Karas, Svetlana (Ben-Gurion University of the Negrev)
Zangvil, Abraham (same affiliation)
The Mediterranean basin experiences a seasonal influence of cyclone activity. In the present study we analyze summer and winter cyclones and their tracks over the Mediterranean and vicinity, based on the National Meteorological Center Grid Point Data Set Version II. The surface cyclone tracks and tracks of minimum height patterns at 500hPa were subjectively defined using two methods. First, using tracks of cyclone centers based on actual pressure and heigh distribution and second, by using tracks of minima of daily deviations from monthly mean pressure and heigh distribution. The second type of analysis shows a large increase in number of detectable cyclone tracks on "deviation" maps. In addition, using this method we can observe cyclone tracks for a period of 5-6 days in comparison with 2-3 days in the conventional track analysis. Even in summer, when the conventional analysis yields mostly a stationary low pressure center associated with the Persian Gulf Trough we obtained signs of moving westerly disturbances and a weak trace of an "easterly wave".