Numerical Simulation of Air pollutants in Tehran Based on Wind patterns By TAPM Model

Through this article, the distribution of pm10 in Tehran was simulated based on wind patterns without the presence of synoptic patterns by a model called TAPM (a meso-scale model). The simulation covers three horizontal resolution domains 30, 10 and 3 kilometres. The pollutant chosen for this simulating was PM10. The result showed that the model was successful in simulating the pollutant emissions about 61 percent this score is good according to the TAPM designers. The simulation result can be acceptable because the air pollution stations measure the pollutants based on point sources while the model does simulation in the surface level (area source). The statistical output from this research showed that the concentration of pollutants increases from north to south and east to west over the city of Tehran. The variance analysis shows that two municipality zones (11, 12) are the most polluted area and the zone 21 is the cleanest. This is due to the wind direction ruling over Tehran. With the presence of synoptic conditions, the wind speed increases in height level and the contours show harmony while in conditions without the presence of synoptic the wind speed decreases and the contours do not show any harmony. Since the wind speed is almost always less than the Tu. Coefficient, we do not expect the wind to refine the air in Tehran.