Spatial and temporal variability of sea surface temperature in the Baltic Sea based on 32-years (1982-2013) of satellite data

Satellite measurements provide synoptic view of sea surface temperature (SST) and can be used to trace global and regional climate trends. In this study we have examined the multiyear trends and variability of the Baltic Sea SST using 32-years (1982-2013) of satellite data. Our results indicate that there is a statistically significant trend of increasing SST in the entire Baltic Sea, with values ranging from 0.03 to 0.06 degrees C year(-1), depending on the location. SSTs averaged over the entire Baltic Sea increase at the rate of 0.05 degrees C year(-1). Higher values of SST trend are generally present in the summer months, while trend is not statistically significant in the winter months. The seasonal cycle of SST in the Baltic Sea is characterized by well-defined winter and summer seasons. The average amplitude (16-18 degrees C) of this cycle is significantly larger than in the North Sea waters located at the same latitudes as the Baltic Sea. The analyzed data set also highlights considerable interannual SST variability, which is coherent in different regions of the Baltic Sea and significantly correlated with interannual variability of the air temperature. SST variability in the Baltic Sea in winter can be linked to the North Atlantic Oscillation index. (C) 2015 The Authors. Production and hosting by Elsevier Sp. z o.o. on behalf of Institute of Oceanology of the Polish Academy of Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)