本期覆盖 2026-09-25 至 2026-10-02，共收录高置信度文章 48 篇，边缘相关 3 篇，待人工核实 24 篇。

本周亮点

亮点 1：A Generative AI Framework for Inferring Consistent Ocean Statistics at Depth Using Sea Surface Data

期刊：JPO ｜ DOI：https://doi.org/10.1175/jpo-d-25-0093.1

English summary

This study introduces a generative AI framework based on score-based diffusion models to reconstruct three-dimensional subsurface ocean velocity and buoyancy fields from sea surface data. The method probabilistically infers consistent ocean statistics at depth, including energetic eddy fields, overcoming the sparsity of direct subsurface observations. This represents a significant methodological breakthrough in ocean state estimation, with broad implications for understanding ocean heat and mass transport.

中文解读

该研究提出了一种基于分数扩散模型的生成式AI框架，利用海表数据重建三维次表层海洋速度和浮力场。该方法能够概率性地推断深层一致的海洋统计特征，包括活跃的涡旋场，克服了直接次表层观测稀疏的难题。这是海洋状态估计领域的一项重大方法学突破，对理解海洋热量和质量输运具有广泛意义。

亮点 2：Reassessing the Role of the Antarctic Slope Current in Poleward Ocean Heat Transport

期刊：JGR: Oceans ｜ DOI：https://doi.org/10.1029/2025jc023934

English summary

This paper reassesses the role of the Antarctic Slope Current (ASC) in poleward ocean heat transport using a high-resolution global ocean-sea ice model. Contrary to the conventional view that the ASC acts as a barrier to Circumpolar Deep Water (CDW) transport, the study finds weak correlations (average 0.3) between ASC velocity and CDW heat transport, with less than 25% of the continental slope showing significant linkage. This challenges existing theoretical understanding of the ASC’s role in modulating heat delivery to Antarctic ice shelves.

中文解读

本文利用高分辨率全球海洋-海冰模型重新评估了南极斜坡流（ASC）在向极地海洋热量输运中的作用。与传统认为ASC是环极深层水（CDW）输运屏障的观点相反，研究发现ASC速度与CDW热量输运之间的相关性较弱（平均0.3），且不到25%的大陆坡区域显示出显著关联。这挑战了关于ASC在调节向南极冰架热量输送中作用的既有理论认识。

文章详览

1. JPO — On the ventilation of the Gulf of Mexico

Abstract

Abstract Long term in-situ observations reveal that at equivalent depths, the waters of the Gulf of Mexico below the Yucatan Sill are warmer than the Caribbean and Atlantic water. Using long-term regional simulations of the Gulf of Mexico at 1/12° horizontal resolution and a water-mass transformation analysis we show that these warmer conditions are sustained by a downward flux of heat controlled to first order by interactions between deep currents and topography, with large contributions below the Loop Current and along the Sigsbee escarpment. The analysis reveals that tides, high-frequency winds, and geothermal heat flux have little effect, and points to interactions between geostrophic currents and topography as the primary category of processes responsible for deep-water mixing. This is in contrast to the paradigm for the global deep ocean which attributes buoyancy sources mostly to tidal vertical mixing. Consequences for the evolution of the water masses of the Gulf of Mexico and the exchanges with the Caribbean Sea are explored using a passive dye tracer designed to be representative of waters coming from the Caribbean. The tracer propagation experiment provides estimates of the age of Gulf of Mexico water masses. Results suggest that in the upper 1500 meters, waters are renewed on timescales of roughly 50 years, while below 1500 meters, the timescale for a 90% renewal of Gulf waters reaches about 350 years. The analysis also reveals age differences of approximately 50 years between the eastern and western parts of the Gulf.

中文摘要

摘要 长期现场观测表明，在等效深度上，尤卡坦海槛以下的墨西哥湾水体比加勒比海和大西洋水体更暖。利用1/12°水平分辨率的墨西哥湾长期区域模拟以及水团转化分析，我们表明这些偏暖条件由热量的向下通量维持，而该通量在一阶上受深层洋流与地形之间相互作用的控制，在环流下方以及沿Sigsbee陡崖区域贡献显著。分析揭示，潮汐、高频风和地热热通量影响甚微，并指出地转流与地形之间的相互作用是导致深水混合的主要过程类别。这与全球深层海洋的范式形成对比，后者将浮力来源主要归因于潮汐垂向混合。利用一种旨在代表来自加勒比海水体的被动染料示踪剂，探讨了其对墨西哥湾水团演变以及与加勒比海交换的影响。示踪剂传播实验提供了对墨西哥湾水团年龄的估计。结果表明，在1500米以浅，水体以约50年的 timescale 更新，而在1500米以下，墨西哥湾水体90%更新所需的时间尺度约为350年。分析还揭示，墨西哥湾东部与西部之间的年龄差异约为50年。

2. JPO — A Simple Model for Tidally Forced Standing Waves in a Submarine Canyon

Abstract

Abstract Submarine canyons are recognized as energetic sites for internal tides and enhanced mixing, yet the mechanisms by which tidal forcing excites these motions remain poorly understood. To address this gap, we develop a simplified theoretical model that represents a canyon as a long, narrow rectangular box. The analysis reveals that the dominant wave modes in this idealized geometry are standing internal Kelvin waves, generated at the canyon-top interface by barotropic tides in the open ocean and accompanied by the radiation of internal tides back into the open ocean. The amplitude of these standing waves depends on the tidal forcing strength, the geometry-determined proximity to resonance with a given tidal frequency, and the width-to-length aspect ratio, which controls wave-radiation efficiency. Theoretical calculations indicate that the canyon’s tidal kinetic energy is sustained primarily by a balance between tidal energy input and losses through radiated internal tides, with bottom drag and turbulent mixing contributing an order of magnitude less. Idealized MITgcm simulations forced by barotropic tides at the boundaries support these theoretical predictions. While the model adopts a simplified geometry, the framework can be extended to more realistic continental slope settings, providing new insight into internal tide dynamics within submarine canyons. Significance Statement While recent observations identify submarine canyons as hotspots for intense internal tides, the mechanisms governing their generation remain poorly understood. This study presents a quantitative theory using an idealized model to elucidate the dynamics of wave generation within these topographic features. These findings provide a critical theoretical foundation for future observational and modeling studies, advancing our understanding of how submarine canyons contribute to mixing and general ocean circulation.

中文摘要

摘要 海底峡谷被认为是内潮和增强混合的活跃区域，然而潮汐强迫激发这些运动的机制仍知之甚少。为填补这一空白，我们建立了一个简化理论模型，将峡谷表示为长而窄的矩形盒体。分析表明，该理想化几何结构中的主导波模态为驻立内Kelvin波，由外海正压潮在峡谷顶部界面处生成，并伴随内潮向外海辐射。这些驻波的振幅取决于潮汐强迫强度、由几何结构决定的与给定潮汐频率共振的接近程度，以及控制波辐射效率的宽长比。理论计算表明，峡谷的潮汐动能主要由潮汐能量输入与辐射内潮损失之间的平衡维持，而底摩擦阻力和湍流混合的贡献小一个量级。在边界处由正压潮强迫的理想化MITgcm模拟支持了这些理论预测。尽管该模型采用简化几何结构，但该框架可推广至更真实的陆坡环境，为海底峡谷内潮动力学提供新的认识。意义声明 尽管近期观测将海底峡谷识别为强内潮的热点区域，但其生成机制仍知之甚少。本研究提出了一种定量理论，利用理想化模型阐明这些地形特征内波生成的动力学。这些发现为未来的观测和模拟研究提供了关键的理论基础，推进了我们对海底峡谷如何贡献于混合和总体海洋环流的理解。

3. JPO — Deep Boundary Current mixing driven by flow-topography interactions

Abstract

Abstract The deep boundary currents that transport dense waters around much of the abyssal ocean are a key component of the meridional overturning circulation. The mixing processes in deep boundary currents enable the bottom waters to upwell and return toward the surface, closing the overturning loop. Here we perform a case study of mixing processes in a deep boundary current conveying Antarctic Bottom Water from the Weddell Sea to the Scotia Sea through the Orkney Passage, which was extensively surveyed in an observational campaign in 2017. We use high-resolution regional simulations to elucidate the flow-topography interaction processes generating turbulence within the deep boundary current, exploring the sensitivity of the turbulent processes to barotropic flow variations, as well as to the characteristics of small-scale topography. We find that a variety of processes extract energy from the deep boundary current: hydraulic control at the sill accelerates the current and leads to shear instability at the sill; the rotating hydraulic jump leads to lateral shear instability away from the slope; frictional downwelling at the sloping topography produces the conditions for submesoscale instabilities. Small-scale topographic features generate additional turbulence in their wake, associated with boundary layer separation. The intensity of these processes exhibits a marked sensitivity to that of the barotropic flow, thus connecting wind-forced barotropic flow changes to changes in mixing and dense water properties within deep boundary currents. Adding barotropic tides to this buoyancy-driven flow provides an additional source of variability and tends to enhance dissipation in the same locations as the buoyancy-driven flow, by periodically increasing the flow over the sill.

中文摘要

摘要 深层边界流将高密度水体输运至深渊海洋的大部分区域，是经向翻转环流的关键组成部分。深层边界流中的混合过程使底层水能够上涌并返回表层，从而闭合翻转环流回路。本文针对一条深层边界流中的混合过程开展了个例研究，该边界流经由Orkney Passage将南极底层水从Weddell海输运至Scotia海，2017年的一次观测活动对该区域进行了广泛调查。我们利用高分辨率区域模拟来阐明在深层边界流内部产生湍流的水流-地形相互作用过程，并探讨湍流过程对正压流变化以及小尺度地形特征的敏感性。我们发现，多种过程从深层边界流中提取能量：海槛处的的水力控制使水流加速并导致海槛处的切变不稳定；旋转水跃在远离斜坡处导致侧向切变不稳定；倾斜地形上的摩擦下降流为亚中尺度不稳定创造了条件。小尺度地形特征在其尾流中产生额外湍流，与边界层分离有关。这些过程的强度对正压流的强度表现出显著的敏感性，从而将风驱动的正压流变化与深层边界流中混合及高密度水性质的变化联系起来。将正压潮汐叠加到该浮力驱动流上，提供了额外的变率来源，并倾向于在浮力驱动流相同的 locations 增强耗散，这是通过周期性增加海槛上方的流速实现的。

4. JPO — A Generative AI Framework for Inferring Consistent Ocean Statistics at Depth Using Sea Surface Data

Abstract

Abstract Understanding subsurface ocean dynamics is essential for quantifying oceanic heat and mass transport, but direct observations at depth remain sparse due to logistical and technological constraints. In contrast, satellite missions provide rich surface datasets—such as sea surface height, temperature, and salinity—that offer indirect but potentially powerful constraints on the ocean interior. Here, we present a probabilistic framework based on score-based diffusion models to reconstruct three-dimensional subsurface velocity and buoyancy fields, including the energetic ocean eddy field, from surface observations. Using a 15-level primitive equation simulation of an idealized double-gyre system, we evaluate the skill of the model in inferring the mean circulation and the mesoscale variability at depth under varying levels of surface information. We find that the generative model successfully recovers key dynamical structures and provides physically meaningful uncertainty estimates, with predictive skill diminishing systematically as the surface resolution decreases or the inference depth increases. These results demonstrate the potential of generative approaches for ocean state estimation and uncertainty quantification, particularly in regimes where traditional deterministic methods are underconstrained or ill-posed.

中文摘要

摘要 理解次表层海洋动力学对于量化海洋热量与质量输运至关重要，但由于后勤与技术方面的限制，深层直接观测仍然稀疏。相比之下，卫星任务提供了丰富的海表数据集——如海表高度、温度和盐度——这些数据对海洋内部提供了间接但可能强有力的约束。在此，我们提出一个基于分数扩散模型的概率框架，用于从海表观测重建三维次表层速度场和浮力场，包括能量活跃的海洋涡旋场。利用一个理想化双涡旋系统的15层原始方程模拟，我们评估了模型在不同海表信息水平下推断平均环流和深层中尺度变率的能力。我们发现，该生成模型成功恢复了关键动力结构，并提供了具有物理意义的不确定性估计，其预测能力随着海表分辨率降低或推断深度增加而系统性减弱。这些结果展示了生成方法在海洋状态估计和不确定性量化方面的潜力，特别是在传统确定性方法约束不足或问题不适定的情形下。

5. JGR: Oceans — Generation and Propagation of Eastern Subpolar North Atlantic Salinity Anomalies

Abstract

Abstract The Eastern Subpolar North Atlantic (E‐SPNA) upper ocean experiences pronounced interannual salinity variations that influence the global overturning circulation, yet a quantitative understanding of their life cycle remains lacking. Based on an ocean circulation state estimate, we combine budget analysis with particle tracking to quantify the generation and propagation of E‐SPNA salinity anomalies. Analyzing salinity for each day between 1992 and 2017 reveals that changes in circulation, forcing, and stratification contribute similarly to interannual salinity variability. Most anomalies originate within 2 years prior to entering the E‐SPNA, near the Grand Banks and along the North Atlantic Current (NAC). Two salinity extremes are also examined. The 2016 E‐SPNA fresh event primarily resulted from circulation changes near the Grand Banks, with a smaller contribution from vertical diffusion at its onset, whereas the 2007 E‐SPNA salty event arose from a combination of dry atmospheric conditions and Subtropical Gyre expansion along the NAC.

中文摘要

摘要 东部副极地北大西洋（E‐SPNA）上层海洋经历显著的年际盐度变化，这些变化影响全球翻转环流，然而对其生命周期仍缺乏定量认识。基于一个海洋环流状态估计，我们将收支分析与粒子追踪相结合，以量化E‐SPNA盐度异常的生成与传播。对1992年至2017年间逐日盐度的分析表明，环流、强迫和层结变化对年际盐度变率的贡献相近。大多数异常在进入E‐SPNA之前2年内产生，位于Grand Banks附近以及沿North Atlantic Current（NAC）一带。本文还考察了两次盐度极端事件。2016年E‐SPNA淡水事件主要源于Grand Banks附近的环流变化，其发生时垂直扩散的贡献较小；而2007年E‐SPNA高盐事件则源于干燥的大气条件与副热带环流沿NAC扩张的共同作用。

6. JGR: Oceans — Reassessing the Role of the Antarctic Slope Current in Poleward Ocean Heat Transport

  • 作者：Wilton Aguiar, Taimoor Sohail, Adele K. Morrison, Ellie Q. Y. Ong, Fabio Boeira Dias, Wilma G. C. Huneke, Paul Spence, Matthew H. England
  • 发表日期：2026-09-29
  • DOI：https://doi.org/10.1029/2025jc023934

Abstract

Abstract The Antarctic Slope Current (ASC) is often considered a barrier to the poleward transport of Circumpolar Deep Water (CDW), yet its vast extent has hindered circumpolar analysis of this relationship. Here, we use a high‐resolution global ocean‐sea ice model that resolves the slope current to assess the link between variability in the ASC and poleward CDW heat transport, circumpolarly and across varying timescales. We find that the ASC velocity and CDW heat transport have weak correlations, with an average 0.3, over the continental slope. In fact, less than 25% of the continental slope has a correlation of over either seasonal or interannual timescales. Isolated regions of strong covariability occur where the isopycnal depth at the shelf break varies substantially in time. Overall, our results suggest that circumpolarly, the ASC is weakly associated with poleward CDW heat transport, cautioning against the general assumption of a consistent dynamical link between the two around Antarctica.

