{"title":"中国东南沿海大气Cl2的驱动因素及光化学影响","authors":"Gaojie Chen, Xiaolong Fan, Ziyi Lin, Xiaoting Ji, Ziying Chen, Lingling Xu, Jinsheng Chen","doi":"10.1038/s41612-025-01022-y","DOIUrl":null,"url":null,"abstract":"<p>The elevated levels of molecular chlorine (Cl<sub>2</sub>) have been observed both during the daytime or nighttime, yet the key drivers influencing Cl<sub>2</sub> formation remain unclear. In this study, we observed the distinct daytime and nighttime peaks of Cl<sub>2</sub> in coastal atmosphere of Southeast China. Field observations combined with machine learning revealed that daytime Cl<sub>2</sub> generation was driven by nitrate (especially ammonium nitrate) photolysis, and aerosol iron photochemistry, while the N<sub>2</sub>O<sub>5</sub> uptake on aerosols containing chloride contributed to nighttime Cl<sub>2</sub> formation. Around noon, alkane oxidation rates by Cl radicals generated from Cl<sub>2</sub> photolysis surpassed those of OH radicals, leading to a 44% increment in RO<sub>2</sub> radical levels and a 42% enhancement in net O<sub>3</sub> production rates. This study offers new insights into the production and loss processes of Cl<sub>2</sub> in the tropospheric atmosphere, emphasizing its significance in coastal photochemical pollution.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"15 1","pages":""},"PeriodicalIF":8.5000,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Driving factors and photochemical impacts of Cl2 in coastal atmosphere of Southeast China\",\"authors\":\"Gaojie Chen, Xiaolong Fan, Ziyi Lin, Xiaoting Ji, Ziying Chen, Lingling Xu, Jinsheng Chen\",\"doi\":\"10.1038/s41612-025-01022-y\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The elevated levels of molecular chlorine (Cl<sub>2</sub>) have been observed both during the daytime or nighttime, yet the key drivers influencing Cl<sub>2</sub> formation remain unclear. In this study, we observed the distinct daytime and nighttime peaks of Cl<sub>2</sub> in coastal atmosphere of Southeast China. Field observations combined with machine learning revealed that daytime Cl<sub>2</sub> generation was driven by nitrate (especially ammonium nitrate) photolysis, and aerosol iron photochemistry, while the N<sub>2</sub>O<sub>5</sub> uptake on aerosols containing chloride contributed to nighttime Cl<sub>2</sub> formation. Around noon, alkane oxidation rates by Cl radicals generated from Cl<sub>2</sub> photolysis surpassed those of OH radicals, leading to a 44% increment in RO<sub>2</sub> radical levels and a 42% enhancement in net O<sub>3</sub> production rates. This study offers new insights into the production and loss processes of Cl<sub>2</sub> in the tropospheric atmosphere, emphasizing its significance in coastal photochemical pollution.</p>\",\"PeriodicalId\":19438,\"journal\":{\"name\":\"npj Climate and Atmospheric Science\",\"volume\":\"15 1\",\"pages\":\"\"},\"PeriodicalIF\":8.5000,\"publicationDate\":\"2025-04-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"npj Climate and Atmospheric Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1038/s41612-025-01022-y\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"npj Climate and Atmospheric Science","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1038/s41612-025-01022-y","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
Driving factors and photochemical impacts of Cl2 in coastal atmosphere of Southeast China
The elevated levels of molecular chlorine (Cl2) have been observed both during the daytime or nighttime, yet the key drivers influencing Cl2 formation remain unclear. In this study, we observed the distinct daytime and nighttime peaks of Cl2 in coastal atmosphere of Southeast China. Field observations combined with machine learning revealed that daytime Cl2 generation was driven by nitrate (especially ammonium nitrate) photolysis, and aerosol iron photochemistry, while the N2O5 uptake on aerosols containing chloride contributed to nighttime Cl2 formation. Around noon, alkane oxidation rates by Cl radicals generated from Cl2 photolysis surpassed those of OH radicals, leading to a 44% increment in RO2 radical levels and a 42% enhancement in net O3 production rates. This study offers new insights into the production and loss processes of Cl2 in the tropospheric atmosphere, emphasizing its significance in coastal photochemical pollution.
期刊介绍：
npj Climate and Atmospheric Science is an open-access journal encompassing the relevant physical, chemical, and biological aspects of atmospheric and climate science. The journal places particular emphasis on regional studies that unveil new insights into specific localities, including examinations of local atmospheric composition, such as aerosols.
The range of topics covered by the journal includes climate dynamics, climate variability, weather and climate prediction, climate change, ocean dynamics, weather extremes, air pollution, atmospheric chemistry (including aerosols), the hydrological cycle, and atmosphere–ocean and atmosphere–land interactions. The journal welcomes studies employing a diverse array of methods, including numerical and statistical modeling, the development and application of in situ observational techniques, remote sensing, and the development or evaluation of new reanalyses.
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