CAVIAR: Climate variability of the Baltic Sea area and the response of the general circulation of the Baltic Sea to climate variability

No abstracts are to be cited without prior reference to the author.

The warming trend for the entire globe (1850–2005) is 0.04°C per decade. A specific warming period started around 1980 and continues at least until 2005, with a temperature increase of about 0.17°C per decade. This trend is equally well evident for many areas on the globe, especially in the northern hemisphere in observations and climate simulations. For the Baltic Sea catchment, which lies between the maritime temperate and continental Subarctic climate zones, an even stronger warming of ca. 0.4°C per decade has appeared since 1980. The annual mean air temperature increased by ca. 1°C until 2004. A similar warming trend can be observed for the sea surface temperature of the Baltic Sea. Even the annual mean water temperatures averaged spatially and vertically for the deep basins of the Baltic Sea show similar trends. We provide a detailed analysis of the climate variability and associated changes in the Baltic Sea catchment area as well as in the Baltic Sea itself for the period 1958–2009, in which the recent acceleration of the climate warming happened. Changes in the atmospheric conditions cause corresponding changes in the Baltic Sea, not only for temperature and salinity but also for currents and circulation. These changes in the physical conditions have strong impact on the marine ecosystem structure and processes.