Atmospheric Environment最新文献

{"title":"Sources and potential health indicators in urban aerosols revealed by gas chromatography-mass spectrometry combined with nitrogen chemiluminescence detector: evidence from a megacity (Tianjin) of China","authors":"Jingying Ma ,&nbsp;Yulin Qi ,&nbsp;Yufu Han ,&nbsp;Jinfeng Ge ,&nbsp;Ling Wen ,&nbsp;Xiaoli Fu ,&nbsp;Wei Hu ,&nbsp;Zongbo Shi ,&nbsp;Dietrich A. Volmer ,&nbsp;Pingqing Fu","doi":"10.1016/j.atmosenv.2025.121345","DOIUrl":"10.1016/j.atmosenv.2025.121345","url":null,"abstract":"<div><div>Understanding the chemical complexity of atmospheric aerosols and their associated health risks remains a significant challenge, particularly in rapidly urban regions. Although PM_2.5-associated organic compounds have received growing attention, nitrogen-containing hazardous species such as nitrosamines remain under-explored. Here, comprehensive chemical characterization of urban PM_2.5 was conducted using two-dimensional gas chromatography–mass spectrometry (GC × GC-MS) for non-targeted profiling, together with a nitrogen chemiluminescence detector (NCD) for the quantification of nitrosamines at a trace level of 1.1 ppb. Aerosol samples were collected in Tianjin (a mega city in China) in 2022, including the Beijing Winter Olympics period. The study revealed seasonal variations in hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), with elevated levels of carcinogenic nitrosamines observed in winter, particularly during the Olympics. And interestingly, the estimated carcinogenic risk of nitrosamines is quite consistent with the local incidence rate in Tianjin. These findings emphasize the need for targeted pollution control strategies to minimize hazardous aerosols and human exposure, particularly during large-scale events.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121345"},"PeriodicalIF":4.2,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global health impacts of PAHs based on high-resolution modeling by dynamic simulation and relative emission downscaling","authors":"Zichen Wu ,&nbsp;Xueshun Chen ,&nbsp;Yuanlin Wang ,&nbsp;Wenyi Yang ,&nbsp;Yang Wang ,&nbsp;Zhe Wang ,&nbsp;Huansheng Chen ,&nbsp;Lianfang Wei ,&nbsp;Wending Wang ,&nbsp;Huiyun Du ,&nbsp;Zhuoran Wang ,&nbsp;Ying Wei ,&nbsp;Xiao Tang ,&nbsp;Jie Li ,&nbsp;Lin Wu ,&nbsp;Zifa Wang","doi":"10.1016/j.atmosenv.2025.121340","DOIUrl":"10.1016/j.atmosenv.2025.121340","url":null,"abstract":"<div><div>Polycyclic aromatic hydrocarbons (PAHs) are one of the highly toxic pollutants that require strict control. High-resolution distribution of PAHs is crucial for accurately quantifying their population exposure levels. However, due to the high computational cost, few models applying the dynamical approach could simulate global PAHs to evaluate health effects with resolution down to 1–10 km. This study simulated the global distribution of PAHs by combining the IAP-AACM model with a nonlinear downscaling method based on relative anthropogenic emissions and observations. A global high-resolution (0.1° × 0.1°, ∼10 km in middle latitudes) dataset of Benzo[a]pyrene (BaP, the most representative PAHs) in 2013 and 2018 is generated to support exposure studies. The 0.1° × 0.1° results are comparable to the nested simulation and have better consistency with observations than that of the 1° × 1° simulation. The 0.1° × 0.1° estimation shows significantly higher population-weighted total incremental lifetime cancer risks (PTILCR), with an increase larger than 50 %, compared to the 1° × 1° simulation. The PTILCR is greatly higher in winter than in other seasons and it is larger for children and young adults than for adolescents and seniors. The study has significant implications for the reliable assessment of global health risks of PAHs and the development of scientific management strategies for different age groups.