Aerosol–photolysis interaction reduces particulate matter during wintertime haze events

Significance Aerosol–radiation interaction (ARI) not only constitutes one of the major uncertainties in climate prediction, but also significantly deteriorates particulate matter (PM) pollution during heavy haze events. However, modification of photolysis caused by aerosol absorbing and/or scattering solar radiation (referred to as aerosol–photolysis interaction or API) changes atmospheric oxidizing capability and influences secondary aerosol formation. The synergetic effect of API and ARI on PM pollution is quantitatively assessed during a persistent heavy haze episode from a modeling perspective in the study. The results reveal that API hinders secondary aerosol formation and substantially mitigates the PM pollution caused by ARI. Future research on the radiative forcing of API is essential to improve the understanding of the aerosol climate effect.