摘要：The distributions of ice season characteristics in the Baltic Sea during 1982–2016 were studied. A shift in the ice season regime was observed in 2006–2007. Ice season characteristics before and after the shift were determined in the northern and southern regions of the Baltic Sea, and the contributions of these areas to the shift regime were evaluated. To study changes in ice conditions, satellite data on the daily ice concentration over the Baltic Sea provided by the Copernicus Marine Environment Monitoring Service were used. The ice cover extent and number of ice days were calculated. The maximal ice extent event of the ice season shifted from the beginning of March to the end of January in 2007. The average ice concentration over the Baltic Sea was 18% and 10% before and after the shift, respectively. On average, 32 and 19 ice days occurred before and after the shift, respectively. The average ice concentration in the northern Baltic was 54% before and 34% after the shift, and the concentration in the southern Baltic was 8% before and 7% after the shift. The determined shift of the ice season characteristics indicated that extensive ice cover does not last long during the after-shift seasons.
关键词：Baltic Sea climate ice season ice concentration climatic regime regime shift ice days
