Recent Progress in Atmospheric Chemistry Research in China: Establishing a Theoretical Framework for the “Air Pollution Complex”

Advances in Atmospheric Sciences, Journal Year: 2023, Volume and Issue: 40(8), P. 1339 - 1361

Published: April 28, 2023

Atmospheric chemistry research has been growing rapidly in China the last 25 years since concept of "air pollution complex" was first proposed by Professor Xiaoyan TANG 1997. For papers published 2021 on air (only included Web Science Core Collection database were considered), more than 24 000 authored or co-authored scientists working China. In this paper, we review a limited number representative and significant studies atmospheric few years, including (1) sources emission inventories, (2) chemical processes, (3) interactions with meteorology, weather climate, (4) between biosphere atmosphere, (5) data assimilation. The intention not to provide complete all progress made but rather serve as starting point for learning about advances reviewed paper have enabled theoretical framework complex be established, provided robust scientific support highly successful control policies China, created great opportunities education, training, career development many graduate students young scientists. This further highlights that developing low-income countries are heavily affected can benefit from these advances, whilst at same time acknowledging challenges still remain hopefully addressed over next decades.

Language: Английский

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Reactive Chlorine Species Advancing the Atmospheric Oxidation Capacities of Inland Urban Environments

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(39), P. 14638 - 14647

Published: Sept. 22, 2023

Chlorine (Cl) radicals from photolabile chlorine species are highly reactive and can affect the fate of air pollutants in atmosphere. Although several campaigns have been conducted, typically coastal environments, long-term observations their impacts on atmospheric oxidation capacities (AOCs) lacking. Here, we report nearly full-year Cl2 ClNO2 levels Beijing evaluate AOC with a box model coupled Cl chemistry. promote circulation OH–HO2–RO2 by accelerating OH chain lengths up to 12.6% average, hence boosting AOC, especially winter or spring. This promotion effect is nonlinearly dependent VOC NOx concentrations, thus leading slight shift ozone formation VOC-sensitive regime transition seasonal differences. Given ubiquitous chlorines polluted inland urban regions, AOCs secondary will be underestimated if neglected.

Language: Английский

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Mechanistic insights into chloroacetic acid production from atmospheric multiphase volatile organic compound–chlorine chemistry

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(6), P. 3753 - 3764

Published: March 31, 2025

Abstract. Chlorine-containing oxygenated volatile organic compounds (Cl-OVOCs) are indicators of atmospheric chlorine chemistry involving (VOCs). However, their formation mechanisms insufficiently understood. Herein, a strong diel pattern chloroacetic acid (C2H3O2Cl) was observed with daytime peaks at 19 and 13 ppt (1 h averages) in 2020 2021, respectively, coastal site southern China. Ethene previously proposed as the primary precursor responsible for C2H3O2Cl levels, but photochemical box model based on Master Chemical Mechanism (MCM) simulations indicates that ethene accounts less than 1 %. Quantum chemical calculations suggest other alkenes also can act precursors. Using an updated gas-phase VOC–Cl model, we find isoprene, most abundant VOC sampling site, along its oxidation products, 7 % C2H3O2Cl. Moreover, simulation MCM produces appreciable levels Cl-OVOCs, especially chloroacetaldehyde, We multiphase reaction Cl-OVOCs to reconcile overestimation underestimation our model. The estimated reactive uptake coefficients various range from 3.63×10-5 2.34×10-2, quantum linear relationship modelling. shows heterogeneous conversion chloroacetaldehyde contribute 24 %–48 levels. Our study thus proposes mechanism gaseous highlights potential importance processes formation.

Language: Английский

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Biogenic volatile organic compounds enhance ozone production and complicate control efforts: Insights from long-term observations in Hong Kong

Atmospheric Environment, Journal Year: 2023, Volume and Issue: 309, P. 119917 - 119917

Published: June 28, 2023

Language: Английский

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Intensive photochemical oxidation in the marine atmosphere: evidence from direct radical measurements

