Journal of Geophysical Research-Oceans最新文献

{"title":"High-Resolution Assessment of SST Summer Cycle Changes in the Mediterranean Sea (1982–2024): A Multi-Scale Phenological Analysis","authors":"S. Benzouaï","doi":"10.1029/2025JC023878","DOIUrl":"https://doi.org/10.1029/2025JC023878","url":null,"abstract":"<p>Accelerated ocean warming from greenhouse gas emissions is altering marine thermal cycles globally. While ocean warming is well documented, its impacts on Sea Surface Temperature (SST) seasonal cycles remain less understood, particularly in the Mediterranean Sea. Summer SST exhibits the highest warming trends, yet summer cycle dynamics are poorly characterized. Understanding these changes is critical to anticipate impacts on climate processes and marine ecosystems. In this study, 43 years (1982–2024) of daily SST data across the Mediterranean Basin were analyzed, with a focus on the summer period. Key phenological metrics were extracted: onset, end, duration, phase (defined as the timing of maximum SST in the seasonal cycle maximum), SST at onset/end, maximum SST, and amplitude. Results revealed statistically significant shifts. Start of season advanced significantly (<i>p</i> &lt; 0.05) at −2.01 ± 1.76 days decade⁻¹, end delayed +3.27 ± 2.65 days decade⁻¹ (<i>p</i> &lt; 0.05), extending Summer by 4.24 ± 3.29 days decade⁻¹ (<i>p</i> &lt; 0.05), which corresponds to ∼17.80 ± 13.81 days. Time of maximal SST shows no significant basin-scale trends, although significant regional advances occurred within a very limited part of the study area. Annual cycle amplitude increased by +0.40 ± 0.36°C in 40 years (<i>p</i> &lt; 0.01) over the entire Mediterranean Sea. Strong correlations emerged between warming SST and phenological shifts, directly linking temperature increase to the changes occurring in the summer SST cycle. By explicitly quantifying SST seasonal cycles, this study provides critical baselines for assessing ecosystem responses to accelerated seasonal changes within the warming Mediterranean.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823234","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 Pivotal Role of Subsurface Cold Water in the Secondary Cooling Phase in Multi-Year La Niña Events","authors":"Shan Liu,&nbsp;Licheng Feng,&nbsp;Rong-Hua Zhang","doi":"10.1029/2026JC024311","DOIUrl":"https://doi.org/10.1029/2026JC024311","url":null,"abstract":"<p>Composite analysis for single-year La Niña (SL) events and multi-year La Niña (ML) events of the GODAS data set since 1980s are conducted in this study. Compared to SL events, the progress of sea surface temperature in ML events shows the most significant differences in the second half of the persistence year (year 01). Analysis of surface and subsurface temperature anomalies reveals that subsurface exhibits strong negative temperature anomalies in ML events. Vertical profiles of temperature indicate that this colder water primarily originates from the Southern Hemisphere. An oblique section further clarifies the subsurface intrusion process from the southeast Pacific. An adjusted flux method is used to quantitatively analyze the heat transport during the secondary cooling phase, ML events exhibit negative net heat transport to the key ocean domain, in stark contrast to the positive net heat transport observed in SL events during the same period. Among all these boundaries, the eastern and bottom boundaries contribute the most, accounting for 87.1% of the total cooling transport, which aligns well with the subsurface cold water intrusion from the southeast Pacific. Further analysis reveals that, the primary contributor to the cold transport difference is the advection of mean zonal temperature difference by anomalous zonal currents at the eastern interface. As for the bottom boundary, both the advection of anomalous temperature difference by mean flow and the advection of mean temperature difference by anomalous flow exert crucial effects.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823237","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":"Cross-Shelf Transport Across Different Bathymetric Zones of the Northern South China Sea Shelf: Quantification and Mechanisms","authors":"Pengpeng Hu,&nbsp;Guang Zhang,&nbsp;Suan Hu,&nbsp;Yan Sun,&nbsp;Yanfu Wei,&nbsp;Heng Zhang,&nbsp;Wenping Gong","doi":"10.1029/2026JC024396","DOIUrl":"https://doi.org/10.1029/2026JC024396","url":null,"abstract":"<p>The dynamics of cross-shelf transport in the northern South China Sea (NSCS) are critical to regional material transport, whereas the quantities and governing mechanisms, particularly under the monsoon-driven seasonal reversals, remain incompletely explored. This study investigates the dynamics and seasonal variability of cross-isobath volume transport over the NSCS shelf using high-resolution numerical simulations. Results indicate pronounced seasonal reversals in shelf circulation: during the summer southwesterly monsoon, the combined Guangdong Coastal Current and South China Sea Western Boundary Current (SCSWBC) drive northeastward flow, yielding net onshore transport at the 50-m and 100-m isobaths. In contrast, the winter northeasterly monsoon reverses the circulation, resulting in offshore transport at the same isobaths. Conversely, the 200-m isobath exhibits opposing dynamics, with offshore transport in summer and onshore transport in winter. Dynamical diagnosis shows that transport on inner and middle shelves is