Dust storm phenomenon is one of the main features over the Sistan plain, eastern Iran. To examine of dust storm structure in the Sistan area, an experiment was conducted by forth-generation regional climate model in an area between 20°–48°N and 42°–78°E during the cold period of 2000 and 2002 years with two horizontal resolutions (20 and 80 km) in 6-h time step. Validation of satellite data and NCEP/NCAR re-analysis were used to stimulate model outputs. In order to have information pertaining to the dust storms, model is coupled with chemical scheme of the atmosphere, showing dust emission based on various factors. There is a systematic underestimation of dust emission especially over Sistan plain when compared with analyzed data in 80 km. However vectors and streamlines show the same direction in both resolutions but they are show better and near the fact in 20 km horizontal grid spacing compared with NCEP/NCAR re-analysis results, while 20 km will be shown the complex-terrain conditions in studied region. An additional experiment was showed that by using different resolutions and running model to calculate the dust storm factors over the Sistan plain, in 20 km resolution all land surface coverage and functions are better than 80 km resolution and this feature affected on the model outputs. This item led to obtain a clear insight regarding to dust storms when it is indicated in wind velocity cross section and sea level pressure while they are influenced by the Sistan situation.

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