Analyzing andTracing ofDustHazard inRecentYears inKermanshah Province

Different patterns of pressure systems together with local factors, leads in generation, rising
and spread of dust in West of Iran. In this study, to investigate the factors causing the occurrence of dust in
Kermanshah province, 132 cases of dust phenomena (code: 06) were selected and analyzed using Kermanshah
synoptic station data for the spring and summer seasons in a period of 5 years (2005-2009). The Factor
analysis had been implemented and days with higher correlation coefficient extracted, then clustering operation
was performed on the data. 4 dust emission patterns were identified and from each pattern, a certain pattern
was selected as a representative day. Using GRADS and NCEP data, maps of geopotential heights, wind speed
and vorticity advection were produced and analyzed. To identify the source of dust generation, tracing and
simulating the path of dust, HYSPLIT model Lagrangian approach of backward trajectory was used. Generally
existence of low pressure cells in the central and southern regions of Iran can lead to the convergence and air
intake at near ground levels and strong positive vorticity, which result in cyclonic movements in western
regions of Iran Including Kermanshah. These results in the transfer of dust from the dry desert areas of Iraq and
high speed winds in the lower levels of dust particles in the region has accelerated the transfer rate. Based on
the HYSPLIT outputs, major sources of dust generation, were arid zones of Southern Turkey, Iraq deserts,
Syria, North East of Saudi Arabia and Kuwait.