Satellite inspired hydrology in an uncertain future: a H SAF and HEPEX workshop

This study investigates the capability of LDAS-Monde global offline LDAS to monitor and forecast the impact of extreme events on Land Surface Variables (LSVs). LDAS-Monde is driven by ERA-5 atmospheric forcing from ECMWF and is able to ingest information from satellite-derived surface soil moisture (SSM) and leaf area index (LAI) observations to constrain the ISBA land surface model.
A global 2010-2018, 0.25°x0.25º spatial resolution, reanalysis of the LSVs is first evaluated thanks to global estimates of SSM, LAI, evapotranspiration , Gross Primary Production, Sun Induced Fluorescence and several in situ measurements of soil moisture, river discharge, and flux measurements. This 9-yr reanalysis is used to provide a climatology of the LSVs. Significant anomalies are used to decide on where to focus for a more detailed monitoring and forecasting activity. 19 regions across the globe were investigated for 2018. Two of them, presenting large negative anomalies of SSM and LAI were further analysed: Western-Europe and the Murray-Darling river basin in southeastern Australia. LDAS-Monde was operated forced by ECMWF IFS high-resolution atmospheric analysis leading to a 0.1°x0.1° reanalysis. It complements the coarse-resolution LDAS-Monde operated using ERA5. The IFS forecast capacity initialised by LDAS-Monde analysis is also presented.