The hydrographic-hydrochemical state of the Baltic Sea in 2013

The article summarizes the hydrographic-chemical conditions in the western and central Baltic Sea in 2013. Based on meteorological conditions, the horizontal and vertical distribution of temperature, salinity, oxygen/hydrogen sulphide and inorganic and organic nutrients are described on a seasonal scale.

For the southern Baltic, the ‛cold sum“ of the air temperature in Warnemünde of 109.5 K d 2012/13 ranks on place 26 of the coldest winters since the beginning of the record in 1948 and was slightly above the long-term mean. The summer ‛heat sum“ of 230.4 K d was well above the long-term mean of 148.8 K d and ranks on place 10 of the warmest summers.

In 2013, inflow events with estimated volumes between 100 and 300 km³ took place four times: in December 2012/January 2013 (157 km³), in January/February (195 km³); both of barotropic type. A more baroclinic inflow in March April brought 160 km³ into the Baltic. In November/December several phases of westerly winds imported around 200 km³. However, all these inflow events did not reach the central Gotland Sea where the stagnation period continued undiminished.

Dr. Günther Nausch