Preprints
https://doi.org/10.5194/egusphere-2024-887
https://doi.org/10.5194/egusphere-2024-887
13 May 2024
 | 13 May 2024

Enhanced daytime secondary aerosol formation driven by gas-particle partitioning in downwind urban plumes

Mingfu Cai, Chenshuo Ye, Bin Yuan, Shan Huang, E Zheng, Suxia Yang, Zelong Wang, Yi Lin, Tiange Li, Weiwei Hu, Wei Chen, Qicong Song, Wei Li, Yuwen Peng, Baolin Liang, Qibin Sun, Jun Zhao, Duohong Chen, Jiaren Sun, Zhiyong Yang, and Min Shao

Abstract. Anthropogenic emissions from city clusters can significantly enhance secondary organic aerosol (SOA) formation in the downwind regions, while the mechanism is poorly understood. To investigate the effect of pollutants within urban plumes on organic aerosol (OA) evolution, a field campaign was conducted at a downwind site of the Pearl River Delta region of China in the fall of 2019. A time-of-flight chemical ionization mass spectrometer coupled with a Filter Inlet for Gases and Aerosol (FIGAERO-CIMS) was used to probe the gas- and particle-phase molecular composition and thermograms of organic compounds. For air masses influenced by urban pollution, strong daytime SOA formation through gas-particle partitioning was observed, resulting in higher OA volatility. The obvious SOA enhancement was mainly attributed to the equilibrium partitioning of non-condensable (C * ≥ 100.5 μg m-3) organic vapors. We speculated that the elevated NOx concentration could suppress the formation of highly oxidized products, resulting in a smooth increase of condensable (C * < 100.5 μg m-3) organic vapors. Evidence showed that urban pollutants (NOx and VOCs) could enhance the oxidizing capacity, while the elevated VOCs was mainly responsible for promoting daytime SOA formation by increasing the RO2 production rate. Our results highlight the important role of urban anthropogenic pollutants in SOA control in the suburban region.

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Journal article(s) based on this preprint

27 Nov 2024
Enhanced daytime secondary aerosol formation driven by gas–particle partitioning in downwind urban plumes
Mingfu Cai, Chenshuo Ye, Bin Yuan, Shan Huang, E Zheng, Suxia Yang, Zelong Wang, Yi Lin, Tiange Li, Weiwei Hu, Wei Chen, Qicong Song, Wei Li, Yuwen Peng, Baoling Liang, Qibin Sun, Jun Zhao, Duohong Chen, Jiaren Sun, Zhiyong Yang, and Min Shao
Atmos. Chem. Phys., 24, 13065–13079, https://doi.org/10.5194/acp-24-13065-2024,https://doi.org/10.5194/acp-24-13065-2024, 2024
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

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This study investigated the daytime secondary organic aerosol (SOA) formation in urban plumes....
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