Relevance of Global Remote-sensing Fapar Products to Carbon Flux Estimates

This contribution gives an overview of the Medium Resolution Imaging Spectrometer (MERIS) global land product corresponding to the biophysical variable of the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR). This product can be used in largescale biosphere modeling for better estimating the carbon fluxes since they directly represent the amount of solar energy which serves as a ‘battery’ during the photosynthetic process. The daily FAPAR value is operationally estimated from MERIS data and the (demonstration) global products, recently produced at European Space Research Institute (ESRIN) by the grid on demand system, are first compared against the Joint Research Centre (JRC) SeaWiFS global datasets which is available since September 1997 [1][2]. The second part presents a first evaluation against the simulations by the Biosphere Energy Transfer Hydrology Scheme (BETHY) model [3][4][5] for a 10 year period and over 3 regional windows. The results show a good agreement between both space remote sensing data and model simulations which promotes the assimilation of the MERIS FAPAR products into a Carbon Cycle Data Assimilation System (CCDAS) [6].