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(3), P. 1825 - 1839

Published: Feb. 8, 2024

Abstract. Comprehensive observations of hydroxyl (OH) and hydroperoxy (HO2) radicals were conducted in October 2019 at a coastal continental site the Pearl River Delta (YMK site, 22.55∘ N, 114.60∘ E). The daily maximum OH HO2 concentrations (4.7–9.5) × 106 (4.2–8.1) 108 cm−3, respectively. synchronized air mass transport from northern cities South China Sea exerted time-varying influence on atmospheric oxidation. Under typical ocean-atmosphere (OCM), reasonable measurement model agreement was achieved for both using 0-D chemical box incorporating regional chemistry mechanism version 2-Leuven isoprene (RACM2-LIM1), with averages 4.5 4.9 Land (LAM) promoted more active photochemical processes, 7.1 5.2 cm−3 HO2, Heterogeneous uptake had certain effects HOx chemistry, but halogen limited by NOx level. Intensive photochemistry occurred after precursor accumulation, allowing local net ozone production comparable surrounding suburban environments (5.52 ppb h−1 during LAM period). rapid oxidation process accompanied higher diurnal nitrous acid (HONO) concentration (> 400 ppt). After sensitivity test, HONO-related elevated rate 33 % 39 OCM periods, nitric (P(HNO3)) sulfuric (P(H2SO4)) formation rates also increased simultaneously (∼ 43 ∼ 48 sectors, respectively). In ozone-prediction simulated O3 decreased 75 to global background 35 ppb) without HONO constraint, daytime reduced low level 70 For cities, particularity tends ozone-sensitive system eventually magnifies ozone. Therefore, promotion precursors deserves lot attention when aiding pollution mitigation policies.

Language: Английский

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Significant Impact of a Daytime Halogen Oxidant on Coastal Air Quality

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 24, 2025

Chlorine radicals (Cl·) are highly reactive and affect the fate of air pollutants. Several field studies in China have revealed elevated levels daytime molecular chlorine (Cl2), which, upon photolysis, release substantial amounts Cl· but poorly represented current chemical transport models. Here, we implemented a parametrization for formation Cl2 through photodissociation particulate nitrate acidic environments into regional model assessed its impact on coastal quality during autumn South China. The could reproduce over 70% high level measured at site, revealing discernible presence released adjacent areas. Abundant alters oxidative capacity atmosphere, consequently increasing O3 (6–12%) PM2.5 (10–16%) concentrations high-NOx areas reducing (3%) concentration low-NOx Accounting chemistry shifts – precursor relationships from VOC limited to mixed or NOx -limited regimes, enhancing benefits emission reduction mitigating pollution. Our findings suggest that tightening control two pollutants, SO2, would alleviate production adverse quality.

Language: Английский

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Pollution mechanisms and photochemical effects of atmospheric HCHO in a coastal city of southeast China

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 859, P. 160210 - 160210

Published: Nov. 14, 2022

Language: Английский

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Chemical ionization mass spectrometry: Developments and applications for on-line characterization of atmospheric aerosols and trace gases

TrAC Trends in Analytical Chemistry, Journal Year: 2023, Volume and Issue: 168, P. 117353 - 117353

Published: Oct. 11, 2023

Language: Английский

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Anthropogenic short-lived halogens increase human exposure to mercury contamination due to enhanced mercury oxidation over continents

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(12)

Published: March 11, 2024

Mercury (Hg) is a contaminant of global concern, and an accurate understanding its atmospheric fate needed to assess risks humans ecosystem health. Atmospheric oxidation Hg key the deposition this toxic metal Earth’s surface. Short-lived halogens (SLHs) can provide halogen radicals directly oxidize perturb budget other oxidants (e.g., OH O 3 ). In addition known ocean emissions halogens, recent observational evidence has revealed abundant anthropogenic SLHs over continental areas. However, impacts on human exposure contamination remain unknown. Here, we show that inclusion substantially increased local and, consequently, in/near source regions by up 20%, thereby decreasing export from clean environments. Our modeling results indicated lead higher than estimated in previous assessments, e.g., with increases 8.7% 7.5% China India, respectively, consequently leading Hg-related health risks. These highlight urgent need for policymakers reduce emissions. We conclude substantial should be included model assessments associated at scales.

Language: Английский

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Typhoon- and pollution-driven enhancement of reactive bromine in the mid-latitude marine boundary layer

National Science Review, Journal Year: 2024, Volume and Issue: 11(4)

Published: Feb. 13, 2024

Tropospheric reactive bromine is important for atmospheric chemistry, regional air pollution, and global climate. Previous studies have reported measurements of species in different environments, proposed their main sources, e.g. sea-salt aerosol (SSA), oceanic biogenic activity, polar snow/ice, volcanoes. Typhoons other strong cyclonic activities (e.g. hurricanes) induce abrupt changes earth system processes, causing widespread destructive effects. However, the role typhoons regulating abundance sources remains unexplored. Here, we report field observations oxide (BrO), a critical indicator bromine, on Huaniao Island (HNI) East China Sea July 2018. We observed high levels BrO below 500 m with daytime average 9.7 ± 4.2 pptv peak value ∼26 under influence typhoon. Our measurements, supported by model simulations, suggest that typhoon-induced drastic increase wind speed amplifies emission SSA, significantly enhancing activation from SSA debromination. also detected enhanced mixing ratios NO

Language: Английский

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