Atmospheric Environment最新文献

{"title":"Tracking NO2 and CO pollution hotspots at provincial scale in China with TROPOMI observations and image segmentation method","authors":"Mingyu Zeng ,&nbsp;Minghui Tao ,&nbsp;Rong Li ,&nbsp;Pengfei Ma ,&nbsp;Lijuan Zhang ,&nbsp;Jun Wang ,&nbsp;Lunche Wang ,&nbsp;Yi Wang ,&nbsp;Haijun Huang ,&nbsp;Liangfu Chen","doi":"10.1016/j.atmosenv.2025.121176","DOIUrl":"10.1016/j.atmosenv.2025.121176","url":null,"abstract":"<div><div>Satellite measurements of short-lived gaseous pollutants such as nitrogen dioxide (NO₂) and carbon monoxide (CO) provide an unprecedented opportunity to infer global distribution of their emission sources. However, the great differences in the magnitude of anthropogenic emissions have hampered the identification of pollution sources with satellite observations. In this study, we identified NO₂ and CO pollution hotspots in China with oversampled TROPOspheric Monitoring Instrument (TROPOMI) concentration data by utilizing an image segmentation method at provincial scale. We also determined the major emitting sectors associated with the pollution hotspots in each province. Based on NO₂ pollution hotspots, we can find major emission sources, such as ports, airports, industrial and urban areas. In the hotspots of most provinces, Steel plant, Coke plant, and Power plant were identified as the main NO_x emission sources. CO pollution hotspots were closely linked to Steel plant, with additional contributions from Coke plant, Chemical industry, and Non-ferrous metal smelting in certain provinces. The pollution hotspots and their corresponding concentrations yielded a relatively strong correlation with Multi-resolution Emission Inventory for China (MEIC) (For NO₂, the R² was 0.937 in provinces with small land area and 0.654 in others, while for CO, the R² was 0.849 and 0.659, respectively). Our results can provide an observational constraint on the spatial locations of NO_x and CO emission sources for emission inventories.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121176"},"PeriodicalIF":4.2,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716005","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":"Molecular level characteristics and sources of rainwater water-soluble organic matter in different regions of China by FT-ICR MS","authors":"Cuiping Ning ,&nbsp;Yutong Tang ,&nbsp;Shuai Sun ,&nbsp;Dan Wang ,&nbsp;Yuan Gao","doi":"10.1016/j.atmosenv.2025.121175","DOIUrl":"10.1016/j.atmosenv.2025.121175","url":null,"abstract":"<div><div>Rainwater water-soluble organic matter (WSOM) constitutes a complex mixture that holds a pivotal role in biogeochemical cycles and climate change. Understanding its chemical composition helps better to reveal its atmospheric behavior. In this study, rainwater samples were collected from three Chinese cities to explore their WSOM molecular composition and sources. These rainwater samples contained significant amounts of both natural and anthropogenic WSOM owing to diverse environmental settings and extensive human activities. Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to analyze the molecular diversity of rainwater WSOM. A total of 1684, 2024, and 1104 molecular formulas were identified in rainwater WSOM from Anshan, Guangzhou, and Nanjing, China, respectively. The results reveled that sulfur-containing compounds (including CHOS and CHONS) dominated the rainwater WSOM in Anshan (74.9 %), with a notable presence of nitrooxy-organosulfates. In contrast, in Guangzhou, typical biogenic derivatives of CHO compounds contributed more to the rainwater WSOM (50.5 %). In Nanjing, the sulfur-containing compounds and CHO compounds were primarily composed of nitrooxy-organosulfates and saturated fatty acids, respectively, comprising 48.6 % and 43.8 % of the rainwater WSOM. On the whole, rainwater WSOM mainly originated from industrial emissions, secondary generation, biomass burning, and vehicle emissions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121175"},"PeriodicalIF":4.