Review of Brown Carbon Aerosols in China: Pollution Level, Optical Properties, and Emissions

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(16)

Published: Aug. 9, 2022

Abstract Brown carbon (BrC) has been recognized as an important contributor to global warming due its absorption of solar radiation with strong wavelength dependence. While early studies mostly consider biomass burning a major emission source, few recent have suggested coal combustion and vehicle exhaust contributors BrC emissions. Considering dominant consumption, large residential biofuel usage, the increasing number vehicles, pollution could result in remarkable regional climate effects China. This study gives overview sources, chemical composition properties BrC, focusing on categorization measurement techniques. The basic features China, including surface concentrations, column burden, sources associated absorbing are then summarized compared other countries. emissions well optical at 365 nm from primary China also provide more straightforward understanding light‐absorbing With detailed comparison existing publications, deeper insight into uncertainties measurements will improve effect BrC. review recommends key research areas for further investigation future.

Language: Английский

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Emissions of Carbonaceous Particulate Matter and Ultrafine Particles from Vehicles—A Scientific Review in a Cross-Cutting Context of Air Pollution and Climate Change

Applied Sciences, Journal Year: 2022, Volume and Issue: 12(7), P. 3623 - 3623

Published: April 2, 2022

Airborne particulate matter (PM) is a pollutant of concern not only because its adverse effects on human health but also visibility and the radiative budget atmosphere. PM can be considered as sum solid/liquid species covering wide range particle sizes with diverse chemical composition. Organic aerosols may emitted (primary organic aerosols, POA), or formed in atmosphere following reaction volatile compounds (secondary SOA), some these partition between gas aerosol phases depending upon ambient conditions. This review focuses carbonaceous gaseous precursors by road traffic, including ultrafine particles (UFP) polycyclic aromatic hydrocarbons (PAHs) that are clearly linked to evolution formation species. Clearly, solid fraction has been reduced during last two decades, implementation after-treatment systems abating approximately 99% primary mass concentrations. However, role brown carbon effect climate generation nucleation vapour dilution exhaust remain unclear phenomena will need further investigation. The increasing gasoline vehicles emissions highlighted, particularly through thermodynamic gases their propensity produce particles. remaining carbon-containing from brakes, tyres wear still problem even future full electrification vehicle fleet. Some key conclusions recommendations proposed support decision makers view next regulations worldwide.

Language: Английский

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Optical properties of vehicular brown carbon emissions: Road tunnel and chassis dynamometer tests

Environmental Pollution, Journal Year: 2023, Volume and Issue: 320, P. 121037 - 121037

Published: Jan. 11, 2023

Language: Английский

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Predictions of the Optical Properties of Brown Carbon Aerosol by Machine Learning with Typical Chromophores

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(46), P. 20588 - 20597

Published: Nov. 7, 2024

The linkages between BrC optical properties and chemical composition remain inadequately understood, with quantified chromophores explaining less than 25% of ambient aerosol light absorption. This study characterized 38 typical in aerosols collected Xi'an, absorption contributions to ranging from 1.6 ± 0.3 5.8 2.6% at 365 nm. Based on these chromophores, an interpretable machine learning model the Shapley Additive Explanation (SHAP) method were employed explore relationships composition. attained high accuracy Pearson correlation coefficients (

Language: Английский

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Insight into the abundance and optical characteristics of water-soluble organic compounds (WSOC) in PM2.5 in urban areas

Chemosphere, Journal Year: 2025, Volume and Issue: 372, P. 144103 - 144103

Published: Jan. 17, 2025

Language: Английский

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Significant N-containing brown carbon emission from heavy-duty diesel vehicles revealed by the molecular and chromophore analysis using ultra-high resolution mass spectrometry

Research Square (Research Square), Journal Year: 2025, Volume and Issue: unknown

Published: March 29, 2025

Brown carbon (BrC) holds scientific significance by influencing radiative balance, cloud condensation dynamics, and regional air quality. This study demonstrated that heavy-duty diesel vehicles (HDDVs) emit substantially higher levels of light-absorbing carbonaceous aerosols under aggressive conditions, such as frequent acceleration high-speed phases investigating the emission profiles, formula distribution, chromophore characteristics various driving conditions. A non-targeted analysis BrC was performed using Fourier-transform ion cyclotron resonance mass spectrometry coupled with a soft electrospray ionization source. The light absorption properties were assessed revealed significantly during compared to low-speed phases. Formula distribution highlighted substantial presence nitrogen-containing species, constituting 53-65% identified peaks, high O/N ratios (≥ 3), double bond equivalent values (DBE > 10), aromaticity (X_c ≥ 2.5), which indicated contribution aromatic structures, condensed aromatics, nitrooxy functionalities chromophores.

