Abstract:Using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model and ERA_INTERIM data, this paper calculated the 72 h backward trajectories in February during 2013-2017 starting from the Beijing National Olympic Sports Center (hereinafter referred to as Sports Center). Combined with cluster analysis and pollutant concentration data in the Sports Center, the influence of different trajectory paths on the concentration of pollutants in the Sports Center was analyzed. Four different trajectory analysis methods were used to analyze the source characteristics of the pollutants in the Sports Center, and then its advantages, disadvantages and applicability were illustrated by examples. The results showed that the dominant airflow in the Sports Center is obvious in February, following the northwestern path with a probability of 55.85%. The cleaning path is northward airflow, and the pollution sources are a southward path and an eastward path, corresponding to the highest particulate matter concentration. By trajectory statistical method, the main sources of particulate matter at the Sports Center in February are Hebei Pro-vince, Shandong Peninsula, Yellow Sea Region, northern Xinjiang and Hexi Corridor. The PSCF and CWT methods are suitable for close-range pollution source identification. In the method of RTWC, the deterministic method is used to accurately identify the main pollutant sources of the Sports Center through iteration. The QTBA method introduces the concept of uncertainty, which is suitable for the identification of a wide range of deterministic sources of pollution, but at the same time it produces some false pollutant sources. However, the combination of the RTWC method and the QTBA method can eliminate the false pollution sources brought by the QTBA method.