中文摘要

摘要 南极斜坡流（ASC）通常被视为环极深层水（CDW）向极输运的屏障，然而其广阔的分布范围阻碍了对这一关系的环极分析。本文采用一套能够解析斜坡流的高分辨率全球海洋—海冰模式，评估ASC变率与向极CDW热输运之间的联系，分析在环极尺度以及不同时间尺度上的表现。我们发现，在大陆斜坡区域，ASC流速与CDW热输运之间的相关性较弱，平均仅为0.3。事实上，在季节尺度或年际尺度上，大陆斜坡中相关性超过该值的区域不足25%。强协变区域呈孤立分布，出现在陆架折点处等密面深度随时间显著变化的地方。总体而言，我们的结果表明，在环极尺度上，ASC与向极CDW热输运之间关联较弱，因此对南极周边两者之间存在一致动力学联系的普遍假设应持谨慎态度。

7. JGR: Oceans — Impacts of Precipitation on Upper‐Ocean Responses: A COAWST Modeling Study

Abstract

Abstract This study investigates how precipitation‐induced freshwater flux affects the upper‐ocean structure during Typhoon Mangkhut (2018) using an atmosphere‐ocean coupled model (COAWST). It was found that accounting for precipitation forcing can modulate the simulated intensity of tropical cyclones (TCs). At a buoy near the TC center, freshwater input from precipitation induces a warmer (+0.3°C), fresher (−0.2 psu) and shallower mixed layer. Spatially, analysis found a heterogeneous sea surface temperature (SST) responses but homogeneous freshening sea surface salinity responses. Quantitatively, precipitation enhances inner‐core (within 125 km) SST cooling by 0.006°C (1.75%) while suppressing outer‐region (within 250 km) cooling by 0.014°C (6.3%). This signal reversal marks a regime shift from shear‐dominated mixing inside the radius of maximum winds to stratification‐dominated suppression farther outward. Although precipitation‐driven stratification and current shear are strongly positive correlated ( r = 0.81 ∼ 0.91) in both the inner‐core and outer regions, neither variables correlates strongly with SST anomalies ( r < 0.3). This indicates that freshwater flux alters ocean thermal structure via competing mechanisms between stabilizing the mixed layer while enhancing turbulence mixing. These results underscore the necessity of incorporating precipitation effects in coupled TC models, particularly for improved representation of subsurface processes and their potential impact on TC intensity.

中文摘要

摘要 本研究利用海气耦合模式（COAWST）探讨了降水引起的淡水通量如何影响台风山竹（2018）期间上层海洋结构。研究发现，考虑降水强迫能够调制热带气旋（TC）的模拟强度。在TC中心附近的浮标处，降水带来的淡水输入导致混合层偏暖（+0.3°C）、偏淡（−0.2 psu）且变浅。在空间上，分析发现海表温度（SST）响应具有非均匀性，而海表盐度淡化响应则具有均匀性。在定量上，降水使内核心区（125 km以内）的SST冷却增强0.006°C（1.75%），同时抑制外区（250 km以内）的冷却0.014°C（6.3%）。这种信号反转标志着从最大风速半径以内由切变主导的混合向外围由层结主导的抑制的机制转变。尽管在内核心区和外区，降水驱动的层结与流切变均呈强正相关（r = 0.81 ∼ 0.91），但这两个变量均与SST异常的相关性不强（r < 0.3）。这表明淡水通量通过稳定混合层与增强湍流混合之间的竞争机制改变海洋热结构。这些结果凸显了在耦合TC模式中纳入降水效应的必要性，特别是对于改进次表层过程的表征及其对TC强度的潜在影响。

8. JGR: Oceans — On A Novel Estimation Method of Stickiness Parameter of Suspended Particles From Tank Experiments

Abstract

Abstract Stickiness is a key factor in characterizing coagulation dynamics (aggregation or flocculation). Previous studies have developed methods for estimating constant stickiness parameters. These methods estimate the stickiness parameter based on the reduction rate of the number of particles observed in a simple stirred tank. However, their applicability is limited to dense particles with monodisperse (or sufficiently narrow) particle size distributions (PSDs). In this study, we developed a novel estimation method that poses fewer assumptions on fractal structures and PSD shapes through theoretical analysis of the coagulation equation and numerical experiments that imitated tank experiments. First, we demonstrated that the reduction rate depends on the fractal dimension and the polydispersity of suspended particles, and both effects can be quantitatively integrated into a single correction factor. Second, we developed a novel estimation method for the stickiness parameter by incorporating the correction factor. This novel method is applicable to polydisperse particles with a single fractal dimension. We tested the consistency and the performance of our method using two polydisperse PSDs. Coagulation experiments were numerically conducted here to evaluate the performance of the proposed estimation method using a validated particle model. Our results show that the correction factor reduces the estimation error of the stickiness parameter from hundreds of percent (obtained by previous methods) to a few percent. Using the averaged correction factor evaluated from multiple PSD measurements during tank experiments, the estimation accuracy improved further to less than 1%.

中文摘要

黏性系数是表征凝聚动力学（聚集或絮凝）的关键因素。以往研究已发展了估算恒定黏性参数的方法。这些方法基于简单搅拌槽中观测到的颗粒数量减少率来估算黏性参数。然而，其适用性仅限于单分散（或粒径分布足够窄）的致密颗粒。本研究通过凝聚方程的理论分析和模拟搅拌槽实验的数值实验，开发了一种对分形结构和粒径分布形状假设更少的新型估算方法。首先，我们证明了颗粒数量的减少率取决于分形维数和悬浮颗粒的多分散性，且这两种效应可定量整合为单一校正因子。其次，我们通过引入该校正因子，开发了一种新的黏性参数估算方法。该新方法适用于具有单一分形维数的多分散颗粒。我们使用两种多分散粒径分布检验了该方法的一致性和性能。本文通过数值凝聚实验，利用经过验证的颗粒模型评估了所提出估算方法的性能。结果表明，校正因子将黏性参数的估算误差从以往方法获得的数百个百分点降低至几个百分点。利用搅拌槽实验中多次粒径分布测量所评估的平均校正因子，估算精度进一步提高至小于1%。

9. JGR: Oceans — Mode‐2 Nonlinear Internal Wave Generation and Propagation on an Energetic Continental Shelf

Abstract

Abstract While mode‐2 nonlinear internal waves (NLIWs) can play an important role in mixing and transporting material, their generation and evolution remain less well‐understood than their mode‐1 counterparts. Field observations from a mooring in 330 m water on the Australian North West Shelf revealed the frequent occurrence of mode‐2 NLIWs, with leading wave amplitudes of 23 8 m, followed by a train of trailing waves, and a propagation direction of 54° 12° SE (i.e., inshore). While these mode‐2 NLIWs typically occurred every 12–12.4 hr, they were not directly linked to the local tidal forcing. Furthermore, the amplitude of the leading waves increased when the background stratification shifted from a 2‐layer to a 3‐layer regime (a structure influenced by the passage of TC Veronica ). We used a non‐hydrostatic (NH) ocean model to understand the mode‐2 generation and propagation process and its link to the background density stratification and forcing. We first ran a series of 2‐dimensional (2D) NH model runs, driven by both remote internal tides (RIT) with a low‐frequency phase modulation and local barotropic forcing. The 2D modeling demonstrated that non‐phase‐locked mode‐1 remotely‐generated internal tides (RITs) scattered energy to high mode beams at the shelf break. The shoreward‐propagating internal wave beams then interacted resonantly with the double‐pycnocline (3‐layer) stratification to ultimately generate mode‐2 NLIWs in shallower water at depths of around 500 m. Using knowledge from these 2D simulations, we then ran a 3D NH model with phase‐modulated RITs and local barotropic forcing, and the model results were in good agreement with the observations. The crest length of the mode‐2 NLIWs was ∼5 km and the crest width was less than 1 km in the shelf waters, as determined by the correlation length scales calculated from the numerical model results.

中文摘要

摘要 尽管模态2非线性内波（NLIWs）在混合与物质输运中可能发挥重要作用，但其生成与演化相较于模态1内波仍认识不足。来自澳大利亚西北陆架330 m水深处一套锚系观测系统的现场观测显示，模态2 NLIWs频繁出现，前导波振幅为23±8 m，其后跟随一系列尾随波，传播方向为54°±12° SE（即向岸方向）。虽然这些模态2 NLIWs通常每12–12.4 hr出现一次，但它们与局地潮汐强迫并无直接联系。此外，当背景层结从二层结构转变为三层结构时（该结构受TC Veronica过境影响），前导波振幅增大。我们采用非静力（NH）海洋模式来理解模态2的生成与传播过程及其与背景密度层结和强迫的联系。我们首先进行了一系列二维（2D）NH模式运行，由具有低频相位调制的远场内潮（RIT）和局地正压强迫共同驱动。二维模拟表明，非锁相的模态1远场生成内潮（RITs）在陆架坡折处将能量散射至高阶模态波束。随后，向岸传播的内波波束与双跃层（三层）层结发生共振相互作用，最终在约500 m深度的较浅水域生成模态2 NLIWs。基于这些二维模拟的认识，我们随后运行了一个三维NH模式，包含相位调制的RITs和局地正压强迫，模式结果与观测吻合良好。根据数值模式结果计算的相关长度尺度确定，模态2 NLIWs在陆架水域的波峰长度约为5 km，波峰宽度小于1 km。

10. JGR: Oceans — Contrasting Regulation of Upper‐Ocean Temperature and Salinity Responses to Tropical Cyclones by the Barrier Layer

Abstract

Abstract This study investigates the role of the pre‐storm barrier layer (BL) in modulating the upper‐ocean response to tropical cyclones (TCs) from a global perspective. By synthesizing multi‐sensor satellite observations and in situ Argo profiles from 2003 to 2022, we show that the barrier layer thickness (BLT) exerts contrasting effects on the upper‐ocean temperature and salinity anomalies. For temperature, a thick BL acts as an effective thermal insulator that significantly weakens surface cooling and accelerates thermal recovery by restricting the deepening of the mixed layer and limiting entrainment of colder thermocline water. In contrast, surface salinification is amplified in regions with thick BLs. This enhancement arises from the strong vertical salinity gradient associated with thick BLs, where a fresh surface lens overlies a sharp and shallow halocline, allowing saltier subsurface water to be efficiently entrained into the mixed layer during TC passage. Subsurface composites from Argo floats further corroborate this mechanism, showing that thick BLs weaken the vertical thermal response while generating a pronounced salinity response, characterized by enhanced surface salinification and subsurface freshening. These findings underscore the BL as a critical regulator of vertical exchange during TC forcing, leading to a relatively warm and salty wake in freshwater‐influenced basins. Consequently, accurately representing this dual modulation is essential for coupled models to capture realistic upper‐ocean responses and associated air–sea fluxes.

中文摘要

摘要 本研究从全球视角探讨了风暴前障碍层（BL）在调控上层海洋对热带气旋（TC）响应中的作用。通过综合2003年至2022年的多传感器卫星观测和Argo现场剖面数据，我们表明障碍层厚度（BLT）对上层海洋温度异常和盐度异常产生相反的影响。就温度而言，厚障碍层起到有效的热绝缘体作用，通过限制混合层的加深和抑制较冷温跃层水的夹卷，显著减弱表层冷却并加速热力恢复。相比之下，在障碍层较厚的区域，表层盐度增加被放大。这种增强源于与厚障碍层相关的强垂向盐度梯度，即淡的表层透镜状水体覆盖在尖锐且浅的盐跃层之上，使得在热带气旋过境期间，较咸的次表层水能够被有效地夹卷进入混合层。Argo浮标的地下合成剖面进一步证实了这一机制，表明厚障碍层减弱了垂向热力响应，同时产生了显著的盐度响应，其特征为表层盐度增加增强和次表层淡化。这些发现强调了障碍层在热带气旋强迫期间作为垂向交换的关键调节因子，导致在受淡水影响的海盆中形成相对温暖且偏咸的尾迹。因此，准确表征这种双重调制对于耦合模式捕捉真实的上层海洋响应及相关的海气通量至关重要。

11. JGR: Oceans — Relative Roles of Surface Fluxes and Strait of Hormuz Exchanges to the Arabian Gulf Salinity Evolution

  • 作者：Panagiotis Vasou, George Krokos, Sarantis S. Sofianos, William E. Johns, Sabique Langodan, Ibrahim Hoteit
  • 发表日期：2026-09-29
  • DOI：https://doi.org/10.1029/2025jc022801

Abstract

Abstract This study investigates the interannual salinity variability in the Arabian Gulf and its relationship with surface freshwater fluxes and lateral water exchanges through the Strait of Hormuz (SoH). Using a 29‐year high‐resolution MIT general circulation model simulation (1993–2021), we quantify basin‐mean salinity changes and their driving mechanisms through a salt and water mass budget framework. The modeled basin‐mean salinity is approximately 0.2 psu lower on average during 1993–1999 than during 2001–2021, indicating an earlier‐to‐later mean‐state contrast within the simulation, superimposed on pronounced interannual variability. Linear regression over 1993–2021 gives a fitted increase of 0.09 ± 0.03 psu per decade, but this slope primarily summarizes the contrast between the earlier and later modeled states rather than indicating persistent linear salinification, and its exact value remains sensitive to conditions during the early simulation years. The cumulative modeled salinity increase reflects the combined effect of persistent net surface freshwater loss (evaporation minus precipitation minus river runoff; E − P − R ) and compensating water mass exchanges through the SoH. Precipitation variability drives much of the year‐to‐year variations in E − P − R and associated salinity anomalies, while the higher post‐2000 mean state of E − P − R reflects contributions from both increased evaporation and reduced precipitation. Annual salinity fluctuations are primarily governed by variability in SoH salt fluxes, while long‐term changes in these fluxes are driven mainly by changes in transport strength (exchanged volume) rather than by changes in the salinity of exchanged waters.

