1. Cruise observation of ambient volatile organic compounds over Hong Kong coastal water
- Author
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Sun, Hao, Gu, Dasa, Feng, Xin, Wang, Zhe, Cao, Xiangyunong, Sun, Mingyao, Ning, Zhi, Zheng, Penggang, Mai, Yuchen, Xu, Zijie, Chan, Wai Ming, Li, Xin, Zhang, Wentai, Lee, Ho Wun, Leung, Ka Fung, Yu, Jianzhen, Lee, Eddie, Louie, Peter K.K., Leung, Kenneth, Sun, Hao, Gu, Dasa, Feng, Xin, Wang, Zhe, Cao, Xiangyunong, Sun, Mingyao, Ning, Zhi, Zheng, Penggang, Mai, Yuchen, Xu, Zijie, Chan, Wai Ming, Li, Xin, Zhang, Wentai, Lee, Ho Wun, Leung, Ka Fung, Yu, Jianzhen, Lee, Eddie, Louie, Peter K.K., and Leung, Kenneth
- Abstract
Air pollution is a major environmental issue in Hong Kong, and ozone (O3) is one of the most concerned pollutants because of its notable rising trend during the past three decades. Volatile organic compounds (VOCs) are the main precursors to O3 formation, but their characteristics over coastal water in Hong Kong were not well studied due to a lack of observations. We conducted sixteen cruise campaigns and collected 109 VOC canister samples over Hong Kong coastal water between August 2020 and July 2021. 95 VOC species were analyzed from the samples by a GC-MSD/ECD/FID system to investigate their concentration distributions, reactivities, and potential emission sources. The average concentrations of alkanes, alkenes, aromatics, alkynes, halocarbons, and alkyl nitrates over Hong Kong coastal water were 8.94 ± 5.64 ppbv, 1.18 ± 1.09 ppbv, 1.90 ± 1.48 ppbv, 1.05 ± 0.63 ppbv, 3.82 ± 1.23 ppbv, and 0.09 ± 0.04 ppbv, respectively. Source apportionment results from positive matrix factorization (PMF) analysis suggest that liquefied petroleum gas (LPG) usage (24.9%), biomass burning (19.4%), gasoline evaporation (16.2%), ship emissions (15.6%), solvent usage (14.8%), and aged air mass (9.1%) were main VOC sources over Hong Kong coastal water during the study period. Toluene, ethene and m + p-xylene were found to be the top contributors to the O3 formation over Hong Kong coastal water, while isoprene had less O3 formation contributions compared with land measurements. This study provides important insights into the reactivities and sources of VOCs over Hong Kong coastal water and serves as a stepping stone to understanding the VOC characteristics and O3 formation mechanisms in a complex coastal environment.
- Published
- 2024