Atmospheric Research最新文献

{"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}

{"title":"Revealing ozone persistence under typhoon subsidence in the Greater Bay Area using lidar observations","authors":"Rui He ,&nbsp;Zhongcai Wang ,&nbsp;Yongfan Wu ,&nbsp;Yan You ,&nbsp;Yan Xiang ,&nbsp;Andi Zhang ,&nbsp;Chenglei Pei ,&nbsp;Tianshu Zhang","doi":"10.1016/j.atmosres.2026.108737","DOIUrl":"10.1016/j.atmosres.2026.108737","url":null,"abstract":"<div><div>Ozone (O₃) pollution poses a critical air quality challenge in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), particularly under typhoon peripheral circulation. However, the vertical processes governing O₃ persistence remain poorly understood. This study investigates a persistent O₃ pollution episode in July 2023 using the WRF-Chem model, data assimilation, and the GBA O₃ Lidar Network. Results reveal pronounced city-specific differences in O₃ persistence mechanisms. In Macao, extended O₃ exceedance was driven by persistent typhoon-induced subsidence, suppressed boundary-layer mixing, and convergence of transported O₃-rich air masses, forming a regional O₃ pool. Conversely, Shenzhen experienced rapid O₃ dissipation due to the inflow of cleaner maritime masses. Lidar observations captured distinct O₃ stratification within boundary layer under the influence of typhoon subsidence. These findings elucidate city-specific O₃ responses under complex meteorological conditions, providing robust scientific guidance for tailored air quality strategies in coastal megacity clusters.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"333 ","pages":"Article 108737"},"PeriodicalIF":4.4,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895034","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":"Gobi-sourced dust and dust–climate feedbacks in the March 2023 East Asian storm","authors":"Shuna Liang ,&nbsp;Bin Wang ,&nbsp;Yurui Zhang ,&nbsp;Junhua Yang ,&nbsp;Ove W. Haugvaldstad ,&nbsp;Hui Tang","doi":"10.1016/j.atmosres.2025.108735","DOIUrl":"10.1016/j.atmosres.2025.108735","url":null,"abstract":"<div><div>Amid escalating climate change and environmental instability, understanding the origins, transport mechanisms, and climatic-environmental impacts of intensifying East Asian dust storms has become crucial for global sustainability science. However, current research still faces critical limitations with lacking city- or site-level resolution for source apportionment, and quantitative assessments of the climatic and environmental effects of severe dust events are still insufficient. Here, we integrated in situ measurements, reanalysis datasets, and numerical simulations to investigate the extreme East Asian dust storm in March 2023. Results indicated that the Gobi Desert was the dominant source, contributing approximately 74.9–94.6 % to PM₁₀ levels across four northern Chinese cities. Fine particles (2.5–5.0 μm) exhibited faster and higher-altitude transport than coarse particles (&gt;7.5 μm), with consistent northwestward advection. Size-dependent deposition regimes emerged – dry deposition peaked for 7.5–10 μm particles, while wet deposition shifted from 5 to 7.5 μm in source regions to 2.5–5.0 μm in downwind North China. Crucially, we quantify the dust–climate feedback loop where aerosol-induced surface cooling by reducing surface solar radiation of 2.4–4.8 W m⁻², which in turn suppresses surface turbulent kinetic energy and decrease the boundary layer height up to 40 m. The enhanced boundary layer stability subsequently promoted futher dust accumulation. By elucidating this positive feedback mechanism, our study moves beyond established correlations to reveal a key process amplifying extreme dust storms, with critical implications for predicting their intensity and impacts under a changing climate.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108735"},"PeriodicalIF":4.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895038","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":"Near-surface wind field characterization of medicanes using satellite observations","authors":"Stefano Sebastianelli,&nbsp;Leo Pio D'Adderio,&nbsp;Paolo Sanò,&nbsp;Daniele Casella,&nbsp;Giulia Panegrossi","doi":"10.1016/j.atmosres.2025.108734","DOIUrl":"10.1016/j.atmosres.2025.108734","url":null,"abstract":"<div><div>MEDIterranean hurriCANES (Medicanes) represent a subcategory of Mediterranean cyclones that typically originate as extratropical systems then acquiring characteristics similar to tropical cyclones (TCs). These include the warm core, a nearly symmetric near-surface wind circulation, and eye-like features with spiraling rainbands. This study employs satellite scatterometer data to analyse ocean near-surface wind field in order to detect the rotational center by means the newly developed Medicane Rotational Center Automated Detection (MeRCAD) algorithm. As for TCs, the radius of maximum wind (RMW) is defined as the distance between the rotational center and the area of maximum wind. Results show a significant decrease in RMW, often down to a few tens of kilometres, when the wind field is featured by a nearly symmetric circulation. This allows wind features to be used as an indicator of the possible transition to the mature stage. We also found that the maximum sustained wind associated with the medicanes' mature phase is mostly beyond 95th percentile of values observed for all Mediterranean cyclones, although they appear substantially weaker than TCs. In addition, if the tropical transition occurs, the warm core is fueled by an area of deep convection that may be located near the rotational center at distances shorter than the RMW. However, the presence of an almost symmetrical wind circulation alone is insufficient to indicate the occurrence of the mature phase, due to the possible lack of a warm core. Vice versa, the warm core may occur without the characteristic nearly-symmetric wind circulation.