中文摘要

摘要 本研究探讨了阿拉伯湾盐度的年际变率及其与表层淡水通量和经霍尔木兹海峡（SoH）的侧向水体交换之间的关系。利用为期29年的高分辨率MIT大气环流模式模拟（1993—2021年），我们通过盐分和水体质量收支框架量化了海盆平均盐度变化及其驱动机制。模拟的海盆平均盐度在1993—1999年期间平均比2001—2021年期间低约0.2 psu，表明模拟中存在早期至后期的平均态差异，并叠加在显著的年际变率之上。对1993—2021年的线性回归给出的拟合增量为每十年0.09 ± 0.03 psu，但该斜率主要概括了模拟早期与后期状态之间的差异，而非表明持续性的线性盐化，其确切数值对模拟早期年份的条件仍然敏感。模拟的累积盐度增加反映了持续性净表层淡水损失（蒸发减降水减河流径流；E − P − R）与经霍尔木兹海峡的补偿性水体交换的共同作用。降水变率驱动了E − P − R及其相关盐度异常的大部分年际变化，而2000年后E − P − R较高的平均态则反映了蒸发增加和降水减少两者的贡献。年盐度波动主要受霍尔木兹海峡盐通量变率的控制，而这些通量的长期变化主要由输运强度（交换体积）的变化驱动，而非由交换水体盐度的变化驱动。

12. JGR: Oceans — Baffin Bay Freshwater Content Seasonal Variability and Budget: A Modeling Approach

Abstract

Abstract Baffin Bay plays a significant role as an exporter of freshwater from the Arctic to the North Atlantic. However, we still do not completely understand how this freshwater is stored and transformed within the bay before it exits. Here, we use a six‐member ensemble built using the Nucleus for European Modelling of the Ocean (NEMO)—at 1/4° horizontal spatial resolution—to investigate the annual variability of the freshwater content (FWC) in Baffin Bay. We have quantified Baffin Bay’s seasonal FWC budget (with salinity reference of 33.1) and found that the net freshwater flux is positive (into the bay) from May to September and negative (out of the bay) during the other months of the year, mainly led by the flux from sea ice production and melting. The net freshwater flux from all sources and sinks considered in this study is positive, indicating accumulation of 592.7 (±39.8) km 3 along a climatological year. We have also applied a Common Empirical Orthogonal Function (CEOF) analysis to Baffin Bay’s FWC, which revealed that the first mode of variability (81.4%) is likely related to sea ice melting in central Baffin Bay and to land runoff along the coastal areas. The second mode represents around 11.9% of the FWC total variance, is driven by ocean surface stress and is connected to a seasonal cross‐shelf recirculation system along Baffin Island shelf break.

中文摘要

摘要 巴芬湾作为北极向北大西洋输送淡水的出口，发挥着重要作用。然而，对于这些淡水在离开巴芬湾之前如何在湾内储存和转化，我们仍未完全了解。本研究利用基于欧洲海洋模拟核心（NEMO）构建的六成员集合模拟——水平空间分辨率为1/4°——来研究巴芬湾淡水含量（FWC）的年际变化。我们量化了巴芬湾的季节性淡水含量收支（盐度参考值为33.1），发现净淡水通量在5月至9月为正值（流入湾内），而在一年中其余月份为负值（流出湾内），主要由海冰生产和融化产生的通量主导。本研究中考虑的所有源和汇的净淡水通量为正值，表明在气候态一年内累积了592.7（±39.8）km³的淡水。我们还对巴芬湾的淡水含量应用了共同经验正交函数（CEOF）分析，结果表明第一模态变率（81.4%）可能与巴芬湾中部的海冰融化以及沿岸地区的陆地径流有关。第二模态约占淡水含量总方差的11.9%，由海洋表面应力驱动，并与沿巴芬岛陆架边缘的季节性跨陆架再循环系统相关联。

13. JGR: Oceans — Depth‐Resolved Surfzone Wave and Roller Transformation

Abstract

Abstract The vertical structures of cross‐shore wave, roller, and other momentum forcing terms are examined using a two‐phase Reynolds‐averaged Navier‐Stokes model driven with field and laboratory measured waves and bathymetry. Modeled wave height, setup, and undertow agree well with field observations along a cross‐shore transect extending from the shoreline to about 5‐m water depth, and with measurements in a wave flume. Momentum flux carried by wave, roller, vertical turbulence transfer, pressure slope, and vertical inertia primarily balance near the surface, while wave, vertical turbulence transfer, vertical inertia, and setup primarily balance in the mid‐to lower‐water column. Turbulence transports momentum downward, while vertical inertia transfers momentum upwards. Combined wave and roller forcing agrees with a linear wave theory parametrization offshore of the sandbar and on a near‐planar beach, and combined wave, roller, and vertical inertia agrees with linear theory onshore of the sandbar. Roller thickness is related to local wave height, similar to previous studies. Sub‐surface offshore‐directed mean currents (undertow) can be estimated from the mid‐to lower‐water column momentum balance. Turbulence production dominates the near‐surface turbulence‐energy‐flux balance, and its penetration depth in the sandbar trough is correlated with local wave height.

中文摘要

摘要：本文利用由现场和实验室实测波浪与地形驱动的两相雷诺平均Navier-Stokes模型，研究了跨岸波浪、滚波及其他动量强迫项的垂向结构。模拟的波高、增水和离岸流与从岸线延伸至约5 m水深的跨岸断面现场观测结果吻合良好，也与波浪水槽中的测量结果一致。波浪、滚波、垂向湍流输运、压力坡度和垂向惯性携带的动量通量在近水面处基本平衡，而波浪、垂向湍流输运、垂向惯性和增水在中下层水体中基本平衡。湍流将动量向下输运，而垂向惯性将动量向上输运。波浪与滚波联合强迫在沙坝向海侧和近平面海滩上与线性波浪理论参数化方案一致，波浪、滚波与垂向惯性联合强迫在沙坝向岸侧与线性理论一致。滚波厚度与当地波高相关，与先前研究结果类似。次表层向海方向平均流（离岸流）可由中下层水体动量平衡估算。湍流生成在近水面湍流能量通量平衡中占主导地位，其在沙坝槽中的穿透深度与当地波高相关。

14. JGR: Oceans — The 18.6‐Year Lunar Nodal Cycle in Internal Tides

Abstract

Abstract Both the 18.6‐year lunar nodal cycle (LNC) and long‐term quasi‐linear trends in oceanic internal tides are detected using 30 years of satellite altimeter data (1993–2022). The data are divided into 28 overlapping equal‐sized subsets, from which 28 sets of global internal tide fields are constructed for mode‐1 , , and constituents. Their global‐mean amplitude and phase time series demonstrate that the detected LNC is consistent with the equilibrium theory. The detected quasi‐linear trends are evidently the anticipated consequence of the increasingly stratified ocean caused by global warming. The global distribution of internal tidal energy is significantly modulated by the 18.6‐year LNC, because (a) and are 180 out of phase with in the cycle, and (b) the diurnal and semidiurnal constituents have different spatial patterns. We suggest that the nodal modulation of internal tides may affect internal tide‐driven ocean mixing and thus large‐scale ocean circulations.

中文摘要

摘要：利用30年（1993—2022年）的卫星高度计数据，同时检测到18.6年月球交点周期（LNC）和海洋内潮中的长期准线性趋势。数据被划分为28个重叠的等大小子集，由此构建了28组针对模态一、M₂、K₁和O₁分潮的全球内潮场。其全球平均振幅和相位时间序列表明，检测到的LNC与平衡潮理论一致。检测到的准线性趋势显然是全球变暖导致的海洋层结增强的预期结果。内潮能量的全球分布受到18.6年LNC的显著调制，原因在于：(a) M₂和K₁在周期中与O₁相位相差180°；(b) 全日分潮和半日分潮具有不同的空间格局。我们认为，内潮的交点调制可能影响内潮驱动的海洋混合，进而影响大尺度海洋环流。

15. JGR: Oceans — Microbial Respiration Across Subtropical Eddies: Submesoscale Variability and Biogeochemical Drivers

Abstract

Abstract Island‐induced eddies from the Canary Islands region propagate southwestward along the Canary Eddy Corridor, exporting biological and biogeochemical properties to the oligotrophic open ocean. However, their contribution to organic matter remineralization, and consequently to the biological carbon pump, throughout their life cycle remains poorly understood. Using respiratory electron transport system (ETS) activity as a proxy for microbial respiration, we investigated two cyclonic and two anticyclonic eddies at different stages of development and found distinct respiration patterns. Epipelagic respiration peaked in the most intense cyclonic eddy, whereas mesopelagic respiration showed localized maxima beneath most eddies and tended to be higher in cyclonic than in anticyclonic eddies. At submesoscale resolution, plume‐like ETS structures emerged within the mesopelagic layer, modulating respiration variability across eddies. Mesopelagic respiration variability was driven primarily by suspended particulate organic matter, whereas dissolved organic matter and its chromophoric and fluorescent protein‐like fractions contributing less. This contrasts with the greater contribution of dissolved organic matter to apparent oxygen utilization. Notably, fluorescent humic‐like substances were negatively correlated with respiration, indicating reduced microbial activity in older water masses. These findings demonstrate that mesoscale eddies can strongly regulate microbial organic matter remineralization and, consequently, influence ocean carbon cycling.

中文摘要

摘要 加那利群岛区域由岛屿产生的涡旋沿加那利涡旋走廊向西南传播，将生物和生物地球化学属性输出至贫营养的开阔大洋。然而，在其整个生命周期中，这些涡旋对有机质再矿化以及由此对生物碳泵的贡献仍知之甚少。本研究以呼吸电子传递系统（ETS）活性作为微生物呼吸的替代指标，对处于不同发育阶段的两个气旋式涡旋和两个反气旋式涡旋进行了调查，发现了截然不同的呼吸模式。上层海洋呼吸在最强的气旋式涡旋中达到峰值，而中层海洋呼吸在大多数涡旋下方表现出局地最大值，且气旋式涡旋中的呼吸倾向于高于反气旋式涡旋。在亚中尺度分辨率下，中层海洋层内出现了羽流状ETS结构，调节着涡旋间的呼吸变异性。中层海洋呼吸变异性主要由悬浮颗粒有机物驱动，而溶解有机物及其有色和类荧光蛋白组分贡献较小。这与溶解有机物对表观耗氧量贡献较大形成对比。值得注意的是，类荧光腐殖质物质与呼吸呈负相关，表明较老水团中微生物活性降低。这些发现表明，中尺度涡旋能够强烈调控微生物有机质再矿化，进而影响海洋碳循环。

16. JGR: Oceans — Impact of Model Resolution on Antarctic Bottom Water Representation in Coupled Climate Models

  • 作者：Qi Shu, Qiang Wang, Zhaomin Wang, Yongqiang Yu, Jiping Liu, Caili Liu, Bo An, Zhenya Song, Fangli Qiao
  • 发表日期：2026-09-28
  • DOI：https://doi.org/10.1029/2025jc023640

Abstract

Abstract Antarctic Bottom Water (AABW) formation plays a crucial role in the climate system by driving the lower branch of the global overturning circulation, redistributing heat and salt, storing anthropogenic carbon dioxide, and delivering oxygen to the deep ocean. However, the representation of AABW formation in most climate models remains inadequate, since coarse spatial resolution fails to capture the intense ocean‐ice‐atmospheric interactions in a few small areas around the Antarctic continental shelf. This study evaluates the impact of model resolution on AABW simulations, using three climate models from the High Resolution Model Intercomparison Project (HighResMIP). By comparing the climatological mean state and projected changes of AABW in both low‐ and high‐resolution simulations, we find that climate models with approximately 4 km resolution better capture AABW formation and export processes along the Antarctic continental shelf than their lower‐resolution counterparts. High‐resolution climate models also project more pronounced future AABW changes than low‐resolution models. However, spurious AABW formation through open‐ocean deep convection becomes more prevalent in two of the three high‐resolution models, and thus the overall property biases in these models remain comparable to those in the low‐resolution models. Our results advance the understanding of how climate model resolution affects climate simulations and offer insights into the progress and challenges in representing AABW in climate models.

中文摘要

南极底层水（AABW）的形成在气候系统中发挥着至关重要的作用，它驱动着全球翻转环流的下支，重新分配热量和盐分，储存人为二氧化碳，并向深海输送氧气。然而，大多数气候模式对AABW形成的表征仍然不足，因为粗空间分辨率无法捕捉南极大陆架周围少数小区域中强烈的海洋-海冰-大气相互作用。本研究利用高分辨率模式比较计划（HighResMIP）中的三个气候模式，评估了模式分辨率对AABW模拟的影响。通过比较低分辨率和高分辨率模拟中AABW的气候态平均状态及预估变化，我们发现约4 km分辨率的气候模式比低分辨率模式能更好地捕捉沿南极大陆架的AABW形成和输出过程。高分辨率气候模式还预估出比低分辨率模式更为显著的未来AABW变化。然而，在三个高分辨率模式中的两个里，通过开阔大洋深对流产生的虚假AABW形成变得更加普遍，因此这些模式的整体属性偏差仍与低分辨率模式相当。我们的结果增进了对气候模式分辨率如何影响气候模拟的理解，并为气候模式中AABW表征的进展与挑战提供了见解。

17. JPO — Energetics of Frontogenesis in Simple Balanced Models

Abstract

Abstract Submesoscale fronts have been proposed to act as conduits funneling kinetic energy from geostrophically constrained mesoscale eddies down to small scales, where the energy can be dissipated. Realistic primitive equation simulations suggest that the downscale energy transfer at submesoscales is strongly concentrated in sharpening fronts, with convergence on the cyclonic side playing a dominant role. This study explores how much of this phenomenology can be captured by simple quasigeostrophic (QG) and semigeostrophic (SG) theories of frontogenesis. An analysis of the kinetic energy budget of classical strain-induced frontogenesis shows that there is downscale transfer in both QG and SG fronts. In QG frontogenesis, the narrowing jet along the sharpening front is powered by buoyancy production, but geostrophic downscale transfer due to the strain field plays an important role. In SG frontogenesis, where frontal sharpening is accelerated by the ageostrophic cross-frontal circulation, ageostrophic advection enhances this downscale transfer on the cyclonic side of the front, where the surface flow is convergent. On the anticyclonic side, where the ageostrophic circulation is divergent, the ageostrophic-scale transfer of kinetic energy is upscale and partially offsets the geostrophic downscale transfer. While matching patterns in realistic primitive equation simulations, the ageostrophic-scale transfers remain important but not dominant in the adiabatic and frictionless theory considered here. This suggests that processes absent from these theories may play an important role. For example, mixed layer turbulence may enhance the ageostrophic circulation and the associated dipole of scale transfers. The advection of ageostrophic momentum may also be important in some circumstances.

