Limited Regional Aerosol Changes Despite Unprecedented Decline in
Nitrogen Oxide Pollution During the February 2020 Coronavirus Shutdown
in China
Abstract
Following the emergence of a novel coronavirus in Wuhan, the People’s
Republic of China instituted a number of strict lockdown and more
general socio-economic shutdown measures throughout the country starting
in late January and continuing into February 2020 in order to arrest the
spread of the disease. This resulted in a sharp economic contraction
unparalleled in recent Chinese history. Satellite remote sensing shows
that nitrogen oxide pollution declined by an unprecedented amount
(~50% regionally) from its expected unperturbed value,
but regional-scale column aerosol loadings and cloud microphysical
properties were not detectably affected. The disparate impact may be
tied to differential economic impacts of the shutdown, in which the
transportation sector, a disproportionate source of nitrogen oxide
emissions, underwent drastic declines (~90% reductions
in passenger traffic), whereas industry and power generation,
responsible for >90% of particulate emissions, were
relatively less affected (~10% reductions in
electricity and thermal power generation).