LAI_eff Subroutine

public subroutine LAI_eff(mp, lai_pft, HGT_pft, HgtAboveSnow, reducedLAIdue2snow)

This subroutine computes the leaf-area index of a canopy when there is snow present. The formulae assume that the leaf area is distributed uniformly in the vertical within the canopy.

Leaf area, LAI, accounting for the presence of snow, is given by

where is evaluated in subroutine HgtAboveSnow. The LAI is decreased proportionally to the canopy height with/without snow.

The effective canopy height used to evaluate the proportional decrease in LAI takes a minimum value of 0.01m. This condition prevents numerical issues when the canopy height (without snow) is small.

Warning: To follow up

Can HgtAboveSnow be greater than MAX(0.01, Hgt_PFT)? If yes then there is an issue to resolve. HgtAboveSnow can sit at its minimum value of 10 so if then LAI can increase if there is snow!

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: mp

Number of land points (-)
real, intent(in) :: lai_pft(mp)

Leaf area index without snow (m m

real, intent(in) :: HGT_pft(mp)

! height of canopy without snow (m)
real, intent(in) :: HgtAboveSnow(mp)

height of canopy above the snow surface (m)
real, intent(out) :: reducedLAIdue2snow(mp)

Output. Modified leaf area index for snow (m m)

Called by

proc~~lai_eff~~CalledByGraph proc~lai_eff LAI_eff proc~ruff_resist ruff_resist proc~ruff_resist->proc~lai_eff proc~cbm cbm proc~cbm->proc~ruff_resist proc~define_canopy define_canopy proc~cbm->proc~define_canopy proc~define_canopy->proc~ruff_resist proc~mpidrv_worker~2 mpidrv_worker proc~mpidrv_worker~2->proc~cbm proc~serialdrv serialdrv proc~serialdrv->proc~cbm program~cable_offline_driver cable_offline_driver program~cable_offline_driver->proc~serialdrv