Dataset Information

Photodissociation of particulate nitrate as a source of daytime tropospheric Cl₂.

ABSTRACT: Chlorine atoms (Cl) are highly reactive and can strongly influence the abundances of climate and air quality-relevant trace gases. Despite extensive research on molecular chlorine (Cl₂), a Cl precursor, in the polar atmosphere, its sources in other regions are still poorly understood. Here we report the daytime Cl₂ concentrations of up to 1 ppbv observed in a coastal area of Hong Kong, revealing a large daytime source of Cl₂ (2.7 pptv s^-1 at noon). Field and laboratory experiments indicate that photodissociation of particulate nitrate by sunlight under acidic conditions (pH < 3.0) can activate chloride and account for the observed daytime Cl₂ production. The high Cl₂ concentrations significantly increased atmospheric oxidation. Given the ubiquitous existence of chloride, nitrate, and acidic aerosols, we propose that nitrate photolysis is a significant daytime chlorine source globally. This so far unaccounted for source of chlorine can have substantial impacts on atmospheric chemistry.

SUBMITTER: Peng X

PROVIDER: S-EPMC8854671 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature

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Photodissociation of particulate nitrate as a source of daytime tropospheric Cl2.

Peng Xiang X Wang Tao T Wang Weihao W Ravishankara A R AR George Christian C Xia Men M Cai Min M Li Qinyi Q Salvador Christian Mark CM Lau Chiho C Lyu Xiaopu X Poon Chun Nan CN Mellouki Abdelwahid A Mu Yujing Y Hallquist Mattias M Saiz-Lopez Alfonso A Guo Hai H Herrmann Hartmut H Yu Chuan C Dai Jianing J Wang Yanan Y Wang Xinke X Yu Alfred A Leung Kenneth K Lee Shuncheng S Chen Jianmin J

Nature communications 20220217 1

Chlorine atoms (Cl) are highly reactive and can strongly influence the abundances of climate and air quality-relevant trace gases. Despite extensive research on molecular chlorine (Cl2), a Cl precursor, in the polar atmosphere, its sources in other regions are still poorly understood. Here we report the daytime Cl2 concentrations of up to 1 ppbv observed in a coastal area of Hong Kong, revealing a large daytime source of Cl2 (2.7 pptv s-1 at noon). Fie ...[more]

PMID: 35177585

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Dataset Information

Photodissociation of particulate nitrate as a source of daytime tropospheric Cl₂.

Publications

Photodissociation of particulate nitrate as a source of daytime tropospheric Cl<sub>2</sub>.

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