Atmospheric Research最新文献

{"title":"Global monsoon variability in a 1.5 °C warming climate: Observational changes and end-century projections","authors":"Ricky Anak Kemarau ,&nbsp;Zulfaqar Sa'adi ,&nbsp;Najeebullah Khan ,&nbsp;Bassim Mohammed Hashim ,&nbsp;Leonardo Goliatt ,&nbsp;Sajjad Firas Abdulameer ,&nbsp;Zaher Mundher Yaseen ,&nbsp;Shamsuddin Shahid","doi":"10.1016/j.atmosres.2026.108765","DOIUrl":"10.1016/j.atmosres.2026.108765","url":null,"abstract":"<div><div>Monsoon systems underpin the water, food, and economic security of over two-thirds of the global population, yet they are entering a state of instability as global temperatures have now surpassed +1.5 °C above pre-industrial levels. This crossing of the 1.5 °C threshold raises a critical problem: Are monsoon onset, duration, and extreme rainfall already shifting in detectable, regionally differentiated ways? Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 framework, we screened 784 peer-reviewed studies (2000–2024) and synthesized 72 high-quality articles. A complementary global diagnostic using Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS; 1981–2024) ensured uniform comparison across monsoon regions. Results reveal onset shifts of ±15 days, rainfall-intensity increases of +10–60%, and duration changes of ±15 days, with the strongest signals in South Asia, East Asia, the Western North Pacific, and Southeast Asia. Attribution using CMIP5/CMIP6, ERA5, TRMM, GPM, and IMERG identifies El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), sea-surface temperature anomalies, and greenhouse-gas (GHG)–aerosol interactions as dominant drivers. Although seasonal totals often change modestly, clustering of extremes and lengthening dry spells markedly elevate compound flood–drought risk. This review establishes the first harmonized global baseline of observed monsoon change and highlights urgent needs for convection-permitting regional models, improved subseasonal prediction, expanded observational networks, and increased representation of African and South American monsoon systems.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"335 ","pages":"Article 108765"},"PeriodicalIF":4.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the spatial heterogeneity of black carbon variation drivers in China: Views from explainable machine learning","authors":"Huang Zheng ,&nbsp;Weiwei Chen ,&nbsp;Xiaohui Bi ,&nbsp;Nan Chen ,&nbsp;Cheng Wu ,&nbsp;Mingming Zheng ,&nbsp;Shaofei Kong","doi":"10.1016/j.atmosres.2026.108749","DOIUrl":"10.1016/j.atmosres.2026.108749","url":null,"abstract":"<div><div>Differences in black carbon (BC) emissions and diverse climate zones in China result in significant spatial heterogeneity of BC levels. Understanding the roles of emissions, meteorological conditions, and other factors in BC variation is important for mitigating its adverse effects. This study conducted synchronous observations of BC in Changchun (CC), Tianjin (TJ), Wuhan (WH), and Guangzhou (GZ) during winter. Results showed that BC levels were highest in WH compared to the other cities (<em>p</em> &lt; 0.001). Simulations using the Flexible Particle Dispersion (FLEXPART) model and BC emission inventories quantified the contributions from local transport and different sectors. Results indicated that local emissions were the dominant geographical source of observed BC levels at all four sites. BC from residential, commercial, and other sectors was the dominant source in TJ, WH, and GZ. Using the SHapley Additive exPlanations (SHAP) method, emissions were identified as the predominant factor influencing BC variation at the four sites. While changes in meteorological conditions were the most influential factor contributing to BC concentration increases as air quality worsened from clean to polluted in CC, TJ, and WH. Regarding the impacts of features on model outputs, emissions showed a linear relationship with simulated BC, while the effects of transport and meteorological conditions exhibited spatial heterogeneity. This study highlights the need for continuous reduction of BC emissions to decrease ambient BC levels, and this recommendation can be extended to other parts of the country.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108749"},"PeriodicalIF":4.