Ice season in the Baltic Sea and its climatic variability

Abstract

Ice forms annually in the Baltic Sea. The length of the ice season is 5-8 months, maximum annual ice thickness is 50-120 cm, and maximum annual ice extent is 12.5-100% of the Baltic Sea area. The ice cover of this brackish basin is marine type, with biota in brine inclusions and presence of leads and ridges due to ice drift. Ice has an important role in the ecology and human life conditions in the region. Thermal memory of the Baltic Sea is a few months, and the variability of ice seasons is connected to the strength of the North-Atlantic westerlies bringing mild winter weather. Ice seasons are sensitive to climate: for 1°C change in air temperature the length of the ice season changes by 1-2 weeks and the areal extent changes by 2.5% units of the Baltic Sea area. © 2012 Springer-Verlag Berlin Heidelberg.