中文摘要

摘要 亚中尺度锋面被认为可作为通道，将动能从受地转约束的中尺度涡旋向下传递至小尺度，并在该尺度上耗散。真实的原始方程模拟表明，亚中尺度下的向下尺度能量传递强烈集中于锋面锐化过程中，其中气旋侧的辐合起主导作用。本研究探讨了简单的准地转（QG）和半地转（SG）锋生理论能在多大程度上捕捉这一现象。对经典应变诱导锋生的动能收支分析表明，在QG和SG锋面中均存在向下尺度传递。在QG锋生中，沿锐化锋面的窄化急流由浮力产生驱动，但应变场导致的地转向下尺度传递也起重要作用。在SG锋生中，锋面锐化由非地转跨锋环流加速，非地转平流增强了锋面气旋侧的向下尺度传递，该处表面流为辐合。在反气旋侧，非地转环流为辐散，非地转尺度动能传递为向上尺度，并部分抵消地转向下尺度传递。尽管与实际原始方程模拟中的模式相符，但在此处所考虑的绝热无摩擦理论中，非地转尺度传递仍然重要但并非主导。这表明这些理论中缺失的过程可能起重要作用。例如，混合层湍流可能增强非地转环流及相关的尺度传递偶极子。非地转动量平流在某些情况下也可能很重要。

18. JPO — Orthogonality of Coastal-Trapped Waves

Abstract

Abstract Coastal-trapped wave modes are shown to be orthogonal in the sense that they make independent contributions to the energy of the wave field. The hydrostatic Boussinesq dynamics on an f plane, linearized around a state of rest, are formulated as a (generalized) Schrödinger equation, which exposes the Hermitian structure of the wave operator that implies the orthogonality of eigenmodes. This formulation, which becomes particularly simple in weak form, is parlayed into a finite-element discretization that preserves the symmetries of the original problem and therefore the energy conservation and orthogonality of modes. The geostrophic momentum approximation, under which the orthogonality of modes has been recognized previously, is reprised and discussed in the present context to emphasize that low-frequency coastal-trapped waves are edge waves. Their dynamics are governed by boundary potential vorticity anomalies, both Bretherton-type contributions familiar from the quasigeostrophic equations and lateral contributions that are important for steep slopes and coastal walls.

中文摘要

摘要 海岸陷波模态被证明是正交的，即它们对波场能量做出独立贡献。在f平面上，围绕静止状态线性化的静力Boussinesq动力学被表述为（广义）Schrödinger方程，由此揭示了波算符的Hermitian结构，而该结构意味着本征模态的正交性。这一表述在弱形式下尤为简洁，并被转化为有限元离散化，该离散化保持了原问题的对称性，从而保持了能量守恒和模态正交性。地转动量近似——在此近似下模态的正交性此前已被认识——在本文语境中被重新审视和讨论，以强调低频海岸陷波是边缘波。其动力学由边界位涡异常控制，既包括准地转方程中熟悉的Bretherton型贡献，也包括对陡坡和海岸壁重要的侧向贡献。

19. JPO — Langmuir Mixing Effects on a Coastal Upwelling Front

Abstract

Abstract Langmuir turbulence can generate vigorous vertical mixing in the ocean surface boundary layer and has the potential to influence coastal upwelling fronts. However, its impact on the dynamics of these fronts remains poorly understood. In this study, we investigate this influence by incorporating a recently developed KPP-based Langmuir mixing parameterization into a coupled wave–circulation model. The results show that Langmuir mixing plays a dominant role in controlling frontal evolution. Strong Langmuir mixing reduces the vertical shear of frontal currents, suppresses the development of frontal instability, and weakens the vertical-shear-driven forward energy transfer. Sensitivity experiments further indicate that when Langmuir mixing is weak, as reflected by a small Langmuir enhancement factor, its influence on frontal instability is minimal. These findings demonstrate that Langmuir mixing can fundamentally alter the dynamics and energetics of coastal upwelling fronts and highlight the importance of including Langmuir mixing parameterizations to achieve accurate simulations of coastal circulation and frontal processes. Significance Statement Coastal upwelling fronts serve as essential feeding grounds for fish, marine mammals, and seabirds. However, several critical questions remain regarding the evolution of these fronts in complex environments. One key issue is how vertical mixing driven by Langmuir turbulence influences the upwelling fronts. In this study, we demonstrate that Langmuir-induced mixing significantly affects the dynamics of upwelling fronts, including frontal currents, instabilities, and energy transfer processes. These findings underscore the importance of incorporating Langmuir mixing effects to accurately understand the evolution of upwelling fronts, which is crucial for both coastal circulation modeling and the health of marine ecosystems.

中文摘要

摘要 朗缪尔湍流能够在海洋表面边界层中产生强烈的垂向混合，并具有影响沿岸上升流锋的潜力。然而，其对这些锋面动力学的影响仍知之甚少。在本研究中，我们通过将最近开发的基于KPP的朗缪尔混合参数化方案纳入耦合波浪-环流模式，研究了这一影响。结果表明，朗缪尔混合在控制锋面演化中起主导作用。强朗缪尔混合减弱了锋面流的垂向切变，抑制了锋面不稳定性的发展，并削弱了由垂向切变驱动的正向能量传递。敏感性实验进一步表明，当朗缪尔混合较弱时，即朗缪尔增强因子较小时，其对锋面不稳定性的影响极小。这些发现表明，朗缪尔混合能够从根本上改变沿岸上升流锋的动力学和能量学，并凸显了纳入朗缪尔混合参数化方案以实现沿岸环流和锋面过程准确模拟的重要性。意义声明 沿岸上升流锋是鱼类、海洋哺乳动物和海鸟的重要觅食场所。然而，关于这些锋面在复杂环境中的演化，仍存在若干关键问题。其中一个核心问题是朗缪尔湍流驱动的垂向混合如何影响上升流锋。在本研究中，我们证明朗缪尔引起的混合显著影响上升流锋的动力学，包括锋面流、不稳定性和能量传递过程。这些发现强调了纳入朗缪尔混合效应以准确理解上升流锋演化的重要性，这对于沿岸环流模拟和海洋生态系统健康均至关重要。

20. JPO — Energetic Wind-Generated Near-Inertial Waves Observed in a Cyclonic Eddy

Abstract

Abstract The propagation of wind-generated near-inertial waves (NIWs) is well documented in anticyclonic eddies (ACEs) but remains rarely reported in cyclonic eddies (CEs). Here, subsurface mooring observations in the northwestern Pacific captured two distinct NIW packets (WP1 and WP2) generated by Typhoon Sanvu within a CE. In the typhoon’s wake, WP1 was confined to the upper 80 m, with little energy penetrating deeper despite strong wind forcing. A linear internal wave model and ray-tracing experiments suggest that the shallow mixed layer and the repelling effect of the CE favor lateral propagation of near-inertial energy rather than downward penetration. About 2 weeks later, WP2 emerged at 450–900-m depth with a velocity amplitude of 0.3 m s −1 and persisted for nearly 1 month. Wind work and Wentzel–Kramers–Brillouin (WKB)-scaled near-inertial kinetic energy indicate that WP2 was decoupled from local surface energy and unrelated to WP1. Spectral and modal analyses show that WP2 had the characteristics of low-mode and long-range-propagating NIWs. Ray-tracing and dynamical analyses suggest a plausible remote-source interpretation for WP2, in which it may have originated from a remote cyclonic region 250–350 km away and reached the mooring along a pathway modulated by mesoscale eddies. However, because the present analysis does not resolve the wave packet’s horizontal extent, spatial inhomogeneity of NIW energy may also affect the mooring observations and thus the interpretation of the decay of WP1, the later arrival of WP2, and the apparent lack of downward-moving energy between them. These results highlight the complexity of NIW propagation in eddy-rich environments. Significance Statement Wind-generated near-inertial waves (NIWs) are ubiquitous in the ocean. Using a subsurface mooring, we document two dynamically distinct NIW packets in a cyclonic eddy (CE). One is confined to the surface layer of the CE in the wake of the typhoon, with minimal downward energy penetration. Two weeks later, another energetic NIW packet appears in the deep layer of the CE, and its timing is consistent with arrival from a remote source region via long-range propagation. These observations provide a useful reference for future model refinement and also suggest that spatial inhomogeneity of NIW energy may strongly influence how subsurface wave packets are recorded at a single-mooring site.

中文摘要

摘要 风生近惯性波（NIWs）的传播在反气旋涡（ACEs）中已有充分记录，但在气旋涡（CEs）中却鲜有报道。本文利用西北太平洋的次表层潜标观测，捕获了台风“三巴”在一个CE内生成的两个不同的近惯性波包（WP1和WP2）。在台风尾迹中，WP1被限制在上层80 m以内，尽管风强迫很强，但几乎没有能量向更深层穿透。一个线性内波模型和射线追踪实验表明，浅混合层和CE的排斥效应有利于近惯性能量的侧向传播，而非向下穿透。约2周后，WP2出现在450–900 m深度，速度振幅为0.3 m s⁻¹，并持续了近1个月。风做功和Wentzel–Kramers–Brillouin（WKB）标度的近惯性动能表明，WP2与局地表面能量解耦，且与WP1无关。谱分析和模态分析表明，WP2具有低模态和远距离传播近惯性波的特征。射线追踪和动力学分析为WP2提供了一个合理的远源解释，即它可能起源于250–350 km外的一个遥远气旋区域，并沿着受中尺度涡调制的路径到达潜标。然而，由于目前的分析未能解析该波包的水平范围，近惯性波能量的空间不均匀性也可能影响潜标观测，从而影响对WP1衰减、WP2后期到达以及两者之间明显缺乏向下传播能量的解释。这些结果凸显了涡旋丰富环境中近惯性波传播的复杂性。意义声明 风生近惯性波（NIWs）在海洋中普遍存在。利用一台次表层潜标，我们记录了一个气旋涡（CE）中两个动力学上不同的近惯性波包。一个被限制在台风尾迹中CE的表层，向下能量穿透极少。两周后，另一个能量丰富的近惯性波包出现在CE的深层，其出现时间与通过远距离传播从遥远源区到达一致。这些观测为未来模式改进提供了有益参考，同时也表明近惯性波能量的空间不均匀性可能强烈影响次表层波包在单一潜标站点的记录方式。

21. JPO — Barotropic-to-Baroclinic Transition in Tidal Flows

Abstract

Abstract As the ocean tide flows over the rough seafloor, it induces topographic stresses that feed back on the strength of the tide. Here, we examine how these topographic stresses change as the dynamical regime transitions from barotropic to baroclinic with increasing stratification and/or decreasing topographic length scale, thereby bridging between previous work which studied one or other regime in isolation. Our investigation is conducted using linear theory validated by comparison with a suite of over 100 fully nonlinear numerical simulations. For superinertial tidal flows across an isolated ridge, it is shown that the topographic stress rapidly transitions from out of phase with the tidal flow to in phase with the tidal flow at ridge widths of 1–2 times the baroclinic mode-1 wavelength. This change in stress is associated with a switch from topographically confined perturbation flows in the barotropic regime to radiating waves in the baroclinic regime. The transition becomes more complicated in the presence of multiple ridges due to the interference of the waves generated at each. These interactions lead to significant changes in both the magnitude and phase of the topographic stress as compared to the sum of the contributions from two isolated ridges. Further, particular combinations of ridges—so-called “invisible topographies”—lead to exactly zero stress and, therefore, have no effect on the barotropic tide. These results have implications for improving models of ocean tides and tidally driven mixing.

中文摘要

摘要：当海洋潮汐流过粗糙的海底时，会诱发地形应力，进而对潮汐强度产生反馈。本文研究了这些地形应力如何随着动力状态从正压向斜压转变而变化，该转变由层结增强和/或地形长度尺度减小所驱动，从而弥合了以往孤立研究某一状态的工作之间的间隙。本研究采用线性理论进行，并通过与超过100组完全非线性数值模拟的对比加以验证。对于跨越孤立海脊的超惯性潮汐流动，结果表明：当海脊宽度为斜压第一模态波长的1至2倍时，地形应力从与潮汐流动反相迅速转变为与潮汐流动同相。这种应力的变化与从正压状态下的地形受限扰动流向斜压状态下的辐射波的转换相关联。在存在多条海脊的情况下，由于各海脊所生成波的干涉，该转变变得更加复杂。与两条孤立海脊贡献之和相比，这些相互作用导致地形应力的幅度和相位均发生显著变化。此外，海脊的特定组合——即所谓的“不可见地形”——导致应力恰好为零，因此对正压潮汐没有影响。这些结果对改进海洋潮汐模型和潮汐驱动混合模型具有重要意义。

22. JPO — Forced-Dissipative Two-Layer Quasigeostrophic Waves, Instability, and Turbulence over an Aligned Sloping Bottom

Abstract

Abstract Bottom topography affects ocean turbulence across a vast range of temporal and spatial scales. Here, we show that, outside of the tropics, the ocean’s most energetic regions have large-scale topographic potential vorticity (PV) gradients aligned with background vertical-shear PV gradients. We investigate such aligned bottom slopes of varying sign and magnitude using forced-dissipative two-layer quasigeostrophic (QG) simulations. In two-layer QG turbulence, small-to-moderate bottom slopes support topographic wave energization, while moderate-to-large bottom slopes support cascade arrest, jet formation, and surface-intensified baroclinic waves. Topographic waves are not energized over steep bottom slopes, since the flow is arrested by linear waves at scales smaller than those of topographic waves. Eastward-prescribed flow and emergent jets over bottom slopes that support eastward (westward) topographic wave propagation are prograde (retrograde). Retrograde jets are persistent and self-maintaining, while prograde jets are transient. We show that both jet types act as waveguides, using frequency–wavenumber energy spectra and dispersion relations that account for the emergent zonal-mean jet flow. For a given bottom slope magnitude, prograde-prescribed flows have smaller characteristic length scales than retrograde-prescribed flows, which is rationalized using the Doppler shift of the linear wave modes. Linear wave theory is also used to predict the length scale of the maximum diagnosed turbulent time scale. Last, we suggest two (unclosed) methods for predicting zonal eddy kinetic energy levels and length scales. These results inform both fundamental theory of baroclinic turbulence over a bottom slope and topography-aware parameterizations of ocean eddies. Significance Statement The global seafloor is made up of topography on scales ranging from centimeters to thousands of kilometers. Exactly how sloping bottoms on the scale of hundreds of kilometers affect wave energization and propagation, and turbulence, is still poorly understood. Here, we investigate how topography affects geophysical flows in various stages of the energy cycle, such as stable wave modes, unstable wave modes, and turbulent flow, using an idealized two-layer representation of a large patch of the ocean. The role of topography is shown to be highly dependent upon the bottom slope magnitude and sign. These results have implications for the fundamental understanding of geophysical fluid mechanics and how to represent topographic effects in the ocean components of relatively coarse climate models.

