Journal of Geophysical Research: Atmospheres最新文献

{"title":"Characteristics and Ambient Conditions of Mesoscale Convective Systems Moving Offshore in the Yangtze-Huai River Basin, East China","authors":"Yue Wei,&nbsp;Zhixiao Xu,&nbsp;Xin Xu,&nbsp;Yuanzhe Zhang,&nbsp;Shushi Zhang,&nbsp;Long Huang,&nbsp;Zeyong Guo","doi":"10.1029/2026JD047065","DOIUrl":"https://doi.org/10.1029/2026JD047065","url":null,"abstract":"<p>This work for the first time studies the characteristics and environment conditions of mesoscale convective systems (MCSs) that move offshore (i.e., land to sea, LS) in the Yangtze-Huai River Basin (YHRB), East China. In the warm season (April–September), LS MCSs account for 25.5% of the total MCSs, exhibiting a decreasing trend from spring (April–May) to later summer (August–September). LS MCSs most frequently occur from late morning to early evening. Compared to land-only (LO) MCSs, LS MCSs form closer to the coastline and have significantly longer lifetimes, greater intensities and larger areas. Both two types of MCSs develop under favorable synoptic conditions, including upper-level jets, mid-level troughs, low-level southwesterly jets and surface cyclones. The environment conditions that distinguish LS MCSs from LO ones change with seasons. In spring, the offshore propagation of LS MCSs is driven dynamically by the cold, dry flow behind the mid-tropospheric short-wave trough in the midlatitudes, featured by stronger low-level vertical wind shear (VWS) but lower most unstable convective available potential energy (MUCAPE) than LO ones. Conversely in late summer, LS MCSs are mainly driven thermodynamically, with higher MUCAPE but weaker low-level VWS than LO ones. It is the low-level warm, moist southwesterly flow along the northwestern periphery of the Western Pacific Subtropical High that steers the LS MCSs toward the ocean. Revealing this seasonal reversal of dominant forcings can provide useful insights into the prediction of offshore propagation of MCSs and associated several convective weather in the coastal region of the YHRB.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199042","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":"Investigating Buoyant Plume Dynamics Induced by Localized Fire-Simulated Heating Over Plant Canopies Using LES","authors":"Ajinkya Desai,&nbsp;Antonio Quim Cervantes,&nbsp;Tirtha Banerjee","doi":"10.1029/2025JD045722","DOIUrl":"https://doi.org/10.1029/2025JD045722","url":null,"abstract":"<p>Plume interaction with a forest canopy results in flow features distinct from those in grasslands. Here, we model the turbulence dynamics of a buoyant plume in a homogeneous plant canopy with a crosswind using Large-Eddy Simulations. As the plume interacts with the crosswind, we observe increased vorticity at the windward and tilted hair-pin-like vortical structures on the leeward sides. Strong rotational cores, representing counter-rotating vortex pairs (CVPs), form as the flow twists and spirals into the leeward side of the buoyancy source. Flow patterns aloft exhibit helical motions as the CVPs propagate downstream, trailing the plume. We also simulate a no-canopy environment for comparison. In the canopy case, the plume tilts less steeply near the source due to the canopy drag and its leeward side is marked by flow recirculation, which obstructs the approaching upstream flow. Moreover, the plume transition to the bent-over phase is delayed and oscillations in the far-field mean plume centerline are more damped. The spatial organization of momentum-flux events also differs between the two environments. Upstream of the plume centerline, there is downward momentum transfer primarily via ejections above and sweeps within the canopy. On the leeward side, counter-gradient motions (outward interactions) prevail in transferring momentum away from the buoyancy source. Contrarily, in the no-canopy environment, counter-gradient motions near the surface are wedged between ejection- and sweep-dominated regions on the upstream and downstream sides, respectively. Insights into plume behavior in canopy versus no-canopy environments are vital for comparing with experiments and refining fire-behavior and plume-rise models.