Study on Pollution Characteristics of PM_(2.5) in the Aerosol,Tracing and Tracking Atmospheric Particulates in Beijing City

This study focused on the pollution characteristics of fine particles in the aerosol in Beijing city,analyzed the correlation between variation of mass concentration and various kinds of natural factors.Tracing and tracking the particulates have been done with HYSPLIT model of the U.S.Air Resources Laboratory.What we do will provide important basic data for getting a correct understanding of pollution situation of PM2.5 in urban areas and give reference for future comparative research and development of corresponding pollution control measures.The research results are as follows:(1) the highest value of mass concentration of PM2.5 appears in sand and dust weather in April;spring has the highest mass concentration in the four seasons due to sand and dust weather.(2) Mass concentration of PM2.5 shows strong but different correlations with the temperature in different seasons or different range of temperature;wind speed has a negative correlation with the concentration when it is below 10 km/h and positive correlation when above that.(3) Dust mainly comes from the northwest,northwest by north or west direction;outside sources are the Gobi or desert areas in Russia,Mongolia,Kazakhstan and other countries;sources inside China are mainly the Gobi or desert in west as well as a wide range of arid and semi-arid areas in Inner Mongolia;after arriving in Beijing,dust moves to the east,northeast or southeast,entering into North Korea,South Korea,Japan,Russia and other neighboring countries.