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations between the thermal spring timing variability and atmospheric teleconnection patterns over the past six decades in Finland","authors":"Sadegh Kaboli ,&nbsp;Ville Kankare ,&nbsp;Ali Torabi Haghighi ,&nbsp;Cintia Bertacchi Uvo ,&nbsp;Elina Kasvi","doi":"10.1016/j.atmosres.2026.108752","DOIUrl":"10.1016/j.atmosres.2026.108752","url":null,"abstract":"<div><div>The timing of the spring season in the boreal region is shifting under global warming, with profound impacts on ecosystems and hydrological processes. However, the mechanisms driving this transition and its considerable interannual variability are not well described, especially regarding the influence of large-scale atmospheric teleconnection patterns. This study examines the temporal variability of the observed thermal spring season across Finland, a boreal country warming faster than the global average. Key spring timing indices, including onset, end, duration, and growing season onset, were calculated and analyzed using high-resolution (1 km × 1 km) daily mean temperature data from 1961 to 2023. Spatial and temporal patterns were identified through Empirical Orthogonal Function (EOF) decomposition, and their associations with major atmospheric teleconnection patterns were examined. Results indicated that during the past six decades, the spring onset has advanced by 2–6 days/decade, with the most pronounced changes in the coastal and southwestern parts of the country. The duration of the spring season has extended by 3–6 days/decade in the northern areas and along the southwestern coast. The early spring onset was associated with a strong positive phase of the Arctic Oscillation (AO), and delayed spring end and growing season onset were linked to the positive phase of the East Atlantic–West Russia (EAWR) pattern. By contrast, an early growing season start was linked to the positive phase of the North Atlantic Oscillation (NAO). The duration of the thermal spring season showed a strong association with the Scandinavian (SCA) pattern.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108752"},"PeriodicalIF":4.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric CO₂ concentration gradients at the coastal region of the Yangtze River Delta: Patterns and drivers","authors":"Yi Lin ,&nbsp;Honggang Lv ,&nbsp;Kehan Chen ,&nbsp;Peng Guo ,&nbsp;Yifei Jiang ,&nbsp;Lin Xiao ,&nbsp;Tienan Zhao ,&nbsp;Haiyan Wang ,&nbsp;Yuanyuan Chen ,&nbsp;Kunpeng Zang ,&nbsp;Shuangxi Fang","doi":"10.1016/j.atmosres.2026.108746","DOIUrl":"10.1016/j.atmosres.2026.108746","url":null,"abstract":"<div><div>Atmospheric carbon dioxide (CO₂), the primary anthropogenic greenhouse gas, is a critical tracer for understanding carbon-cycle–climate feedback. Despite intense industrialization and population density, the Yangtze River Delta (YRD) lacks high-frequency in situ CO₂ observations in its coastal and marine-influenced zones. In this study, the continuous atmospheric CO₂ measurements collected between December 2020 and December 2022 at an urban tower in Shanghai and a coastal background site in Shengsi were analyzed. Results reveal a distinct bimodal diurnal cycle in Shanghai, primarily driven by local anthropogenic emissions, whereas Shengsi exhibits a unimodal pattern more closely coupled to biospheric processes and marine dilution. Nighttime data from Shanghai station reliably represents urban background concentrations, as the stable concentration performance, less planetary boundary layer (PBL) and anthropogenic impacts. Wind and trajectory analyses link CO₂ enhancement at Shanghai to emissions from northern and northwestern sectors, whereas Shengsi concentrations are modulated by ocean-atmosphere carbon exchange—as evidenced by correlations with sea surface temperature, salinity, and pressure, alongside stronger negative links to normalized difference vegetation index (NDVI) and air temperature compared to Shanghai. Furthermore, partial least squares regression (PLSR) further highlights the dominance of local emissions at Shanghai (&lt; 200 km scale) and oceanic/biospheric drivers at Shengsi, with regional transport amplifying variability across scales. These findings advance understanding of CO₂ spatiotemporal variability in coastal megaregions and provide an empirical basis for improving top-down carbon flux estimates and informing targeted climate mitigation strategies in eastern China.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108746"},"PeriodicalIF":4.