Atmospheric Environment最新文献

{"title":"Lower atmospheric profiling for climate studies pertaining to aerosols, radiation and turbulence using Unmanned Aerial System in India: Initial results","authors":"Padmakumari B,&nbsp;Sanket Kalgutkar,&nbsp;Mahesh Nikam,&nbsp;Subrata Mukherjee","doi":"10.1016/j.atmosenv.2025.121211","DOIUrl":"10.1016/j.atmosenv.2025.121211","url":null,"abstract":"<div><div>The lower atmosphere close to the Earth's surface, though crucial for various process studies and models, still remained a gap area for a long. The Indian Institute of Tropical Meteorology (IITM) pioneered in collecting aerosol and cloud data using manned aircraft. However, to fill the data gap in the lower atmosphere, IITM envisaged Unmanned Aerial System (UAS) as an innovative aerial platform and the program ‘<em>Lower Atmospheric Research using Unmanned Aerial System Facility (LARUS)</em>’ is instigated to demonstrate the efficacy of a fixed-wing medium size UAS for probing the lower atmosphere for climate studies. The UAS is equipped with lightweight advanced science payload and an isokinetic aerosol inlet, for targeted in-situ measurements of aerosol, chemistry, radiation, turbulence and meteorological parameters (temperature (T) and Relative Humidity (RH)). The vertical profiles on different flight days depicted high vertical diurnal variability of the measured parameters. Comparison of T &amp; RH profiles of INSAT-3DR Sounder and UAS depicted huge data gap in satellite profiles in the lower altitudes. The new approach in our study is obtaining high frequency simultaneous in-situ measurements within the footprint of 5 km with high vertical resolution to study local atmospheric processes.</div><div>The data emphasises elevated absorbing aerosol layers (AAL) or haze layers with maximum absorption up to 500 m above the ground due to local anthropogenic activities. The sample filter papers revealed the type, source and morphology of the observed aerosols. The incoming and reflected (outgoing) shortwave radiation indicated distinct features with an albedo of 0.178 above the haze layer (at 500 m) and 0.017 at the surface and solar absorption of 70 W/m² in the layer 0–500 m. The presence of haze also influenced the turbulence parameters (u, v, w) and Turbulent Kinetic Energy (TKE) at those altitudes. This study demonstrates instrumented UAS for lower atmospheric research, the first of its kind in India, highlighting various results essential for climate studies.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121211"},"PeriodicalIF":4.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748680","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":"Impact of the actinic radiative effect of scattering aerosols on ozone vertical distribution in the Pearl River Delta, China","authors":"Tao Deng ,&nbsp;Shanshan Ouyang ,&nbsp;Xiaoyang Chen ,&nbsp;Guowen He ,&nbsp;Xue Zhang ,&nbsp;Jeremy Cheuk-Hin Leung ,&nbsp;Qing Wang ,&nbsp;Zebiao Zhang ,&nbsp;Yu Zou ,&nbsp;Boru Mai ,&nbsp;Li Liu ,&nbsp;Xuejiao Deng ,&nbsp;TiJian Wang","doi":"10.1016/j.atmosenv.2025.121207","DOIUrl":"10.1016/j.atmosenv.2025.121207","url":null,"abstract":"<div><div>Currently, the Pearl River Delta (PRD) region faces the concurrent issues of aerosol and ozone pollution. Aerosols have a significant impact on the actinic radiative flux, which greatly influences the formation of ozone. This study quantitatively estimates the impact of scattering aerosol actinic radiative effect on the vertical distribution of ozone and secondary pollutants during a double high pollution episode in October 2012 using a localized parameterization formula for aerosol extinction profiles and the Weather Research Forecast–Community Multiscale Air Quality (WRF-CMAQ) model. Scattering aerosols can increase photolysis rates when the Aerosol Optical Depth is low. Aerosol actinic radiative effect reduces ground level ozone and PM_2.5 in the morning. In the core area of the PRD, the reduction in ozone reaches up to 20 ppb, while PM_2.5 decreases by 4–8 μg/m³. But it increases ozone and PM_2.5 levels in the upper and middle layers of the boundary layer