SIF.GPP_v2C
Optimization of SIF model v1.2 vs TROPOSIF+FLUXNET_GPP data with 11 optimized parameters (set C)

Optimization configuration

• L-BFGS-B algorithm limited to 25 iterations
• FLUXNET2015 sites (117 in total) grouped in 12 PFTs simulated using in-situ atmospheric data for different periods across 1992-2015
• driven by the fit to SIF and GPP data (mean seasonal cycle at daily frequency calculated across all available years for CTESSEL and FLUXNET-GPP, 2019-2020 for TROPOSIF)
• 11 optimized parameters (set C), including:
• 4 parameters used in CAMS41 (A1, B1, VCMAX25 and HUMREL)
• 3 parameters from Farquhar module (ASJ, ASV, GB_REF)
• 4 parameters from Fluor module (ALA, SLA, K_P, CLUMPING)
• parameter ranges of variation are set to ±25% of its default, except ALA [25; 65], K_P [3.5; 5.5], CLUMPING [0.45; 1]
• prior parameter uncertainty is set to 15% of its range of variation
• prior model uncertainty is set to the root-mean-square difference between the prior simulations and TROPOSIF/FLUXNET-GPP data (mean seasonal cycle)

Select PFT: Synthesis PFT1 (Crops, mixed farming, C3) PFT2 (Short grass, C3) PFT3 (Evergreen needleleaf, C3) PFT5 (Deciduous broadleaf, C3) PFT6 (Evergreen broadleaf, C3) PFT7 (Tall grass, C4) PFT9 (Tundra, C3) PFT11 (Semidesert, C4) PFT13 (Bogs and marshes, C3) PFT16 (Evergreen shrubs, C4) PFT17 (Deciduous shrubs, C3) PFT18 (Mixed forest - Wood, C3)

Parameter	VCMAX25__1	HUMREL__1	A1__1	B1__1	ASJ__1	ASV__1	GB_REF	ALA__1	SLA__1	K_P	CLUMPING__1
prior	60	1	0.85	0.14	659.7	668.39	0.04	57.4	0.026	4	0.75
min	45	0.75	0.6375	0.105	494.775	501.2925	0.03	25	0.0195	3.5	0.45
max	75	1.25	1.0625	0.175	824.625	835.4875	0.05	65	0.0325	5.5	1
post	74.1	0.755	1.06	0.105	500	507	0.0365	27.9	0.0198	3.52	0.457

SITE LOCATION	SIF (daily)	SIF (seasonal cycle)	FLUXNET-GPP (daily)	FLUXNET-GPP (seasonal cycle)	FLUXSAT-GPP (daily)	FLUXSAT-GPP (seasonal cycle)	GPP vs SIF