Analysis of the Characteristics and Evolution Modes of PM2.5 Pollution Episodes in Beijing, China During 2013

International Journal of Environmental Research and Public Health

Ci Song²  Tao Pei²  Ling Yao¹ 

[1] State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;

关键词: PM_2.5 concentration;    PM_2.5 pollution episodes;    seasonal variations;    peak patterns;    air quality;   

DOI  :  10.3390/ijerph120201099

来源: mdpi

【 摘 要 】

Fine particulate matter (PM_2.5) has been recognized as a serious hazard linked to deleterious health effects. In this study, all PM_2.5 Pollution Episodes (PPEs) in Beijing during 2013 were investigated with hourly PM_2.5 observations from the Olympic Sport Center site, and then their characteristics and evolution modes analysed. Results show that 80 PPEs, covering 209 days, occurred in Beijing during 2013. Average PM_2.5 concentrations during PPEs were almost twice (1.86) the annual mean value, although the PPEs showed significant seasonal variations. The most hazardous PPEs tended to occur in winter, whereas PPEs with long duration occurred in autumn. The PPEs could be divided into six clusters based on their compositions of different pollution levels, which were strongly related to meteorological factors. We used series peaks of PM_2.5 concentrations to analyse the evolution modes of PPEs and found that the more peaks there were within the evolution mode, the longer the duration, and the higher the average and maximum PM_2.5 concentrations. Each peak within a PPE can be identified by “rise” and “fall” patterns. The “rise” patterns are widely related to relative humidity, whereas the “fall” patterns are affected principally by wind speed for one-peak PPEs and boundary layer height for multi-peak PPEs. The peak patterns cannot be explained fully by meteorological factors; however, they might also be closely related to complex and diversified human activities.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.