Aerosol‐Radiation Interactions of Dust Storm Deteriorate Particle and Ozone Pollution in East China

Abstract East Asia features frequent dust storms and intensive anthropogenic emissions. The mixing of natural dust and anthropogenic pollutants exerts complicated impacts on air pollution and regional climate. Studies have focused on chemical interactions of the mixed pollution, while the meteorological feedback and influences on atmospheric chemistry have not been fully investigated. Here, a comprehensive study on a widespread dust storm and its influence on the air quality downwind was conducted by combining multiple observations and modeling. We found that dust originated from Gobi Desert was mixed with anthropogenic pollutants after transported to the Yangtze River Delta (YRD). Through scattering and absorbing radiation, dust aerosol perturbed solar energy budget and led to a more stabilized planetary boundary layer (PBL). A reduction of 15% in PBL height (184 m) weakened the dispersion of locally emitted pollutants and increased primary pollution by 10% in YRD city clusters. Besides, the mixed plume over offshore areas warmed the entire lower atmosphere and increased surface evaporation. Accordingly, ozone formation was accelerated by ∼1 ppbv/h within PBL under higher temperature, and secondary aerosol was increased due to faster photochemical and heterogeneous oxidation. Such enhancements substantially contributed to air quality deterioration in YRD region. This work reveals the complexity of interactions between natural dust and anthropogenic pollutants through both atmospheric chemistry and meteorological feedbacks, which is of great importance in both regional air pollution and climate.