influenced by the bottom pressure torque, driven by the along-shelf sea-level gradients resulting from water accumulation or depletion against the western boundary formed by Hainan Island and Leizhou Peninsula. In summer, the strong horizontal density gradient enhances the significance of the joint effect of baroclinicity and relief (<i>Q</i>_<i>JEBAR</i>) in the cross-shelf transport balance, while strong winter mixing weakens this effect. On the outer shelf, <i>Q</i>_<i>JEBAR</i> and surface wind stress-induced transport governs transport variability through baroclinic adjustments influenced by SCSWBC, Slope Current, and Kuroshio interactions, and wind-induced Ekman transport. These findings highlight distinct dynamical regimes across different shelf zones, providing a mechanistic framework for understanding seasonal cross-shelf carbon and nutrient fluxes in the NSCS.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148785092","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":"Wave Energy Transfer in Shallow Water: Numerical Investigation of Slope and Offshore Wave Condition Effects","authors":"M. P. de Ridder,&nbsp;P. Mares-Nasarre,&nbsp;M. R. A. van Gent","doi":"10.1029/2025JC023751","DOIUrl":"https://doi.org/10.1029/2025JC023751","url":null,"abstract":"&lt;p&gt;This study advances the understanding of nonlinear wave interactions in shallow water by numerically quantifying how foreshore slope and offshore conditions influence energy transfer and wave evolution over a broad range of conditions. Two non-hydrostatic models, SWASH and XBeach, are validated against physical experiments and applied across a wide range of conditions. The two-layer SWASH model accurately reproduces wave parameters, third-order statistics, and nonlinear energy transfer. Results show that the relative water depth &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;mi&gt;k&lt;/mi&gt;\u0000 &lt;mi&gt;h&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(kh)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, the offshore wave steepness &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mi&gt;deep&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({s}_{m-1,0,mathrm{deep}}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and the Iribarren number &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;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(xi )$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; are key parameters for describing the interaction strength and biphase behavior. The slope mainly affects high-frequency biphase behavior, whereas for the other nonlinear interactions it primarily alters the magnitude of the energy transfer. For &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;ξ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $xi $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; smaller than 0.2, low-frequency energy is redistributed toward higher frequencies within the surf zone, while low-frequencies at steeper slopes only receive energy. In shallow water &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;mi&gt;k&lt;/mi&gt;\u0000 &lt;mi&gt;h&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023751","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784564","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":"Inverting Tropical Cyclone Eye Geometry via the Deep-Ocean Acoustic Notch","authors":"Xiaoming Cui,&nbsp;Qing Hu,&nbsp;Huayong Yang","doi":"10.1029/2026JC024147","DOIUrl":"https://doi.org/10.1029/2026JC024147","url":null,"abstract":"<p>The radius of maximum wind <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mi>max</mi>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left({R}_{max }right)$</annotation>\u0000 </semantics></math> is a key descriptor of tropical-cyclone structure, but it remains difficult to observe continuously over the open ocean. This study examines whether <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mi>max</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${R}_{max }$</annotation>\u0000 </semantics></math> can be inferred from deep-ocean low-frequency ambient noise generated by storm-forced surface processes. The central observable is an acoustic notch, a local minimum in vertical-array response associated with the weaker source region of the storm eye relative to the surrounding eyewall. A forward framework couples a parametric vortex wind model, wind- and rain-related surface-noise parameterizations, and parabolic-equation acoustic propagation. Idealized simulations show that notch distance is strongly related to storm scale, yielding a near-linear calibration with an RMSE of 1.2 km. Evaluation against ERA5-derived radial wind slices from three typhoons confirms that the notch retains meaningful structural sensitivity under realistic forcing, yielding a correlation of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>r</mi>\u0000 <mo>=</mo>\u0000 <mn>0.83</mn>\u0000 </mrow>\u0000 <annotation> $r=0.83$</annotation>\u0000 </semantics></math>, though with expectedly larger scatter (RMSE of 27.3 km). Sensitivity tests indicate that frequencies near 50 Hz provide a practical balance of propagation efficiency and robustness to idealized rain perturbation. The retrieval remains interpretable over practical array apertures and moderate geometric mismatch, but is sensitive to array depth and storm-induced sound-speed perturbations. These results support the acoustic notch as a physically interpretable low-frequency proxy for tropical-cyclone inner-core scale in favorable deep-ocean environments, rather than as a standalone operational retrieval system.