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JD045722","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microphysics and Kinematics of a High Flash Rate Storm With a Bottom-Heavy Charge Structure","authors":"Bruno L. Medina,&nbsp;Wiebke Deierling,&nbsp;Lawrence D. Carey,&nbsp;Eric C. Bruning,&nbsp;Marquette N. Rocque","doi":"10.1029/2025JD045105","DOIUrl":"https://doi.org/10.1029/2025JD045105","url":null,"abstract":"<p>An atypical thunderstorm with unusual lightning and charge structure characteristics propagated through Cordoba province, Argentina, during the austral warm season in late 2018. This storm exhibited echo tops near 10.5 km, with high lightning activity concentrated at low altitudes. Storm total flash rate surpassed 120 min⁻¹, with peak initiation altitude at 6 km, the inferred altitude interface between a lower positive charge region and an overlying negative region. An in-depth analysis of kinematics, eddy dissipation rate (EDR), and microphysics was performed to understand what caused intense low-altitude flash rates, bottom-heavy charge structure, and few flashes in the upper-level positive charge region. Environment and synoptic conditions led to the unusually cold troposphere and low freezing level, which influenced storm microphysics and charge structure characteristics. Positive buoyancy was limited to the −20°C isotherm level, and maximum updraft speed varied between 10 and 14 m s⁻¹ during the period of highest flash rates. Larger volumes of graupel and hail were observed at altitudes associated with the lower positive charge layer. Larger volumes of high EDR fluctuated in altitude following surges in updraft volume, but no clear relation was found for flash initiation and propagation relative to EDR. Infrequent flashes in the upper positive charge layer suggest limited charging of ice crystals at that altitude. Small warm cloud depth and high cloud water content might have played a role in decreasing the charging reversal temperature and enhancing the development of a positive charge layer in the lower mixed-phase layer.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JD045105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Energy Dissipation Rate at the Standard Weather Observatory Under Various Atmospheric Conditions and Its Application to Aviation Turbulence Intensity","authors":"Jeonghoe Kim,&nbsp;Jung-Hoon Kim,&nbsp;Hyeyum Hailey Shin,&nbsp;Wiebke Deierling,&nbsp;Robert D. Sharman,&nbsp;Moon-Soo Park,&nbsp;Hee-Wook Choi,&nbsp;Sang-Sam Lee","doi":"10.1029/2026JD047740","DOIUrl":"https://doi.org/10.1029/2026JD047740","url":null,"abstract":"<p>Accurate prediction of low-level turbulence (LLT) is critical for aviation safety, particularly for the emerging urban air mobility industry and aircraft takeoffs and landings. To better understand and predict these hazards, the characteristics of the energy dissipation rate (EDR) in the atmospheric boundary layer (ABL) were investigated using 8-year high-frequency sonic anemometer observations collected at multiple altitudes of the 307-m meteorological tower in the Boseong Standard Weather Observatory (BSWO), South Korea. EDR was estimated using the inertial dissipation technique with second-order structure functions after applying quality control procedures to the sonic anemometer data. The probability density functions (PDFs) of EDR, representing the characteristics of EDR, exhibited lognormal distributions, although a transition toward log-Weibull-like distributions was observed near the surface and under unstable conditions. The PDFs of EDR had distinct characteristics on days dominated by sea breezes at the BSWO, showing lower EDR values and lognormal-like distributions compared to non-sea breeze days. This was attributed to weaker large-scale forcings, wind shear, and turbulence kinetic energy, which may cascade down to the inertial subrange, resulting in lower EDR. The anisotropic nature of turbulence in the ABL was observed from the relationship between EDR estimates of different velocity components, with streamwise EDR estimates being larger than vertical estimates. The ensemble mean of EDR obtained from best-fit lognormal distributions to the observed PDFs of EDR was in the reasonable ranges presented in previous studies, yet showing different magnitudes. These findings provide essential statistical parameters for developing LLT forecasting systems optimized for the Korean Peninsula.