The analysis of Meteorological Parameters Influencing dust Genesis over the Middle East

Dust storms are a characteristic feature of the climate of the Middle East, where major regions of winderosion activity are located on the Tigris-Euphrates alluvial plains in eastern Syria, Iraq and the Iran–Iraqborder, the deserts of the Arabian Peninsula, and southeast Iran (Middleton, ۱۹۸۶; Barkan et al., ۲۰۰۴; Caoet al., ۲۰۱۵; Hamzeh et al. ۲۰۲۱). Destruction of agricultural land by wind erosion happened in many areasof the world (Oldeman, ۱۹۹۲). At the field scale (less than one square kilometer), wind erosion hasdestructive effects on crop growth, livestock production, agriculture, infrastructure and ecosystem health(Leys, ۱۹۹۶; Shao, ۱۹۹۳). This study presents a meteorological analysis and synoptic classification of dustpatterns over the Middle East, using ۳h interval synoptic stations visibility present weather data, ECMWFReanalysis Data, Aerosol Optical Depth(AOD), and dust storm index (DSI) during the years ۲۰۰۹ to ۲۰۱۸.The dust behavior as a matter of frequency, duration, intensity as well as spatial and temporal variation ofdust occurrence has been analyzed. Moreover, potential dust sources in the Middle East were modified inthe synoptic analysis. The study of seasonal and annual average values of ۵۵۰nm AOD during ۲۰۰۹-۲۰۱۸in the Middle East shows that changes in this parameter in different seasons of the year are affected bysynoptic, micro and mesoscale patterns affecting dust genesis over the area. Moreover, the synopticpatterns leading to the formation of dust occurrence in the region during summer and winter are analyzedbased on synoptic weather maps, satellite images and AOD. The blowing of southeasterly winds over thePersian Gulf caused by the front in the southwestern regions of the country, provide the conditions foractivating internal dust sources in the southeast of Khuzestan, which leads to an increase in the value of۵۵۰nm AOD. Gradually, as the warm season approaches, the pattern of dust formation is strengthened bynortherly and northwesterly winds and canalization of the wind field due to convergent topography,especially in Mesopotamia. On the other hand, in the warm season of the year on the border of Iran andAfghanistan, the dust formation with the pattern of low-level jets leads to an increase in the value of AOD.

Keywords:

Dust , AOD , visibility , Middle East , Dust Storm Index (DSI)