during midday and the afternoon, with ozone increasing by 5–20 ppb and PM_2.5 by 1–2 μg/m³. Enhanced oxidizing capacity promotes the generation of sulfate and secondary organic aerosols, further increasing scattering aerosols and forming a positive feedback loop. The acinic radiative effect of aerosols lead to a diurnal variation in the reduction of surface ozone concentration, with a more pronounced effect in the morning. When radiation is weak in the morning and there is sufficient precursor for ozone, changes in radiation have a greater impact on ozone. As radiation becomes stronger, even though aerosols attenuate the radiation, there is still sufficient radiative flux to drive actinic reactions, and the impact of scattering aerosols on surface ozone concentration at midday is not significant. The mechanisms by which aerosol actinic radiative effect influence secondary organic aerosols (SOA) and sulfates are similar to those for ozone described above.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"352 ","pages":"Article 121207"},"PeriodicalIF":4.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776432","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":"El Niño-Southern Oscillation and its impact on population exposure to ozone pollution and heatwave compound events in China","authors":"Lijun Liu ,&nbsp;Youjia Liang ,&nbsp;Tianyu Zhang","doi":"10.1016/j.atmosenv.2025.121209","DOIUrl":"10.1016/j.atmosenv.2025.121209","url":null,"abstract":"<div><div>The El Niño Southern Oscillation (ENSO) has complex effects on human health through ozone pollution and heatwave compound events (OPHW). Although the climatic driving mechanisms of single extreme events in China have been preliminarily confirmed, the nexus of ENSO-OPHW-population exposure risk remains unclear. This study collected Niño 3.4 index, surface O3 and 209 Chinese cities' meteorological station data during the warm seasons (May–October) of 2013–2020, to reveal the effects of the ENSO on the three types of OPHW (ozone pollution-daytime heatwave: OPDH, ozone pollution-nighttime heatwave: OPNH, and ozone pollution-daytime and nighttime compound heatwave: OPCH) and the OPHW risks in major cities in China, via spatiotemporal statistics and geographical and temporal weighted regression (GTWR) modeling. Trend analyses indicate that ozone concentration, temperature, and the co-occurrence days of the three types of OPHW increase at a higher rate during El Niño periods than during La Niña periods. The driving effect of ENSO are found to amplify the OPHW is ranked as follows: ozone concentration (6.1 μg m⁻³) &gt; temperature (1.8 °C) &gt; co-occurrence days (0.2 days). Driven by the position of the subtropical high and anticyclonic changes over the continent, clear skies, high temperatures, low humidity, and low wind speeds significantly influence the three types of compound events. Moreover, during La Niña periods, the anomalous low-level anticyclone shows a significant southward shift compared to El Niño periods. During El Niño periods, the population exposure risk caused by OPHW is generally higher than during La Niña periods. OPDH, OPNH, and OPCH lead to the maximum relative changes of population exposure risk in the middle reaches of the Yangtze River (100 %), Sichuan-Chongqing (44.5 %), and Beijing-Tianjin-Hebei (11.2 %) urban agglomerations, respectively. These findings highlight the need for targeted research on the differential impacts of various compound events on regional population health and ecosystems. This study provides critical insights and methodological support for coordinated responses to extreme event changes and ozone pollution management.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121209"},"PeriodicalIF":4.