中文摘要

摘要 海底地形在广泛的时间与空间尺度上影响海洋湍流。本文表明，在热带以外区域，海洋中能量最强的区域具有与背景垂直切变位涡（PV）梯度对齐的大尺度地形位涡梯度。我们利用强迫-耗散两层准地转（QG）模拟，研究了此类具有不同符号和量级的对齐底坡。在两层QG湍流中，小至中等底坡支持地形波获能，而中至大底坡则支持级串中止、急流形成以及表面强化的斜压波。在陡峭底坡上，地形波不会获能，因为流动在小于地形波尺度上被线性波阻滞。在支持向东（向西）地形波传播的底坡上，向东规定的流动和涌现急流为顺行（逆行）。逆行急流具有持续性和自维持性，而顺行急流则是瞬态的。我们利用频率-波数能量谱以及考虑了涌现纬向平均急流的频散关系，表明这两种急流类型均充当波导。对于给定的底坡量级，顺行规定的流动比逆行规定的流动具有更小的特征长度尺度，这可利用线性波模式的多普勒频移加以解释。线性波理论还被用于预测最大诊断湍流时间尺度的长度尺度。最后，我们提出了两种（未闭合的）方法来预测纬向涡动能水平和长度尺度。这些结果既有助于底坡上斜压湍流的基础理论，也有助于考虑地形的海洋涡旋参数化。意义声明 全球海底由从厘米到数千公里尺度的地形构成。数百公里尺度的倾斜海底究竟如何影响波获能和传播以及湍流，目前仍知之甚少。本文利用理想化两层表示来模拟一大片海洋，研究地形如何影响能量循环各阶段的地球物理流动，如稳定波模式、不稳定波模式和湍流。结果表明，地形的作用高度依赖于底坡量级和符号。这些结果对于地球物理流体力学的基础理解，以及在相对粗分辨率气候模式的海洋分量中如何表示地形效应，具有重要意义。

23. JPO — Global Significance of Dipole-Pattern SST Anomalies in Mesoscale Eddies

Abstract

Abstract Mesoscale ocean–atmosphere coupling modulates global climate. As a major participant, sea surface temperature anomalies (SSTAs) induced by mesoscale eddies exhibit significant diversity and complexity, typically classified into monopole SSTA and various residue as dipole SSTA. However, the distinct global distribution patterns and their variance contributions remain insufficiently understood. Analysis of 29-yr satellite observations reveals that dipole SSTA cyclonic (anticyclonic) eddies account for 49.3% (51.5%) of global cyclonic (anticyclonic) eddy-induced SSTA variance. Using idealized models, we show that zonal eddy relative drift plays a notable role in shaping SSTA structures. Monopole SSTAs mainly appear in the extensions of the Gulf Stream, Kuroshio, and Antarctic Circumpolar Current (ACC) with strong eastward relative drifting, while dipole SSTAs are more common in eastern ocean basins where weak zonal relative drifting favors their development. This discovery challenges the monopole-centric paradigm of mesoscale ocean–atmosphere coupling and provides a benchmark for improving eddy representation in climate models. Significance Statement Mesoscale eddies significantly influence climate by transporting heat and modulating air–sea interactions. Our study reveals that dipole-pattern sea surface temperature anomalies (SSTAs) account for notable part of global eddy-induced SSTAs, challenging the traditional focus solely on monopole patterns. We demonstrate that monopole SSTAs typically develop in regions with strong eastward currents, whereas dipole SSTAs are more commonly found in eastern ocean basins. These insights enhance our understanding of ocean–atmosphere coupling and can improve climate models, leading to more accurate climate predictions.

中文摘要

摘要 中尺度海气耦合调制全球气候。作为主要参与者，中尺度涡旋引起的海表温度异常（SSTAs）表现出显著的多样性和复杂性，通常被分类为单极型SSTA和作为偶极型SSTA的各种残余。然而，其独特的全球分布格局及其方差贡献仍未得到充分理解。对29年卫星观测的分析表明，偶极型SSTA气旋式（反气旋式）涡旋占全球气旋式（反气旋式）涡旋诱导SSTA方差的49.3%（51.5%）。利用理想化模型，我们表明纬向涡旋相对漂移在塑造SSTA结构中发挥显著作用。单极型SSTA主要出现在Gulf Stream、Kuroshio和Antarctic Circumpolar Current（ACC）的延伸区，这些区域具有强烈的东向相对漂移，而偶极型SSTA在东部大洋盆地更为常见，那里较弱的纬向相对漂移有利于其发展。这一发现挑战了以单极型为中心的中尺度海气耦合范式，并为改进气候模式中的涡旋表征提供了基准。意义声明 中尺度涡旋通过输送热量和调制海气相互作用显著影响气候。我们的研究揭示，偶极型海表温度异常（SSTAs）在全球涡旋诱导SSTA中占显著部分，挑战了传统上仅关注单极型格局的做法。我们证明，单极型SSTA通常发展于具有强东向流的区域，而偶极型SSTA更常见于东部大洋盆地。这些认识增进了我们对海气耦合的理解，并能够改进气候模式，从而实现更准确的气候预测。

24. JPO — Influence of Tidally Driven Lagrangian Residual Flow on Buoyant Particle Convergence in a Gravitationally Driven Estuary

Abstract

Abstract Convergence of buoyant material in an estuary is important because it can facilitate interactions between particles related to predator–prey dynamics, access to nutrients, and exposure to pollutants. Convergence is often associated with lateral transport in an estuary. Traditionally viewed in a tidally averaged framework, a common mechanism of convergence is differential advection due to lateral density gradients. Recently, a time-dependent, Lagrangian convergence mechanism has been suggested and tested for a highly idealized estuary with constant density and Coriolis force. This mechanism found that a lateral phase shift in the lateral flows can result in a Lagrangian residual circulation and lead to lateral convergence. Here, we explore the combined effects and competition of Eulerian and Lagrangian convergence in a tidally resolved idealized estuary model. We find that, in both high and low vertical eddy viscosity cases, the Eulerian mean flow drives convergence toward the channel center. However, the direction of the lateral phase propagation shifts from divergence under high vertical eddy viscosity to convergence under low vertical eddy viscosity, altering the overall convergence rate relative to the Eulerian flow alone. We suggest the use of a nondimensional parameter to predict if a system will exhibit convergent or divergent Lagrangian residual circulation. We also explore the sensitivity of the Lagrangian residual circulation to changing width, depth, and the inclusion of Coriolis force. Overall, Lagrangian mechanisms are important to consider because they can control buoyant particle convergence rates and potentially alter their trajectory relative to the Eulerian mean flow. Significance Statement Estuaries are key pathways for buoyant materials, both naturally occurring and pollutants, between land and ocean. Lateral convergence of these materials can influence particle interactions related to predator–prey dynamics, nutrient access, and pollutant exposure. We examine how lateral residual circulation due to phase propagation interacts with traditionally studied tidally averaged mechanisms to shape buoyant particle convergence. The tidally averaged currents drive convergence toward the channel center, but the residual circulation can either enhance or counter this effect. When the two are aligned, convergence accelerates. When the two are opposed, fewer particles aggregate than predicted by the tidally averaged flow alone.

中文摘要

摘要 河口中浮力物质的辐聚具有重要意义，因为它能够促进与捕食者—猎物动力学相关的颗粒间相互作用、营养盐获取以及污染物暴露。辐聚通常与河口中的横向输运相关联。在传统的潮平均框架下，一种常见的辐聚机制是由横向密度梯度引起的差异平流。近年来，一种时间依赖的拉格朗日辐聚机制被提出，并在具有恒定密度和科里奥利力的高度理想化河口中进行了检验。该机制发现，横向流动中的横向相位偏移可以产生拉格朗日残余环流并导致横向辐聚。本文在一个潮汐分辨的理想化河口模型中探讨了欧拉辐聚与拉格朗日辐聚的联合效应及其竞争关系。我们发现，在高垂直涡黏性和低垂直涡黏性两种情况下，欧拉平均流均驱动向河道中心的辐聚。然而，横向相位传播的方向从高垂直涡黏性下的辐散转变为低垂直涡黏性下的辐聚，从而相对于仅考虑欧拉流的情况改变了整体辐聚速率。我们建议使用一个无量纲参数来预测系统将表现为辐聚还是辐散的拉格朗日残余环流。我们还探讨了拉格朗日残余环流对宽度变化、深度变化以及科里奥利力纳入的敏感性。总体而言，拉格朗日机制值得重视，因为它们能够控制浮力颗粒的辐聚速率，并可能改变其相对于欧拉平均流的轨迹。 意义声明 河口是浮力物质（包括天然存在的物质和污染物）在陆地与海洋之间输运的关键通道。这些物质的横向辐聚可以影响与捕食者—猎物动力学、营养盐获取和污染物暴露相关的颗粒相互作用。我们研究了由相位传播引起的横向残余环流如何与传统的潮平均机制相互作用，从而塑造浮力颗粒的辐聚。潮平均流驱动向河道中心的辐聚，但残余环流既可以增强也可以抵消这一效应。当两者方向一致时，辐聚加速。当两者方向相反时，颗粒聚集量少于仅由潮平均流所预测的结果。

25. JPO — The Labrador Boundary Current System in Summer and Fall: Mean, Variability, and Influence on Cross-Shelf Exchange

Abstract

Abstract The Labrador boundary current system significantly impacts freshwater pathways and upper-ocean stratification in the subpolar North Atlantic, which in turn influences the state of the Atlantic meridional overturning circulation. In this study, we analyze an extensive collection of shipboard hydrographic and velocity sections across the Labrador shelf and slope, occupied in the summer and fall seasons since 1940 along the Seal Island transect. The mean sections provide a quantitative view of the boundary current system and its velocity structure, consisting of the Labrador Coastal Current (LCC), the Labrador Current (LC), and a permanent recirculation associated with Hamilton Bank situated between the two currents. The LCC, which flows adjacent to the coast, is strongly influenced by local wind forcing. It has exhibited increasing volume and freshwater transports since around 2010, while its baroclinic component has progressively strengthened since the early 1970s, largely influenced by increased river runoff from northern Canada. By contrast, the LC, situated at the shelf break, is more closely linked to large-scale atmospheric patterns—captured by the North Atlantic Oscillation (NAO)—rather than local winds. Over the past decade, the LC has been in a strengthened regime, associated with a positive phase of the NAO, with enhanced equatorward freshwater transport. On the midshelf, the recirculation and its associated mixing facilitate a net offshore flux of freshwater.

中文摘要

拉布拉多边界流系统显著影响副极地北大西洋的淡水输运路径和上层海洋层结，进而影响大西洋经向翻转环流的状况。本研究分析了自1940年以来在夏季和秋季沿Seal Island断面所获取的大量拉布拉多陆架和陆坡的船测水文与流速剖面数据。平均剖面提供了该边界流系统及其流速结构的定量图像，该系统由拉布拉多沿岸流（LCC）、拉布拉多流（LC）以及位于两者之间与Hamilton Bank相关的永久性再循环组成。LCC沿岸流动，受局地风强迫的强烈影响。自约2010年以来，其体积输运和淡水输运呈增加趋势，而其斜压分量自20世纪70年代初以来逐步增强，主要受加拿大北部河流径流增加的影響。相比之下，位于陆架边缘的LC与以大西洋涛动（NAO）为代表的大尺度大气模态联系更为密切，而非局地风。过去十年间，LC处于增强状态，与NAO正位相相关联，向赤道方向的淡水输运增强。在陆架中部，再循环及其相关的混合促进了淡水的净离岸通量。

26. JPO — A Field Study of Breaking Waves in Developing Seas

  • 作者：Sagi Knobler, Jesus Ruiz-Plancarte, Ryan Yamaguchi, Qing Wang, Milan Curcic, William M. Drennan, Hans C. Graber, Brian K. Haus, David G. Ortiz-Suslow
  • 发表日期：2026-10-01
  • DOI：https://doi.org/10.1175/jpo-d-26-0068.1

Abstract

Abstract Breaking waves are the dominant pathway by which energy is dissipated at the ocean surface, yet their definition, dynamics, and energetics remain subjects of ongoing debate. Here, we present results from a 6-week field campaign during the Coastal Land–Air–Sea Interaction project, where wave breaking was detected across scales using an array of air–sea interaction spar buoys. Application of the wavelet-based Liberzon phase-discontinuity method identified more than 3.2 million wave crests and over 269 000 breaking events from high-frequency wave-wire measurements. From these elevation records, we developed an observation-constrained, crest-resolved parameterized framework for estimating breaking-induced energy dissipation. We introduce a breaking-strength parameterization in terms of locally measured nonlinear steepness that is consistent with inertial scaling after application of a constant empirical correction. Breaking fraction and associated dissipation depend strongly on wind forcing, wave age, and effective fetch, deviating from traditional whitecap-coverage power-law formulations. During active wind-wave coupling, breaking accounts for approximately 20%–50% of the local atmospheric reference energy flux, underscoring its dynamical significance. Together, these results provide a physically grounded, observation-constrained, and crest-resolved picture of breaking-wave energetics from small-scale spilling events to larger, energetic whitecaps—and offer new constraints for improving dissipation schemes in spectral wave models under developing sea conditions.

