Comment on egusphere-2026-3286
Rattachement africain : cn, us. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Abstract. Atmospheric oxidizing capacity (AOC) drives the formation of secondary pollutants, yet conventional surface observations fail to resolve its pronounced vertical heterogeneity, often leading to incomplete interpretations of regional pollution chemistry. Using ground-based hyperspectral vertical remote sensing observations collected between March and August 2023 at representative urban (AHU) and rural (CF) sites in the Yangtze-Huai River Basin, we quantified the vertical contributions of HONO, HCHO, and O3 photolysis to OH production. AOC showed a strong positive correlation with aerosol loading (R = 0.88–0.93), indicating that enhanced atmospheric oxidation promotes secondary aerosol formation. In urban air masses, the AOC regime exhibited distinct vertical stratification. Rapid oxidation below 1 km was primarily driven by HCHO and HONO, whereas O3 photolysis became the dominant OH source above 2.8 km, accounting for more than 74 % of total OH production. Urban OH production transitioned from near surface HONO dominance in spring (P(OH)HONO=4.43×10-4 ppb·s-1) to HCHO dominance in summer (P(OH)HCHO=5.22×10-4 ppb·s-1). A pronounced elevated HONO enhancement layer emerged near 2.4 km during summer, driven by intensified heterogeneous conversion, with a peak contribution of 30.6 % and a conversion rate C(HONO) of 0.053 h-1. By contrast, near surface OH production at the rural site remained consistently dominated by biogenic HCHO in both spring and summer (P(OH)HCHO=1.82×10-3 ppb·s-1). These findings challenge the conventional assumption that heterogeneous chemistry is confined to the near surface atmosphere. They further provide critical vertical constraints for three-dimensional atmospheric chemistry models and offer a mechanistic explanation for the limited effectiveness of surface-based NOx mitigation strategies under vertically decoupled upper-atmospheric photochemistry.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Comment on egusphere-2026-3286
- Date Crossref
- 16/07/2026
- Éditeur
- Copernicus GmbH
- Type
- peer-review
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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University of Science and Technology of China Department of Precision Machinery and Precision Instrumentation pays non établi dans la noticeUniversité ou école supérieure
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Anhui Institute of Optics and Fine Mechanics pays non établi dans la noticeStructure de recherche
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Precision Research (United States) pays non établi dans la noticeEntreprise
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Beijing Technology and Business University State Environmental Protection Key Laboratory of Food Chain Pollution Control pays non établi dans la noticeUniversité ou école supérieure
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China National Environmental Monitoring Center pays non établi dans la noticeStructure de recherche
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Chinese Academy of Sciences pays non établi dans la noticeOrganisme public
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Hefei Institutes of Physical Science pays non établi dans la noticeStructure de recherche
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School of Environmental Science and Optoelectronic Technology pays non établi dans la noticeUniversité ou école supérieure
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Key Lab of Environmental Optics & Technology pays non établi dans la noticeStructure de recherche
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China National Environmental Monitoring Centre pays non établi dans la noticeInstitution
Department of Precision Machinery and Precision Instrumentation — University of Science and Technology of China, Anhui Institute of Optics and Fine Mechanics et Precision Research (United States), avec 7 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.