%0 journal article %@ 1561-8633 %A Staneva, J., Wahle, K., Koch, W., Behrens, A., Fenoglio-Marc, L., Stanev, E.V. %D 2016 %J Natural Hazards and Earth System Sciences %N 11 %P 2373-2389 %R doi:10.5194/nhess-16-2373-2016 %T Coastal flooding: impact of waves on storm surge during extremes. A case study for the German Bight %U https://doi.org/10.5194/nhess-16-2373-2016 11 %X This study addresses impact of wind, waves, tidal forcing and baroclinicity on the sea level of the German Bight during extremes. The role of waves-induced processes, tides and baroclinicity is quantified and the results are compared with observational data that include various in-situ measurements as well as satellite data. A coupled, high-resolution, model system is used to simulate the wind waves, water level and three-dimensional hydrodynamics. The effects of the wind waves on sea level variability are studied accounting for wave-dependent stress, wave-breaking parameterization and wave-induced effects on vertical mixing. The analyses of the coupled model results reveal a closer match with observations than for the stand-alone circulation model, especially during the extreme storm Xaver in December 2013. The predicted surge of the coupled model enhances significantly during extremes when considering wave-current interaction processes. The wave-dependent approach yields to a contribution of more than 30 % in some coastal area during extremes. The improved skill resulting from the new developments justifies further use of coupled wave and three dimensional circulation models for improvement of coastal flooding predictions.