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121340"},"PeriodicalIF":4.2,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of surface ozone pollution in Yangtze Rriver Delta between 2019 and 2022: influences of meteorology and emissions","authors":"Ying Zhang ,&nbsp;Fenfen Zhang ,&nbsp;Mei Wan ,&nbsp;Yu Bo ,&nbsp;Kebin He ,&nbsp;Rui Liu","doi":"10.1016/j.atmosenv.2025.121339","DOIUrl":"10.1016/j.atmosenv.2025.121339","url":null,"abstract":"<div><div>The Yangtze River Delta (YRD) suffers severe surface ozone (O₃) pollution during summer (June-July-August, JJA). Elucidating the role of meteorology and emissions is crucial for effective controls on O₃ pollution. We used the Weather Research and Forecasting (WRF) - Community Multiscale Air Quality (CMAQ) modeling system to quantify the influences of meteorology, anthropogenic and biogenic emissions on O₃ variations in the YRD between 2019 and 2022. Contrasting trends in surface O₃ were found in the Hangzhou Bay (HZB) (3.3 μg m⁻³ yr⁻¹) and the rest of the YRD (−1.9 μg m⁻³ yr⁻¹). Underlying factors affecting surface O₃ differed between these two subregions. In HZB, meteorological variations dominated the strong O₃ increase with a contribution of ∼94 %. By contrast, in the rest of the YRD, meteorology (42 %) and anthropogenic emissions (53 %) were both key contributors to the modest O₃ decrease. Our results reveal a shift in O₃ drivers in contrast to 2013–2019, characterized by an increasing importance of meteorology and a decreasing contribution of anthropogenic emissions. Consequently, the anthropogenically driven O₃ decrease, which ensues from current pollutant control policies, is difficult to offset the strong positive meteorological influence such as in HZB. There is an urgent need for stricter and more efficient control of O₃ precursor emissions to mitigate the substantial influences of meteorology. Emissions of non-methane volatile organic compounds are of particular concern, as they are still on the rise.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121339"},"PeriodicalIF":4.2,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental significance of sulfur wet deposition in ecological barrier region, Qinghai-Tibet Plateau","authors":"Zhang Baijuan ,&nbsp;Li Zongxing ,&nbsp;Wang Xufeng ,&nbsp;Li Zongjie ,&nbsp;Zhang Baiting ,&nbsp;Gui Juan ,&nbsp;Cui Qiao","doi":"10.1016/j.atmosenv.2025.121344","DOIUrl":"10.1016/j.atmosenv.2025.121344","url":null,"abstract":"<div><div>The Qilian Mountains are a significant ecological barrier in China. but the research on the characteristics of atmospheric Sulfur(S) wet deposition and the analysis of potential sources of SO₂ in this region are not adequate. In the study, 1382 samples of precipitation from 27 stations in the Qilian Mountains were analyzed. We quantified the wet deposition of atmospheric S on the Qilian Mountains, and the following conclusions were drawn. The annual average S wet deposition flux in the Qilian Mountains is 37.59 kg/hm². Due to the influence of precipitation patterns, the distribution of S wet deposition flux is uneven throughout the year, with 78.75 % of the total deposition occurring between May and October. Also, the S wet deposition flux shows an obvious spatial variability, with an increasing variation characteristic trend from west to east. Additionally, altitude, meteorological factors, and ecosystem types influenced the S wet deposition. The main sources and mechanisms of individual air pollutants in the Qilian Mountains are highly complex. The concentrations of SO₂ are strongly influenced by the regional transport of emissions, mainly from severe pollution source regions in South Asia, Western China, and Central Asia. It is recommended to reduce SO₂ emissions and protect ecological quality through industrial reforms, energy optimization, clean heating, land use adjustments, and ecological projects to improve public well-being.