نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
One of the issues that has been observed especially in recent years in the West Asian region is the simultaneous occurrence of snow or rain along with dust storm. On May 5-10, 2024, the presence of atmospheric fronts associated with low-pressure systems over the West Asia region caused heavy rainfall in some areas and dust storms in other areas at the same time. The aim of this study is to comprehensively investigate these simultaneous atmospheric events. For this purpose, a set of satellite data and products and reanalysis data were used. Since it is difficult to forecast these phenomena, the output of the WRF-Chem model was examined in order to qualitatively evaluate the dust and rain forecast in the region. On May 5, 2024, the Occluded front, associated with the low-pressure system, covered Turkey from the east to the center of the country. On this day, from the east of the Black Sea to the north of the Red Sea, cold and warm fronts followed each other. The warm front extended from the east of the Black Sea to the north of the Caspian Sea. There was a cold front in the northwest of Iran and cold and warm fronts in the north of Saudi Arabia and the border areas of this country with Iraq and Syria. Further, with the movement of low-pressure systems to the east and northeast, their fronts were also moved. During this period, on the one hand, strong winds caused by cold fronts over Iraq, Syria, Northern Saudi Arabia, Turkmenistan and southwest and center of Iran and on the other hand, the presence of thermal low-pressure systems over Saudi Arabia and the southern half of Pakistan caused dust emission in the region. The relative humidity (RH) and streamlines maps at 700hPa level show the transfer of moisture from the east of the Mediterranean Sea, the Black Sea and the Caspian Sea at higher latitudes and from the Red Sea, the Arabian Sea, the Persian Gulf, the Oman Sea and the northern Indian Ocean at lower latitudes in the presence of atmospheric fronts and ascending movements due to instability, caused rain over parts of the region. The severe gradient of RH over the region caused simultaneous occurrence of rain along with dust during this time interval. The output of the WRF-Chem model showed that this model was able to forecast the simultaneous occurrence of dust and precipitation in its 48-hour forecast. The pattern of precipitation and dust in the output of the WRF-Chem model is very similar to the satellite products.
کلیدواژهها English