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748687","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":"Source attribution of near-surface ozone pollution in Jiangsu Province of China over 2013–2019","authors":"Siqi He ,&nbsp;Yang Yang ,&nbsp;Hailong Wang ,&nbsp;Pinya Wang ,&nbsp;Hong Liao","doi":"10.1016/j.atmosenv.2025.121205","DOIUrl":"10.1016/j.atmosenv.2025.121205","url":null,"abstract":"<div><div>Near-surface ozone (O₃) is one of the most severe air pollutants in China, particularly over densely populated Jiangsu Province in the Yangtze River Delta. In this study, an O₃ source tagging technique is utilized in a chemistry-climate model to quantify the source contributions of various emission sectors and regions for nitrogen oxides (NO_x) and volatile organic compounds (VOCs) to O₃ concentrations in Jiangsu Province during 2013–2019. The results show that the near-surface O₃ in Jiangsu Province is mainly contributed by surrounding and remote anthropogenic NO_x emissions through long-range transport. Local anthropogenic NO_x emissions account for only 13 % and 18 % of the annual and summertime mean near-surface O₃ in Jiangsu Province, respectively. Anthropogenic NO_x emissions from the surface transportation, industry, and energy sectors account for 21 %, 22 % and 20 % of the annual mean near-surface O₃ concentration in Jiangsu Province, respectively. Biogenic and anthropogenic VOCs emissions each explains one-third of the annual mean near-surface O₃ concentration in Jiangsu, while methane and stratospheric chemical production contribute 21 % and 6 %, respectively. The sources from stratospheric production, aircraft, lightning, and foreign emissions are the primary contributors to O₃ in the mid- and high troposphere. During high pollution days in Jiangsu Province, the near-surface O₃ concentrations increase with the maximum exceeding 20 ppb, which is attributed to both the enhanced photochemical production and regional transport in favorable meteorological conditions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"352 ","pages":"Article 121205"},"PeriodicalIF":4.2,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785459","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":"Inferring near-surface ozone production regimes: Insights from using satellite retrievals over the contiguous US","authors":"Akanksha Singh ,&nbsp;Allison M. Ring ,&nbsp;Hao He ,&nbsp;Dale J. Allen ,&nbsp;Russell R. Dickerson ,&nbsp;Ross J. Salawitch ,&nbsp;Timothy P. Canty","doi":"10.1016/j.atmosenv.2025.121208","DOIUrl":"10.1016/j.atmosenv.2025.121208","url":null,"abstract":"<div><div>Surface ozone regulation policies rely heavily on air quality models, such as CAMx, for guidance. Comparison with observations is crucial to evaluating a model's ability to represent ozone production chemistry. Identifying factors influencing surface ozone formation is complicated because ozone photochemical production rates are non-linearly dependent on concentrations of precursors such as nitrogen oxides (NO_x) and volatile organic compounds (VOCs). We compare ozone production regimes (OPRs) identified from satellite observations and model simulations, as defined by the ratio of column formaldehyde to nitrogen dioxide (FNR, HCHO/NO₂). We performed CAMx simulations for summer 2016 over the Contiguous United States (CONUS) and compared output against two OMI NO₂ and HCHO retrievals. Our analysis spans diurnal and altitudinal variations of OPRs, offering important insights for effective policy formulation. At the time of the OMI overpass oz(∼1:30 p.m. LT), OPR is NO_x-limited over most of the CONUS, as determined from OMI column ratios. Analysis of CAMx column ratios shows similar results. In contrast, more regions are VOC-limited when we constrain our ratio to within the Planetary Boundary Layer (PBL). In the morning (∼9 a.m. LT), the CAMx PBL column ratios shift towards VOC-limited regime compared to the afternoon. We highlight areas of the CONUS where satellite measurements of FNR may not be an accurate indicator of near-surface OPRs. Air quality regulations based on satellite observations should consider the diurnal variations of surface OPRs and assess how well their ratios represent near-surface OPR. Our results have implications for interpretation of TEMPO data for policy relevant applications.