Towards a coupled km-scale Atmosphere-Land Reanalysis for Europe

Modelling studies in hydrology depend on a good representation of forcing data, in particular precipitation, for a good process representation, especially at the catchment  or sub-catchment scale. Forcing data is often provided through reanalysis, that use observations to obtain model states with the smallest possible errors and biases. Here, we present a prototype convection-permitting reanalysis system using a coupled atmosphere-land model system utilizing ICON-eCLM for the EURO-CORDEX domain at a resolution of 3km. Due to the high resolution it is expected that in particular precipitation will be better represented than in existing reanalyses, leading to more realistic forcing data. We analyzed precipitation and other near-surface observables from preliminary model runs and evaluated them in comparison to other widely used reanalysis products such as ERA-5 as well as to output of an ICON standalone simulation to assess potential improvements of the new reanalysis. We show potential use cases of the new reanalysis and discuss limitations of this dataset, which are related to the currently short available time series.