中文摘要

摘要 破碎波是海洋表面能量耗散的主要途径，然而其定义、动力学和能量学仍然是持续争论的主题。本文介绍了海岸陆-气-海相互作用项目期间为期6周的野外观测活动的结果，其中利用海气相互作用浮标阵列在多个尺度上检测了波浪破碎。应用基于小波的Liberzon相位不连续方法，从高频波浪导线测量中识别出超过320万个波峰和超过269 000次破碎事件。基于这些波高记录，我们建立了一个受观测约束的、波峰分辨的参数化框架，用于估算破碎引起的能量耗散。我们引入了一个以局地测量的非线性陡度为参数的破碎强度参数化方案，该方案在应用恒定经验修正后与惯性标度一致。破碎比例及相关耗散强烈依赖于风强迫、波龄和有效风区，偏离了传统的白冠覆盖率幂律公式。在活跃的风-浪耦合期间，破碎约占局地大气参考能量通量的20%–50%，凸显了其动力学重要性。综合而言，这些结果为从微小尺度溢出事件到较大能量白冠的破碎波能量学提供了一个具有物理基础、受观测约束且波峰分辨的图像——并为改进发展海况下谱波浪模型中的耗散方案提供了新的约束。

27. JPO — Seasonal Response of the Arctic Sea Ice to Meltwater Runoff from the Greenland Ice Sheet

  • 作者：Xi Liang, Kang Yang, Chengyan Liu, Xichen Li, Ruibo Lei, Xiangyu Wu, Zhongxiang Tian, Fu Zhao, Ming Li, Na Liu, Jiaying Huang, Ye Yuan
  • 发表日期：2026-10-01
  • DOI：https://doi.org/10.1175/jpo-d-26-0025.1

Abstract

Abstract Meltwater runoff from the Greenland ice sheet (GrIS) has been increasing since the early 1990s, which has exerted widespread influences on local and remote systems. Most previous studies have emphasized the influences of the GrIS meltwater runoff on global climate, the Atlantic meridional overturning circulation, and sea level rise. In this study, we focus on the seasonal response of the Arctic sea ice to the GrIS meltwater runoff in a regional high-resolution Arctic Ocean–sea ice coupled model. It is found that the GrIS meltwater runoff induces a southward expansion of wintertime sea ice extent in the Labrador Sea. The GrIS meltwater runoff leads to more sea ice in autumn and less sea ice in spring–summer in the Nordic seas. In the central Arctic Ocean deep basin area, the GrIS meltwater runoff causes less sea ice area in the Canadian Basin and more sea ice area in the Eurasian and Makarov Basins in summer, while less sea ice volume in the Canadian Basin annually and more sea ice volume in the Eurasian and Makarov Basins during winter–summer. Studies have suggested that the GrIS meltwater runoff is projected to increase under the Arctic amplification. This work indicates that the GrIS meltwater runoff at the southern Greenland coast could impact the Canadian Basin sea ice quickly and strongly in the future.

中文摘要

摘要 自20世纪90年代初以来，格陵兰冰盖（GrIS）的融水径流持续增加，对局地和遥远系统产生了广泛影响。以往多数研究强调了格陵兰冰盖融水径流对全球气候、大西洋经向翻转环流以及海平面上升的影响。本研究聚焦于区域高分辨率北冰洋–海冰耦合模式中北冰洋海冰对格陵兰冰盖融水径流的季节性响应。研究发现，格陵兰冰盖融水径流引起拉布拉多海冬季海冰范围向南扩张。格陵兰冰盖融水径流导致北欧海秋季海冰增多、春夏季海冰减少。在北冰洋中部深海盆地区域，格陵兰冰盖融水径流导致夏季加拿大海盆海冰面积减少、欧亚海盆和馬卡罗夫海盆海冰面积增加，而加拿大海盆海冰体积全年减少、欧亚海盆和馬卡罗夫海盆海冰体积在冬季至夏季增加。研究表明，在北极放大背景下，格陵兰冰盖融水径流预计将增加。本项工作表明，未来格陵兰南部海岸的格陵兰冰盖融水径流可能快速且强烈地影响加拿大海盆海冰。

28. JPO — Ice Pumping: Influence of Ice Thickness Gradients on the Arctic Ocean Circulation

Abstract

Abstract Surface currents beneath sea ice are influenced by ice thickness in much the same way bottom currents are influenced by bathymetry. Despite the gentle slope of the ice cover—only a few meters over thousands of kilometers—surface currents on the order of a few centimeters per second generate vertical velocities of a few meters per year, which are the same order of magnitude as the surface Ekman pumping. We dub this vertical velocity “ice pumping.” Using theory and numerical modeling, we show that this ice pumping exerts a first-order control on both the structure and intensity of the large-scale Arctic Ocean circulation. We find that the dominant effect is the generation of a basin-scale anticyclonic circulation anomaly, forced by the interaction of the Transpolar Drift Current with the overlying sea ice that grows thicker toward Greenland. The most notable consequence is a shift of the Transpolar Drift Current itself toward the Eurasian coast and a modulation of the intensity of the large-scale circulation. Ice pumping should therefore be considered alongside Ekman pumping, mesoscale eddies, and the ice–ocean governor as a fundamental constraint on Arctic circulation and is likely to be important in other scenarios, such as underneath ice shelves and on ice-covered exoplanets.

中文摘要

摘要 海冰下的表面流受冰厚影响的方式与底层流受水深地形影响的方式大致相同。尽管冰盖坡度平缓——在数千公里范围内仅数米——但量级为每秒几厘米的表面流会产生每年数米的垂向速度，这与表面Ekman抽吸的量级相同。我们将这一垂向速度称为“冰抽吸”。利用理论和数值模拟，我们表明这种冰抽吸对北冰洋大尺度环流的结构和强度均具有一阶控制作用。我们发现，其主要效应是产生一个盆地尺度的反气旋环流异常，该异常由Transpolar Drift Current与向Greenland方向逐渐增厚的上覆海冰之间的相互作用所驱动。最显著的后果是Transpolar Drift Current本身向Eurasian海岸的偏移以及大尺度环流强度的调制。因此，冰抽吸应与Ekman抽吸、中尺度涡旋以及冰-海洋调节器一并被视为北极环流的基本约束因素，并且很可能在其他情形中同样重要，例如冰架之下以及被冰覆盖的系外行星上。

29. JC — The interannual variability of the day-night compound hot days in the Yangtze River Basin: dynamic origins and seasonal predictability

Abstract

Abstract Day-night compound hot days (CHDs) poses substantially greater risks to human health, ecosystems, and socioeconomic systems than that heat extremes occurring only during the day or night. Here, we investigate the spatiotemporal characteristics, physical mechanisms, and seasonal predictability of CHDs within the Yangtze River Basin (YRB), a recognized hotspot for CHDs in China. We show that CHDs are primarily associated with a local anomalous barotropic high-pressure/anticyclone, which is jointly influenced by a La Niña-like sea surface temperature pattern in the Pacific and a positive sea level pressure tendency over the North Atlantic through distinct atmospheric teleconnections. Based on these two physically interpretable ocean-atmosphere precursors, we develop a physics-based empirical model using data from 1980 to 2010. During the independent validation period of 2011–2022, the model exhibits substantial prediction skill, with a temporal correlation coefficient of 0.67. Nevertheless, it markedly underestimates the record-breaking CHDs in 2022. A comparison with 2013, when the second-highest CHDs was successfully predicted, revealed that land-atmosphere interactions, including the soil moisture-temperature positive feedback and the cloud-water vapor warming effects in the YRB, significantly amplified the CHDs in 2022. Because these land-atmosphere processes are not represented in the model, the exceptional severity of the 2022 CHDs is underestimated.

中文摘要

摘要 昼夜复合高温日（CHDs）对人类健康、生态系统和社会经济系统构成的风险远高于仅发生在白天或夜间的高温极端事件。本文研究了长江流域（YRB）——中国公认的CHDs热点区域——CHDs的时空特征、物理机制及季节可预测性。研究表明，CHDs主要与局地异常正压高压/反气旋相关，该异常受到太平洋类La Niña海表温度型态和北大西洋海平面气压正趋势通过不同大气遥相关过程的共同影响。基于这两个具有物理可解释性的海洋-大气前兆因子，我们利用1980年至2010年的数据建立了一个基于物理的经验模型。在2011—2022年的独立验证期内，该模型表现出显著的预测技巧，时间相关系数为0.67。然而，该模型明显低估了2022年破纪录的CHDs。与2013年（当年第二高的CHDs被成功预测）的对比表明，陆-气相互作用，包括长江流域的土壤湿度-温度正反馈以及云-水汽增温效应，显著放大了2022年的CHDs。由于这些陆-气过程未在模型中体现，2022年CHDs的极端严重程度被低估。

30. GRL — Relative Sea Surface Temperature Regulates Tropical Cyclone Size‐Intensity Evolution Through Convective Features

Abstract

Abstract Relative sea surface temperature (SST), defined as local SST minus the tropical mean, is linked to tropical cyclone (TC) size growth, but its role in coupled size‐intensity evolution remains unclear. Using 23 years of global observations, we show that relative SST regulates very deep convection (infrared brightness temperature <208K), thereby modulating both TC intensification and size expansion. Across all intensity categories, convective areal extent increases systematically with relative SST. Higher relative SST enhances inner core convective coverage and expands the radial extent of very deep convection. For storms with similar incipient sizes, higher relative SST accelerates size expansion at a given intensification rate. Relative SST affects the peak intensity a storm can achieve, while peak size depends on both relative SST and incipient size. These findings identify relative SST as an important control on TC size–intensity evolution and highlight the influence of remote SST on TC development.

中文摘要

相对海表温度（SST）定义为局地SST减去热带平均值，其与热带气旋（TC）尺度增长相关联，但其在尺度-强度耦合演变中的作用仍不明确。利用23年全球观测资料，我们表明相对SST调控极深对流（红外亮温<208K），进而调制TC的增强和尺度扩张。在所有强度类别中，对流面积范围随相对SST系统性增大。较高的相对SST增强内核对流覆盖率并扩展极深对流的径向范围。对于初始尺度相近的风暴，在给定增强速率下，较高的相对SST加速尺度扩张。相对SST影响风暴所能达到的峰值强度，而峰值尺度取决于相对SST和初始尺度两者。这些发现将相对SST确定为TC尺度-强度演变的重要控制因子，并凸显了远场SST对TC发展的影响。

31. GRL — Nonlinear Release of Subinertial Diurnal Internal Tides Forms Spiral Internal Solitary Waves

Abstract

Abstract Earth’s rotation imposes a dynamical barrier on the free propagation of internal tides at high latitudes, raising questions about the fate of tidal energy poleward of the critical latitude. Satellite observations reveal spiral internal solitary waves (ISWs) along the continental slope of the South Orkney Plateau. Although these waves might be attributed to direct steepening of low‐frequency internal tides, theoretical estimates of their propagation speed are nearly twice those inferred from observations. Using high‐resolution simulations, we resolve this inconsistency by identifying a topographically steered energy cascade: subinertial diurnal internal tides, initially trapped by the slope, undergo nonlinear evolution that generates superinertial harmonics. This frequency upshift allows tidal energy to surpass rotational constraints, radiate offshore, and ultimately evolve into the spiral ISWs. These results identify a distinct energy cascade pathway for internal wave dynamics in polar oceans and demonstrate how tidal energy can be redistributed despite rotational limitations.

中文摘要

摘要 地球自转对高纬度内潮的自由传播施加了动力学障碍，引发了关于临界纬度以极地潮汐能量去向的疑问。卫星观测揭示了沿南奥克尼高原大陆坡的螺旋内孤立波（ISWs）。尽管这些波可能被归因于低频内潮的直接陡化，但其传播速度的理论估算值几乎是观测推断值的两倍。利用高分辨率模拟，我们通过识别一种地形引导的能量级联解决了这一不一致：最初被斜坡捕获的亚惯性全日内潮经历非线性演化，生成超惯性谐波。这种频率上移使潮汐能量能够超越旋转约束，向外辐射，并最终演化为螺旋内孤立波。这些结果揭示了极地海洋内波动力学的一条独特能量级联路径，并展示了潮汐能量如何在旋转限制下仍能重新分布。

32. GRL — Record‐Breaking Humid Heat in Northern China During Summer 2025 Driven by Kuroshio–Oyashio Extension SST Anomalies

Abstract

Abstract A record‐breaking humid‐heat event occurred over northern China during 24 June–13 July 2025, characterized by persistent extreme wet‐bulb temperatures. The event is associated with a strong and persistent positive geopotential height anomaly, which favors the accumulation of heat and moisture. Further analyses reveal that warm sea surface temperature (SST) anomalies over the Kuroshio–Oyashio Extension (KOE) enhance upward turbulent heat fluxes, reducing lower‐tropospheric meridional temperature gradients and baroclinicity, and suppressing transient eddy activity. The associated reduction in transient eddy vorticity forcing favors positive geopotential height anomalies over the KOE, providing a dynamically consistent pathway linking SST anomalies to the large‐scale circulation. Sensitivity experiments with the Community Atmosphere Model version 5 (CAM5) reproduce the key circulation response. These results suggest that KOE SST anomalies likely contributed to the development of this extreme humid‐heat event by shaping a favorable anomalous circulation background.

中文摘要

2025年6月24日至7月13日，中国北方发生了一次破纪录的湿热事件，以持续性极端湿球温度为特征。该事件与一次强盛且持续的正位势高度异常相关联，有利于热量和水汽的积聚。进一步分析表明，Kuroshio–Oyashio Extension（KOE）区域的海表温度（SST）正异常增强了向上的湍流热通量，减小了低层对流层经向温度梯度和斜压性，并抑制了瞬变涡旋活动。与之相关的瞬变涡旋涡度强迫减弱有利于KOE上空的正位势高度异常，从而提供了一条将SST异常与大尺度环流联系起来的动力学一致的路径。利用Community Atmosphere Model version 5（CAM5）进行的敏感性试验再现了关键的环流响应。这些结果表明，KOE的SST异常可能通过塑造有利的异常环流背景，促进了此次极端湿热事件的发展。

33. GRL — Divergent Influences of Oceanic Western Boundary Currents on Weak and Strong Tropical Cyclones

Abstract

Abstract Tropical cyclones (TCs) in the Northern Hemisphere often cross oceanic western boundary currents (WBCs), yet how these warm currents modulate TC intensity remains unclear. We analyze TCs traversing the Kuroshio and Gulf Stream during 1993–2025 and find that weak TCs respond more favorably than strong TCs. Weak TCs crossing WBCs before their lifetime maximum intensity (LMI) strengthen by 30.9% and intensify faster than in the preceding stage, whereas those crossing after LMI weaken by only 13.2%, exhibiting slower decay. In contrast, strong TCs generally weaken over WBCs. These contrasting responses arise from differences in latent heat flux modulated by TC‐induced SST cooling. Over the past three decades, WBC modulation has strengthened for weak TCs but weakened for strong TCs. These trends are linked to WBC upper‐ocean warming and rising strong‐TC intensity at WBC entry, respectively. Our findings highlight the growing role of WBC thermal conditions for coastal TC intensity prediction.

