)) !! equation 2.2.16 in SWAT manual if (hru(j)%sno_mm <= .5) then !! equation 2.2.14 in SWAT manual albday = soil(j)%ly(1)%alb !! equation 2.2.15 in SWAT manual if (pcom(j)%lai_sum > 0.) albday = .23 * (1. - eaj) + soil(j)%ly(1)%alb * eaj else !! equation 2.2.13 in SWAT manual albday = 0.8 end if return end subroutine albedo