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679409","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":"Direct sun total NO2 column measurements at Thessaloniki, Greece with two DOAS systems and comparisons with S5P/TROPOMI","authors":"Dimitrios Nikolis,&nbsp;Alkiviadis Bais,&nbsp;Dimitris Karagkiozidis,&nbsp;Maria-Elissavet Koukouli,&nbsp;Dimitris Balis","doi":"10.1016/j.atmosenv.2025.121161","DOIUrl":"10.1016/j.atmosenv.2025.121161","url":null,"abstract":"<div><div>Multiple Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments have been operating in the Laboratory of Atmospheric Physics (LAP), Thessaloniki, Greece over a decade to monitor trace gases in the troposphere. In this work, we present methodology, applied for the first time in LAP for retrieving total NO₂ columns in the atmosphere by applying the Direct Sun DOAS technique (DS-DOAS) on solar direct radiance spectra acquired with a research grade MAX-DOAS system, Delta. For the retrieval of total NO₂ two spectral fitting methods were tested using cross sections of NO₂ at two different temperatures for the tropospheric and the stratospheric component. The method that is based on concurrent spectral DOAS fittings with NO₂ cross sections at two temperatures (294 K and 220 K) (2T method) produces results of better quality as compared to the method using NO₂ cross section at one 254.5 K (1T method), with latter underestimating the total NO₂ vertical column density by up to 15%. This was verified by the good agreement (correlation coefficient R = 0.973) against the total NO₂ columns measured by an independently calibrated collocated Pandora system. Finally, the total NO₂ columns derived from the Delta instrument were compared with collocated observations by S5P/TROPOMI, showing an underestimation of the latter by up to 40% for days with high NO₂ concentrations, while the agreement is better under low NO₂ conditions. The overall agreement between the satellite and Delta system observations is characterized by a correlation coefficient of 0.82 and a mean bias of −2.63 ± 2.75 Pmolec/cm².</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"352 ","pages":"Article 121161"},"PeriodicalIF":4.2,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hourly estimation of black carbon in China based on sparse observation data and stacking model","authors":"Weijie Li ,&nbsp;Yaqiang Wang ,&nbsp;Zhaoliang Zeng ,&nbsp;Ziwei Yi ,&nbsp;Huizheng Che ,&nbsp;Xiaoye Zhang","doi":"10.1016/j.atmosenv.2025.121164","DOIUrl":"10.1016/j.atmosenv.2025.121164","url":null,"abstract":"<div><div>Black carbon (BC) is a highly absorbent aerosol that significantly impacts regional air quality, public health, and global climate change. In this study, we develop a machine learning-based stacking model to estimate hourly BC in China, using observational data from 36 BC sites of the China Atmosphere Watch Network (CAWNET) from 2020 to 2023. The stacking model shows strong robustness and high accuracy nationwide, achieving a Pearson correlation coefficient (R) of 0.79 and a root mean square error (RMSE) of 0.60 μg/m³. Compared to Tracking Air Pollution in China (TAP), the stacking model reduces bias by 33.8% in urban areas and 56.9% in rural areas. According to this model, the urban BC concentration is 48.5% higher than that in rural areas across China. North China Plain, Central China, and the Sichuan Basin continue to be the regions with the highest BC concentrations in China, with average concentrations of 1.73 ± 0.66 μg/m³, 1.61 ± 0.55 μg/m³, and 1.71 ± 0.58 μg/m³, respectively, from 2020 to 2023. During the COVID-19, urban areas experienced a consistent decline in BC concentrations from 2020 to 2022, followed by a rebound in 2023 (rural areas rebound in early 2022). Our research highlights that these high-quality hourly estimated BC concentrations can reveal pollution distribution patterns in both urban and rural areas, as well as during specific time periods, thereby providing crucial support for developing more accurate and effective emission reduction strategies, improving air quality, mitigating climate change, and protecting public health.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121164"},"PeriodicalIF":4.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601286","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":"Sugars in clouds: Measurements and modelling investigation of their aqueous photodegradation","authors":"Angelica Bianco ,&nbsp;Lucas Pailler ,&nbsp;Muriel Joly ,&nbsp;Anne-Marie Delort ,&nbsp;Sophie Darfeuil ,&nbsp;Jean-Luc Jaffrezo ,&nbsp;Laurent Deguillaume","doi":"10.1016/j.atmosenv.2025.121167","DOIUrl":"10.1016/j.atmosenv.2025.121167","url":null,"abstract":"<div><div>Currently, studies show that only 10–30% at best of the organic matter dissolved in cloud water is characterized and sugars are among the compounds still unexplored. Numerous studies on the atmospheric particulate matter (PM) demonstrate their ubiquity, and their incorporation into cloud phase is therefore expected in light of their solubility.