Victoria Ezzatian - Esfahan Meteorological office.PHD.In Climateology

Dust has adverse effects on the environment and imposes heavy costs on the community, so accurate monitoring of the status and identifying the factors affecting the escalation and creation of it is important. The continuity of drought in Zayandehrood River is one of the effective factors in increasing dust in Isfahan. In this study, in order to monitor the dust, the experimental index of dust storms in the period of 2012-2015 was calculated based on Horizontal Field Measurement. The results indicate that at 4 stations, the dust storm has happened more than the rest, and in the north-east of Isfahan the highest values were calculated. In 2013 in Isfahan, in 258 days dust was higher than the permitted limit of 35.4 μgr/m2, so this year was specifically examined. Studies have shown that the establishment of high pressure system, severe weather cooling, and sustainability have been the factors that exacerbated the dust in the cold season. Meanwhile, fluctuations and precipitation rates were compared between two stations in southwest and northeast of Isfahan. Northeast station is located near the Segzi Desert and its dust level is more than other areas. Studies have shown that light rainfalls are less than short-time heavy rainfalls in the northeast of Isfahan. The presence of dust particles has reduced the formation of Stratiform Clouds (leading to light and continuous rainfall), and the strengthening of Convective Clouds (resulting in heavy rainfall) and decreasing the size of cloud droplets and weakening the cloud formation process.

DSI index, Cloud mechanism, Light rain, Shower rain, Stratus and Convection Cloud