Aerosol light absorption alleviates particulate pollution during wintertime haze events
Abstract
Aerosol light absorption has been widely considered as a contributing factor to the worsening of particulate pollution in large urban areas, primarily through its role in stabilizing the planetary boundary layer (PBL). Here, we report that absorption-dominated aerosol–radiation interaction can decrease near-surface fine particulate matter concentrations ([PM 2.5 ]) at a large-scale during wintertime haze events. A “warm bubble” effect by the significant heating rate of absorbing aerosols above the PBL top generates a secondary circulation, enhancing the upward motion (downward motion) and the convergence (divergence) in polluted (relatively clean) areas, with a net effect of lowering near-surface [PM 2.5 ]. Furthermore, aerosol absorption of ultraviolet-wave light effectively reduces the photolysis of chemical species, i.e., aerosol–photolysis interaction, hindering ozone formation, reducing atmospheric oxidizing capability, and suppressing secondary aerosol concentrations. Our model assessment reveals that the synergetic two effects decrease near-surface [PM 2.5 ] by around 7.4%, so the presence of light-absorbing aerosols can considerably alleviate particulate pollution during wintertime haze events. Such negative feedbacks to the aerosol loading should be considered in weather/climate prediction and health assessment models.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (19)
Jiarui Wu
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences
Naifang Bei
School of Human Settlements and Civil Engineering, Xi’an Jiaotong University
Yuan Wang
Xiaoli Su
Ningning Zhang
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences
Lili Wang
Department of Chemistry
Bo Hu
Qiyuan Wang
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences
Qian Jiang
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences
Chenchong Zhang
Department of Earth System Science, Stanford University
Yangfan Liu
Department of Earth System Science, Stanford University
Ruonan Wang
State Key Laboratory of Common Mechanism Research for Major Diseases, Department of Biophysics and Structural Biology
Xia Li
Yuxuan Lu
Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Coal-based Value-added Chemicals Green Catalysis Synthesis
Zirui Liu
Junji Cao
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences
Xuexi Tie
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences
Guohui Li
Interdisciplinary Research Center for Biology and Chemistry
John Seinfeld
Department of Chemical Engineering, California Institute of Technology