Anomalous Dynamics of Tropospheric Ozone in the Spring of 2020 in Central Russia

Anomalously low ozone concentrations in the surface atmosphere in central Russia were recorded in spring of 2020. The increase in the ozone content usual for spring due to a seasonal increase in the temperature and light was followed by a monotonic decrease. The maximum daily values of surface ozone concentrations averaged over the month in April 2020 were three times less than the values recorded at the same time in 2019. Both a decrease in regional background ozone concentrations in the near-surface atmosphere and a decrease in the intensity of its photochemical formation were observed. The most probable cause of the observed phenomenon is a decrease in combustion product emissions into the atmosphere in China, Europe, and Russia due to the introduction of special regimes in connection with the COVID-19 pandemic.