Phase wise spatial and temporal variations of nitrogen dioxide during and pre COVID-19 lockdown period in tier-1 cities of India

The novel coronavirus (COVID-19) pandemic disrupted basic lifestyle of everyone across the globe. To stop the conveyance of the coronavirus into the human body and to flatten the transmission rate curve, almost every country imposed a lockdown. In India, the emergency lockdown was imposed on the 24th of March 2020 which created an economic crisis in the country but proved a boon in disguise for the environment to improve its quality. The study analysed the statuses of air quality with respect to NO(2) in pre and during the COVID-19 lockdown period in eight districts of India where tier I cities are located. Nitrous Oxide concentration was determined through Sentinel 5P satellites imagery and Central Pollution Control Board ground station data. The lockdown across the country has helped the environment to regain, and therefore, more studies are required to assess other parameters to explore the implementation of the provision of the well-planned lockdown of 1-week duration in a year for giving enough time to the environment to recuperate. These results show that the study areas (Ahmedabad, Hyderabad, Delhi, Kolkata, Mumbai, Chennai, Bengaluru, and Pune) have witnessed a significant drop in nitrogen dioxide (14–62%) as compared to the same period in 2019. This propose an idea that the devilish, COVID-19 lockdown has proved to be an unknown tool for tranquillizing air pollution (NO(2)) during a lockdown within the Territory of Indian.