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"334 ","pages":"Article 108734"},"PeriodicalIF":4.4,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145895041","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":"Enhancing wind forecasts through assimilation of maximum wind observations in WRF-3DVar: A comparison with conventional AWS data for a severe squall line","authors":"Dongmei Xu ,&nbsp;Ruonan Zhao ,&nbsp;Wei Sun ,&nbsp;Jinzhong Min ,&nbsp;Zhixin He ,&nbsp;Feifei Shen","doi":"10.1016/j.atmosres.2025.108733","DOIUrl":"10.1016/j.atmosres.2025.108733","url":null,"abstract":"<div><div>Convective-scale wind analysis and short-range forecast remains challenging due to the limited availability of high-temporal-resolution surface wind observations. This study investigates the impact of assimilating conventional 10-min average wind (CAW) and maximum 2-min average wind (MAW) observations from automatic weather stations on convective-scale wind analysis and short-term forecasting, focusing on a severe squall line event that affected Beijing on 30 May 2024. A series of sensitivity experiments were conducted using the WRF-3DVar system, including both single observation tests and full-domain assimilation experiments. Results indicate that CAW data, owing to their high temporal frequency, contribute to localized improvements in near-surface wind analysis and enhance the depiction of cold pool intensity. In contrast, MAW data exert broader, more profound influence that extends through multiple vertical layers, enabling a markedly more accurate reconstruction of three-dimensional wind and the full spatial footprint of the cold pool in the convective system. The comparative analysis demonstrates that MAW assimilation generates larger wind increments, broader spatial coverage, and better agreement with mesoscale observations than CAW assimilation. Additionally, MAW data yield a more realistic temporal evolution of surface winds and more coherent representation of gust front dynamics. These findings underscore the superior capability of MAW observations in convective-scale wind assimilation. Their expansive spatial reach and robust dynamical coherence offer greater potential for improving short-term convective forecasts, positioning them as an indispensable resource for the next generation of nowcasting and data-assimilation frameworks.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"333 ","pages":"Article 108733"},"PeriodicalIF":4.4,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845314","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":"Simulation and analysis of CO2 concentration in China from 2009 to 2021 based on the WRF-Chem model","authors":"Wenhao Liu,&nbsp;Yong Xue,&nbsp;Xiaolu Ling,&nbsp;Botao He,&nbsp;Chenggang Li,&nbsp;Liying Han","doi":"10.1016/j.atmosres.2025.108732","DOIUrl":"10.1016/j.atmosres.2025.108732","url":null,"abstract":"<div><div>Monitoring carbon dioxide (CO₂) concentration is considered an effective approach to controlling greenhouse gas emissions. Simulating CO₂ concentration variations using atmospheric chemistry models can compensate for the spatial and temporal limitations of ground-based and satellite observations. In this study, the WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) model was employed to simulate CO₂ concentrations over central and eastern China from 2019 to 2021. The reliability of the simulation results was verified through comparisons with satellite data from OCO-2 (Orbiting Carbon Observatory 2), OCO-3 (Orbiting Carbon Observatory 3), and GOSAT (Greenhouse Gases Observing Satellite). Additionally, the results were validated against observational data from TCCON (Total Carbon Column Observing Network) and WDCGG (World Data Centre for Greenhouse Gases). The RMSE of the WRF-Chem simulation results compared to TCCON and WDCGG station observations were 2.146 ppm and 2.239 ppm, respectively, with R of 0.716 and 0.825. When compared to OCO-2, OCO-3, and GOSAT satellite observations, the RMSE were 2.000 ppm, 2.080 ppm, and 1.827 ppm, respectively, with R values of 0.792, 0.831, and 0.837. Based on a comparative analysis integrating WRF-Chem simulations from 2009 to 2021, this study reveals an upward trend in XCO₂ concentrations over China, with an average annual growth rate of approximately 2.0 to 2.5 ppm. Although the growth rate slowed during 2019 to 2020, likely influenced by the COVID-19 pandemic, concentrations continued to increase annually. This result indicates that short-term variations in anthropogenic emissions can moderate the rate of increase but do not alter the long-term trend. The consistency between simulated CO₂ concentrations, MEIC inventory emission trends, and ground-based observations further validates the simulation accuracy and suggests the reliability of MEIC in characterizing China's carbon emission changes during the pandemic.