## 3 Results
### LDAS-Monde Impact
#### 3.2.3 Evaluation Using Independent Datasets  
For evapotranspiration and GPP, seasonal scores (RMSD and R values in Figure 14) are computed for the model and for the analysis in both the LDAS-ERA5 and LDAS-ERAI configurations. Only vegetated grid points (>90%) are considered. After the joint assimilation of SSM and LAI, a small positive impact on evapotranspiration is observed for the correlations, as found in [40], and it is interesting to note a small degradation of the RMSD values in the second part of the year (August to December). However, there is a clear improvement in GPP in terms of the RMSD and R scores, especially from January to August (Figure 14c,d). While the impact on R values of the analysis is equally distributed over the domain for both evapotranspiration and GPP, a larger (positive) impact on RMSD values is found on the southern part of the domain (not shown). This is in agreement with the analysis impact on LAI described above. LDAS-ERA5 generally performs better than LDAS-ERAI  
Figure 13: Seasonal correlations for (**a**) anomaly time series between SSM estimates from the CGLS project and SSM from the second layer of soil of ISBA LSM (in blue) and the assimilation (in red) over the period of 2007–06/2018 for both the LDAS-ERA5 and LDAS-ERAI configurations. (**b,c**) Maps of the anomaly correlation between SSM of the model, the analysis, and the SSM estimates from CGLS, respectively, (**d**) map of the correlation differences. (**a–c**) are for the LDAS-ERA5 configuration. for both the openloop and the analysis. It is particularly true when considering RMSD values for evapotranspiration (Figure 14a). Figure 14a indicates, however, the degradation of the evapotranspiration estimation by LDAS-ERA5 and LDAS-ERAI when compared to the GLEAM dataset. It is worth noting that the GLEAM dataset is not a direct remotely sensed observation, but rather a remote sensing-based evaporation retrieved model with its own uncertainties. For instance, [PERSON] et al. (2018) [PERSON] et al. (2018) have recently assessed the potential of satellite observations of solar-induced chlorophyll fluorescence (SIF), normalized by photosynthetically-active radiation (PAR), to diagnose the ratio of transpiration to potential evaporation (\"transpiration efficiency\") from several state of the art models, including SURFEX and GLEAM. They obtained better results with SURFEX than with GLEAM, in particular during the vegetation decaying phase. Looking at the seasonal time series of the analysis increments (Figure 15 for the LDAS-ERA5 configuration), it is very interesting to notice that the degradation from the analysis over the open-loop (from August in both the LDAS-ERA5 and LDAS-ERAI configuration) corresponds to a sign inversion in the LAI increments (from positive to negative) as well as a sharp positive increase in soil moisture increments (analysis increments of soil moisture from the second (WG2) and fourth (WG4) layer of soil are presented). This situation in the vegetation decaying period seems conflictual and may suggest a lack of consistency between the two observation types (LAI and SSM), leading to the observed degradation in RMSD values. Figure 14: Seasonal evapotranspiration (**a**,**b**) and gross primary production (GPP) (**c**,**d**) scores when compared to the observations over January 2001 to June 2018. For SIF, seasonal scores (R values in Figure 16) comparing the observed SIF and simulated GPP for vegetated grid points are computed for model and analysis estimates in both the LDAS-ERA5 and LDAS-ERAI configurations. A positive impact of DA on R can be seen from January to August with an averaged improvement of 0.1 on R for both configurations. For the rest of the year, the impact is rather neutral. Using ERA5 or ERA-Interim as atmospheric forcing does not have much influence on R. This was also the case for FLUXCOM GPP in Figure 14. This is due to a diminished impact of atmospheric forcing on the modelled GPP. The positive impact is of the same scale for the three agroclimatic areas covering BF (not shown).