The article describes changes in the frequency and activity of cyclones moving from the Mediterranean Sea basin to the area of Central and Eastern Europe in the period 1958-2008. Furthermore, long-term trends in the amount of precipitation in Poland are analyzed, as well as the moisture content in the atmosphere over Poland related to the activity of Mediterranean cyclones. A relationship was observed between the amount of precipitation,the precipitable water in the atmosphere over Poland and the cyclone trajectories. In the analyzed period, the number of Mediterranean cyclones reaching Central and Eastern Europe decreased. Moreover, signs of decreasing activity of these cyclones were also noted. The average moisture content in the atmosphere over Poland also showed a downward trend. The precipitation totals associated with the activity of Mediterranean cyclones became lower, while the intensity of precipitation did not change significantly. Mediterranean cyclones are associated with high moisture content in the atmosphere. This surplus amounts to an averageof nearly 15%, and in periods with the highest precipitation it reaches ca. 40%. The maximum daily precipitation reaches nearly 8 times the value of the current moisture content in the atmosphere.
Jan Degirmendžić, Department of Physical Geography, Faculty of Geographical Sciences University of Łódź Narutowicza 88, 90-139 Łódź: Poland
Krzysztof Kożuchowski [email@example.com], Department of Environment Dynamics and Bioclimatology, University of Łódź, Lipowa 81, 90-568 Łódź, Poland