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121344"},"PeriodicalIF":4.2,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144298318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Size-dependent airborne metal solubility and associated analytical techniques at bulk and single particle levels: A review","authors":"Yi-Bo Zhao ,&nbsp;Tse-Lun Chen ,&nbsp;Jing Wang","doi":"10.1016/j.atmosenv.2025.121343","DOIUrl":"10.1016/j.atmosenv.2025.121343","url":null,"abstract":"<div><div>Size-dependent airborne metal solubility in air and living organisms has been identified as a key parameter to understanding aerosol-cloud interactions, global biogeochemical cycles, indoor air quality, and aerosol toxicity. Emission sources play a dominant role in size-dependent airborne metal solubility, which could be enhanced by atmospheric aging. Studies show that toxic metals (e.g., heavy metals) concentrated in submicron particles tend to have a higher solubility compared to crustal metals and possess even higher solubility levels in biological fluids than those in water, which may trigger more adverse health effects. Factors related to metal solubility and particle size, such as liquid water concentrations and acidity levels, mixing states, and particle parameters of particles, were discussed. Analytical techniques on various scales play an essential role in accurately measuring size-dependent metal solubility, particularly for soluble fractions. Available detection techniques at bulk and single particle levels were examined, including offline, online, and mapping analysis. The purpose of this overview is to summarize the current understanding of size-dependent airborne metal solubility and related state-of-the-art analytical techniques. We also identified future challenges and provided perspectives for studies of size-dependent metal solubility and the development of associated analytical techniques.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121343"},"PeriodicalIF":4.2,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the physicochemical properties of secondary organic aerosols formed by photo-oxidation of toluene in the atmospheric processes simulation chamber, K-CAPS","authors":"Jimin Kim ,&nbsp;San Kim ,&nbsp;Hwandong Kim ,&nbsp;Nam Geon Kim ,&nbsp;Sangwon Bang ,&nbsp;Hyoun Cher Jin ,&nbsp;Sooyeol Phyo ,&nbsp;Simal Cam ,&nbsp;Jiwon Lee ,&nbsp;Suk Hyun Lee ,&nbsp;Su-Yeon Choi ,&nbsp;Kyung Hwan Kim ,&nbsp;Jun-Tae Kim ,&nbsp;Meehye Lee ,&nbsp;Jin Young Kim ,&nbsp;Seung-Bok Lee","doi":"10.1016/j.atmosenv.2025.121336","DOIUrl":"10.1016/j.atmosenv.2025.121336","url":null,"abstract":"<div><div>A series of experiments was conducted to characterize a medium-sized 27-m³ smog chamber, KIST atmospheric processes simulation chamber (K-CAPS) in terms of the gas and particle wall losses, spectrum of light sources, and background reactivity and evaluate its suitability for simulating atmospheric reactions. Photo-oxidation experiments using a toluene and NO_x mixture were then carried out to investigate the effects of the UV lamp type, UV intensity, and ammonium sulfate seeds on the formation of secondary organic aerosols (SOA) and O₃, and on the physicochemical properties of SOA including hygroscopicity. When UVA and UVB lamps were used together, formation of SOA and O₃ was faster than that for UVA lamps alone. And higher UV intensity also resulted in faster formation of SOA and O₃, but the increase in O₃ with accumulated OH exposure and the increase in SOA with reacted toluene concentrations are consistent regardless of photolysis rate of NO₂ implying that increment in UV intensity can be acceptable to shorten the experiment time for relatively long aging processes such as multiday reactions. More SOA and less O₃ were formed when ammonium sulfate seeds were initially injected and average RH was relatively higher, compared to the dry experiment without seeds. These results must be useful to understand the physicochemical properties of SOA formed through photo-oxidation of anthropogenic VOCs in real-world atmospheric conditions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121336"},"PeriodicalIF":4.