Climatology
Maryam Teymouri; Bromand Salahi; Mohammad-Ali Nasr Esfahani
Abstract
To study the cyclogenesis within the Mediterranean region in different phases of Madden-Julian Oscillation (MJO) during the cold season (November, December, January, and February) between 1989 and 2020, MJO index and mean sea level pressure data from the European Centre for Medium-Term Atmospheric Prediction, ...
Read More
To study the cyclogenesis within the Mediterranean region in different phases of Madden-Julian Oscillation (MJO) during the cold season (November, December, January, and February) between 1989 and 2020, MJO index and mean sea level pressure data from the European Centre for Medium-Term Atmospheric Prediction, ERA5 section were utilized. For visualizing the frequency, depth, and tracking characteristics of cyclogenesis, the University of Melbourne method was used. The results showed that the strongest cyclones in the region formed in phases 8, 6, and 7, respectively, with a pressure less than 994 hPa. In terms of the frequency of cyclogenesis and the core of cyclones in the region, the highest and the lowest amount of cyclogenesis were related to phase 7 and 1, respectively. The results showed that phases 6 and 7 have the strongest central pressures, whereas phases 1, 3, and 5 have the weakest central pressures of the MJO phases. Phase 2 has the lowest value of central pressure and the highest average pressure is related to phase 5. The tracking of cyclones that formed within the Mediterranean region showed that most of the paths that ended in the western regions of Iran were in phases 2 and 8, whereas in other phases, these tracks had a southwest to northwest direction. These situations were the case during phases 3, 4, 6 and 7, which caused most of the cyclones formed in the cold season of the year to affect most of the north-western regions of Iran.
