A continuous bias-reduced land surface reanalysis dataset over EURO-CORDEX for 2000 to 2022

The simulations were driven by the ECWMF ERA5 forcing data with the biogeochemical module switched off, and used an updated parameter set estimated by the Ensemble Smoother with Multiple Data Assimilation (ES-MDA) framework. In the parameter estimation step, SMAP soil moisture retrievals and in situ evapotranspiration observations from the ICOS network were assimilated to constrain key parameters governing soil hydraulic properties and vegetation physiological processes over the period 2018-2020.

The optimized parameters were then applied in a continuous model simulation from 2000 to 2022 to generate estimates of soil moisture and evapotranspiration. Soil moisture simulations were evaluated using more than 300 stations from the International Soil Moisture Network (ISMN) over the full 2000–2022 period, yielding a bias of −0.003 cm³ cm⁻³ and an unbiased RMSE (ubRMSE) of 0.055 cm³ cm⁻³. Evapotranspiration estimates were validated against ICOS flux tower observations, achieving an unbiased RMSD of 0.88 mm day⁻¹ and a Pearson correlation coefficient of 0.77.