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of the atmospheric behavior of particulate Nitro(so) compounds in the urban atmosphere of Seoul during Spring 2019: Role of the oxides of nitrogen to the formation of Nitro(so) compounds","authors":"Na Rae Choi ,&nbsp;Yong Pyo Kim ,&nbsp;Ji Yi Lee ,&nbsp;Yun Gyong Ahn ,&nbsp;Eunhye Kim ,&nbsp;Soontae Kim ,&nbsp;Hye Jung Shin","doi":"10.1016/j.atmosenv.2025.121337","DOIUrl":"10.1016/j.atmosenv.2025.121337","url":null,"abstract":"<div><div>Atmospheric concentrations and formation mechanisms of particulate nitrosamines and nitramines were investigated in Seoul, South Korea during spring 2019. The total concentration of seven particulate nitrosamines was 17.51 ± 16.74 ng/m³, with nitroso-dibutylamine (NDBA, 7.86 ± 8.59 ng/m³) being the predominant species, while the sum of two nitramines was 0.70 ± 0.52 ng/m³. Correlation analysis showed that nitro(so) compounds were correlated with both primary emission markers (CO, PAHs) and factors associated with secondary formation (the ratio of total nitroso compounds to PM_2.5, and liquid water content). Box model simulations estimated that atmospheric reactions contributed 24.4 ± 25.2 % and 55.4 ± 27.0 % to particulate N-nitrosodimethylamine (NDMA) and N-nitrodimethylamine (DMN) formation, respectively. Multilinear regression analysis identified ozone as the strongest predictor for both measured NDMA (β = 1.035, p &lt; 0.01) and DMN (β = 0.893, p &lt; 0.05) concentrations, although this correlation likely reflects the non-linear relationship between NO_x and O₃ due to O₃ titration in NO_x-saturated conditions rather than direct ozonation effects. Sensitivity analyses revealed that both compounds responded positively to NO₂ increases through enhanced N₂O₃ and N₂O₄ formation, while NO increases showed differential effects: promoting NDMA formation while having minimal impact on DMN concentrations due to their distinct formation pathways. These findings demonstrate the complex atmospheric chemistry of nitro(so) compounds in urban environments and highlight the importance of NO_x chemistry in their formation.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121337"},"PeriodicalIF":4.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating parameterization schemes of dinitrogen pentoxide heterogeneous processes in the presence of organic coatings for size-resolved nitrate simulations over North China","authors":"Yu Qu ,&nbsp;Juan Yang ,&nbsp;Yitian Guo ,&nbsp;Yong Chen ,&nbsp;Xingang Liu ,&nbsp;Hui Chen ,&nbsp;Haiyan Ran ,&nbsp;Jingwei Zhang ,&nbsp;Ying Li ,&nbsp;Junling An","doi":"10.1016/j.atmosenv.2025.121335","DOIUrl":"10.1016/j.atmosenv.2025.121335","url":null,"abstract":"<div><div>The heterogeneous reaction of dinitrogen pentoxide (N₂O₅) is an important pathway for the nighttime formation of nitrate and its parameterization especially in the presence of organic coatings (considering phase changes) is complicated. In this study, an updated combination of inorganic core (Davis08) - organic shell (Gaston14 and Riemer09) parameterization schemes for N₂O₅ hydrolysis was embedded into the Weather Research and Forecasting model with Chemistry to discuss the simulated differences of and organic coating impacts on size-resolved N₂O₅ uptake coefficients and nitrate in North China, which have not been reported. All the three size-resolved N₂O₅ uptake coefficients had significant spatiotemporal variations, with a largest value in size bin 2 (156–625 nm). The values in the eastern coastal and relatively clean areas were generally larger than those in inland and polluted areas due to variations of relative humidity (RH), and were suppressed in nitrate dominated areas. Scheme Riemer09 is related to the thickness of SOA (secondary organic aerosol) package (l/Rp) and produced at least 2 μg/m³ of nitrate inhibition in regions where l/Rp ≥ 0.08 fit <span><math><mrow><msub><mi>γ</mi><mi>D</mi></msub></mrow></math></span> (the uptake coefficient of inorganic core) ≥ 1 × 10⁻². Scheme Gaston14 considers the effects of ambient RH and SOA phase; in those areas where RH was greater than 70 %, the coating effect simulated by scheme Gaston14 was relatively small; when low RH (&lt;40 %) and low O:C ratios (&lt;0.48) coexisted, scheme Gaston14 had a significant coating effect, leading to its simulated nitrate being ∼4 μg/m³ lower than the simulation of scheme Riemer09. The two coating schemes showed a similar vertical trend, with a maximum difference of 15 % of the heterogeneous produced nitrate in size bin 2 in the polluted areas at the height of ∼240m. Scheme Gaston14 exhibited