Estimation of Biomass and CO 2 Fluxes Of Sunflower by Assimilating Hstr Data in a Simple Crop Model
Résumé
Although croplands are affected by climate change and contribute to it, their carbon budgets remain little known because of the lack of tools allowing estimating it at a fine resolution. In this study a modeling approach is proposed, assimilating high spatial and temporal resolution (HSTR) remote sensing optical products in a semi-physical crop model called SAFY-CO 2 to estimate crop production and the components of the carbon budget. The model correctly reproduces the green area index (GAI) (R 2 = 0.98, rRMSE = 8%), the biomass (R 2 = 0.95, rRMSE = 16%) and the components of the carbon budget (GPP: R 2 = 0.90; RMSE = 1.61gC.m -2 .d -1 ; R eco : R 2 = 0.87; RMSE = 0.81 gC.m -2 .d -1 gC.m -2 .d -1 ; NEE: R 2 = 0.86; RMSE = 0.85 gC.m -2 .d -1 ). This approach requires a few input parameters and no information about management practices which makes it suitable for large scale application and monitoring, reporting and verification (MRV) approaches.