Assimilating Sentinel-2 data in a modified vegetation photosynthesis and respiration model (VPRM) to improve the simulation of croplands CO2 fluxes in Europe

Research output: Contribution to journalResearch articleContributedpeer-review


  • Hassan Bazzi - , Université Paris-Saclay, Atos France (Author)
  • Philippe Ciais - , Université de Versailles Saint-Quentin-en-Yvelines (Author)
  • Ezzeddine Abbessi - , Université Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines (Author)
  • David Makowski - , Université Paris-Saclay (Author)
  • Diego Santaren - , Université de Versailles Saint-Quentin-en-Yvelines (Author)
  • Eric Ceschia - , Université de Toulouse (Author)
  • Aurore Brut - , Université de Toulouse (Author)
  • Tiphaine Tallec - , Université de Toulouse (Author)
  • Nina Buchmann - , ETH Zurich (Author)
  • Regine Maier - , ETH Zurich (Author)
  • Manuel Acosta - , Czech Academy of Sciences (Author)
  • Benjamin Loubet - , Université Paris-Saclay (Author)
  • Pauline Buysse - , Université Paris-Saclay (Author)
  • Joël Léonard - , University of Liege (Author)
  • Frédéric Bornet - , University of Liege (Author)
  • Ibrahim Fayad - , Université de Versailles Saint-Quentin-en-Yvelines (Author)
  • Jinghui Lian - , Université de Versailles Saint-Quentin-en-Yvelines (Author)
  • Nicolas Baghdadi - , University of Montpellier (Author)
  • Ricard Segura Barrero - , Autonomous University of Barcelona (Author)
  • Christian Brümmer - , Johann Heinrich von Thunen Institute (Author)
  • Marius Schmidt - , Jülich Research Centre (Author)
  • Bernard Heinesch - , BioDynE research axis (Author)
  • Matthias Mauder - , Chair of Meteorology (Author)
  • Thomas Gruenwald - , Chair of Meteorology (Author)


In Europe, the heterogeneous features of crop systems with majority of small to medium sized agricultural holdings, and diversity of crop rotations, require high-resolution information to estimate cropland Net Ecosystem Exchange (NEE) and its two main components of Gross Ecosystem Exchange (GEE) and the Ecosystem Respiration (RECO). In this context, this paper presents an assimilation of high-resolution Sentinel-2 indices with eddy covariance measurements at selected European cropland flux sites in a new modified version of Vegetation Photosynthesis Respiration Model (VPRM). VRPM is a data-driven model simulating CO2 fluxes previously applied using satellite-derived vegetation indices from the Moderate Resolution Imaging Spectroradiometer (MODIS). This study proposes a modification of the VPRM by including an explicit soil moisture stress function to the GEE and changing the equation of RECO. It also compares the model results driven by S2 indices instead of MODIS. The parameters of the VPRM model are calibrated using eddy-covariance data. All possible parameters optimization scenarios include the use of the initial version vs. the proposed modified VPRM, S2, or MODIS vegetation indices, and finally the choice of calibrating a single set of parameters against observations from all crop types, a set of parameters per crop type, or one set of parameters per site. Then, we focus the analysis on the improvement of the model with distinct parameters for different crop types vs. parameters optimized without distinction of crop types. Our main findings are: (1) the superiority of S2 vegetation indices over MODIS for cropland CO2 fluxes simulations, leading to a root mean squared error (RMSE) for NEE of less than 3.5 μmolm-2s-1 with S2 compared to 5 μmolm-2s-1 with MODIS (2) better performances of the modified VPRM version leading to a significant improvement of RECO, and (3) better performances when the parameters are optimized per crop-type instead of for all crop types lumped together, with lower RMSE and Akaike information criterion (AIC), despite a larger number of parameters. Associated with the availability of crop-type land cover maps, the use of S2 data and crop-type modified VPRM parameterization presented in this study, provide a step forward for upscaling cropland carbon fluxes at European scale.


Original languageEnglish
Article number103666
JournalInternational Journal of Applied Earth Observation and Geoinformation
Publication statusPublished - Mar 2024

External IDs

ORCID /0000-0003-2263-0073/work/163765945
ORCID /0000-0002-8789-163X/work/163766088


Sustainable Development Goals


  • Carbon Cycle, Crop Types, Data-driven Modelling, Eddy covariance, MODIS, Sentinel-2