TY - JOUR
T1 - Photochemical ozone pollution in five Chinese megacities in summer 2018
AU - Liu, Xufei
AU - Guo, Hai
AU - Zeng, Lewei
AU - Lyu, Xiaopu
AU - Wang, Yu
AU - Zeren, Yangzong
AU - Yang, Jin
AU - Zhang, Luyao
AU - Zhao, Shizhen
AU - Li, Jun
AU - Zhang, Gan
N1 - Funding Information:
This study was supported by the Research Grants Council of the Hong Kong Special Administrative Region via Theme-Based Research Scheme ( T24-504/17-N ) and General Research Fund ( PolyU15212421 ), the National Key Research and Development Program of China via grant No. 2017YFC0212001 , and the Strategic Focus Area scheme of The Research Institute for Sustainable Urban Development, Hong Kong Polytechnic University ( 1-BBW9 ).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/12/20
Y1 - 2021/12/20
N2 - To investigate photochemical ozone (O3) pollution in urban areas in China, O3 and its precursors and meteorological parameters were simultaneously measured in five megacities in China in summer 2018. Moderate wind speeds, strong solar radiation and high temperature were observed in all cities, indicating favorable meteorological conditions for local O3 formation. However, the unusually frequent precipitation caused by typhoons reaching the eastern coastline resulted in the least severe air pollution in Shanghai. The highest O3 level was found in Beijing, followed by Lanzhou and Wuhan, while relatively lower O3 value was recorded in Chengdu and Shanghai. Photochemical box model simulations revealed that net O3 production rate in Lanzhou was the largest, followed by Beijing, Wuhan and Chengdu, while it was the lowest in Shanghai. Besides, the O3 formation was mainly controlled by volatile organic compounds (VOCs) in most cities, but co-limited by VOCs and nitrogen oxides in Lanzhou. Moreover, the dominant VOC groups contributing to O3 formation were oxygenated VOCs (OVOCs) in Beijing and Wuhan, alkenes in Lanzhou, and aromatics and OVOCs in Shanghai and Chengdu. Source apportionment analysis identified six sources of O3 precursors in these cities, including liquefied petroleum gas usage, diesel exhaust, gasoline exhaust, industrial emissions, solvent usage, and biogenic emissions. Gasoline exhaust dominated the O3 formation in Beijing, and LPG usage and industrial emissions made comparable contributions in Lanzhou, while LPG usage and solvent usage played a leading role in Wuhan and Chengdu, respectively. The findings are helpful to mitigate O3 pollution in China.
AB - To investigate photochemical ozone (O3) pollution in urban areas in China, O3 and its precursors and meteorological parameters were simultaneously measured in five megacities in China in summer 2018. Moderate wind speeds, strong solar radiation and high temperature were observed in all cities, indicating favorable meteorological conditions for local O3 formation. However, the unusually frequent precipitation caused by typhoons reaching the eastern coastline resulted in the least severe air pollution in Shanghai. The highest O3 level was found in Beijing, followed by Lanzhou and Wuhan, while relatively lower O3 value was recorded in Chengdu and Shanghai. Photochemical box model simulations revealed that net O3 production rate in Lanzhou was the largest, followed by Beijing, Wuhan and Chengdu, while it was the lowest in Shanghai. Besides, the O3 formation was mainly controlled by volatile organic compounds (VOCs) in most cities, but co-limited by VOCs and nitrogen oxides in Lanzhou. Moreover, the dominant VOC groups contributing to O3 formation were oxygenated VOCs (OVOCs) in Beijing and Wuhan, alkenes in Lanzhou, and aromatics and OVOCs in Shanghai and Chengdu. Source apportionment analysis identified six sources of O3 precursors in these cities, including liquefied petroleum gas usage, diesel exhaust, gasoline exhaust, industrial emissions, solvent usage, and biogenic emissions. Gasoline exhaust dominated the O3 formation in Beijing, and LPG usage and industrial emissions made comparable contributions in Lanzhou, while LPG usage and solvent usage played a leading role in Wuhan and Chengdu, respectively. The findings are helpful to mitigate O3 pollution in China.
KW - Ozone formation
KW - VOCs
KW - Radical chemistry
KW - PBM-MCM
KW - Megacity clusters
UR - http://www.scopus.com/inward/record.url?scp=85112739572&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.149603
DO - 10.1016/j.scitotenv.2021.149603
M3 - Journal article
C2 - 34416603
AN - SCOPUS:85112739572
SN - 0048-9697
VL - 801
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 149603
ER -