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205967","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":"Dynamics of the Kuroshio Separation, Instability, and Associated Eddy Formation off Southern Japan","authors":"Yongkang Yuan,&nbsp;Jianping Gan,&nbsp;Xianliang Chen","doi":"10.1029/2026JC024399","DOIUrl":"https://doi.org/10.1029/2026JC024399","url":null,"abstract":"<p>The Kuroshio is well-known for its variability south of Japan, where its complex dynamics lead to the formation of meandering jet and eddies along the stream. In this study, we investigated the relevant processes and physical mechanism that remain ambiguous, using a well-validated high-resolution China Sea Multiscale Ocean Modeling System and a process-oriented numerical modeling. We found that this variability along Kuroshio is chiefly governed by the dynamics of the boundary jet separation. Our analysis shows that the variability follows a sequential dynamical pathway. First, the Kuroshio separation is induced by an inverse along-stream pressure-gradient force associated with the highly nonlinear jet, which decelerates the nearshore flow and induces a coastal countercurrent. In wind-favorable events, Ekman transport can further reinforce this countercurrent, thereby promoting separation. Near protruding coastal capes, bottom pressure torque and topographic vorticity adjustment help anchor the separation point. An accumulation of shear vorticity on the shoreside/seaward side of the separated Kuroshio forms a cyclonic/anticyclonic eddy dipole. Through active dynamic adjustment along the jet, the increasing barotropic and baroclinic instabilities strengthen the meandering jet and eddy, thereby maintaining the separation. This study provides new insight into how boundary-current separation, topographic constraint, wind-favorable countercurrent formation, and jet instability jointly regulate western boundary current variability.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783554","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 Modulation of Tropical Cyclone Intensity by Subsurface Salinity Stratification: An Idealized Study Using Coupled General Circulation Model","authors":"Lei Li,&nbsp;Yi Li,&nbsp;Youmin Tang","doi":"10.1029/2025JC023957","DOIUrl":"https://doi.org/10.1029/2025JC023957","url":null,"abstract":"<p>Tropical cyclone (TC) intensification is strongly influenced by the oceanic thermal structure, shaped by both temperature and salinity stratification. However, the mechanisms by which salinity stratification modulates TC intensity remain insufficiently quantified, particularly regarding the relative contributions of different oceanic dynamical processes. Based on simplified modeling frameworks, previous studies have primarily identified vertical mixing as the main factor controlling ocean response. Here we conducted idealized experiments using a fully coupled atmosphere–ocean model to systematically examine the role of salinity stratification in TC evolution. Heat budget analysis shows that, under varying salinity stratifications, total advection dominates the differences in sea surface temperature (SST) and TC intensity, while vertical mixing only plays a secondary role. Further decomposition of the total advection term reveals that these differences are primarily associated with variations in vertical advection. Specifically, for a fast-moving TC, an intact barrier layer (BL) enhances vertical advection by intensifying vertical velocity gradients. When the TC moves sufficiently slowly, the BL is fully eroded, the inversion layer vanishes, and the influence of salinity stratification on TC intensity is substantially diminished. Overall, this study highlights the key role of total advection in mediating the impact of salinity stratification on TC intensity, providing a process-based understanding of air–sea interaction and a physical basis for improving TC intensity prediction.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783817","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":"Changes in the Efficiency of Meridional Heat Transport as a Snowball Initiation Mechanism","authors":"P. Popović,&nbsp;R. J. Graham,&nbsp;D. S. Abbot","doi":"10.1029/2025JC023495","DOIUrl":"https://doi.org/10.1029/2025JC023495","url":null,"abstract":"<p>The geological record indicates that Earth experienced several global glaciations—so-called “snowball Earth” events—the most recent of which shortly preceded the emergence of complex life. These are usually attributed to a runaway ice-albedo feedback triggered by solar or atmospheric <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mtext>CO</mtext>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${text{CO}}_{2}$</annotation>\u0000 </semantics></math> radiative forcing crossing a critical threshold. In this study, we use the Budyko-Sellers energy-balance model to demonstrate that such events can also be initiated by changes in the efficiency of meridional heat transport, potentially driven by tidal resonances with the Sun or Moon or by continental reconfiguration. We identify two special points associated with this mechanism—the neutral point, where the heat transport efficiency does not affect the ice coverage, and the <i>transcritical</i> point, where the snowball transition