中文摘要

摘要 北半球的热带气旋（TC）经常穿越海洋西边界流（WBC），然而这些暖流如何调制热带气旋强度仍不清楚。我们分析了1993—2025年间穿越黑潮和湾流的热带气旋，发现弱热带气旋比强热带气旋响应更为有利。在生命史最大强度（LMI）之前穿越西边界流的弱热带气旋强度增加30.9%，且增强速度快于前一阶段，而在LMI之后穿越的弱热带气旋仅减弱13.2%，表现出较慢的衰减。相比之下，强热带气旋在西边界流上总体减弱。这些相反的响应源于热带气旋引起的海表温度冷却所调制的潜热通量差异。过去三十年间，西边界流对弱热带气旋的调制作用增强，而对强热带气旋的调制作用减弱。这些趋势分别与西边界流上层海洋增暖及强热带气旋进入西边界流时强度的上升相关联。我们的研究结果凸显了西边界流热力条件在沿岸热带气旋强度预测中日益重要的作用。

34. GRL — Unprecedented Open‐Ocean Polynya in Breid Bay, East Antarctica in Winter 2024

  • 作者：Jeebanjyoti Swain, Babula Jena, Kshitija Suryawanshi, Ashwita Chouksey, S. Kashaboina, C. C. Bajish, Sourav Chatterjee, Rahul Mohan, Meloth Thamban
  • 发表日期：2026-09-27
  • DOI：https://doi.org/10.1029/2026gl122580

Abstract

Abstract We document an unprecedented winter open‐ocean polynya in the Breid Bay, on 4 August 2024, attaining a maximum area of 89,121 km 2 . Prior to opening, sea‐ice concentration declined from ∼96% in early July to below 25% by 30 July 2024, indicating substantial preconditioning of the winter ice cover. The polynya formation was driven by integrated impact of six intense atmospheric rivers (ARs) during July‐August 2024, which generated extreme (>99th percentile) poleward moisture transport (>600 kg m −1 s −1 ), northerly winds, downwelling longwave radiation, atmospheric heatwaves with anomalous warming (∼19°C), increased snowfall (∼0.9 mm w.e. day −1 ), and large heat fluxes (∼97 W m −2 ), that hindered sea‐ice growth. Concurrently, Ekman suction–driven upwelling and enhanced eddy kinetic energy contributed to upper‐ocean warming (∼0.6°C) and sustained marine heatwaves, thereby increasing the ocean‐to‐ice heat flux. The repeated passage of extreme ARs and enhanced oceanic heat supply collectively facilitated the formation of the polynya.

中文摘要

摘要 我们记录了2024年8月4日在Breid Bay出现的一次前所未有的冬季开阔大洋冰间湖，其最大面积达到89,121 km²。在冰间湖形成之前，海冰密集度从7月初的约96%下降至2024年7月30日的不足25%，表明冬季冰盖经历了显著的前期预处理。冰间湖的形成由2024年7—8月期间六次强大气河（ARs）的综合影响所驱动，这些大气河产生了极端（>第99百分位）的向极水汽输送（>600 kg m⁻¹ s⁻¹）、偏北风、向下长波辐射、异常增温约19°C的大气热浪、增加的降雪（约0.9 mm水当量 day⁻¹）以及大热通量（约97 W m⁻²），从而抑制了海冰增长。与此同时，Ekman抽吸驱动的上升流和增强的涡动能促进了上层海洋增暖（约0.6°C）并维持了海洋热浪，进而增加了海洋向冰的热通量。极端大气河的反复过境与增强的海洋热量供给共同促成了该冰间湖的形成。

35. GRL — The Role of ENSO Phase Transition in the Delayed North Atlantic Oscillation Response

Abstract

Abstract The El Niño–Southern Oscillation (ENSO) is the dominant mode of interannual variability in the Earth system, exerting profound influences on global weather and climate. One notable impact is its ability to generate a dipole‐like sea level pressure anomaly pattern over the North Atlantic, resembling the North Atlantic Oscillation (NAO), with El Niño (La Niña) corresponding to a concurrent negative (positive) NAO‐like response during late boreal winter. Recent research further suggests that ENSO can induce an opposite‐phase NAO response in the following winter. Through observational analysis and atmospheric model experiments, we demonstrate that the delayed positive NAO‐like response following El Niño is likely linked to the ENSO cycle, specifically the transition from El Niño to La Niña. Without this phase transition, the reversal of the North Atlantic response 1 year later largely diminishes. This finding highlights the important role of tropical ocean in shaping long‐range climate predictability.

中文摘要

摘要 厄尔尼诺-南方涛动（ENSO）是地球系统中年际变率的主导模态，对全球天气和气候产生深远影响。其显著影响之一是在北大西洋上空生成类似偶极型的海平面气压异常型态，类似于北大西洋涛动（NAO），其中厄尔尼诺（拉尼娜）对应北半球晚冬期间同时出现的负（正）NAO型响应。近期研究进一步表明，ENSO可在随后冬季引发反相的NAO响应。通过观测分析和大气模式试验，我们证明厄尔尼诺之后延迟出现的正NAO型响应很可能与ENSO循环有关，特别是从厄尔尼诺向拉尼娜的转变。若无此位相转变，1年后北大西洋响应的反转在很大程度上减弱。这一发现凸显了热带海洋在塑造长期气候可预报性中的重要作用。

36. GRL — Iceberg Freshwater Transport Alleviates Future Weakening of Antarctic Bottom Water Formation

Abstract

Abstract Intensification of calving in a warmer future climate would result in production of more Antarctic icebergs, and iceberg freshwater flux would play a more consequential role in ice‐climate interactions. Distribution of iceberg freshwater flux under future climate scenarios, however, has not been assessed with full consideration of changes and uncertainties in climate conditions and calving rates. Here we drive an iceberg model with output from an ice sheet model and five climate models to simulate iceberg freshwater flux under an intensive future warming scenario. Results show that Antarctic iceberg freshwater flux increases markedly and may exceed ice shelf basal melting. Iceberg freshwater exported to the open ocean is governed by competing effects from atmospheric‐oceanic warming and changes in winds and currents. Simulations consistently show an increase in the portion of iceberg freshwater exported beyond Antarctic continental shelves, which may alleviate the future weakening of Antarctic Bottom Water formation.

中文摘要

摘要 在未来更暖气候下，崩解作用的增强将导致更多南极冰山产生，而冰山淡水通量在冰-气候相互作用中将发挥更为重要的作用。然而，未来气候情景下冰山淡水通量的分布尚未在充分考虑气候条件和崩解速率变化及其不确定性的情况下得到评估。本研究以冰盖模式和五个气候模式的输出驱动冰山模型，模拟在强烈未来增暖情景下的冰山淡水通量。结果表明，南极冰山淡水通量显著增加，并可能超过冰架底部融化量。输出至开阔大洋的冰山淡水受大气-海洋增暖与风场和流场变化的竞争性效应所控制。各模拟一致显示，输出至南极大陆架以外的冰山淡水比例增加，这可能缓解未来南极底层水形成的减弱。

37. JC — Combined Effects of Annual Cycle and ENSO on Tropical Cyclone Genesis over the Western North Pacific

Abstract

Abstract El Niño–Southern Oscillation (ENSO) is important to the interannual variability of tropical cyclone (TC) genesis in the western North Pacific (WNP). However, the mechanisms for the TC seasonal changes in ENSO developing phase remain unclear. This study addresses the critical influences of the background sea surface temperature (SST) annual cycle and ENSO-related SST anomalies (SSTAs) in regulating TC genesis seasonal changes. The results show that during eastern Pacific (EP) El Niño years, TC genesis increases in the southeastern WNP and decreases in the northwest in summer, while in autumn, TC genesis strengthens in the east and weakens in the west. For central Pacific (CP) El Niño events, basinwide enhancement occurs in summer, with a southeast–northwest contrast in fall, whereas La Niña developing years exhibit nearly opposite patterns. These variations arise from anomalous convection generated by the combination of warm background SST annual cycle and ENSO SSTA, which modify large-scale conditions for TC genesis. Background SST can also strengthen ENSO evolution via the Bjerknes feedback, amplifying circulation impacts. This work provides a new perspective on the critical role of background SST annual cycle in shaping the ENSO–TC relationship, which is potentially helpful for improving seasonal TC prediction over the WNP.

中文摘要

摘要 厄尔尼诺–南方涛动（ENSO）对西北太平洋（WNP）热带气旋（TC）生成的年际变率具有重要影响。然而，ENSO发展期TC季节变化的机制仍不清楚。本研究探讨了背景海表温度（SST）年循环和ENSO相关海表温度异常（SSTA）在调控TC生成季节变化中的关键影响。结果表明，在东太平洋（EP）厄尔尼诺年，夏季WNP东南部TC生成增加而西北部减少，秋季则东部TC生成增强而西部减弱。对于中太平洋（CP）厄尔尼诺事件，夏季呈现全海盆增强，秋季则表现为东南–西北偶极对比，而拉尼娜发展年则呈现近乎相反的模态。这些变化源于暖背景SST年循环与ENSO SSTA共同作用产生的异常对流，其改变了大尺度TC生成条件。背景SST还可通过Bjerknes反馈增强ENSO演变，放大环流影响。本研究为背景SST年循环在塑造ENSO–TC关系中关键作用提供了新视角，有望为改进WNP季节TC预测提供参考。

38. JC — Enhanced Teleconnections of Maritime Continent Deforestation on North Pacific Climate during La Niña Conditions

Abstract

Abstract This study investigates how deforestation in the Maritime Continent (MC) modulates extratropical atmospheric circulation over the North Pacific during different phases of El Niño–Southern Oscillation (ENSO). By analyzing ensemble idealized deforestation experiments, the research reveals a distinct modulation effect based on the ENSO phase. During El Niño, an elongated subtropical jet stream acts as a waveguide, confining deforestation-induced atmospheric waves, which leads to a flattened Aleutian low over the North Pacific and reduced impacts on North America. Conversely, during La Niña, the contracted subtropical jet allows these waves to propagate toward higher latitudes, where deforestation in the MC triggers a Pacific–North American (PNA)-like pattern and causing significant warming in North America. Linear baroclinic model experiments highlight the sensitivity of the extratropical atmospheric response to MC deforestation, particularly over New Guinea, emphasizing the regional dependency of this sensitivity. These findings suggest that deforestation in the MC may have broader impacts on higher latitudes, particularly during La Niña years or under future global warming scenarios that could favor prolonged or multiyear La Niña conditions. Significance Statement This study uncovers the significant influence of Maritime Continent (MC) deforestation on extratropical atmospheric circulation, particularly over the North Pacific, with effects that vary depending on the phase of El Niño–Southern Oscillation (ENSO). By demonstrating how deforestation-induced atmospheric waves interact differently with the atmospheric jet streams during El Niño and La Niña phases, the research highlights the potential for MC deforestation to drive substantial climatic changes in higher latitudes, especially under La Niña conditions. These findings underscore the broader implications of regional land-use changes on global climate patterns, offering critical insights for future climate projections and mitigation strategies.

中文摘要

摘要 本研究探讨了在厄尔尼诺-南方涛动（ENSO）不同位相下，海洋大陆（MC）森林砍伐如何调制北太平洋中纬度大气环流。通过分析集合理想化森林砍伐试验，研究揭示了基于ENSO位相的显著调制效应。在厄尔尼诺期间，一条拉长的副热带急流充当波导，将森林砍伐引起的大气波限制在一定范围内，导致北太平洋阿留申低压趋于平缓，对北美的影响减弱。相反，在拉尼娜期间，收缩的副热带急流允许这些波向高纬度传播，海洋大陆的森林砍伐在此触发类太平洋-北美（PNA）型遥相关模式，并导致北美显著增暖。线性斜压模式试验凸显了中纬度大气响应对海洋大陆森林砍伐的敏感性，尤其是在新几内亚上空，强调了这种敏感性的区域依赖性。这些发现表明，海洋大陆的森林砍伐可能对高纬度地区产生更广泛的影响，特别是在拉尼娜年份或未来全球变暖情景下——这些情景可能有利于拉尼娜状态的延长或多年度拉尼娜条件的形成。意义声明 本研究揭示了海洋大陆（MC）森林砍伐对中纬度大气环流的显著影响，尤其是在北太平洋上空，其效应随厄尔尼诺-南方涛动（ENSO）位相的不同而变化。通过展示森林砍伐引起的大气波在厄尔尼诺和拉尼娜位相期间与大气急流的差异性相互作用，研究凸显了海洋大陆森林砍伐驱动高纬度地区重大气候变化的潜力，尤其是在拉尼娜条件下。这些发现强调了区域土地利用变化对全球气候模式的更广泛影响，为未来气候预估和减缓策略提供了关键见解。

39. JC — Teleconnections and Topography: How Snowpack Prediction Using Sea Surface Temperature Varies within the Colorado Rocky Mountains

Abstract

Abstract Mountain snowpack in the western United States can be difficult to predict multiple months in advance, especially within the Colorado Rocky Mountains, where snowpack prediction varies widely by location and derives little skill from El Niño–Southern Oscillation (ENSO). Using a high-resolution snow water equivalent (SWE) depth reanalysis dataset, we investigate how seasonal snowpack prediction using sea surface temperature (SST) in the North Pacific and North Atlantic Oceans varies across prominent crests and valleys in the Colorado Rocky Mountains. Possible atmospheric mechanisms are proposed to explain SST patterns associated with enhanced SWE using self-organizing maps. We find that southern areas of the domain receive significant prediction skill from SSTs within a portion of the tropical North Atlantic and that this SST pattern is associated with the frequency of surface cyclone passages southwest of the domain. Northern areas, by contrast, receive significant prediction skill from SSTs further north in the North Atlantic—an SST pattern related to the strength of the North Pacific high. Prediction skill increases from west to east, where a larger fraction of snow accumulation events coincides with the passage of surface cyclones. A forecast experiment is constructed using December SSTs to predict 1 April SWE, which produces an average correlation of 0.51 between predicted and observed SWE across the domain and a maximum correlation of 0.75 on the eastern slope of the Colorado Front Range for the years analyzed. This promising result highlights the potential to predict snowpack in small mountain watersheds more accurately, which may benefit water management in these locations.