</div><div>In this work, a large array of sugars are measured at low concentration levels with an innovative LC-MSMS technique in 28 cloud water samples collected at the puy de Dôme and their environmental variability is analyzed. The total sugar concentration reaches 4.0 μmol L⁻¹, with an average value of 0.98 ± 0.94 μmol L⁻¹, with no clear seasonal trend. This represents on average 1.2% of dissolved organic carbon but reaches up to 3.7% for one sample. The most abundant sugars is levoglucosan (average 247.2 nmol L⁻¹) followed by glucose (168.2 nmol L⁻¹), mannitol (136.5 nmol L⁻¹) and 2-methyl-tetrols (130.6 nmol L⁻¹). Reactivity in the aqueous phase is simulated with the cloud chemistry model CLEPS to gain insights in the half-life time of four selected compounds in different meteorological and chemical scenarios. Results show a fast degradation of sugars in the aqueous phase, especially during summer, that could question the use of these tracers for long range transport in the free troposphere.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121167"},"PeriodicalIF":4.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical distribution and seasonal variations of dicarboxylic acids in urban PM2.5: Insights from multi-level observations on 600 m Canton tower in Guangzhou","authors":"Dian Ye ,&nbsp;Shengzhen Zhou ,&nbsp;Yuxuan Liang ,&nbsp;Chunlei Cheng ,&nbsp;Chenglei Pei ,&nbsp;Yao Li ,&nbsp;Min Gao ,&nbsp;Xijing Sun ,&nbsp;Siqi Chen ,&nbsp;Jian Hang ,&nbsp;Pingqing Fu ,&nbsp;Shaojia Fan","doi":"10.1016/j.atmosenv.2025.121166","DOIUrl":"10.1016/j.atmosenv.2025.121166","url":null,"abstract":"<div><div>Dicarboxylic acids are important constituents of organic aerosols, but the lack of their seasonal and vertical distribution hinders thorough knowledge of atmospheric physicochemical behavior. This study examines dicarboxylic acids at three heights (∼3, 118, and 488 m) on the 600 m high Canton Tower in urban Guangzhou, aiming to illustrate their primary sources and formation pathways across different seasons and heights. The concentration of dicarboxylic acids (678.7 ± 351.9 ng m⁻³) was lower or comparable to those in domestic cities but higher than in remote aeras. Oxalic acid had the highest concentration, with malonic, succinic, glyoxylic, and azelaic acids following. Most dicarboxylic acids peaked in autumn, following by winter, spring and summer. Higher dicarboxylic acids were observed at upper layers. The C₃/C₄ (1.5 ± 0.5) was relatively higher, and the proportion of C₂ in dicarboxylic acids increased with height. Our results showed that combustion and secondary conversion were primary sources of dicarboxylic acids in dry season, while biomass combustion and secondary formation processes dominated during wet season. Significant gas-phase oxidations were prevalent during summer, while aqueous-phase formations were prominent in spring. Aerosol aging process played an important role at higher atmospheric levels throughout the year, suggesting an enhanced atmospheric oxidation capacity in upper boundary layers. These vertical profiling measurements enable the identification of predominant origins and formation pathways of dicarboxylic acids across different seasons and boundary layer dynamics. The findings provide critical insights for understanding atmospheric chemical evolution processes, validating atmospheric models, and developing effective air pollution mitigation strategies.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121166"},"PeriodicalIF":4.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620007","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 benefit assessment of vehicle electrification in the fuel cycle: A case study of Chengdu","authors":"Zhaoyang Fan ,&nbsp;Hui Tong ,&nbsp;Naixiu Sun ,&nbsp;Yangxin Xiong ,&nbsp;Xuan Qu ,&nbsp;Hongjun Mao ,&nbsp;Jianfei Peng","doi":"10.1016/j.atmosenv.2025.121148","DOIUrl":"10.1016/j.atmosenv.2025.121148","url":null,"abstract":"<div><div>In recent years, vehicle emissions have emerged as one of the most significant sources of air pollutants and CO₂ in Chinese cities. Promoting electric vehicles (EVs) has become a critical strategy for mitigating vehicle-related pollution. While replacing conventional internal combustion engine vehicles (ICEVs) with EVs reduces on-road emissions, the associated increase in electricity consumption and power plant emissions may introduce negative environmental impacts. Overlooking emissions from the upstream fuel production stage can lead to overestimating the benefits of vehicle electrification policies. Therefore, it is essential to comprehensively quantify the environmental effects of electric vehicle promotion policies during the whole fuel cycle. Given that generation emissions are closely tied to the electricity mix, Chengdu (a city with over 85% hydropower) was selected as a pilot city for this study. The research follows a