汾渭平原典型污染城市PM2.5来源分布及传输分析

基于后向轨迹模式（HYSPLIT）和美国国家环境预报中心的GDAS数据（2019年3月—2020年2月），模拟了临汾市冬季24 h的气团后向轨迹按季节的聚类，研究了不同来源区域对临汾市PM_2.5的主要污染来源和污染传输通道，阐明了PM_2.5不同轨迹传输的季节特征，结合潜在源贡献（PSCF）分析法和浓度权重轨迹（CWT）分析法，解析了不同污染源区对临汾市的污染贡献强度。结果表明：临汾市PM_2.5污染主要集中在冬季，春秋季次之，夏季最低；通过气团后向轨迹聚类分析发现，沿汾河流域西南与西北方向是大气污染主要传输通道；潜在源贡献和浓度权重轨迹分析发现，临汾市境内、洪洞县、尧都区、襄汾县污染贡献强度较大，周边城市榆林、运城、焦作对临汾市有所影响。

PM2.5 source distribution and transmission analysis in typical polluted cities of Fenwei Plain

Based on HYSPLIT backward trajectory model and NCEP's GDAS data (from March 2019 to February 2020), the seasonal clustering of air mass backward trajectory in Linfen City for 24 hours in winter was simulated, the main pollution sources and pollution transmission channels of PM2.5 from different source areas were studied, and the seasonal characteristics of different trajectory transmission of PM2.5 were clarified. Combined with the potential source contribution factor (PSCF) analysis method and the concentration weighted trajectory (CWT) analysis method, the pollution contribution intensity of different pollution source areas to Linfen City was analyzed. The results showed that PM2.5 pollution in Linfen City was mainly concentrated in winter, followed by spring and autumn, and the lowest in summer. Through the cluster analysis of the backward trajectory of the air mass, it was found that the southwest and northwest directions along Fenhe River Basin were the main pollution transmission channels of air pollution. Through the analysis of potential source contribution and concentration weight trajectory, it was found that the pollution contribution intensity in Hongtong County, Yaodu District, and Xiangfen County of Linfen City was relatively strong, and the surrounding cities of Yulin, Yuncheng, and Jiaozuo had a certain impact on Linfen City.