Opened 3 years ago
Last modified 4 months ago
#735 new defect
Potential issues in the way transmitted light is calculated
| Reported by: | gmarie | Owned by: | Matthew Mcgrath |
|---|---|---|---|
| Priority: | minor | Milestone: | ORCHIDEE 4.2 |
| Component: | Physical processes | Version: | trunc |
| Keywords: | transmitted light, diffuse light, albedo | Cc: |
Description
In the file where transmitted light is calculated : albedo_surface.f90
at line 945, the following equation is used to calculate transmitted light from one layer to another one.
Light_Tran_Tot(ipts,ivm,:) = direct_light_weight*(Isotrop_Tran_Coll(:) + Isotrop_Tran_Uncoll(:)) + (un-direct_light_weight)*(Isotrop_Tran_Coll(:) + Isotrop_Tran_Uncoll(:))
direct_light_weight equal 0.5 meaning that the source is composed by 50% of direct and 50% of diffuse light.
But the minimum value obtain for Light_Tran_Tot is 0.5 for a very dense canopy. It seems that Isotrop_Tran_Coll and Isotrop_Tran_Uncoll have been use twice instead of Collim_Tran_Coll and Collim_Tran_UnColl.
Change History (2)
comment:1 Changed 7 months ago by luyssaert
- Milestone changed from ORCHIDEE 4.3 to ORCHIDEE 4.2
comment:2 Changed 4 months ago by xnwang
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A fix is applied in the revision [8016], after a discussion between MM and XW.
Light_Tran_Tot(ipts,ivm,:) = direct_light_weight*(Collim_Tran_Coll(:) + & Collim_Tran_Uncoll(:)) + (un-direct_light_weight)*(Isotrop_Tran_Coll(:) + &