structured approach of ‘emission inventory establishment - air quality simulation - environmental benefit assessment - policy scenario analysis'. We systematically account for fleet emissions in Chengdu over the fuel cycle, simulate pollutant concentrations using the SMOKE-WRF-CMAQ model, estimate premature deaths through the GEMM model with Chinese population distribution data, and evaluate energy-saving and carbon-reduction potentials under various scenarios. The findings reveal that the Electricity Vehicles (EV) scenario reduces annual GHG-100 emissions by nearly 80% compared to the Business As Usual (BAU) scenario, while the Electricity Vehicles with Low-Carbon power grid (EVLC) scenario brings an additional 2.3% reduction. The EV policy significantly reduces PM_2.5, NO_X, and SO₂ concentrations in Chengdu's central urban area but leads to a notable increase in O₃ levels. These differences are further amplified when considering population-weighted concentrations, reflecting fluctuations in population prevalence. Finally, we monetise the impacts of pollutant and greenhouse gas emissions using the Value of a Statistical Life (VSL) and Social Cost of Carbon (SCC), estimating that the promotion of EVs avoids approximately 3913 million yuan in economic losses. These results provide a theoretical foundation and data support for the scientific promotion of vehicle electrification policies and the formulation of low-carbon green development strategies for urban transport in Chengdu.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121148"},"PeriodicalIF":4.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592958","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":"Deciphering aerosol carbon fractions in PM2.5 & PM10 and their possible sources in Eastern Himalaya region","authors":"Sweta Kumari ,&nbsp;Anirban Middey","doi":"10.1016/j.atmosenv.2025.121165","DOIUrl":"10.1016/j.atmosenv.2025.121165","url":null,"abstract":"<div><div>This study provides a comprehensive assessment of particulate matter (PM10 and PM2.5) and their carbonaceous fractions-organic carbon (OC) and elemental carbon (EC), across the Sikkim Himalaya region during the summer and winter of 2022. Sampling was conducted at four strategically selected locations: Gangtok (1151m), Pelling (1962m), Mangan (1353m), and Lachen (2740m). Due to harsh winter condition, Lachen was inaccessible, limiting winter sampling to the remaining three sites. Quartz filter-based low volume air sampling was employed to ensure high precision data collection. Annual average concentrations of PM2.5 exceeded the National Ambient Air Quality Standards (NAAQs) of 40 μg/m³, with the values of 66.48 ± 10.81 μg/m³ (Gangtok), 42.05 ± 17.48 μg/m³ (Pelling), and 61.39 ± 13.24 μg/m³ (Mangan). PM10 levels followed a similar trend: 89.99 ± 12.04 μg/m³ (Gangtok), 58.64 ± 20.17 μg/m³ (Pelling), 82.71 ± 14.94 μg/m³ (Mangan). Winter exhibited significantly higher OC and EC concentrations, especially in Gangtok, attributed to intensified vehicular emissions and biomass burning. The OC/EC ratio exceeding 2 in winter suggests enhanced secondary organic carbon formation, predominately from biomass and coal combustion. Gangtok exhibits the highest SOC/OC ratio, indicating enhanced secondary organic aerosol formation, likely due to higher anthropogenic emissions or favourable atmospheric conditions. In contrast, lower SOC/OC ratios in Pelling and Mangan suggest weaker atmospheric processing or lower VOC emissions. Correlation analysis indicates primary emissions as the dominant source of OC and EC, with transboundary pollution playing a critical role. Air mass Trajectory analysis highlights substantial pollution transport from Afghanistan, and the Indo-Gangetic plain, emphasizing the regional impact on Himalayan air quality. This study underscores, the urgent need for integrated air quality management strategies to mitigate both local and cross-border pollution, safeguarding the fragile Himalayan ecosystem and public health. A combination of emission control policies, real-time monitoring, and predictive modelling is essential to address the escalating air pollution crisis in this ecologically sensitive region.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121165"},"PeriodicalIF":4.