Cyclone track variability over Turkey in association with regional climate

In this study a set of cyclone frequency statistics is developed and the pr evailing tracks of cyclones are derived for a region of the world that has not been previously investigated in detail. Analysis reveals that Turkey ex periences the effects of five dominant cyclone trajectories. Investigation of the seasonal variability of the cyclone frequencies shows that the highe st number of cyclones occurs during winter. The variability of the subtropi cal jetstream latitude is analysed by multi-variable regression involving c yclone numbers, the numbers of occurrences of the Mediterranean Persistence High Pressure (MPHP), which is an extension of the Azore High Pressure and their periods. This analysis revealed that the most important factor among the three factors chosen is the number of observed blocking cases over Tur key. Although the northern parts of Turkey are accepted as having a transit ional type climate between the Mediterranean and temperate regions, our res ults showed that they are more influenced by cyclones of Mediterranean orig in. Copyright (C) 2000 Royal Meteorological Society.