LONGLOVE

Long term global monitoring of the terrestrial biosphere from satellite data raised an increasing interest in the context of the global change studies. Among the variables accessible from remote sensing, LAI (Leaf Area Index) and FAPAR (Fraction of Absorbed Photosynthetic Active Radiation) have been identified as Essential Climate Variables intervening within key processes, including photosynthesis, respiration and transpiration.

The vegetation cover fraction (FCOVER) appears also as a very pertinent variable that can be used in surface energy balance models to separate the contribution of the soil from that of the canopy. Long time series of these biophysical variables are essential for discerning anomalies and trends in vegetation responses to climate change and improve our understanding of climate forcing on vegetation dynamics.

The objective of LONGLOVE project is to generate continuous time series of global LAI, FAPAR and FCOVER variables from AVHRR observations for the last three decades at 0.05º spatial resolution every 10 days. Special emphasis will be put on achieving consistency with GEOV2/VGT products derived in Copernicus Global Land Service in order to get the longest time series of biophysical variables and ensuring continuity.

CREAF, in collaboration with INRA, will provide scientific support to CNES for the development and validation of the GEOV2/AVHRR products. Products will be accessible freely through the portal of THEIA land data centre. These time series are expected to contribute to better understand the mechanisms behind vegetation-climate interactions, and the role of the biosphere in global change studies and Earth science applications.