Effects of aerosol emission changes on sea ice concentration and thickness in the Russian Arctic during the 2020 lockdown

Abstract

During the COVID-19 lockdown, large industries in the Russian Arctic region were closed for two months, leading to a significant reduction in anthropogenic aerosol emissions. This decline in aerosols resulted in a decrease in the human-made aerosol cooling effect. The strict lockdown measures implemented after 18 March 2020 caused a drastic downward fall in considered aerosols. Consequently, there was an impact on air temperature, with temperature differences exceeding 3 K in November and February, while clear-sky top net solar flux values were greater than 13 W m−2. Throughout the lockdown period, the Russian Arctic's annual area average sea ice concentration was 7.72% in 2019 and 7.64% in 2020. The decrease in radiation-scattering pollutants contributed to an increase in global warming. Some pollutants, like sulfur, carbon dioxide, and methane, produced a cooling effect by mitigating greenhouse gases, which could affect the speed of sea ice melt. However, due to the short duration of the pandemic, it remains challenging to determine whether the aerosol changes accelerated or decelerated the sea ice melting process. HIGHLIGHTS COVID lockdown resulted in a drastic drop in the amount of anthropogenic aerosol emitted over the Russian Arctic.; Arctic haze was experienced during April 2020.; The decline in aerosol emissions, black carbon, and sulfur dioxide led to reductions in total aerosol cooling.; Net solar radiation flux showed values greater than 13 W m−2 during lockdown.; No significant effect of anthropogenic activities on the sea ice condition was observed.;

Keywords

• air temperature
• anthropogenic aerosols
• russian arctic
• sea ice concentration