Regional climate model COSMO-CLM developed by DWD used for dynamical downscaling of observed storm events and potential storm surge events in future GHG scenarios (see www.clm-community.eu for a detailed model description). COSMO-CLM driven by reanalysis data: The model was used for dynamical downscaling of wind for the most extreme observed historic storm surge events. As this study concentrated on the atmospheric influences we choosed storm surges with the highest wind surge values. The model data was used to compare wind speed estimates over the German Bight region with the storm surge atlas from the station Cuxhaven (provided by G. Gönnert, LSBG Hamburg). COSMO-CLM driven by ECHAM5/MPI-OM model data: To estimate possible future changes of storm surge risk due to increased GHG concentrations, the model was used to downscale events (detected in GCM model data) with high effective wind speeds (wind projected on the direction 295°) over the German Bight region. A comparison between the most intense events detected in GCM data under recent climate conditions (20C) and under possible future climate conditions (A1B) was used to estimate changes in storm surge intensity and frequency under future climate conditions. For most potential storm surge events (driven by GCM data) and for observed storm surge events (driven by ERA-Interim reanalysis data) each event is simulated by a five member mini ensemble. These members differ due to their model domain, which is shifted by 8 grid boxes to north, south, east and west. The results of this ensemble can be used to estimate the uncertainty of the storm surge event.

Hydrographic: This is the first version (1.0) of a hydrographic climatology for the region 47 to 65 °N, 15 °W to 15 °E. It contains monthly and yearly mean temperature and salinity data at 179 depth levels on a 0.25° x 0.5° latitude-longitude grid in the period 1890 to 2011. For the calculation of the means all available temperature and salinity data from water sample, CTD, and float measurements in this period were selected from the World Ocean Database 2009, the ICES (International Council for the Exploration of the Sea) data base, and the BSH data base, rejecting double stations. The derived data base consisted of about 735,000 stations. The original profiles of temperature and salinity were interpolated on 179 depth levels. There was no interpolation if the gap between two measurements in the original profile was too large. The data were then sorted in 0.25° x 0.5° latitude-longitude boxes. Atmospheric: This is the first version (1.0) of a meteorological climatology for the region 47 to 65 °N, 15 °W to 15 °E. It contains monthly mean air temperature, air pressure, dew point, relative humidity and windspeed data on a 1° x 1° latitude-longitude grid in the period 1950 to 2010. For the calculation of the means all available data from voluntary ship observations and buoys measurements in this period provided quality controlled by the DWD (Deutscher Wetterdienst) were taken. Data citations: Hydrographic: Manfred Bersch, Viktor Gouretski, Remon Sadikni (2013): The hydrographic climatology of the North Sea and surrounding regions, Centre for Earth System Research and Sustainability (CEN), University of Hamburg Atmospheric: Remon Sadikni, Manfred Bersch, Annika Jahnke-Bornemann (2013): The meteorolgical climatology of the North Sea and surrounding regions, Centre for Earth System Research and Sustainability (CEN), University of Hamburg