Estimate of the Time of Downfall Phenomenon Dusty Days Using the Correlation of Pm10 Data and Sunphotometer Data

Nowadays, urban air pollution has become a social problem and therefore various tools have been used to measure pollutants. Such as these tools are the system that measure in-situ aerosol concentration and remote sensing instruments the ground-based. In this study, we estimate dust duration in Zanjan for few dust days using data achieved from aerosols sampling ground-based and sunphotometer instruments. Particulate matter less than 10 micrometer (PM10) has been achieved by using ground-based instrument at a height of 3 meters upper than ground while aerosols optical depth which is reagent of aerosols amount in atmosphere orthogonal column has been achieved by sunphotometer instrument. According to the correlation coefficient between of PM10 and AOD in 9th, 10th, 24th, and 25th June 2010, the maximum values was obtained at o’clock 2, 6, 3, and 3, respectively. It means that 2, 6, 3, and three hours took, respectively, that the PM10 reached to the ground surface.