occurs precisely at the neutral point. We find that these points correspond to special climate states characterized by maximal meridional heat transfer, entropy production, and sensitivity to perturbations. Moreover, we show that when the climate is marginally baroclinically stable, the transport efficiency is near the value that maximizes the rate of entropy production, so that any mechanism pushing the climate toward marginal baroclinic stability also pushes it toward a state of maximum entropy production. Finally, by partitioning the model into an ocean and an atmosphere, we show that destabilization into a snowball state can result either from increased atmospheric or decreased oceanic transport efficiency. Our findings suggest a novel mechanism for snowball initiation and the organization of global climate that should be further investigated with large-scale models and geological tests.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783553","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":"Observations of High-Frequency Internal Waves Near Submesoscale Fronts","authors":"Mingming Shao,&nbsp;Brian K. Haus,&nbsp;Jody M. Klymak,&nbsp;Björn Lund,&nbsp;Ruben Carrasco,&nbsp;Jochen Horstmann,&nbsp;Darek Bogucki,&nbsp;Tamay M. Özgökmen,&nbsp;Jun A. Zhang","doi":"10.1029/2026JC023981","DOIUrl":"https://doi.org/10.1029/2026JC023981","url":null,"abstract":"<p>Nonlinear high-frequency internal waves (HIWs) can occur at oceanic frontal interfaces but are rarely observed directly. This study presents field observations of HIWs near submesoscale fronts (SFs) in the northern Gulf of Mexico. A marine X-band radar detected a series of organized bands, with a spacing of 50 ∼ 300 m, near SFs. The bands propagate toward SFs at speeds of 0.10–0.40 m/s, derived from consecutive radar backscatter intensity images. These fortuitous bands were identified as the surface expression of HIWs. This identification is supported by corresponding temperature undulations from a thermistor chain below a wave glider. The ship-based observations provided vertical density and current (buoyancy and shear) profiles at a large frontal scale. These profiles, taken beneath and upstream of the HIW signature, are employed in the Taylor-Goldstein equation using the mixed layer depth as a surrogate bottom, which predicts the shear instability growth rate at different wavelengths and corresponding phase speeds. The theoretically predicted fastest-growing mode wavelength and its phase speed closely align with the observed HIWs after adjustments to the background shear and buoyancy uncertainty ranges. These findings support a shear–stratification instability framework for HIW generation along the shoaling thermohaline front. As HIWs influence local mixing and energy dissipation, they may bear the significance of the frontal energy budget and forward energy cascade from the submesoscale currents to isotropic turbulence in the upper ocean.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JC023981","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783598","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":"Submarine Flank Collapses at Tagoro Volcano: Insights From Bathymetric Surveys and 3D Multiphase Simulations","authors":"E. P. Montellà,&nbsp;A. Romano,&nbsp;G. Barajas,&nbsp;J. A. Lozano,&nbsp;J. T. Vázquez,&nbsp;J. L. Lara,&nbsp;E. Fraile-Nuez","doi":"10.1029/2025JC023976","DOIUrl":"https://doi.org/10.1029/2025JC023976","url":null,"abstract":"<p>Volcanic islands are prone to flank instabilities that can generate tsunamis even when mobilized volumes are moderate. This study investigates submarine collapses during the 2011–2012 eruption south of El Hierro, which built the Tagoro submarine volcano. Repeated multibeam bathymetric surveys captured the rapid growth, collapse, and reconstruction of the edifice, providing an exceptional record of seafloor change during an active submarine eruption. This record is used to develop a hybrid survey-modeling methodology that links observed collapse morphology to scenario-based estimates of the near-field wave response. First, two OpenFOAM-based approaches are benchmarked against laboratory experiments of submerged landslide-tsunami generation: a computationally efficient viscoplastic mixture model and a more detailed Eulerian-Eulerian two-phase model. The two-phase model is included as a reference to help assess the simplified mixture approach in the laboratory benchmark. The mixture model is then applied at field scale to simulate the largest Tagoro collapse. In the absence of tide gauge records, the numerical parameter set for the field scale simulations is selected based on its agreement with the erosion and deposition patterns inferred from bathymetric differencing. The resulting simulations reproduce the main landslide pathway and predict a strongly directional near-field wave field, with local amplification over the island shelf controlled by bathymetry. The results show that repeated bathymetric monitoring, combined with physics-based 3D modeling, can bridge observed volcanic seafloor change and plausible landslide-tsunami scenarios. This approach is not intended for real-time warning, but provides a transferable framework for local hazard assessment during prolonged submarine eruptions.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023976","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783555","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}