Understanding the Regional Transport Contributions of Primary and Secondary PM2.5 Components Over Beijing During a Severe Pollution Episodes
Aerosol and Air Quality Research, 18: 1720–1733, 2018 Copyright © Taiwan Association for Aerosol Research ISSN: 1680-8584 print / 2071-1409 online doi: 10.4209/aaqr.2017.10.0406 Understanding the Regional Transport Contributions of Primary and Secondary PM2.5 Components over Beijing during a Severe Pollution Episodes Wei Wen1,2, Xiaodong He1*, Xin Ma3**, Peng Wei4, Shuiyuan Cheng5, Xiaoqi Wang5, Lei Liu2 1Institute of Urban Meteorology, China Meteorological Administration, Beijing 100089, China 2 Key Laboratory of Atmospheric Chemistry, China Meteorological Administration, Beijing 100081, China 3 National Meteorological Center, Beijing 100081, China 4 Chinese Research Academy of Environment Science, Beijing 100012, China 5 Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China ABSTRACT This study applied the CAMx model to study the regional transport of various PM2.5 components in Beijing during a severe pollution episodes. The results revealed that during the episodes, Beijing had the average PM2.5 pollution value of –3 –3 119 µg m . It was 1.58 times of the PM2.5 national air quality standard (75 µg m Level II). The wind speed was low (< 2 m s–1) and relative humidity reached 98%. The anticyclone in Eastern China showed weak local flow fields and southerly winds at the surface and strong temperature inversion under 1000 m, which promote pollution accumulation. The 2– – contribution of monthly regional transport to primary PM2.5 components and SO4 , NO3 , and secondary organic aerosol concentrations in Beijing were 29.6%, 41.5%, 58.7%, and 60.6%, respectively. The emissions from Baoding had the greatest effect on the primary components of PM2.5 (6.1%) in Beijing.
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