Assessing the Trends of Three Main Air Pollutants in Tehran City Using Data from Sentinel-5 †.

In recent years, by expanding cities, air pollution has become one of the most important problems caused by humans. Tehran, as the capital of Iran, is expanding gradually and its population is rising day by day. Therefore, the increase in human activities causes many problems, such as air pollution, in this area. In this study, data from Sentinel-5 for Tehran city are used from the last month of 2018 to present and collected from the Google Earth Engine. Three main parameters of air pollution are studied, including aerosol, ozone and CO. Different statistics of each parameter are calculated. Then, temporal evolutions are analyzed using Statgraphics. From the analysis, the calculated aerosol median is −0.555 mol m − 2 and the interquartile range is 1.248 mol m − 2 . For the ozone parameter, the median is calculated to be 0.131 mol m − 2 and the interquartile range is 0.015 mol m − 2 . Also, for the CO parameter, the median is 0.037 mol m − 2 and the interquartile range is 0.011 mol m − 2 . The total trend of aerosol is increasing, especially during the summer months, when aerosol amounts are higher than in the winter months. Our statistics show a decreasing trend for the ozone parameter, but in the winter months, ozone is higher than in the summer months. The trends for aerosol and ozone are statistically significant at the 95% confidence level. The trend of CO is totally stable but a little higher at the end of fall and during the first days of winter. [ABSTRACT FROM AUTHOR]