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636633","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":"Spatial and seasonal variations and trends in carbon monoxide over China during 2013–2022","authors":"Yanlun Xie ,&nbsp;Han Han ,&nbsp;Jane Liu","doi":"10.1016/j.atmosenv.2025.121163","DOIUrl":"10.1016/j.atmosenv.2025.121163","url":null,"abstract":"<div><div>Carbon monoxide (CO) pollution is one of the unsolved atmospheric environmental issues over countries worldwide. Here, we comprehensively assess the spatial-seasonal variations and trends in CO over China during 2013–2022, by site categorization and cause analysis, which have not been reported in previous studies. Our analysis is based on surface observations, statistical classification techniques, and sensitivity simulations from a global chemical transport model, GEOS-Chem. The results show that CO concentrations and their seasonal variation are higher over the North China Plain than other areas of China during 2013–2022. CO concentrations have decreased at −38.2 ± 31.4 ppbv yr⁻¹ (−3.7% ± 1.8% yr⁻¹) over China during 2013–2022. The declining trends in CO concentrations vary with space, stronger over larger, more polluted, and more industralized cities. GEOS-Chem simulations suggest that the decrease in CO anthropgenic emissions in China would be the main driver for the decreasing trends of CO over China, with a contribution of 80% to the trend. Meteorology, CO anthropgenic emissions over foreign regions, and emissions from biomass burning are the remaining drivers. Our results suggest remarkable benefits of emission reductions in China in abating CO pollution and enhance our understanding on trends of long-term CO pollution over China during 2013–2022.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121163"},"PeriodicalIF":4.2,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-range transport influence on wintertime submicron aerosol chemical composition from simultaneous measurements in Lithuania and Southern Sweden","authors":"Agnė Minderytė ,&nbsp;Julija Pauraite ,&nbsp;Erik Ahlberg ,&nbsp;Adam Kristensson ,&nbsp;Steigvilė Byčenkienė ,&nbsp;Axel C. Eriksson","doi":"10.1016/j.atmosenv.2025.121162","DOIUrl":"10.1016/j.atmosenv.2025.121162","url":null,"abstract":"<div><div>Due to the large extent of seawater surface over the globe, aerosol particles spend significant time being transported over this type of surface. Therefore, global aerosol circulation is largely impacted by the processes particles undergo during long-range transport overseas. In this study, we investigated submicron aerosol (PM₁) chemical composition changes during long-range transport events over the southern Baltic Sea across two sites in Sweden (Hyltemossa) and Lithuania (Preila). The chemical composition was determined simultaneously using mass spectroscopy (time-of-flight aerosol chemical speciation monitor (ToF-ACSM)) in Hyltemossa and quadrupole ACSM (Q-ACSM) in Preila and filter-based optical (AE33 in Hyltemossa and AE31in Preila) methods. The aim of the study was to investigate the effect of long-range air mass transport over the sea on PM₁ chemical composition at the two remote background sites in the southern Baltic Sea region. The campaign average PM₁ concentration in Preila (11.2 μg/m³) was higher than in Hyltemossa (6.3 μg/m³). Yet, during long-range transport events, PM₁ concentration in Preila, downwind, was 40% lower (2.5 μg/m³) than in Hyltemossa (4.3 μg/m³), upwind, suggesting aerosol removal and dilution processes over the sea. We used the meteorological and spatial parameters from backward trajectory analysis to categorise the long-range air mass transport events across the two sites. Then the combinations of dilution, wet and dry deposition, emissions over land and other processes were labelled as the sea transport effect, wet deposition processes and land-atmosphere interaction. The results showed that during the events when air mass trajectories stretched from west to east from over Hyltemossa to Preila without precipitation along the path, the PM₁ concentration decreased on average by 50%. The addition of precipitation resulted in a larger decrease (70%) of PM₁ concentration. However, during the events with precipitation when air mass trajectories passed over a continental area before arriving at the downwind site, the net decrease was the lowest (27%). The lowest relative change in PM₁ concentration during those events suggests the potential uptake of pollutants into the air mass over land with more significant anthropogenic pollution sources. Our approach allows us to quantitively assess the mitigating effects of sea transport, wet deposition processes and the opposite effect when air mass is advected over land on PM₁ concentration using the proposed classification based on meteorological and spatial parameters of HYSPLIT backward trajectories.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"350 ","pages":"Article 121162"},"PeriodicalIF":4.2,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}