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"352 ","pages":"Article 121208"},"PeriodicalIF":4.2,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792659","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":"Heterogeneous reactions of toluene/NO2/NH3 on α-Fe2O3/α-Al2O3 particles: The effects of pollutant content and temperature changes on the formation of N-containing organic compounds (NOCs)","authors":"Sijie Wen ,&nbsp;Xiang He ,&nbsp;Aiyilaiti Kudesi ,&nbsp;Shuangxi Wang ,&nbsp;Xin Liu ,&nbsp;Mingsong Dong ,&nbsp;Xiaolong Yu","doi":"10.1016/j.atmosenv.2025.121195","DOIUrl":"10.1016/j.atmosenv.2025.121195","url":null,"abstract":"<div><div>Heterogeneous reactions of toluene with mineral oxides play a crucial role in the formation processes of N-containing organic compounds (NOCs). However, less attention was paid to the effects of pollutant content and temperature changes on the formation of NOCs under combined pollution. In this study, the combined effects on the heterogeneous reaction of toluene/NO₂/NH₃ with α-Fe₂O₃/α-Al₂O₃ particles were investigated by using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results show that the characteristic peak of the R-ONO₂ group appears at 1295 cm⁻¹, indicating benzyl nitrate formation in the presence of α-Fe₂O₃ with or without α-Al₂O₃. The addition of α-Al₂O₃ promotes the R-ONO₂ formation on the particle surface compared to pure α-Fe₂O₃ as a result of the dispersion and oxidation of the additional particles. The optimal mass ratio of α-Fe₂O₃ and α-Al₂O₃ particles is 3:1. Furthermore, the optimal concentration ratio for toluene, NO₂ and NH₃ is determined as 2.5:2.5:1. It is obvious that NO₂ and toluene are the primary sources of organic nitrates production. Higher concentration proportions of NO₂ and toluene within a certain range lead to higher formation amounts of NOCs during the heterogeneous reaction. Spectral analysis demonstrates that reaction kinetics, such as reaction rate and uptake coefficient, are sensitive to temperature variations. When temperature decreases from 298 K to 253 K, the reaction rate increases from (1.59 ± 0.04) × 10¹⁸ ions g⁻¹ s⁻¹ to (2.38 ± 0.02) × 10¹⁸ ions g⁻¹ s⁻¹. Low temperature favors the production of R-ONO₂, resulting from an exothermic process during the heterogeneous reaction. These findings are helpful for further exploring the combined effects on particulate NOCs formation and partly contribute to understanding of multicomponent reaction systems in real environment conditions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121195"},"PeriodicalIF":4.2,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734507","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":"Persistent influence of dust on aerosol properties in summer over the northeast Tibetan Plateau explored by surface and tethered balloon-borne observations","authors":"Liang Ran ,&nbsp;Zhaoze Deng ,&nbsp;Yunfei Wu ,&nbsp;Zhixuan Bai ,&nbsp;Wanyun Xu ,&nbsp;Xuelian Xu ,&nbsp;Shengcang Wang ,&nbsp;Ping Tian ,&nbsp;Mengyu Huang ,&nbsp;Xiangao Xia ,&nbsp;Jianchun Bian","doi":"10.1016/j.atmosenv.2025.121194","DOIUrl":"10.1016/j.atmosenv.2025.121194","url":null,"abstract":"<div><div>Aerosol properties over the Tibetan Plateau exert important impacts on weather and climate in this area and downstream regions. The influence of dust on aerosol properties over this region has been demonstrated by previous studies based on remote sensing. However, there is still a lack of knowledge regarding how aerosol properties were influenced by dust and the evolution of dust events, especially in a temporally and vertically resolved way. In this study, aerosol microphysical and optical properties in summer were investigated by in-situ surface and tethered-balloon borne observations, which were also utilized to explore dust events with a joint analysis of the MERRA-2 reanalysis data and HYSPLIT backward trajectories. The PM₁/PM₁₀ ratios and scattering Ångström exponents were found to be quite low at most of the time during the campaign even in the absence of dust events, evidently suggesting that surface aerosol properties were persistently influenced by dust. Particle mass size distributions in the free troposphere also clearly revealed fingerprints of dust. An examination on individual dust event indicated that dust particles could be of local origins or long-range transported from deserts to the north of the plateau. This study helps improve our understanding on the influence of dust on aerosol properties, possible sources of observed dust particles and the evolution of dust events over this region. A future effort is worth undertaking to address potential impacts of dust-influenced aerosol properties on atmospheric processes of climatic importance by integrating various observations and model simulations.