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MCF-XCO2: A cross-mission consistency and fusion framework for integrating multi-satellite XCO2 observations","authors":"Yutang Yu ,&nbsp;Wenjie Tian ,&nbsp;Lili Zhang ,&nbsp;Tao Yu ,&nbsp;Yu Wu ,&nbsp;Tianhai Cheng","doi":"10.1016/j.atmosres.2026.108747","DOIUrl":"10.1016/j.atmosres.2026.108747","url":null,"abstract":"<div><div>Carbon satellites, as an essential means of obtaining atmospheric XCO₂ concentration, play a key role in monitoring the global carbon cycle. However, the differences in observation platforms, resolutions, and inversion algorithms among different satellites lead to apparent inconsistencies among multi-source XCO₂ data, which limits the joint application and comprehensive analysis of the data. In this paper, we develop a framework named <strong>MCF-XCO</strong>_{<strong>2</strong>} (<strong>M</strong>ulti-source <strong>C</strong>onsistency <strong>F</strong>usion of <strong>XCO</strong>_{<strong>2</strong>}) for correcting multi-source satellite XCO₂ observations and performing uncertainty-weighted fusion. The method leverages high-precision satellite products as references, while minimizing the need for direct ground-based correction, to enhance the consistency and overall accuracy of multi-source observations. Based on this framework, multi-source satellite data, including GOSAT, GOSAT-2, OCO-2, and OCO-3, were integrated to construct a sparsely gridded global XCO₂ fusion dataset at 0.01° × 0.02° nominal spatial resolution and nominal daily sampling, reflecting available observations. The findings indicate that the fused dataset shows improved coverage in grids with available observations compared to individual satellite products, improved accuracy, and better consistency over time. Independent validation against TCCON ground-based observations further confirms the method's effectiveness, with R² = 0.91, RMSE = 1.09 ppm, bias = 0.07 ppm, and MRE = 0.2 %. The spatial and temporal dynamic analysis of the fused dataset reveals the typical spatial structure and seasonal variation of global carbon concentration, demonstrating the potential application of this dataset in studying the carbon cycle. The MCF-XCO₂ framework is also designed to accommodate future satellite missions, supporting timely updates and extended temporal coverage.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108747"},"PeriodicalIF":4.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Case study of aircraft icing in-cloud measurements and explicit supercooled water prediction in Eastern China","authors":"Liping Luo ,&nbsp;Ming Xue ,&nbsp;Xin Xu ,&nbsp;Lin Deng ,&nbsp;Junxia Li ,&nbsp;Rong Zhang","doi":"10.1016/j.atmosres.2026.108748","DOIUrl":"10.1016/j.atmosres.2026.108748","url":null,"abstract":"<div><div>In the morning of 12 November 2022, severe aircraft icing occurred over Anhui Province, Eastern China during weather modification operations. In-situ airborne measurements revealed the presence of a substantial concentration of supercooled droplets with effective diameter exceeding 45 <span><math><mi>μ</mi></math></span>m, and liquid water content (LWC) above 1.2 g m⁻³ during the icing event.</div><div>Given the importance of microphysical parameterization (MP) scheme for icing conditions, simulations using different multi-moment MP schemes, i.e., WDM6, NSSL, Milbrandt-Yau (MY) schemes, are conducted at 1-km grid spacing for the case. Comparisons against satellite observations indicate that the general evolution of the frontal system and surface precipitation are well reproduced by the simulations. However, all simulations underpredict upper-level clouds with cloud-top temperature below 240 K over the northeastern part of the front. Besides, WDM6 scheme produces ice cloud-top area (CTA) closest to satellite observations but only produces approximately half of the observed CTA for supercooled cloud tops. The Milbrandt-Yau scheme shows superior performance in simulating the cloud top features during the icing event. Examinations of explicit supercooled cloud water (SCW) prediction skills indicate that WDM6 generates excessive total number concentration (<em>Nt</em>) of small SCW, with <em>Nt</em> reaching up to 10¹¹ m⁻³ and effective diameter (<em>ED</em>) below 20 <span><math><mi>μ</mi></math></span>m. In contrast, the NSSL scheme produces significantly larger SCW particles but substantially lower <em>Nt</em> at approximately 10⁷ m⁻³ and <em>ED</em> of above 200 <span><math><mi>μ</mi></math></span>m. Notably, the particle size distribution of SCW predicted by MY scheme is more realistic compared with in-situ aircraft measurements.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108748"},"PeriodicalIF":4.