Unprecedented reduction in airborne aerosol particles and nitrogen
dioxide level in response to COVID-19 pandemic lockdown over the
Indo-Pak region
Abstract
The present study have used space observations of NO emission (OMI) and
aerosol optical depth (AOD) (MODIS) from the last couple of years
(2015-2019) to investigate the changes in air pollution in response to
COVID-19 pandemic during the lockdown period (Mar-May, 2020) over the
Indo-Pak region. Result of this study reveals a huge drop in air
pollution that accounted for 40-50% reduction in NO emissions and 45%
in AOD over the whole Indo-Pak region. The major metropolitan areas
(cities) of the region showed a remarkable decrease in NO emissions,
whereas the calculated rate of reduction was found highest for the city
of Lahore (Pak) ranges between 29-52% followed by Ahmadabad (Chennai)
as 27-52% (32-42%) respectively. The geospatial analysis revealed the
existence of positive correlation (range from 0.23-0.50) between AOD and
NO emissions, which further implies that a decrease in AOD may be
attributed to reduction in NO to some extents.