Enhanced Particulate Nitrate Formation in Residual Layer Exacerbates Near‐Surface Pollution: Insights From Tethered Airship and Long‐Term Ground Measurements

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(4)

Published: Feb. 14, 2025

Abstract Recent years have witnessed a surge in nitrate‐driven aerosol pollution across China with N 2 O 5 hydrolysis emerging as critical formation pathway. Common surface measurements may misleadingly imply this process due to low nighttime ozone at level winter. However, our study reveals more complex picture by unveiling the vertical dynamics of nitrate through an integration tethered airship campaign, long‐term ground measurements, and model simulations. Interestingly, we observed rapid growth approximately 400 m altitude, where box revealed optimal conditions for sustained nocturnal production. The accumulated overnight residual layer (RL) is transported downward next morning boundary breaks down, substantially increasing surface‐level thus exacerbating pollution. Annual‐averaged diurnal patterns measured station clearly confirm increase. mixing from RL contributes up 80% total 10:00 LT its influence persisting 31% even after sunset. Air mass trajectory analysis further confirms that emissions city‐cluster significantly contribute downwind transporting pollutants into RL. This research underscores important role chemical processes, facilitated elevated ozone, shaping It highlights indispensability profiling understanding advocates regionally coordinated control strategies eastern China.

Language: Английский

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Nitroaromatic Compounds from Secondary Nitrate Formation and Biomass Burning Are Major Proinflammatory Components in Organic Aerosols in Guangzhou: A Bioassay Combining High-Resolution Mass Spectrometry Analysis

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(51), P. 21570 - 21580

Published: Nov. 21, 2023

The limited characterization and detection capacity of unknown compounds hinder our understanding the molecular composition toxic in PM2.5. present study applied Fourier transform ion cyclotron resonance mass spectrometry coupled with negative positive electrospray ionization sources (ESI–/ESI+ FT-ICR-MS) to probe characteristics dynamic formation processes effective proinflammatory components organic aerosols (OAs) PM2.5 Guangzhou for one year. We detected abundant molecules OAs, mainly classified as CHON (compounds composed C, H, O, N atoms) elemental nitroaromatic (NACs) structures. From perspective process, we discovered that these molecules, especially NACs, were largely driven by secondary nitrate biomass burning (in emission source), well SO2 atmospheric evolution). In addition, results indicated had replaced primary main contributing source OAs. This highlights importance community measures control production derived from urban areas.

Language: Английский

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Research on the impact of land use and land cover changes on local meteorological conditions and surface ozone in the north China plain from 2001 to 2020

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Jan. 15, 2025

Land use and land cover changes (LULCC) alter local surface attributes, thereby modifying energy balance material exchanges, ultimately impacting meteorological parameters air quality. The North China Plain (NCP) has undergone rapid urbanization in recent decades, leading to dramatic cover. This study utilizes the 2020 data obtained from MODIS satellite replace default 2001 Weather Research Forecasting-Community Multiscale Air Quality (WRF-CMAQ) model. It simulates analyzes direct impact of LULCC on indirect ozone (O3) concentration through physical chemical processes during July summer. Six rapidly urbanizing cities were selected represent Plain. results show that significantly increased sensible heat flux 2-m temperature areas throughout diurnal cycle, with more pronounced effects daytime, ranging 6.49 23.46 W/m2 0.20–0.59 °C, respectively. 10-m wind speed decreased at night day, − 0.43 0.27 m/s 0.16 0.15 day. planetary boundary layer height generally increased, a larger rise 23.63 84.74 m. Simultaneously, O3 concentrations both daytime nighttime. increase ranged 2.89 9.82 μg/m3, while nighttime 1.76 7.77 μg/m3. enhanced as well vertical transport, an O3. At same time, it reduced horizontal transport dry deposition processes. These are related variations. was not limited but extended top (approximately 1500 m). Below 500 m, concentrations, concentrations. Additionally, induced by showed above surface, whereas process had smaller surface. reveals significant urban expansion regional optimizes model's simulation quality provides new insights into understanding conditions

Language: Английский

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Hindered visibility improvement despite marked reduction in anthropogenic emissions in a megacity of southwestern China: An interplay between enhanced secondary inorganics formation and hygroscopic growth at prevailing high RH conditions

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 895, P. 165114 - 165114

Published: June 26, 2023

Language: Английский

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Cognitive impairment associated with individual and joint exposure to PM2.5 constituents in a Chinese national cohort

Frontiers of Environmental Science & Engineering, Journal Year: 2024, Volume and Issue: 18(9)

Published: June 25, 2024

Language: Английский

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One-year observation of the mixing states of oxygenated organics-containing single particles in Guangzhou, China

Frontiers of Environmental Science & Engineering, Journal Year: 2024, Volume and Issue: 18(5)

Published: March 11, 2024

Language: Английский

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Machine learning unveils the impact of anthropogenic emission changes on urban PM2.5 and O3: A case study in Wuhu

Journal of Environmental Sciences, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 1, 2024

Language: Английский

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