  Air pollution has been a long-existing problem for most of the major
metropolitan cities of the world. Several measures including strict climate
laws and reduction in the number of vehicles were implemented by several
nations. However, in the recent wake of the COVID19 pandemic, there has been a
renewed interest in revisiting the problem of low air quality. Several
countries implemented strict lockdown measures halting the vehicular traffic
and other economic activities, in order to reduce the spread of COVID19. In
this paper, we analyze the impact of such COVID19-induced lockdown on the air
quality of the atmosphere. Our case study is based in the city of Dublin,
Ireland. We analyze the average concentration of common gaseous pollutant
majorly responsible for industrial and vehicular pollution, \textit{viz.}
nitrogen dioxide (NO$_2$). These concentrations are obtained from the
tropospheric column of the atmosphere collected by Sentinel-5P, which is an
earth observation satellite of European Space Agency. We observe that Dublin
had a significant drop in the level of NO$_2$ concentration, owing to the
strict lockdown measures implemented across the nation.
