Identification of the Most Important Synoptic Patterns of Dust Generation in Kohgiluyeh and Boyer-Ahmad County

This research aims to identify the synoptic patterns of dust generation in Kohgiluyeh and Boyer Ahmad provinces. Therefore, two sets of data including the daily data of dust code 06 from Hamdid stations in the statistical years 2007 to 2017 and the variables of air temperature, geopotential height, sea level pressure, orbital wind, meridian wind, specific humidity, and omega were used as upper atmosphere data. To check the synergism of the dust-generating patterns in the given years, the uneven circulation patterns of the geopotential height of 500 hectopascals in the dusty days of the province were drawn. After determining the days of dust using cluster analysis and integration by the Ward method, 5 patterns were extracted and drawn on the roughness data of peninsular height of 500 hectopascals. The results of this research showed that there is the most significant relationship between the synoptic patterns of the Middle East region and dust events in the province by circulation patterns number 2 and 5 at the level of 500 hectopascals. For a better conclusion of the conditions and factors causing the dust phenomenon in Kohgiluyeh and Boyer Ahmad provinces, maps of average sea level pressure, specific humidity at levels of 1000, 850, and 700 hectopascals, omega (vertical air velocity in the atmosphere) at levels of 1000 and 400 hectopascals, Tavai ( Convergence and divergence of wind) at 500, 700 and 1000 hPa levels and drawing of a jet (river of wind) at 200 hPa level during the rule of each of the models were drawn and analyzed.