Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - "APEC Blue"
T2 - Secondary Aerosol Reductions from Emission Controls in Beijing
AU - Sun, Yele
AU - Wang, Zifa
AU - Wild, Oliver
AU - Xu, Weiqi
AU - Chen, Chen
AU - Fu, Pingqing
AU - Du, Wei
AU - Zhou, Libo
AU - Zhang, Qi
AU - Han, Tingting
AU - Wang, Qingqing
AU - Pan, Xiaole
AU - Zheng, Haitao
AU - Li, Jie
AU - Guo, Xiaofeng
AU - Liu, Jianguo
AU - Worsnop, Douglas R.
PY - 2016/2/18
Y1 - 2016/2/18
N2 - China implemented strict emission control measures in Beijing and surrounding regions to ensure good air quality during the 2014 Asia-Pacific Economic Cooperation (APEC) summit. We conducted synchronous aerosol particle measurements with two aerosol mass spectrometers at different heights on a meteorological tower in urban Beijing to investigate the variations in particulate composition, sources and size distributions in response to emission controls. Our results show consistently large reductions in secondary inorganic aerosol (SIA) of 61-67% and 51-57%, and in secondary organic aerosol (SOA) of 55% and 37%, at 260 m and ground level, respectively, during the APEC summit. These changes were mainly caused by large reductions in accumulation mode particles and by suppression of the growth of SIA and SOA by a factor of 2-3, which led to blue sky days during APEC commonly referred to as "APEC Blue". We propose a conceptual framework for the evolution of primary and secondary species and highlight the importance of regional atmospheric transport in the formation of severe pollution episodes in Beijing. Our results indicate that reducing the precursors of secondary aerosol over regional scales is crucial and effective in suppressing the formation of secondary particulates and mitigating PM pollution.
AB - China implemented strict emission control measures in Beijing and surrounding regions to ensure good air quality during the 2014 Asia-Pacific Economic Cooperation (APEC) summit. We conducted synchronous aerosol particle measurements with two aerosol mass spectrometers at different heights on a meteorological tower in urban Beijing to investigate the variations in particulate composition, sources and size distributions in response to emission controls. Our results show consistently large reductions in secondary inorganic aerosol (SIA) of 61-67% and 51-57%, and in secondary organic aerosol (SOA) of 55% and 37%, at 260 m and ground level, respectively, during the APEC summit. These changes were mainly caused by large reductions in accumulation mode particles and by suppression of the growth of SIA and SOA by a factor of 2-3, which led to blue sky days during APEC commonly referred to as "APEC Blue". We propose a conceptual framework for the evolution of primary and secondary species and highlight the importance of regional atmospheric transport in the formation of severe pollution episodes in Beijing. Our results indicate that reducing the precursors of secondary aerosol over regional scales is crucial and effective in suppressing the formation of secondary particulates and mitigating PM pollution.
KW - POSITIVE MATRIX FACTORIZATION
KW - CHEMICAL SPECIATION MONITOR
KW - NORTH CHINA PLAIN
KW - MASS-SPECTROMETER
KW - COLLECTION EFFICIENCIES
KW - FORMATION MECHANISM
KW - ORGANIC AEROSOLS
KW - URBAN CANOPY
KW - AIR-QUALITY
KW - POLLUTION
U2 - 10.1038/srep20668
DO - 10.1038/srep20668
M3 - Journal article
VL - 6
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
M1 - 20668
ER -