Analysis of Transport Channel and Pollution Source Area of Atmospheric Particulate Matter in Beijing, China Based on Hybrid Single-Particle Lagrangian Integrated Trajectory Model

Abstract

Regional air pollution is affected not only by local pollution emissions but also by the trans-regional transportation of pollutants in adjacent areas. To explore the potential contribution source area of atmospheric particulate matter affecting Beijing, based on the Global Data Assimilation System of the National Centers for Environmental Prediction (December 2016 ~ November 2021), this study uses the Hybrid Single-Particle Lagrangian Integrated Trajectory model to cluster the 72-hour backward airflow trajectory arriving in Beijing by season. Combined with the ground observation data of PM2.5 and PM10 mass concentration, the spatial characteristics of different traffic routes in Beijing and their contribution to the accumulation of PM2.5 and PM10 concentration are analyzed by using the Potential Source Contribution Function and the Concentration Weighted Trajectory, which provides a reasonable theoretical basis for the coordinated treatment of regional air pollution. The results show that the distribution of potential contribution source areas of PM2.5 and PM10 in Beijing has obvious seasonal characteristics, and the concentration contribution of different transportation routes is significantly different. In winter, the distribution of potential source areas shows a trend from northwest to Southeast, which forms a conveyor belt from central Inner Mongolia of China to Beijing through Zhangjiakou of Hebei Province. The high concentration contribution areas of PM2.5 and PM10 are concentrated in the urban area of Beijing, Baoding of Hebei Province, and the west of Tianjin. In spring and autumn, the potential source areas are distributed from south to north, which mainly cover the central part of Hebei Province and the urban area of Beijing. The high concentration contribution areas of PM2.5 and PM10 are smaller than those in winter, and are dotted in Baoding, Shijiazhuang and other places of Hebei Province.

Keywords: atmospheric particulate matter, backward trajectory mode, Beijing, cluster analysis, concentration weighted trajectory, potential contribution source area, potential source contribution function