SEN4GPP – Sentinels for Terrestrial Carbon Production

Project overview

The total amount of CO₂ absorbed and turned into organic matter through photosynthesis can be quantified as Gross Primary Productivity (GPP), which represents the integration of all organic matter produced by all the plants in a defined area per unit time. Terrestrial vegetation GPP is responsible for fixing approximately 120 to 170 PgC per year, making it both the largest and the most uncertain portion of the global carbon cycle.

The objective of the Sen4GPP project is to improve our knowledge of the spatio-temporal variations of GPP associated with terrestrial ecosystems, through a synergistic exploitation of the complementary information (Land Surface Temperature – LST, Solar-Induced Fluorescence – SIF, Fraction of Absorbed Photosynthetically Active Radiation – FAPAR, and land cover) provided by the Sentinel missions (Sentinel-2, Sentinel-3 and Sentinel-5P) at multiple spatial and temporal resolutions, as well as other Earth Observation and in situ data.

Project description

Three estimation approaches are implemented to generate the experimental GPP datasets derived from Sentinel observations at high and medium to coarse spatial resolutions: Light Use Efficiency (LUE) models and Machine Learning (ML) approaches (data-driven), already documented in a large body of literature for similar applications, and a more innovative approach relying on the scaling of solar-induced fluorescence (SIF) estimates of terrestrial ecosystems derived from Sentinel-5P observations.

The experimental GPP datasets are generated over a set of regions of interest (Europe, United States, Australia, Amazonia) and evaluated against available ground truth and other comparable GPP products (derived from Earth Observation and from terrestrial biosphere model simulations).

Project partners

• NOVELTIS, France
• University of Southampton, United Kingdom
• Max Planck Institute for Biogeochemistry, Germany
• Universitat Politècnica de València, Spain
• Euro-Mediterranean Center on Climate Change (CMCC), Italy
• Laboratoire des Sciences du Climat et de l'Environnement (LSCE), France