Formation Mechanisms and Source Apportionments of Nitrate Aerosols in a Megacity of Eastern China Based On Multiple Isotope Observations

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(6)

Published: March 6, 2023

Abstract Inorganic nitrate (NO 3 − ) is a crucial component of fine particulate matter (PM 2.5 in haze events China. Understanding the formation mechanisms and sources NO x was critical to control air pollution. In this study, measurements multiple isotope compositions (δ 18 O‐NO , δ 17 15 N‐NO PM were conducted Hangzhou from 9 October 2015 24 August 2016. Our results showed that oxygen anomaly (Δ : 20.0‰–37.9‰) nitrogen −2.9‰ 18.1‰) values higher winter lower summer. Based on Δ observation Bayesian model, radical chemistry found dominate winter, while photochemical reaction 2 + OH) main pathway After considering isotopic fractionation (g) ‐NO (p) conversion, average contributions coal combustion, vehicle exhausts, biomass burning, soil emission 50% ± 9%, 19% 12%, 26% 15%, 5% 4%, respectively, aerosols during whole sampling period. Coal combustion most important source Hangzhou, especially (∼56%). The contribution increased significantly summer due active microbial processes under high temperature environment.

Language: Английский

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Quantification of NO sources contribution to ambient nitrate aerosol, uncertainty analysis and sensitivity analysis in a megacity

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 926, P. 171583 - 171583

Published: March 8, 2024

Language: Английский

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Nitrogen isotopes in nitrate aerosols collected in the remote marine boundary layer: Implications for nitrogen isotopic fractionations among atmospheric reactive nitrogen species

Atmospheric Environment, Journal Year: 2020, Volume and Issue: 245, P. 118028 - 118028

Published: Oct. 26, 2020

Language: Английский

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Isotopic Interpretation of Particulate Nitrate in the Metropolitan City of Karachi, Pakistan: Insight into the Oceanic Contribution to NO_x

Environmental Science & Technology, Journal Year: 2020, Volume and Issue: 54(13), P. 7787 - 7797

Published: June 3, 2020

Nitrogen oxide (NOx) abatement has become the focus of air quality management strategies. In this study, we examined NOx sources and atmospheric conversion in Karachi, Pakistan, a megacity South Asia with serious particulate pollution problems. Oceanic contributions to were quantified for first time based on novel approach using nitrogen/oxygen isotopic analysis nitrate (δ15N-NO3-; δ18O-NO3-) Bayesian model. Our results showed that δ15N-NO3- Karachi varied between -10.2‰ +12.4‰. As indicated by δ18O-NO3- findings (+66.2 ± 7.8‰), •OH pathway dominated throughout nearly two-year observation, but high NO3- events attributed O3 pathway. Coal combustion was most significant source (32.0 9.8%) higher autumn winter; similar situation occurred biomass burning + lightning (30.3 6.5%). However, mobile (25.2 6.4%) microbial processes (12.5 7.5%) exhibited opposite seasonal trends. The oceanic estimated be 16.8%, which lightning, shipping emissions, accounted 20.3%, 46.3%, 33.4%, respectively, emphasizing dominance emissions as an source.

Language: Английский

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Nitrate aerosol formation and source assessment in winter at different regions in Northeast China

Atmospheric Environment, Journal Year: 2021, Volume and Issue: 267, P. 118767 - 118767

Published: Sept. 29, 2021

Language: Английский

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Oxidation pathways and emission sources of atmospheric particulate nitrate in Seoul: based on <i>δ</i><sup>15</sup>N and Δ<sup>17</sup>O measurements

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(8), P. 5099 - 5115

Published: April 19, 2022

Abstract. PM2.5 haze pollution driven by secondary inorganic NO3- has been a great concern in East Asia. It is, therefore, imperative to identify its sources and oxidation processes, for which nitrogen oxygen stable isotopes are powerful tracers. Here, we determined the δ15N (NO3-) Δ17O of Seoul during summer 2018 winter 2018–2019 estimated quantitatively relative contribution pathways particulate investigated major NOx emission sources. In range mass concentration from 7.5 µg m−3 (summer) 139.0 (winter), mean was −0.7 ‰ ± 3.3 3.8 3.7 ‰, 23.2 2.2 27.7 winter, respectively. While OH dominant pathway (87 %), nighttime formation via N2O5 NO3 relatively more important (38 %) when aerosol liquid water content (ALWC) ratio (NOR) were higher. Interestingly, highest coupled with lowest NOR record-breaking episodes, revealing critical role photochemical process severe development. For sources, atmospheric (NOx) measured considering isotope fractionation effects indicates vehicle emissions as most source Seoul. The biogenic soil coal combustion slightly increased Our results built on multiple-isotope approach provide first explicit evidence processes megacity suggest an effective mitigation measure improve pollution.

Language: Английский

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Long‐Term Evolution of Particulate Nitrate Pollution in North China: Isotopic Evidence From 10 Offshore Cruises in the Bohai Sea From 2014 to 2019

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(11)

Published: May 30, 2022

Abstract Atmospheric nitrate (NO 3 − ) pollution has become an obstacle to efforts further reduce fine particulate (PM 2.5 concentration in North China. However, there have been limited long‐term measurements of NO and isotopic knowledge (δ 15 N, δ 18 O) on the driving factors during changes. Here, we report observations 10 voyages from 2014 2019 conducted Bohai Sea, a typical background area The results show that average proportion PM increased 0.08 0.16 over study period. N–NO ranged −4.1‰ +20.5‰, with significant annual decline ( p < 0.01), especially winter. O–NO was +72.6 ± 13.5‰, Monte Carlo calculation revealed contribution •OH pathway formation declined by 27.4% winter, implying increase O pollution. Coal combustion remained most important contributor (46.6 15.9%), but its showed downward trend consistent control disperse coal use Enhancement atmospheric oxidation unexpected large microbial processes were found be main causes increasingly serious In addition, spike 2018 indicates coal‐control policy needs reinforced.

Language: Английский

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Vertical Differences of Nitrate Sources in Urban Boundary Layer Based on Tower Measurements

Environmental Science & Technology Letters, Journal Year: 2022, Volume and Issue: 9(11), P. 906 - 912

Published: Oct. 18, 2022

Reducing nitrogen oxide (NOx) emissions is key to limiting fine particulate pollution globally. Nitrogen isotopes are powerful tools for exploring sources of atmospheric nitrate and its precursor NOx. This work performed simultaneous vertical measurements (δ15N(NO3–)) at 8 260 m heights on a meteorological tower in Beijing. Although δ15N(NO3–) the two were close, significant difference (P < 0.01) δ15N oxides was found winter after considering isotope fractionation between NOx constrained by oxygen anomaly (Δ17O) nitrate. Combining estimated Bayesian model, it that proportion coal combustion aerosols higher (54% ± 9%) than ground surface (31% 10%) winter, suggesting air masses carrying coal-derived reached upper Beijing through regional transport. In summer, variations not obvious. Our findings suggest conventional ground-based observations may underestimate contribution urban boundary layer as pollutants influenced combination local emissions, meteorology,

Language: Английский

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What controls aerosol δ15N-NO3−? NOx emission sources vs. nitrogen isotope fractionation

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 871, P. 162185 - 162185

Published: Feb. 11, 2023

Language: Английский

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Important contributions of natural gas combustion to atmospheric nitrate aerosols in China: Insights from stable nitrogen isotopes

Science Bulletin, Journal Year: 2024, Volume and Issue: 69(19), P. 3001 - 3004

Published: Aug. 10, 2024

Language: Английский

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