Investigating the effect of reducing activities and traffic during the outbreak of Coronavirus on temporal-spatial changes of nitrogen dioxide pollutant using Sentinel 5 satellite images in East Azarbaijan

Air pollution is one of the most significant challenges in today's world, particularly in developing countries. Therefore, it is necessary to monitor and control the amount of pollutants that threaten human health. In recent years, remote sensing data related to the Sentinel 5 Tropomy sensor has been considered a rich and up-to-date source of information for monitoring and investigating the temporal-spatial changes of air pollutants. In this study, the Google Earth Engine system was used to obtain Tropomi sensor products to check the amount of nitrogen dioxide pollutants in East Azerbaijan province. For this purpose, the distribution map of the NO2 was produced in four consecutive years (1397-1400). Additionally, due to the effective role of motor vehicle traffic in increasing the amount of this pollutant on the one hand and the restriction of activities and traffic of cars during the spread of the Covid-19 virus on the other hand, the changes of nitrogen dioxide in different time periods were investigated to determine the effect of restrictions on the concentration of this pollutant quantitatively. Also, in order to investigate the impact of the reopening of schools and universities after the corona pandemic, pollutant distribution maps were produced and compared for April 1400 and April 1401. The results showed that the density of NO2 in the center of the province was higher than in other cities in all time periods, and the 14-day closure in 2019 had the greatest effect in reducing the pollutant, which was about 59% in Tabriz.