A climatological study: wet season cyclone tracks in the East Mediterranean region

Abstract

This work identifies a total of 1,992 cyclone tracks over the East Mediterranean region using six hourly sea level pressure fields taken from National Center for Environmental Prediction and the National Center for Atmospheric Research (NCEP/NCAR) reanalysis for the period 1958–2010. A classification method is developed to classify the long-track cyclones into four key routes. Besides these, two other routes are considered, which are classified as either stationary or having a short track length. This study reveals that the East Mediterranean region has three main cyclogenesis areas and four main cyclolysis areas. Analysis of the relationships between the main cyclogenesis and cyclolysis areas indicates that the Anatolian Mountain region generates the largest number of cyclones and that they terminate in four cyclolysis areas. It is also found that 19.0, 29.4, and 51.6 % of the cyclones are stationary, short, and long tracks, respectively, while only 1.6 % of the cyclones are explosive. The average lifetime of the tracks is between 2 and 3 days, although a few live up to 5 or 6 days. The study of the synoptic composition of the routes indicates that the East Mediterranean cyclones are controlled by two key processes: (i) the possibility of merging tracks with low pressure systems over the Arabian Peninsula and (ii) the extensions of both the Azores and the Siberian highs into the East Mediterranean, as well as by the wind speeds in the upper atmosphere.