A Lagrangian view on severe haze in Beijing: local and long-range sources of trace gases and primary and secondary aerosols

作者：Benjamin Foreback, Petri Clusius, Metin Baykara, Alexander Mahura, Lukas Pichelstorfer, Carlton Xavier, Putian Zhou, Tom Kokkonen, Veli‐Matti Kerminen, Yongchun Liu, Men Xia, Xin Chen, Chenjie Hua, Zongcheng Wang, Paul I. Palmer, Roman Nuterman, Alexander Baklanov, Giancarlo Ciarelli, Victoria A. Sinclair, Zhi-Song Liu, Taiwo Ashu, Valery Ashu, Markku Kulmala, Pauli Paasonen, Michael Boy · 发表于：Atmospheric Environment · 年份：2025 · DOI：10.1016/j.atmosenv.2025.121602 · 被引用次数：1 · 研究领域：Atmospheric chemistry and aerosols、Air Quality Monitoring and Forecasting、Air Quality and Health Impacts

Beijing is particularly prone to frequent wintertime haze episodes. In this study, we introduce the FLEXPART (FLEXible PARTicle dispersion model) and SOSAA (the model to Simulate the concentration of Organic vapors, Sulfuric Acid, and Aerosols) modeling system for air quality analysis and applied the newly developed modeling system to a severe pollution episode during a case study in Beijing in November 2018. FLEXPART-SOSAA uses a Lagrangian approach following backward trajectories, and its novelty includes detailed chemical and aerosol mechanisms along each trajectory, incorporating aerosol size distribution in addition to simple mass concentrations. This is particularly valuable from a health perspective. In this study, we demonstrated FLEXPART-SOSAA's capabilities along 7-day backward trajectories to investigate the origins and processes of haze during the case study. Our findings indicate that approximately 75 % of the particles in Beijing originated from outside the city. During the haze episode, the back-trajectories passed through the high-emission region of southern Hebei province. Some of the particle mass was traced back to the Xinjiang region in far western China. After evaluating the results, we tested reduced-emission scenarios and sensitivity tests. We determined that comprehensive emission control across multiple emission sectors was more effective than addressing only one individual sector, and emission control at a regional or national level would be signific...