Comprehensive Insights Into O ₃ Changes During the COVID‐19 From O ₃ Formation Regime and Atmospheric Oxidation Capacity

Economic activities and the associated emissions have significantly declined during the 2019 novel coronavirus (COVID‐19) pandemic, which has created a natural experiment to assess the impact of the emitted precursor control policy on ozone (O 3 ) pollution. In this study, we utilized comprehensive satellite, ground‐level observations, and source‐oriented chemical transport modeling to investigate the O 3 variations during the COVID‐19 pandemic in China. Here, we found that the significant elevated O 3 in the North China Plain (40%) and Yangtze River Delta (35%) were mainly attributed to the enhanced atmospheric oxidation capacity (AOC) in these regions, associated with the meteorology and emission reduction during lockdown. Besides, O 3 formation regimes shifted from VOC‐limited regimes to NO x ‐limited and transition regimes with the decline of NO x during lockdown. We suggest that future O 3 control policies should comprehensively consider the effects of AOC on the O 3 elevation and coordinated regulations of the O 3 precursor emissions.