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121194"},"PeriodicalIF":4.2,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726083","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":"Ozonolysis of prenol, a second-generation biofuel, in atmospheric simulation chambers: Temperature dependent kinetics and gas-phase products analysis","authors":"Reem Al Mawla ,&nbsp;Cécile Cœur ,&nbsp;Nicolas Houzel ,&nbsp;Sylvain Billet ,&nbsp;Fatima Al Ali ,&nbsp;Vincent Gaudion ,&nbsp;Paul Genevray ,&nbsp;Fabrice Cazier ,&nbsp;Manolis N. Romanias","doi":"10.1016/j.atmosenv.2025.121188","DOIUrl":"10.1016/j.atmosenv.2025.121188","url":null,"abstract":"<div><div>Prenol (3-methyl-2-buten-1-ol), a second-generation biofuel, is released in the atmosphere during its use and storage where it can react with atmospheric oxidants. In this study, the ozonolysis reaction of prenol was investigated in two atmospheric simulation chambers CHARME (CHamber for the Atmospheric Reactivity and Metrology of the Environment) and THALAMOS (Thermally Regulated Atmospheric Simulation Chamber). PTR-ToF-MS and SIFT-MS were used to monitor the concentrations of organic compounds versus time. The room temperature (293 ± 2 K) rate coefficient was determined using the relative and pseudo-first order methods. The values obtained using both methods in the two chambers were in accordance, leading to an average rate coefficient of (3.26 ± 0.33) × 10⁻¹⁶ cm³ molecule⁻¹ s⁻¹. The temperature-dependent rate coefficient of this reaction was also investigated using the relative method in the temperature range 283–353 K. The following Arrhenius expression: <span><math><mrow><mi>k</mi><mo>=</mo><mrow><mo>(</mo><mrow><mn>9.83</mn><mo>±</mo><mn>1.7</mn></mrow><mo>)</mo></mrow><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>16</mn></mrow></msup><mo>×</mo><mi>exp</mi><mrow><mo>(</mo><mrow><mfrac><mrow><mo>−</mo><mn>331</mn><mspace></mspace><mo>±</mo><mn>53</mn></mrow><mi>T</mi></mfrac><mspace></mspace></mrow><mo>)</mo></mrow></mrow></math></span> cm³ molecule⁻¹ s⁻¹ was obtained. The gas-phase oxidation products formed, at room temperature (293 ± 2 K), from this reaction were investigated using PTR-ToF-MS, SIFT-MS and GC-EI-MS analyses. Several products were identified and quantified (in %), including acetone (9 ± 2), whose formation yield was determined using a calibration standard, and acetaldehyde (30 ± 5), glycolaldehyde (30 ± 5), formaldehyde (8 ± 1), methylglyoxal (8 ± 1) and hydroxyacetone and/or methylacetate (5 ± 1) %, whose formation yields were estimated using a generic H₃O⁺ rate coefficient for their protonation reaction. Glyoxal was also observed but not quantified. The kinetic data are compared with literature and a reaction mechanism is proposed. To our knowledge, this work is the first one presenting the mechanistic study and Arrhenius equation for the ozonolysis reaction of prenol.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"352 ","pages":"Article 121188"},"PeriodicalIF":4.2,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768227","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":"Crucial VOCs influences on ozone formation in North China: A spatial perspective","authors":"Donghui Liu ,&nbsp;Shangfei Hai ,&nbsp;Junlei Meng ,&nbsp;Weihang Zhang ,&nbsp;Yang Zhou ,&nbsp;Yuanhong Zhao ,&nbsp;Xiaoyu Liu ,&nbsp;Wenshuai Li ,&nbsp;Lifang Sheng","doi":"10.1016/j.atmosenv.2025.121183","DOIUrl":"10.1016/j.atmosenv.2025.121183","url":null,"abstract":"<div><div>With the increasing frequency of ozone (O₃) pollution episodes in China, there is a growing emphasis on understanding the contributions of