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JD047740","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Why April Stands Out: Monthly Impacts of Internal Variability on Arctic Amplification","authors":"Skylar Gale,&nbsp;Qiang Fu,&nbsp;Hailong Wang,&nbsp;Edward Blanchard-Wrigglesworth,&nbsp;Muyin Wang,&nbsp;Ash Gilbert,&nbsp;Aodhan Sweeney,&nbsp;Stephen Po-Chedley","doi":"10.1029/2026JD047413","DOIUrl":"https://doi.org/10.1029/2026JD047413","url":null,"abstract":"<p>Observed Arctic amplification (AA), defined as the ratio of Arctic-mean to global-mean surface air temperature (SAT) trends, peaks in April, a feature not captured by climate models. Here, we quantify the impact of internal variability on Arctic-mean SAT trends in March, April, and May from 1980 to 2022 using multiple approaches, including machine learning algorithms—convolutional neural networks (CNNs) and partial least squares (ML-PLS)—as well as dynamical adjustment and wind-nudged experiments. Across all approaches, internal variability emerges as a substantial contributor to Arctic warming in these months, and is particularly prominent in April, when internal variability accounts for 40 ± 31% of the observed Arctic-mean SAT trend, a result consistent across the CNN and wind-nudged estimates. For each spring month, the linear methods estimate 4%–15% smaller contributions of internal variability than CNN estimates, suggesting that nonlinear approaches may more effectively isolate the internal variability component. Removing internal variability largely reconciles the springtime monthly AA discrepancy between climate models and observations. The strong spatial correlation between the observed-minus-multi-model-mean SAT trend pattern and that derived from wind-nudged experiments further suggests that the simulated forced trend pattern is broadly realistic. Finally, the observed springtime monthly circulation–temperature configurations are rare in coupled climate models across all three spring months, suggesting that models have difficulty reproducing the magnitude of Arctic internal variability and/or the observed patterns are a rare manifestation.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JD047413","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How Terrain Geometry and Environmental Instability Shape Precipitation in Mountain-Crossing Mesoscale Convective Systems","authors":"Fan Wu,&nbsp;Kelly Lombardo","doi":"10.1029/2026JD046393","DOIUrl":"https://doi.org/10.1029/2026JD046393","url":null,"abstract":"<p>This study uses idealized large-eddy simulations to systematically examine how terrain geometry and environmental instability modulate precipitation produced by a mountain-crossing mesoscale convective system (MCS). A suite of simulations isolates the effects of base-state convective available potential energy (CAPE), mountain width, and crest height on rainfall distributions. The environmental instability that governs MCS intensity upstream of the mountain is the primary control on over-mountain precipitation, with larger CAPE yielding greater rainfall. Mountain geometry provides an additional control on the spatial distribution of rainfall. Taller, narrower mountains (steeper slopes) yield larger localized windward rainfall enhancements, while taller, wider mountains induce broader areas of moderate enhancement. In the lee, taller and wider mountains induce larger precipitation reductions, as compared to shorter and narrower mountains. Terrain-induced precipitation modifications are also sensitive to CAPE. In low-CAPE environments, MCSs require orographic lift to sustain convection and support successful mountain crossings; without terrain, MCSs weaken rapidly. Therefore, mountains can extend the lifetime of MCSs in low-CAPE environments. In high-CAPE environments, MCSs remain robust and sustain substantial rainfall over flat surfaces without mountain forcing, so terrain contributes a proportionally smaller increase in windward rainfall even as rainfall totals increase, with the largest enhancements concentrated over steeper slopes. After crest passage, terrain-induced reductions in near-surface lifting are associated with larger leeside precipitation reductions, particularly for taller and wider mountains. Extreme rainfall production is also sensitive to CAPE and mountain geometry. Steep slopes increase extreme rainfall areal coverage, although their impact on extreme rainfall rates is more complex.