Untersuchungen zu Änderungen und Einflussgrößen des mittleren Meeresspiegels in der südwestlichen Ostsee

Climate change induced global mean sea level rise is neither spatially nor temporally uniform,
since regional or local processes lead to deviations from the global mean. The development of adapting coastal protection strategies thus poses special challenges for society worldwide. Based on local and regional sea level studies, sea level development can be determined and the individual contributing factors can be separated. For this purpose, mean sea level (MSL) time series are of major importance. This thesis focuses on the compilation and analysis of high quality and long-term MSL time series for the southwestern Baltic Sea coast, considering all available tide gauge records. For the southwestern Baltic Sea a linear trend of 1.2 ± 0.1 mm/a (corrected for glacial isostatic adjustment) is calculated over the 20th century. Due to the predominant westerly wind conditions as well as the temperature and salinity gradients this trend is smaller than in the entire Baltic Sea with 1.7 ± 0.1 mm/a. The interannual sea level variability in the southwestern Baltic Sea is dominated by the compensation of the main influencing factors wind, dynamics (internal steric and external mass input), and sea level pressure. On decadal time scales, on the other hand, sea level variability of the entire Baltic Sea is connected to the North Sea, since the driving force is mainly generated externally by dynamic processes in the North Atlantic (especially variations in steric in the deep ocean). Global sea-level rise is thus also reflected in Baltic Sea MSL change, but superimposed by local
effects. This work contributes to the understanding of past and present sea level changes in the southwestern Baltic Sea and thus provides important knowledge for the assessment of the hydrodynamic load on coastal defences.