ORCHIDEE TRUNK albedo optimization
Round B (07/10/2025)

Select range and step: nirvisstep1-leafstep2-bgstep3-snowpostcheck

Model: ORCHIDEE TRUNK rev9014
Configuration: default FG_CRUJRA_HIST, but TEST_ALB_RT_VEGMAX = y
Resolution: 2°
Period: 2016-2020, monthly
Observations: MODIS (quality flag <= 5, snow fraction == 0)
Optimized parameters: LEAF_SSA and LEAF_PSD per PFT (PFT1 is fixed to default, one common value is used for PFT10 and PFT14)
Method: variational L-BFGS-B with external RT-tool developped by K.Ardaneh
Gradient: finite difference calculation with parameter perturbation of 1e-6 of range of variation
Data selection: (frac_snow == 0) & (tot_bare_soil < 0.5) & (cont_frac > 0.99) & (inland_water < 0.1)
Final parameter values are rounded to 3 digits

ALB_NIR RESULTS

Parameter	PFT1	PFT2	PFT3	PFT4	PFT5	PFT6	PFT7	PFT8	PFT9	PFT10	PFT11	PFT12	PFT13	PFT14	PFT15
ssa_prior	0.70275	0.67834	0.70136	0.68984	0.7341	0.72176	0.69501	0.69201	0.8498	0.71212	0.71501	0.71259	0.71295	0.71212	0.71212
ssa_min	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6
ssa_max	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9
ssa_post	0.703	0.606	0.68	0.617	0.611	0.702	0.6	0.741	0.607	0.697	0.662	0.699	0.79	0.697	0.655
psd_prior	2.006	1.943	2.003	1.975	2.095	2.058	1.988	1.974	2.435	2.024	2.024	2.021	2.024	2.024	2.024
psd_min	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
psd_max	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3
psd_post	2.01	1.82	1.7	1.47	1.09	1.67	0.5	1.93	0.744	1.7	1.54	2.22	2.06	1.7	1.67