The atmospheric oxidizing capacity in China - Part 2: Sensitivity to emissions of primary pollutants

Reducing NOx emissions significantly decreases the concentration of particulate nitrate, which enhances ozone formation through increased HO2 radical levels due to reduced aerosol uptake and diminished aerosol extinction. Additionally, an enhanced atmospheric oxidative capacity, driven by larger contributions from the photolysis of oxidized VOCs (OVOCs) and OH-related reactions, also favors urban ozone formation. With additional reductions in anthropogenic VOC emissions, increases in summertime ozone (VOC-limited areas) can be offset by reduced production of radicals from VOC oxidations.

To effectively mitigate ozone pollution, a simultaneous reduction in the emission of NOx and specific VOC species should be applied, especially regarding alkenes, aromatics, and unsaturated OVOCs, including methanol and ethanol.