The CoVID-19 infections began rising worldwide during the initial weeks of March 2020, reacting to which the Government of India called for nationwide lockdown for ~ 3 weeks. The concentration of pollutants during the lockdown were compared with pollution levels recorded during the preceding year for the same time frame. A direct relationship was established between the high level of air pollutants (PM 2.5 , PM 10 , NO 2 and SO 2 ) and CoVID-19 infections being reported in the Indian cities. The correlation indicates that the air pollutants like PM 2.5 , PM 10 , NO 2 and SO 2 are aggravating the number of casualties due to the CoVID-19 infections. The transmission of the virus in the air is in the form of aerosols; and hence places which are highly polluted may see a proportionate rise in CoVID-19 cases The high-level exposure of PM 2.5 over a long period is found to be significantly correlated with the mortality per unit confirmed CoVID-19 cases as compared to other air pollutant parameters like PM 10 , NO 2 and SO 2 .

Amid the COVID-19 pandemic and countrywide lockdown, the super-cyclone Amphan collided with the eastern coast of India, majorly affecting the Indian state of West Bengal. The lockdown restricted the industrial emissions of greenhouse gases known for increasing the average global temperature, however the sea-surface temperature (SST) profile over the Bay of Bengal indicated higher than average SST values in preceding 5 years. The unexpected increase in sea-surface temperature might have played a major role in formation cyclonic disturbances over the Bay of Bengal, which might have triggered the formation of super cyclone Amphan. The anomalous increase in average SST could be attributed to the sudden lowering of particulate matter concentration due to the lockdown, which resulted in the increase in levels of solar insolation on the sea-surface due to the absence of particulate matter load, which reflects/absorbs the incoming solar radiation to the surface keeping the sea-surface temperature at lower levels.