Effect of SARS-CoV-2 pandemic induced lockdown on the aerosol loading over the coastal state, Goa

The SARS-CoV-2 pandemic resulted in India imposing a nationwide lockdown on 22 March 2020, bringing all human activities to a complete halt The current study focuses on the effect of lockdown on the abundance of atmospheric aerosols over Goa The study focused on pre-lockdown, lockdown and period corresponding to lockdown in 2019 The AOD spectra depicted a decrease in the anthropogenically derived fine mode aerosols during the lockdown compared to the pre-lockdown period Mean AOD(500) for prelockdown and lockdown periods were 0 43 +/- 0 19 and 0 53 +/- 0 11 respectively The higher AOD(500) during lockdown was due to an increase in naturally derived coarse mode aerosols, which is further confirmed with the lower Angstrom exponent values (1 04 +/- 0 11) The mean black carbon mass concentration for the respective periods were 1990 45 +/- 470 87 ng m(-3), and 1109 71 +/- 218 33 ng m(-3), and the mean atmospheric forcing during the respective periods were 25 13 +/- 5 72 W m(-2), 27 31 +/- 3 71 W m(-2) and 30 81 +/- 5 59 W m(-2) respectively