greater advantages under complex meteorological and aerosol conditions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121335"},"PeriodicalIF":4.2,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the long-range dispersion of atmospheric microplastics in the free atmosphere with a numerical model","authors":"Matteo M. Musso ,&nbsp;Silvia Trini Castelli","doi":"10.1016/j.atmosenv.2025.121308","DOIUrl":"10.1016/j.atmosenv.2025.121308","url":null,"abstract":"<div><div>In recent studies available in literature, long-range transport was suggested to play a main role in the motion of microplastics in the free atmosphere, whereas emission sources are located in the planetary boundary layer. In this framework, the Lagrangian particle dispersion model MILORD was used both in forward and in backward modes to investigate the potential effectiveness of the transport and exchange of microplastics between the boundary layer and the free atmosphere. Two pioneering case studies from the literature were considered. The first where microplastics were detected in the free atmosphere above Madrid region, the second where microplastics were collected in the air at the top-mountain site of Pic Du Midi in the French Pyrenees. The simulations showed that the long-range transport plays the main role in determining the presence of microplastics in the free atmosphere above Madrid, while the emissions from the city affect mostly the air in the boundary layer, at regional scale in the surrounding area. The long-range transport towards Pic Du Midi site pointed out also potential contributions connected to the exchange between the marine environments and the atmosphere and to possible dust events from North Africa.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121308"},"PeriodicalIF":4.2,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical distribution and regional transport of air pollution over Northeast China: Insights from an intensive aircraft study","authors":"Ye Shan ,&nbsp;Yujiao Zhu ,&nbsp;Haoxin Sui ,&nbsp;Na Zhao ,&nbsp;Hongyong Li ,&nbsp;Liang Wen ,&nbsp;Tianshu Chen ,&nbsp;Yanbin Qi ,&nbsp;Wenlong Qi ,&nbsp;Xinfeng Wang ,&nbsp;Yuqiang Zhang ,&nbsp;Likun Xue ,&nbsp;Wenxing Wang","doi":"10.1016/j.atmosenv.2025.121327","DOIUrl":"10.1016/j.atmosenv.2025.121327","url":null,"abstract":"<div><div>We report an intensive aircraft study of regional air pollution over Northeast China during July and August 2018, unraveling the vertical distributions and regional transport of a variety of trace gases and aerosols. Major air pollutants, including sulfur dioxide (SO₂), nitric oxide (NO), ozone (O₃), black carbon (BC), aerosol scattering coefficient (Bsc), and volatile organic compounds (VOCs), showed distinct vertical profiles influenced by planetary boundary layer (PBL) dynamics and regional transport processes. Near-surface concentrations of primary pollutants (SO₂, NO, BC) generally decreased with altitude, whereas O₃ levels increased. Notably, residual layers containing aged BC (300 m–1000 m altitude) were observed during early morning, with subsequent downward mixing to the surface following PBL development. A strong negative correlation between BC and O₃ concentrations highlighted their antagonistic behavior in vertically stratified air masses. Vertical VOC distributions were dominated by light alkanes (C₂-C₄) and halocarbons, with profiles governed by their chemical lifetimes and transport mechanisms. A regional air pollution episode was observed in the high altitude atmosphere, characterized by elevated aerosol loading. WRF-Chem simulations revealed that episode was primarily driven by surface-level emissions from the Beijing-Tianjin-Hebei region. These pollutants were uplifted to the convergence zone and subsequently transported over long distance to Northeast China. Our findings enhance the understanding of vertical pollution profiles and the complex interplay between regional transport and local air quality in Northeast China.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"358 ","pages":"Article 121327"},"PeriodicalIF":4.2,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}