Changes in sources and formation mechanisms of carbonaceous aerosols driven by short-term air pollution controls in Megacity Xi'an, China

Carbonaceous aerosols have a significant impact on global climate and human health. Controlling carbonaceous aerosol pollution is a considerable challenge due to the complex sources and the unintelligible secondary formation processes. The 14th National Games of the People's Republic of China were successfully held in Xi'an in 2021, which imposed strict emission controls on air pollution sources for the whole society, providing an experimental opportunity to study the effects of air pollution control measures on carbonaceous aerosols. Based on a combination of atmospheric observation studies and the Weather Research and Forecasting model coupled with online chemistry (WRF-Chem) simulations, we explore the impact of air pollution control on carbonaceous aerosol pollution characteristics, sources, and formation mechanisms. After removing the meteorological conditions, the anthropogenic abatement measures significantly improve regional ambient air quality with the air