Effect of first wave COVID-19 outbreak lockdown measures on satellite-based tropospheric NO2 over Mersin Province, Turkey

Abstract

In recent years, greenhouse-trace gases pollution is one of challenging problems all over the world. Due to the coronavirus (COVID-19) epidemic in the world, almost all countries implemented some restrictions that reduced human activities in cities and industries. As a result of these restrictions, an opportunity occurred to monitor the changes in anthropogenic (human-made) air quality. Among the other air pollutants, NO2 is one of the important trace gases on the atmosphere which can arise with anthropogenic and natural sources. This study investigated NO2 pollution derived from Sentinel-5P satellite associated with the first wave lockdown of COVID-19 pandemic over Mersin city, located at the Mediterranean coast of Southern Turkey. The tropospheric NO2 vertical column density (VCD) data were derived from TROPOMI instrument onboard the Sentinel 5P satellite, and Google Erath Engine (GEE) platform was used for the analyses. The results showed that the substantial 35 % reduction in NO2 concentration was observed over Mersin when comparing the lockdown time in 2020 and the corresponding days in 2019.