Numerical Simulation of a Dust Storm Event Using Mesoscale Models MM5 and TAPM

Injection of dust into the atmosphere influences climate at a variety of spatial and temporal scales. Iran's semi-arid environment is included in the so-called dust belt where dust storms frequently occur, especially in the summer season and dry years. Research is currently surface layer winds in the mountainous Central plateau of Iran. to this end, two mesoscale, models have been employed in simulation of low-level meterology for a specific case study day (in May 2003) when an intense dust storm event occurred in the vicinity of the city of Yazd. The models used for this work are Mesoscale Model (MM5) and The Air Pollution blodel (TAPM). Both models are non-hydrostatic and use telescoping interactive grid-nesting -abilities to enhance spatial resolution down to 1 km grid spacing. Initial results are very pmising with MM5, but not very good with TAPM. Although both models can forecast (nmulate) wind direction fluctuation with reasonable skill, they have more difficulty with PI-iding a more accurate wind speed estimate.