Hydrological Impact of the New ECMWF Multi-Layer Snow Scheme

The representation of snow is a crucial aspect land-surface modelling, as it has strong influence on energy and water balances. Snow schemes with multiple layers have been shown to better describe the snowpack evolution bring improvements soil freezing some hydrological processes. In this paper, wider impact multi-layer scheme, implemented in ECLand model, was analyzed globally hundreds catchments. ERA5-forced reanalysis simulations were coupled CaMa-Flood, hydrodynamic model produce river discharge. Different sensitivity experiments conducted evaluate scheme changes terrestrial processes, particular focus permafrost. It found that default can generally improve discharge simulation, exception permafrost catchments, where snowmelt-driven floods are largely underestimated, due lack surface runoff. also appropriate vertical discretization, destructive metamorphism, snow-soil thermal conductivity freeze temperature could lead large by adjusting temperature, infiltration partitioning between subsurface