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JD046393","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric Circulation Drives Dry-to-Wet Abrupt Alternation in the Lancang–Mekong River Basin","authors":"Yufan Chen,&nbsp;Junguo Liu,&nbsp;Shuyu Zhang,&nbsp;Hong Wang,&nbsp;Haifan Liu,&nbsp;Chen Liang,&nbsp;Deliang Chen,&nbsp;Mingfu Guan","doi":"10.1029/2026JD046922","DOIUrl":"https://doi.org/10.1029/2026JD046922","url":null,"abstract":"<p>The Lancang–Mekong River Basin (LMRB), a crucial transboundary region that sustains millions of people across Southeast Asia, faces growing threats from compound hydrological extremes under climate change. Among them, dry-to-wet abrupt alternation (DWAA) is particularly critical, intensifying risks to agriculture and water security. However, its spatiotemporal patterns and associated dry-to-wet circulation transitions remain poorly understood. This study analyzes DWAA events in the LMRB from 1961 to 2022, with a focus on identifying atmospheric circulation patterns linked to dry and wet extremes and characterizing their paired configurations during dry-to-wet shifts. Results show that DWAAs in the upstream region occur mainly in May and June, while those in the downstream region are most frequent from July onward. A decreasing trend in DWAA frequency is observed in the midstream region, contrasted by increasing occurrences downstream. Three circulation patterns are identified for dry extremes and four for wet extremes. Their complexity and diversity are largely controlled by the Western North Pacific Subtropical High (WNPSH), tropical cyclones (TCs), multi-low-pressure systems, and dual-high-pressure systems. DWAA formation reflects a coherent evolution of large-scale circulation, where the weakening, displacement, or restructuring of dry-phase anomalies rapidly shifts the basin toward moisture-convergent conditions. In terms of DWAA-driving configurations, TC- and WNPSH-related patterns are the dominant drivers. Moreover, WNPSH-coupled configurations have become more frequent, whereas those linked to multi-low-pressure systems have declined.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JD046922","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing Subseasonal Predictability and Sources of Drought-Flood Abrupt Alternation Over Eastern China Using ECMWF S2S Ensemble Forecasts","authors":"Chunxiang Li,&nbsp;Wansuo Duan,&nbsp;Zhe Han","doi":"10.1029/2026JD046625","DOIUrl":"https://doi.org/10.1029/2026JD046625","url":null,"abstract":"<p>Drought–flood abrupt alternation (DFAA) events pose major challenges for subseasonal-to-seasonal (S2S) prediction owing to their rapid hydrological transitions and complex circulation controls. Using ECMWF S2S ensemble forecasts, this study explores the subseasonal predictability of three objectively identified DFAA events over eastern China during 2022–2024. Across the analyzed cases, we find that the forecast skill tends to be higher during the drought phase than during the subsequent transition and flood onset. This tendency is associated with persistent drought conditions being linked to slowly evolving, spatially coherent large-scale circulation anomalies and relatively greater ensemble consistency at subseasonal lead times. An important source of subseasonal predictability is linked to mid-tropospheric circulation anomalies, including Rossby wave trains and subtropical–midlatitude coupling, which provide coherent precursor signals approximately 10–30 days prior to the observed transitions. In contrast, forecast skill degrades notably during the transition period and subsequent flood onset, when short-term triggering processes—particularly tropical cyclone–related circulation—introduce substantial ensemble divergence and timing uncertainty. Among the cases analyzed, the monsoon-related event is associated with relatively higher and more stable subseasonal predictability, whereas the tropical cyclone–influenced event exhibits reduced forecast reliability. These results highlight the importance of large-scale circulation precursors for extended-range monitoring of DFAA events, while underscoring the intrinsic limitations of current S2S systems in predicting the precise timing and intensity of abrupt flooding onset.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145494","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":"Field Evidence of Sand Impact-Controlled Dust Emission From a High-Elevation Source Region on the Northeastern Tibetan Plateau","authors":"Zhengcai Zhang,&nbsp;Lingguang Zhang,&nbsp;Yan Zhang,&nbsp;Lanying Han,&nbsp;Zhibao Dong","doi":"10.1029/2026JD046934","DOIUrl":"https://doi.org/10.1029/2026JD046934","url":null,"abstract":"&lt;p&gt;The impact of saltating sand grains on the ground surface is a fundamental mechanism driving both sand transport and dust emission in aeolian research. In low-air-density and high-elevation regions, the dynamic conditions of dust emission are different with low-elevation regions, which leads to various aeolian sand transport processes and further affects the cycle of sand and dust around the world. Due to the scarcity of field measurements, this process remains poorly understood in high-elevation