Regional differences in winter sea level variations in the Baltic Sea for the past 200 years

Abstract

Decadal sea level variations in selected stations located in the southwestern, central and eastern Baltic Sea are found to be less coherent in the 19th century than in the 20th century. The effect of the North Atlantic sea level-pressure (SLP), precipitation and air-temperature in the 19th and 20th centuries from gridded climate reconstructions, and their relationship to Baltic Sea level, are statistically analysed to explain this difference. The influence of these factors on sea level varies geographically. In the central and eastern Baltic, Sea level variations are well described by SLP alone, whereas in the southern Baltic Sea area-averaged precipitation better explains the decadal sea level variations. The evolution of precipitation in the 19th century could explain the different behaviour of the southern Baltic stations; however, the physical mechanism for this relationship remains unclear. The effect of temperature variations is either already contained in the SLP field or is less important for decadal sea level variations than the other two factors.