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 AOD500 for prelockdown and lockdown periods were 0.43 ± 0.19 and 0.53 ± 0.11 respectively. The higher AOD500 during lockdown was due to an increase in naturally derived coarse mode aerosols, which is further confirmed with the lower Ångström 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.