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"333 ","pages":"Article 108732"},"PeriodicalIF":4.4,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845316","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":"Evaluating microphysics scheme impacts on summer precipitation in Northwestern China using a convection permitting WRF model","authors":"Ya Huang ,&nbsp;Qingyun Duan ,&nbsp;Yong Zhao ,&nbsp;Lihua Chen ,&nbsp;Yanping Li","doi":"10.1016/j.atmosres.2025.108691","DOIUrl":"10.1016/j.atmosres.2025.108691","url":null,"abstract":"<div><div>Microphysics parameterization strongly influences precipitation formation in numerical weather and climate models. This study evaluates three double moment microphysics schemes in the convection permitting WRF ARW model, including Jensen ISHMAEL (JIS), Thompson (TH), and WRF Double Moment 7 class (WDM7), for summer precipitation over Northwestern China using a 4 km simulation for 2009 to 2011. The evaluation, based on IMERG satellite data and surface observations, focuses on spatial distribution, diurnal cycle, hydrometeor structure, and thermodynamic conditions. All three schemes reproduce the major precipitation bands along the Tianshan, Qilian, and Kunlun Mountains, though with wet biases at high elevations and dry biases in the Tarim and Qaidam Basins. For diurnal variations, all schemes capture the characteristic double-peak cycle, with WDM7 providing the most accurate peak timing, TH performing moderately, and JIS showing a delayed, overly strong afternoon peak. Hydrometeor analysis shows that JIS and TH generate deeper, more continuous ice-phase layers in the mid- to upper troposphere, supporting persistent precipitation development. WDM7 produces noticeably weaker mid-level ice content, limiting sustained ice-phase growth. Thermodynamic responses indicate that JIS and TH modify local instability and moisture through stronger latent heating feedbacks, whereas WDM7 exhibits lower atmospheric moisture and instability and a higher lifting condensation level, creating conditions less favorable for deep convection. Among the three schemes, WDM7 exhibited the smallest wet bias and most effectively reduces the overestimation of mountain precipitation present in the JIS and TH simulations. These findings highlight the importance of microphysics selection for improving high resolution precipitation simulation over complex terrain.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"333 ","pages":"Article 108691"},"PeriodicalIF":4.4,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823512","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":"The climatology of complexity: Spatiotemporal analysis of summer subtropical anticyclones over Southwest Asia and adjacent regions","authors":"Morteza Keyhani,&nbsp;Abbas Mofidi,&nbsp;Azar Zarrin","doi":"10.1016/j.atmosres.2025.108713","DOIUrl":"10.1016/j.atmosres.2025.108713","url":null,"abstract":"<div><div>This study provides a comprehensive climatology of summer subtropical anticyclones (SAs) over Southwest Asia using daily ERA-Interim geopotential height data (1990–2019) across six pressure levels (900–100 hPa). Anticyclones were identified on 2760 summer days using combined objective and subjective methods, enabling a multi-level assessment of their frequency, spatial organization, preferred locations, vertical structure, seasonal evolution, and long-term variability. SAs are found throughout the atmospheric column, with maximum frequencies in the mid-troposphere and minimum occurrences near the surface. Distinct spatial modes emerge at different levels—bimodal at 500 hPa, trimodal at 700 hPa, and quadrimodal at 100–200 hPa—revealing finer spatial complexity than earlier climatologies. A key finding is a pronounced vertical seesaw pattern in seasonal occurrence: lower-tropospheric anticyclones peak in June but decline sharply in July, while mid- and upper-tropospheric anticyclones intensify. This indicates a coordinated vertical redistribution of anticyclonic activity during summer. Interlevel relationships exhibit strong coherence in the upper troposphere, whereas weaker correlations between adjacent lower and mid-tropospheric levels suggest level-dependent formation mechanisms and vertical tilt. Regionally, the study refines the characteristics of the Turkmenistan, Zagros, and Arabian anticyclones, highlighting the vertical continuity of the Arabian anticyclone and its sensitivity to surface thermal forcing. Long-term analysis reveals no significant meridional shifts but shows a notable increase in anticyclone frequency at 700 hPa, likely linked to recent warming over the Arabian Peninsula. Overall, the findings demonstrate the dynamical complexity of SAs across Southwest Asia and provide an updated framework for understanding their variability and climate relevance.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"333 ","pages":"Article 108713"},"PeriodicalIF":4.4,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823517","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}