Application of HYSPLIT and WRF/Chem Models to Investigate the Dust Storm Episodes

Background: Long-range transport of dust aerosol has intense impacts on theatmospheric environment over wide areas. Methods: The annual and seasonal changes inmeteorological parameters associated with the occurrence of dust storms were studied. Thefeatures of an intense dust storm and its transport characteristics were studied during June 7thto June 9th 2010 in Ahvaz city. Temporal and spatial distribution of Middle Eastern dust stormevent was analyzed by models of HYSPLIT and WRF/Chem, and in- situ observations. Results:A disagreement between the occurrences of dust storms, temperature, relative humidity andrainfall, show the major source of dust storms over Ahvaz city are neighboring countries. UsingHYSPLIT results, the dust particles are mainly transported from north western region of Iraqand eastern Syria to downward areas including Ahvaz city. The arrived Dust aerosols mixedwith local anthropogenic emissions, led to the highest PM10 concentration of 4200 ppm. Themodel results were found to well reproduce temporal and spatial distribution of mineral dustconcentrations according to in-situ measurements. Conclusion: The performance of WRF/Chemwas acceptable for simulation of temporal and spatial distributions of dust storm events.Therefore, it can be taken as a reference in daily air quality forecasting.