Rapid mass growth and enhanced light extinction of atmospheric aerosols during the heating season haze episodes in Beijing revealed by aerosol–chemistry–radiation–boundary layer interaction

Atmospheric Chemistry and Physics Discussions

article

Lin, Zhuohui¹  Chan, Tommy²  Yan, Chao²  Daellenbach, Kaspar R.²  Chu, Biwu³  Dada, Lubna²  Kangasluoma, Juha¹  Yao, Lei²  Fan, Xiaolong¹  Du, Wei²  Cai, Jing²  Wang, Yonghong²  Cai, Runlong²  Kokkonen, Tom V.²  Zhou, Putian²  Wang, Lili⁵  Petäjä, Tuukka²  Bianchi, Federico¹  Kerminen, Veli-Matti²  Liu, Yongchun¹  Kulmala, Markku¹  Zheng, Feixue¹  Zhou, Ying¹  Guo, Yishuo¹  Feng, Zemin¹  Li, Chang¹  Zhang, Yusheng¹  Hakala, Simo² 

[1] Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology;Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki;Research Center for Eco-Environmental Sciences, Chinese Academy of Science;Joint international research Laboratory of Atmospheric and Earth SysTem sciences (JirLATEST), Nanjing University;State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences

DOI  :  10.5194/acp-21-12173-2021

学科分类：大气科学

来源: Copernicus Publications

【 摘 要 】

Despite the numerous studies investigating haze formation mechanism in China, it is still puzzling that intensive haze episodes could form within hours directly following relatively clean periods. Haze has been suggested to be initiated by the variation of meteorological parameters and then to be substantially enhanced by aerosol–radiation–boundary layer feedback. However, knowledge on the detailed chemical processes and the driving factors for extensive aerosol mass accumulation during the feedback is still scarce. Here, the dependency of the aerosol number size distribution, mass concentration and chemical composition on the daytime mixing layer height (MLH) in urban Beijing is investigated. The size distribution and chemical composition-resolved dry aerosol light extinction is also explored. The results indicate that the aerosol mass concentration and fraction of nitrate increased dramatically when the MLH decreased from high to low conditions, corresponding to relatively clean and polluted conditions, respectively. Particles having their dry diameters in the size of ∼400 –700  nm , and especially particle-phase ammonium nitrate and liquid water, contributed greatly to visibility degradation during the winter haze periods. The dependency of aerosol composition on the MLH revealed that ammonium nitrate and aerosol water content increased the most during low MLH conditions, which may have further triggered enhanced formation of sulfate and organic aerosol via heterogeneous reactions. As a result, more sulfate, nitrate and water-soluble organics were formed, leading to an enhanced water uptake ability and increased light extinction by the aerosols. The results of this study contribute towards a more detailed understanding of the aerosol–chemistry–radiation–boundary layer feedback that is likely to be responsible for explosive aerosol mass growth events in urban Beijing.

【 授权许可】

CC BY