Sea surface temperature distribution during upwelling along the Polish Baltic coast

Among over 150 maps of sea surface temperature in the Polish Baltic coastal region derived from satellite data during the warm period of the year (April–October) in 2000–2002, 41 cases were noted where its distribution showed characteristic features indicating the occurrence of coastal upwelling. The fundamental parameters of range, probability of occurrence and temperature modification caused by water from deeper sea layers raised by an upwelling event and spreading across the surface were established for three regions (Hel, Łeba and Kołobrzeg). The Kołobrzeg upwelling region had the largest spatial range (up to 5000 km2). The region with the smallest spatial range (Hel, up to 1400 km2) had the largest surface temperature amplitude (to 14◦C), the largest maximum temperature gradient (5◦C km−1) and the largest average sea surface temperature decrease in the centre in relation to the background value.