Language: Английский

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Significant N-containing brown carbon emission from heavy-duty diesel vehicles revealed by the molecular and chromophore analysis using ultra-high resolution mass spectrometry

npj Climate and Atmospheric Science, Journal Year: 2025, Volume and Issue: 8(1)

Published: May 27, 2025

Language: Английский

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Light Absorption and Chromophore Characteristics of Brown Carbon in PM Emitted From Agricultural Machinery in China

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(11)

Published: May 28, 2025

Abstract The extensive utilization of agricultural machinery in China has made it a prominent contributor to particulate matter (PM). However, there still exist significant knowledge gaps understanding optical characteristics and molecular composition chromophores brown carbon (BrC) PM emitted from machinery. Therefore, BrC six typical machines were measured investigate the light absorption, chromophore characteristics, influencing factors. Results showed that average emission factors methanol‐soluble organic (MSOC) water‐soluble (WSOC) 0.96 0.21 g (kg fuel) −1 , respectively, exhibiting clear decreasing trends with increasing engine power improving standards. Despite absorption coefficient methanol‐extracted (Abs 365,M ) being approximately 2.2 times higher than water 365,W ), mass efficiency water‐extracted (MAE exhibited significantly greater values MAE . Among detected chromophores, nitro‐aromatic compounds (NACs) highest contribution was about 14.5 more total compared their contributions MSOC (0.04%), followed by polycyclic aromatic hydrocarbons (PAHs) oxygenated PAHs (OPAHs). Besides, integrated simple forcing estimated be 1.5 W for 3.7 WSOC, indicating radiative findings this study not only provide fundamental data climate impact estimation but also propose effective strategies mitigate emissions, such as enhancing standards promoting adoption high‐power

Language: Английский

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Characterization and apportionment of carbonaceous aerosol emission factors from light-duty and heavy-duty vehicle fleets in Maharashtra, India

Environmental Pollution, Journal Year: 2024, Volume and Issue: 345, P. 123479 - 123479

Published: Feb. 5, 2024

Language: Английский

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Implications of the Improvement in Atmospheric Fine Particles: A Case Study of COVID-19 Pandemic in Northern Taiwan

Aerosol and Air Quality Research, Journal Year: 2023, Volume and Issue: 23(5), P. 220329 - 220329

Published: Jan. 1, 2023

The outbreak of COVID-19 pandemic in northern Taiwan led to the implementation Level 3 alert measures during 2021 and thereby impacted air quality significantly, which provided an unprecedented opportunity better understand control strategies on pollutants future. This study investigated variations sources, chemical characteristics human health risks PM2.5 comprehensively. mass concentrations decreased from pre-alert by 49.4%, inorganic ions, i.e., NH4+, NO3- SO42-, dropped even more 71%, 90% 52%, respectively. Nonetheless, organic matter (OM) elemental carbon (EC) simply 36% 13%, caused composition change so that carbonaceous dominated instead ions. Correlation-based hierarchical clustering analysis further showed was clustered with alert, while ions both post-alert periods. Moreover, 6 sources were identified positive matrix factorization (PMF), secondary nitrate (i.e., aging traffic aerosols) exhibited most significant decrease yet primary traffic-related emissions, matter, changed insignificantly. implied aerosols could be easily controlled when volume declined, source needs efforts future, especially for reduction matter. Therefore, cleaner energy vehicles is still needed. Assessments carcinogenic risk non-carcinogenic induced trace elements insignificant decrease, can attributed factories did not shut down alert. serves as a metric underpin mitigation pollution future highlights importance PM2.5.

Language: Английский

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