regions (&gt;3,000 m). This study investigates the number and kinetic energy (KE) of transported sand grains, sand transport rate (&lt;i&gt;Q&lt;/i&gt;), and PM&lt;sub&gt;10&lt;/sub&gt; concentration under natural field conditions to elucidate the role of sand impact in dust emission and transport processes. Field data were also used to evaluate existing shear velocity-based sand transport and dust emission models. Results show that PM&lt;sub&gt;10&lt;/sub&gt; concentration over sandy surfaces in the source region can reach up to 10&lt;sup&gt;5&lt;/sup&gt; µg m&lt;sup&gt;−3&lt;/sup&gt;, substantially higher than previously reported values. The ratio of the number of saltating sand grains at different heights serves as an effective indicator of dust emission intensity: Both &lt;i&gt;Q&lt;/i&gt; and PM&lt;sub&gt;10&lt;/sub&gt; concentration decrease as this ratio increases. During transport events, &lt;i&gt;Q&lt;/i&gt; increases linearly with the number of sand grains near the surface, and PM&lt;sub&gt;10&lt;/sub&gt; concentration exhibits increases linearly with &lt;i&gt;Q&lt;/i&gt;. Both &lt;i&gt;Q&lt;/i&gt; and PM&lt;sub&gt;10&lt;/sub&gt; increase as power functions of shear velocity. We demonstrate that the quadratic scaling between KE and sand transport number (&lt;i&gt;N&lt;/i&gt;) is a direct consequence of low air density saltation dynamics, which enhances dust emission efficiency. The empirical relationships between &lt;i&gt;N&lt;/i&gt;, KE, &lt;i&gt;Q&lt;/i&gt;, and PM&lt;sub&gt;10&lt;/sub&gt; are quantified. Among these, the near quadratic scaling KE &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∝&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $mathit{propto }$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &lt;i&gt;N&lt;/i&gt;&lt;sup&gt;1.66&lt;/sup&gt; is consistent with a low-density saltation physics, while other power-law exponents (e.g., &lt;i&gt;Q&lt;/i&gt; &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∝&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $mathit{propto }$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &lt;i&gt;u&lt;/i&gt;∗&lt;sup&gt;3&lt;/sup&gt;) are site-specific and highlight the need for process-based models that explicitly account for grain size and surface type. Current models systematically underestimate sand transport rates. These findings emphasize the importance of studies in high-elevation regions and the differences of dust emission process between low and high elevation conditions and provide new insights for improving dust emission models and underscore the importance of conducting more comprehensive field studies across diverse arid landscapes to advance pred","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205425","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":"Decadal Surge in Tibetan Plateau 20–30-Day Oscillation Intensity (1995–2005) Linked to Summer NAO Structure and Baroclinic Energy Conversion","authors":"Meirong Wang,&nbsp;Jun Wang,&nbsp;Anmin Duan,&nbsp;Shunwu Zhou,&nbsp;Zhu Zhu,&nbsp;Xuepeng Cui,&nbsp;Jianying Li","doi":"10.1029/2026JD047302","DOIUrl":"https://doi.org/10.1029/2026JD047302","url":null,"abstract":"<p>The 20–30-day intraseasonal oscillation (ISO) over the Tibetan Plateau (TP) significantly modulates summer precipitation, accounting for over 10% of regional rainfall variability. This study identifies a decadal intensification of the summer 20–30-day ISO during 1995–2005 and examines its multidecadal covariation with the summer North Atlantic Oscillation (SNAO). The intensification coincides with a positive phase and eastward-displaced SNAO, which facilitates enhanced Rossby wave propagation toward the central and eastern TP along the Eurasian waveguide. Rather than directly forcing intraseasonal variability, the SNAO modulates the local dynamical environment and vertical motion, thereby regulating the growth of the TP ISO. Energetic diagnostics reveal that baroclinic energy conversion plays a central role in sustaining the oscillation. Crucially, the SNAO-induced forcing provides compensatory energy in the upper troposphere, preserving the vertical coherence and deep-tropospheric structure of the ISO. These findings indicate that the decadal surge arises from frequency-selective energy allocation and optimized growth conditions, highlighting the critical role of teleconnection morphology in shaping the TP hydroclimate.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"131 19","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149147015","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}