precursors to O₃. Identifying key volatile organic compounds (VOCs) that drive O₃ formation has become a primary research focus. However, comprehending these key VOCs' distribution characteristics and patterns remains challenging. This study employs the convergent cross-mapping (CCM) method to identify and quantify causal relationships between 25 VOCs and O₃ simulated by WRF-Chem model. The results indicate that key VOCs identified by CCM can correspond well with those calculated based on observational data. Furthermore, the contributions and sources of various VOCs exhibits notable regional variations, showing a change with the O₃ formation sensitivity (OFS). In areas where OFS is strongly limited by VOCs, such as coastal ports and cities with concentrated resources or populations, alkenes, ketoaldehyde, and alcohols contribute more to O₃ formation. Meanwhile, the proportion of primary emission sources of oxygenated VOCs is relatively high (62.36–78.64 %), while secondary production sources are relatively low. Conversely, in regions where OFS is minimally limited by VOCs, such as agricultural areas in northern China, alkanes, aromatics, and phenols become more important. In this context, primary source contributions diminish while secondary source contributions rise to 19.1 %–45.6 %. Given North China's complex VOCs sources, this study suggests reducing key VOCs by targeting OFS characteristics within specific regions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121183"},"PeriodicalIF":4.2,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748681","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":"Source characteristics of non-refractory particulate matter (NR-PM1) using high-resolution time-of-flight aerosol mass spectrometric (HR-ToF-AMS) measurements in the urban industrial city in India","authors":"Akash S. Vispute ,&nbsp;Prodip Acharja ,&nbsp;Suresh W. Gosavi ,&nbsp;Gaurav Govardhan ,&nbsp;Vinayak Ruge ,&nbsp;M.N. Patil ,&nbsp;T. Dharmaraj ,&nbsp;Sachin D. Ghude","doi":"10.1016/j.atmosenv.2025.121186","DOIUrl":"10.1016/j.atmosenv.2025.121186","url":null,"abstract":"<div><div>This study investigated the source characteristics of submicron non-refractory particulate matter (NR-PM₁) over a highly growing urban industrial city near the western coast of India. Using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), we conducted continuous measurements from June 2020 to May 2021, capturing seasonal variations in aerosol composition. The annual average NR-PM₁ concentration was 16.4 ± 15.4 μg m⁻³, with substantially higher concentrations observed during winter (33.3 ± 22.2 μg m⁻³). Chemical analysis revealed distinct contributions of organic aerosols (OA), nitrate (NO₃⁻), sulfate (SO₄²⁻), ammonium (NH₄⁺), and chloride (Cl⁻) to NR-PM₁. Organic aerosol consistently contained the most significant fraction of NR-PM₁ (49–67 % seasonally). Positive Matrix Factorization (PMF) resolved four distinct OA sources: traffic-related hydrocarbon-like OA (HOA), biomass-burning OA (BBOA), and two oxygenated OA factors (Semi-Volatile Oxygenated OA (SVOOA) and Low-Volatile Oxygenated OA (LV-OOA)). Secondary organic aerosol (SOA) was a large OA fraction, with LVOOA being most abundant in winter and post-monsoon, while SV-OOA was higher in monsoon and summer, suggesting photochemical and potentially aqueous-phase formation. Seasonal changes were also observed in OA elemental composition (O/C: 0.67–0.74; H/C: 1.53–1.61; OM/OC: 2.07–2.16) and carbon oxidation state (OSc: 0.25 in monsoon/winter to −0.06 in summer), further supporting the influence of photochemical processes. Size distribution analysis indicated that aerosols were predominantly in the accumulation mode (300–800 nm), suggesting aged and internally mixed aerosol particles. Back trajectory and Concentration Weighted Trajectory (CWT) analyses indicated varied regional influences on PM₁ source characteristics.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"351 ","pages":"Article 121186"},"PeriodicalIF":4.2,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737971","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}