EGU22-3514
https://doi.org/10.5194/egusphere-egu22-3514
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Assimilation of backscatter observations in a hydrological model: a case study in Belgium using ASCAT data

Pierre Baguis1, Alberto Carrassi2, Emmanuel Roulin1, Stéphane Vannitsem1, Joris Van den Bergh1, Sara Modanesi3, and Hans Lievens3
Pierre Baguis et al.
  • 1Royal Meteorological Institute of Belgium, Surface processes modeling and earth observation (EO) applications, Brussels, Belgium (pierre.baguis@meteo.be)
  • 2Department of Meteorology and NCEO, University of Reading, U.K., Department of Physics and Astronomy "Augusto Righi", University of Bologna, Italy
  • 3Department of Earth and Environmental Sciences, KU Leuven, Belgium

We investigate the possibilities to improve hydrological simulations by assimilating active radar backscatter observations from the Advanced Scatterometer (ASCAT) in the hydrological model SCHEME. This effort is motivated by the great need of accurate initial model states in hydrological forecasting and the potential to improve them by using remotely sensed data of land surface processes. ASCAT data assimilation is enabled by coupling the Water Cloud Model (WCM) with the SCHEME model. We calibrated the WCM over two catchments in Belgium exhibiting different hydrological regimes. We explore a data assimilation system based on the Ensemble Kalman Filter (EnKF) whereby the observation operator is given by the coupling of WCM and SCHEME models. This coupling underlines the advantage of using backscatter data for assimilation purposes instead of a soil moisture product carrying its own climatology. In the present study we focus on optimising the EnKF for the task, unveil the main challenges and investigate possible solutions including methods to address the biases affecting the data assimilation procedure.

How to cite: Baguis, P., Carrassi, A., Roulin, E., Vannitsem, S., Van den Bergh, J., Modanesi, S., and Lievens, H.: Assimilation of backscatter observations in a hydrological model: a case study in Belgium using ASCAT data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3514, https://doi.org/10.5194/egusphere-egu22-3514, 2022.