Climate study of the Cyclonic Tracks over the Atlantic and Sahara Mediterranean Regions

The tracks of cyclones generated over the Atlantic and Saharan Mediterranean regions have been studied using the SLP data from NCEP/NCAR reanalysis data set for the period of 1970 to 2011 over the winter half period (December to May). The distribution of generated Cyclones appears both of the eastern coast of USA and the extra-tropical region in Sahara as a main areas of the cyclone tracks. The first principle mode of inter-annual variation of cyclone tracks were obtained by the Empirical Orthogonal Function (EOF) shows that, the winter half year is affected by two ant-correlated systems, one affected eastern coast of USA, while the second affected Saharan region. The first system is the mainly marked in winter season, while the second is mainly pronounced in Spring season. The surface variation pattern associated with the first principle mode of cyclone tracks indicates that, more cyclone tracks accompanied larger deepening of low pressure systems at both of high latitude Atlantic Ocean, in winter, and at Saharan Mediterranean region, in spring. At the same time, the upper wind variation at 250hPa shows that, most of cyclone tracks, in winter, are accompany of the south and north shifting of the upper maximum wind at Atlantic and Saharan Mediterranean regions; respectively, while they are accompany of the strength of the upper wind at both regions, in spring. The Explosive cyclone tracks confirm the results of the study, and show that, the numbers of the explosive cyclone tracks at winter are large, and deep, in spite of, the total numbers of cyclone tracks at spring are slightly larger.