COVID-19 Pandemic Hopeful Prospect: Air Quality Improvements over Indo-Gigantic Plain

The COVID-19 pandemic has received enormous attention worldwide due to its environmental, and societal impacts. The present study highlights the spatio-temporal variations in air quality parameters (AOD, SO₂, NO₂, and O₃) due to lockdown over the IGP, one of the world's most populated regions. The satellite retrievals of aerosol optical depth (AOD), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and Ozone (O₃) were used to estimate the spatial-temporal extent of major air pollutants in the region during lock down period (March-May, 2020) in comparison to the pre-lockdown period (March-May 2015-2019) and post-lockdown (March-May, 2021) across the IGP. To provide more insight into the changes in air pollutants status, country and city scale percentage increase/decrease have also been calculated. Following strict lockdown implementation, reduction in anthropogenic activities led to a significant decline in AOD, SO₂ and NO_2, whereas a considerable increase in tropospheric O₃ concentration has been noticed that in turns significantly improved the regional air quality. But these trends reversed as soon as the lockdown was relieved and human activities normalized.  Moreover, the comparative analysis among meteorological parameters and ambient air pollutants presented that meteorological factors were not the main reason for the dramatic reductions of pollutants in the atmosphere. The outcome of this study can be a reference to introduce new public policies for promoting adaptive socio-ecological models to understand the synergies and trade-offs between the reduced human interventions and the environmental health of cities systematically.