subroutine CNNFixation(num_soilc, filter_soilc)DESCRIPTION:
On the radiation time step, update the nitrogen fixation rate as a function of annual total NPP. This rate gets updated once per year. All N fixation goes to the soil mineral N pool.
use clmtype use clm_varctl , only: iulog use clm_time_manager, only: get_days_per_year use shr_sys_mod , only: shr_sys_flush use clm_varcon , only: secspdayARGUMENTS:
implicit none integer, intent(in) :: num_soilc ! number of soil columns in filter integer, intent(in) :: filter_soilc(:) ! filter for soil columnsCALLED FROM:
subroutine CNEcosystemDyn, in module CNEcosystemDynMod.F90REVISION HISTORY:
6/1/04: Created by Peter Thornton 2/14/05, PET: After looking at a number of point simulations, it looks like a constant Nfix might be more efficient and maybe more realistic - setting to constant 0.4 gN/m2/yr.LOCAL VARIABLES:
local pointers to implicit in scalars real(r8), pointer :: cannsum_npp(:) ! nitrogen deposition rate (gN/m2/s) local pointers to implicit out scalars real(r8), pointer :: nfix_to_sminn(:) !OTHER LOCAL VARIABLES: integer :: c,fc ! indices real(r8) :: t ! temporary real(r8) :: dayspyr ! days per year