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

The European Centre for Medium Range Weather Forecasts (ECMWF) delivers the core root-zone soil moisture (SM) products for H SAF through an advanced land data assimilation system, running independently of the NWP system. Space borne scatterometer-derived surface SM observations from the ASCAT sensors are assimilated into the root-zone (0-1 m) SM of the H-TESSEL land surface model. Two products are currently operational: (i) A global near-real-time (NRT) product is delivered at 25 km resolution with a timeliness of 36 hours (ii) A reanalysis version covering the scatterometer data record (1992-2016).

A new NRT product has been pre-operational since 2018 and benefits from an optimized production suite, enabling increased resolution (10 km) and reduced timeliness (12 hours). These features will be particularly important for flood forecasting and agriculture monitoring and forecasting applications. A reanalysed version is in development over the period 1992-2018 based on ERA-5 atmospheric forcing. A preliminary evaluation of the new products is presented.