Improved Vegetation Variability

A new deliverable presents the results of improved vegetation variability on surface fluxes modeled with offline land surface models. In this deliverable, we present the integration of the unprecedented vegetation information, from the latest satellite campaigns in the frame of Copernicus, into the land surface models (LSMs) used for reanalysis and initialization of the seasonal to decadal prediction systems. Observational Land Cover (LC) and Leaf Area Index (LAI) from CONFESS deliverable D1-1 are implemented as boundary conditions for the CHTESSEL (ECMWF), EC-Earth HTESSEL-LPJGuess (CNR) and the ISBA-CTRIP (Météo-France) land surface models. The effects of the improved representation of vegetation variability from observations on the LSMs has been evaluated in offline simulations forced by ERA5 atmospheric forcing.

Here we present the effects of seasonally and inter-annually varying LAI (sensitivity experiment), based on Copernicus observational data, on modelled evaporation, compared to evaporation modelled using seasonally varying LAI only (control experiment). Evaporation was evaluated using DOLCEv3 evaporation as reference. The figure below shows the effect of inter-annually varying LAI on the correlation of inter-annual anomaly evaporation for the three models with respect to the reference. The correlation consistently improves (blue colours) for ECMWF and CNR models, with the largest effects in regions with transitional climates. Also for the MF model considerable improvements were found.

The knowledge from the sensitivity analysis in this report is driving the selection of better solutions and configurations to include for the initialization/simulation of the predictions in CONFESS WP3. You can read more about the results in D1.2 Improved vegetation variability.