Studying of Meteorological Patterns, Identifying of Dust Sources and Motion Track of Particles for Dust Storm, July 2009

In arid and semi­arid areas, dust storms occur frequently. When surface winds are strong, large amounts of sand and dust can be lifted from bare, dry soils into the atmosphere and transported downwind affecting regions hundreds to thousands of kilometers away. Dust storms are most commonly caused by strong pressure gradients which cause an increase in wind velocity over a wide area. For countries in and downwind of arid regions, airborne sand and dust presents serious risks to the environment, property and human health. In recent years, systematic research on dust storms has been carried out. Dust storm in the east of Asia, is quite well documented through the analyses of synoptic records over the past 50 years (Sun et al., 2001; Zhou, 2001; Chun et al., 2001; Qian et al., 2002; Natsagdorj et al., 2003; Kurosaki and Mikami, 2003; Shao and Wang, 2003). Sun et al. (2001, 10331) analyzed the synoptic reports over the 40­years period between 1960 and 1999 and found that Gobi in Mongolia and north of China are major dust sources. In this paper, we identify the main sources of dust production, test forward trajectory technique and investigate characteristics of pressure patterns of dust events in July 2009 in Western Iran.