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145902906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"K-means clustering analysis of autumn rainfall patterns over West China and their underlying mechanisms","authors":"Han Zhang,&nbsp;Ke Fan","doi":"10.1016/j.atmosres.2026.108745","DOIUrl":"10.1016/j.atmosres.2026.108745","url":null,"abstract":"<div><div>Through k-means clustering analysis, this study identified three dominant anomalous patterns of autumn rainfall over West China: (1) a region-wide positive anomalies in precipitation, (2) a south-positive–north-negative dipole pattern, and (3) a west-positive–east-negative dipole pattern. The first two patterns account for most of the explained variance annually. The first pattern is influenced primarily by a strengthened and westward-extended western Pacific subtropical high and an intensified East Asian subtropical jet (EAJ), driven mainly by negative sea surface temperature (SST) anomalies in the tropical central-eastern Pacific. Reduced snow cover over the Tibetan Plateau also plays a moderating role by altering the thermal forcing that affects the EAJ. The second pattern is associated mainly with an anomalous anticyclone over the South China Sea and a weakened, southward-shifted EAJ, which are closely linked to El Niño-like SST anomalies in the tropical central-eastern Pacific and cold SST anomalies in the eastern North Atlantic. The above mechanisms were verified using the Linear Baroclinic Model and the ECHAM5 model.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108745"},"PeriodicalIF":4.4,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of orography on extreme rainfall event in Thoothukudi, Tamil Nadu: Role of lateral and cross-barrier mountain effects","authors":"K.L. Arunkumar ,&nbsp;Yesubabu Viswanadhapalli ,&nbsp;C.V. Srinivas ,&nbsp;Naresh Krishna Vissa ,&nbsp;J. Solomon Ivan","doi":"10.1016/j.atmosres.2026.108738","DOIUrl":"10.1016/j.atmosres.2026.108738","url":null,"abstract":"<div><div>On 17 December 2023, an exceptionally heavy rainfall event occurred at the southeastern tip of Tamil Nadu, with Kayalpattinam of Thoothukudi district recording 94 cm of rainfall in a single day, which caused widespread flooding in the region and its neighbourhood. This event was triggered by a low-pressure (LP) system moving northwestward through a complex terrain setting, bordered by the Western Ghats (WG) to the west and the Sri Lankan Mountains to the east. This synoptic event presents a rare opportunity to examine lateral and cross-barrier topographic influences on extreme rainfall. Three high-resolution cloud-resolving simulations were conducted using the Weather Research and Forecasting (WRF) model to investigate the role of mountains in modulating this localised extreme rainfall. The study carried out (1) a control simulation (CNTRL) with natural terrain, (2) a simulation without the Sri Lankan Mountain topography (NTSLI), and (3) a simulation with removing mountains over the entire domain (NTWDOM). The CNTRL simulation accurately reproduced the features of the observed rainfall and indicated an extension of the LP system towards the east coast, leading to a sustained localised moisture convergence and deep convection. Further, the simulation highlighted the formation of a cold pool in the windward regions of the WG due to the evaporative cooling and effective orographic blocking during the event. The NTSLI simulated eastward extension of LP system with its centre shifted in southwestward compared to the CNTRL and exhibited relatively stronger easterly winds in the absence of the Sri Lankan Mountains. The enhanced easterlies produced multiple moisture convergence zones, thereby altering convective processes and leading to reduced rainfall over the Tamil Nadu coast. The simulation indicated a southwestward shift in the rainfall pattern. In contrast, the NTWDOM simulation, with no orographic barriers, inhibited cold pool formation, dispersed moisture convergence, and resulted in weaker convection, as well as a westward displacement of rainfall towards the Arabian Sea. Our results clearly highlight that, apart from cross-orographic barriers, lateral orographic features also play a critical role in modulating the location, intensity, spatial distribution, and evolution of extreme rainfall events by influencing synoptic systems, moisture dynamics, and convective processes.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108738"},"PeriodicalIF":4.4,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tropical Cyclone Intensity Sensitivity to Sea Surface Temperature and Mixed Layer Depth","authors":"Evan David Wellmeyer ,&nbsp;Antonio Ricchi ,&nbsp;Rossella Ferretti","doi":"10.1016/j.atmosres.2025.108726","DOIUrl":"10.1016/j.atmosres.2025.108726","url":null,"abstract":"<div><div>Rapidly intensifying tropical cyclones (TCs) are among the most dangerous and least predictable weather systems. In this work, we focus on two intense Atlantic TCs that showed rapid intensification (RI, defined as at least 36 hPa deepening in 24 h) and which impacted the coast of the Gulf of Mexico. This study focused on how sea surface temperature (SST) and ocean mixed-layer depth (OMLD) modulate the rapid intensification (RI) and maximum intensity (MI) of two hurricanes, Wilma and Rita (2005). Using the Weather Research and Forecasting (WRF) model coupled with a simplified 1D ocean model, 20 simulations were performed to systematically vary SST (±1–3 °C) and OMLD (doubled or halved), as well as remove observed SST anomalies (SSTA). Results show that SST dominates TC intensity changes from around 15–20 hPa °C⁻¹, and correspondingly higher deepening rates. Warmer simulations also exhibit an increased energy transfer from the ocean, supporting increased near-surface equivalent potential temperature, a more symmetrical wind field and elevated accumulated cyclone energy (ACE). By contrast, deeper OMLD enhances thermodynamic support but is constrained by SST conditions, limiting the total surface heat flux in the storm's vicinity. Results also stress that remote heat fluxes across a broader region, not just beneath the storm core, play a crucial role in determining maximum intensity and deepening. Westward landfall shifts up to 300 km are observed in +3 °C scenarios, emphasizing the potential of ocean heat in altering trajectories. These findings highlight the critical importance of accurately representing upper-ocean thermal structures to improve predictions of TC intensity and trajectories, particularly as warmer future SSTs may lead to more frequent and dynamically evolving hurricanes.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108726"},"PeriodicalIF":4.4,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variability and sources of brown carbon in Wuhan: Insights from Bayesian modeling and organic tracers-based source apportionment","authors":"Zongjun Li ,&nbsp;Qiongqiong Wang ,&nbsp;Yongyi Zhao ,&nbsp;Zhongliang Huang ,&nbsp;Kezheng Liao ,&nbsp;Huan Yu ,&nbsp;Shaofei Kong ,&nbsp;Nan Chen ,&nbsp;Bo Zhu ,&nbsp;Xiao He ,&nbsp;Mingjie Xie ,&nbsp;Jian Zhen Yu","doi":"10.1016/j.atmosres.2025.108736","DOIUrl":"10.1016/j.atmosres.2025.108736","url":null,"abstract":"<div><div>Brown carbon (BrC) is an important constituent of atmospheric carbonaceous aerosols, and accurately measuring its mass concentration and optical property is of great importance to reduce its uncertainties in model parametrization. This study deployed the novel Bayesian inference (BI) model to determine the BrC mass concentration and absorption on an hour-by-hour basis, using online measurements of multi-wavelength light absorption and total carbon (TC) data over June and December 2023 in Wuhan, central China. BrC mass contributed to 42 % of the TC aerosol and showed comparable level in two months, while its absorption showed distinct seasonal contrast with much higher values in December. Important BrC compositions including various organic tracers were measured, taking advantage of the concurrently collected daily 12-h offline filter samples. BrC mass and absorption showed good correlations with important components such as oxygenated-polycyclic aromatic hydrocarbons (PAHs), light PAHs and biomass burning tracer-saccharides. Organic-tracer based source apportionment was conducted for both BrC mass and absorption, and nine distinct source factors were resolved. Secondary sources especially secondary organic aerosol (SOA) factor dominated BrC mass contributions in June, while biomass burning emerged as the primary source in December. The primary sources contributing to BrC absorption were SOA and biomass burning in June, while biomass burning dominated in December. Coal combustion, which was a minor source to BrC mass, was a non-negligible contributor to BrC absorption in both months. Different control measures should be implemented to effectively control BrC mass for improved air quality and to mitigate BrC absorption for its climate effect. The results from this study broaden our understandings of the relationship among chemical, optical and sources of BrC, offering significant implications for environmental management.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"333 ","pages":"Article 108736"},"PeriodicalIF":4.4,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}