中文摘要

摘要 美国西部的山地积雪可能难以提前数月进行预测，尤其是在科罗拉多落基山脉地区，该地区积雪预测因地点不同而差异显著，且从厄尔尼诺-南方涛动（ENSO）中获得的预测技巧甚微。利用高分辨率雪水当量（SWE）深度再分析数据集，我们研究了利用北太平洋和北大西洋海表温度（SST）进行季节性积雪预测在科罗拉多落基山脉各主要山脊和河谷之间的差异。我们利用自组织映射提出了可能的大气机制，以解释与SWE增强相关的SST型态。我们发现，该区域南部地区从热带北大西洋部分区域的SST中获得了显著的预测技巧，且该SST型态与该区域西南方向的地面气旋过境频率相关。相比之下，北部地区从北大西洋更北处的SST中获得了显著的预测技巧——该SST型态与北太平洋高压的强度相关。预测技巧从西向东递增，东部有更大比例的积雪累积事件与地面气旋过境同时发生。我们构建了一个预报试验，利用12月SST预测4月1日SWE，在所分析的年份中，该试验在整个区域内产生的预测SWE与观测SWE之间的平均相关系数为0.51，在科罗拉多前山山脉东坡的最大相关系数为0.75。这一有前景的结果凸显了更准确预测小型山地流域积雪的潜力，这可能有利于这些地点的水资源管理。

40. JC — Vertical Structure of the High-Level Cross-Equatorial Flow and Response to ENSO in Boreal Summer

Abstract

Abstract Cross-equatorial flow (CEF) represents a fundamental atmospheric phenomenon in the tropical troposphere. While low-level CEF (LCEF) has been extensively studied, the understanding of high-level CEF (HCEF) remains insufficient. Based on three reanalysis datasets [fifth generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis (ERA5), Japanese 55-yr Reanalysis (JRA-55), and Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2)] and CMIP6 models, this study conducts a comprehensive analysis of HCEF, including its vertical structure, multiple time scale variabilities, and relationship with El Niño–Southern Oscillation (ENSO). The results indicate that HCEF has four primary channels located over the eastern Pacific, the Atlantic, West Africa, and the Indian Ocean–Maritime Continent, respectively. While interannual variability of HCEF is relatively consistent across the datasets, substantial discrepancies exist in its decadal variability and trend. The linkage between HCEF and the underlying LCEF exhibits dataset dependence and channel difference at interannual scales. The eastern Pacific HCEF (EPHCEF) is directly modulated by two types of ENSO due to sea surface temperature anomalies that excite anomalous convection, which in turn modifies patterns of upper-tropospheric convergence and divergence, thereby driving HCEF anomalies. During eastern Pacific (EP) ENSO events, Atlantic HCEF (ALHCEF) and West Africa HCEF (WAHCEF) exhibit significant interannual variability through a physical process similar to that affecting EPHCEF. Statistical analysis suggests that the Atlantic Niño is more likely to be the primary driver of their variability compared with ENSO. The simulation results of CMIP6 for eastern Pacific ENSO are similar to those of the reanalysis datasets but show systematic biases for central Pacific (CP) ENSO. These findings significantly advance our understanding of the tropical upper-tropospheric circulation.

中文摘要

摘要 跨赤道流（CEF）是热带对流层中的一种基本大气现象。尽管低层跨赤道流（LCEF）已得到广泛研究，但对高层跨赤道流（HCEF）的认识仍不充分。基于三套再分析数据集[第五代欧洲中期天气预报中心大气再分析（ERA5）、日本55年再分析（JRA-55）以及现代时代回顾性分析研究与应用第2版（MERRA-2）]和CMIP6模式，本研究对HCEF进行了综合分析，包括其垂直结构、多时间尺度变率及其与厄尔尼诺-南方涛动（ENSO）的关系。结果表明，HCEF有四个主要通道，分别位于东太平洋、大西洋、西非和印度洋-海洋性大陆上空。尽管HCEF的年际变率在各数据集之间相对一致，但其年代际变率和趋势存在显著差异。HCEF与其下方LCEF之间的联系在年际尺度上表现出数据集依赖性和通道差异性。东太平洋HCEF（EPHCEF）直接受到两类ENSO的调制，其机制为海表温度异常激发异常对流，进而改变对流层上层辐合辐散格局，从而驱动HCEF异常。在东太平洋（EP）ENSO事件期间，大西洋HCEF（ALHCEF）和西非HCEF（WAHCEF）通过与影响EPHCEF相似的物理过程表现出显著的年际变率。统计分析表明，与ENSO相比，大西洋尼诺更可能是其变率的主要驱动因素。CMIP6对东太平洋ENSO的模拟结果与再分析数据集相似，但对中太平洋（CP）ENSO表现出系统性偏差。这些发现显著推进了我们对热带对流层上层环流的认识。

41. JC — Tropical Teleconnection Influences on Decadal Trends in West Antarctic Surface Mass Balance

Abstract

Abstract The surface mass balance (SMB) of the Antarctic Ice Sheet is a critical factor influencing global mean sea level rise and has substantial implications for future projections of sea level rise. In recent decades, the Antarctic Ice Sheet SMB trends show pronounced regional disparities, marked by a decrease over the western part but an increase over the eastern part of West Antarctica. Through a synthesis of ice core records and five reanalysis datasets, as well as atmospheric dynamics analysis and numerical model simulations, we demonstrate that the multidecadal trends in tropical sea surface temperature are key drivers of the dipole-like SMB trends in West Antarctica. Specifically, the eastern tropical Pacific cooling associated with the phase changes of the interdecadal Pacific oscillation (IPO) and the tropical Atlantic warming associated with the Atlantic multidecadal oscillation (AMO) can modulate tropical convection and latent-heating anomalies, thereby stimulating Rossby wave trains propagating to West Antarctica, resulting in the contrasting moisture divergence and precipitation changes between the western and eastern parts of West Antarctica. In particular, the statistical analysis and model simulations clarify the seasonality of these teleconnections. Both the Pacific and Atlantic contribute to the dipole-like SMB pattern during austral spring and autumn, while the Pacific is the major contributor during austral summer. Our findings have broad implications for understanding the recent observed SMB trends as well as future projections of Antarctic SMB changes and consequent global sea level rise.

中文摘要

摘要 南极冰盖的表面质量平衡（SMB）是影响全球平均海平面上升的关键因素，并对未来海平面上升的预估具有重大意义。近几十年来，南极冰盖SMB趋势呈现出显著的区域差异，其特征为西南极西部减少而东部增加。通过综合冰芯记录与五个再分析数据集，并结合大气动力学分析和数值模式模拟，我们证明热带海表温度的多年代际趋势是西南极偶极型SMB趋势的关键驱动因子。具体而言，与年代际太平洋振荡（IPO）位相变化相关的东热带太平洋冷异常，以及与北大西洋多年代际振荡（AMO）相关的热带大西洋暖异常，能够调制热带对流和潜热异常，从而激发向西南极传播的Rossby波列，导致西南极西部与东部之间形成对比鲜明的水汽辐散和降水变化。特别是，统计分析及模式模拟阐明了这些遥相关的季节性特征。在澳大拉西亚春季和秋季，太平洋和大西洋均对偶极型SMB格局有所贡献，而在澳大拉西亚夏季，太平洋是主要贡献者。我们的发现对于理解近期观测到的SMB趋势以及南极SMB变化的未来预估和由此导致的全球海平面上升具有广泛的启示意义。

42. JC — Horseshoe Salinity Pattern in the Upper Indian Ocean and Its Decadal Variability

Abstract

Abstract Salinity plays a crucial role in the global hydrological cycle and climate system by regulating upper-ocean stratification and sea surface temperature (SST). Past studies have revealed the dynamics of salinity variation in the world’s major ocean basins and its linkage to global climate on interannual-to-decadal time scales. However, understanding of upper-ocean salinity variability in the Indian Ocean, especially on decadal time scale and its global implications, remains limited. This study identifies a prominent horseshoe salinity pattern (HSP), present in the Indian Ocean, extending from the surface to 150-m depth. It exhibits pronounced decadal variability and is closely associated with SST variability in the southeastern Indian Ocean (SEIO) with a lag of ∼18 months. Composite maps and a sea surface salinity budget analysis reveal that SST anomalies in the SEIO region modulate the local Walker and Hadley circulation anomaly causing variation in the precipitation pattern. These changes drive upper-ocean freshening or salinification, producing the observed HSP. Advection contributes regionally to salinity variability, particularly in the southern Indian Ocean, but does not play a dominant role in shaping the coherent HSP structure. Further, this pattern modulates upper-ocean stratification, leading to the development of SST anomalies in the western tropical Indian Ocean. These findings offer novel insight into the Indian Ocean salinity dynamics, highlighting the role of SST–salinity coupling, and have the potential for improving predictions of decadal climate variability and its global implications. Significance Statement Given the growing focus on decadal climate prediction and the critical role of salinity in global climate, understanding the decadal-scale variability in upper-ocean salinity is important. While past research has focused on sea surface salinity changes in the tropical Indian Ocean, subsurface salinity variability on decadal time scales remains poorly understood. This study uncovers a horseshoe salinity pattern in the upper Indian Ocean up to 150 m, driven by precipitation anomalies linked to southeastern Indian Ocean SST variations. Further, this pattern affects the upper-ocean stratification and causes SST anomalies in the western tropical Indian Ocean. These findings fill a major knowledge gap in Indian Ocean salinity dynamics and have direct implications to improve decadal climate prediction and model evaluation.

中文摘要

摘要 盐度通过调控上层海洋层结和海表温度（SST），在全球水文循环与气候系统中发挥着至关重要的作用。已有研究揭示了全球主要大洋盆地的盐度变化动力学及其在年际至年代际时间尺度上与全球气候的联系。然而，对于印度洋上层海洋盐度变率的认识，尤其是在年代际时间尺度上及其全球影响方面，仍然十分有限。本研究识别出印度洋中存在一种显著的马蹄形盐度模态（HSP），从表层延伸至150 m深度。该模态表现出显著的年代际变率，并与东南印度洋（SEIO）的SST变率密切相关，滞后约18个月。合成图和海表盐度收支分析表明，SEIO区域的SST异常调制了局地Walker环流和Hadley环流异常，从而引起降水格局的变化。这些变化驱动了上层海洋的淡化或盐化，产生了所观测到的HSP。平流在区域尺度上对盐度变率有贡献，尤其是在南印度洋，但在形成连贯的HSP结构方面并未起主导作用。此外，该模态调制了上层海洋层结，导致西热带印度洋SST异常的发展。这些发现为印度洋盐度动力学提供了新的认识，突出了SST–盐度耦合的作用，并具有改进年代际气候变率预测及其全球影响的潜力。意义声明 鉴于年代际气候预测日益受到关注以及盐度在全球气候中的关键作用，理解上层海洋盐度的年代际尺度变率十分重要。尽管过去的研究主要集中于热带印度洋的海表盐度变化，但年代际时间尺度上的次表层盐度变率仍然认识不足。本研究揭示了印度洋上层至150 m深度的一种马蹄形盐度模态，其由与东南印度洋SST变化相关的降水异常所驱动。此外，该模态影响上层海洋层结，并引起西热带印度洋的SST异常。这些发现填补了印度洋盐度动力学中的重大知识空白，并对改进年代际气候预测和模式评估具有直接意义。

43. JC — Seasonal Variations in the MJO Propagation and Decay over the Maritime Continent owing to Background Circulation and Modulation by ENSO

Abstract

Abstract Some Madden–Julian oscillation (MJO) events maintain enhanced convection over the Maritime Continent and propagate into the western Pacific, whereas others weaken near the Maritime Continent. Using satellite-derived outgoing longwave radiation and reanalysis, we identify MJO events during October–April 1985/86–2020/21 and examine monthly variability from November through April. Events are classified by the amplitude of 20–100-day intraseasonal convection over the Maritime Continent into propagating (P type) and decaying (D type) categories. D-type events peak in November, whereas P-type events prevail in January–February. This seasonal cycle accompanies a southward shift of the MJO track. In January–February, the track is often confined to the southern Maritime Continent and northern Australia, limiting interaction with Maritime Continent topography and its barrier effect. Background-state (>100 days) composites show stronger P–D differences in November and weaker differences in January–February. In November, P-type events are accompanied by stronger 850-hPa westerlies, larger precipitable water over the western and central Pacific, and an eastward shift of the ascending branch of the Walker circulation along the MJO path. The El Niño–Southern Oscillation (ENSO) stratification shows that, in November, P-type events occur more often during El Niño, whereas D-type events occur more often during La Niña. This ENSO dependence is consistent with the eastward-shifted Walker circulation ascent during P-type events relative to D-type events. The separation is largest when ENSO is defined by Niño-4 sea surface temperature (SST) anomalies. These results indicate that ENSO-related modulation of the background circulation contributes to whether November MJO events maintain convection across the Maritime Continent. Significance Statement The Madden–Julian oscillation (MJO) is a 30–90-day pulse of rainfall and winds that affects weather beyond the tropics. Over the Maritime Continent (the archipelagic region between the Indian and Pacific Oceans), some MJO events propagate into the western Pacific, while others decay. The fraction of decaying events peaks in November, when the MJO crosses the islands, but is low in January–February, when it tracks along northern Australia and interacts less with island topography. In November, propagating events occur with a moister atmosphere, stronger westerlies, and an eastward-shifted Walker circulation. MJO propagation in November is more frequent during El Niño and decays during La Niña, with these seasonal variations indicating that the background circulation is modulated by El Niño–Southern Oscillation.

中文摘要

摘要 部分Madden–Julian振荡（MJO）事件在海洋性大陆维持增强对流并传播至西太平洋，而另一些事件则在海洋性大陆附近减弱。利用卫星反演的向外长波辐射和再分析资料，我们识别了1985/86–2020/21年10月至4月期间的MJO事件，并考察了11月至4月的逐月变化。根据海洋性大陆上空20–100天季节内对流的振幅，将事件分为传播型（P型）和衰减型（D型）。D型事件在11月达到峰值，而P型事件在1–2月占主导。这一季节循环伴随着MJO路径的南移。在1–2月，路径通常局限于海洋性大陆南部和澳大利亚北部，限制了与海洋性大陆地形的相互作用及其屏障效应。背景态（>100天）合成显示，11月P–D差异较强，而1–2月差异较弱。在11月，P型事件伴随更强的850 hPa西风、西太平洋和中太平洋更大的可降水量，以及沿MJO路径的Walker环流上升支东移。El Niño–Southern Oscillation（ENSO）分层表明，在11月，P型事件更多发生在El Niño期间，而D型事件更多发生在La Niña期间。这种ENSO依赖性与此一致：相对于D型事件，P型事件期间Walker环流上升支东移。当ENSO以Niño-4海表温度（SST）异常定义时，这种分离最大。这些结果表明，ENSO相关的背景环流调制影响了11月MJO事件是否能在海洋性大陆维持对流。意义声明 Madden–Julian振荡（MJO）是一种30–90天的降水和风脉冲，其影响超出热带地区。在海洋性大陆（印度洋和太平洋之间的群岛区域），一些MJO事件传播至西太平洋，而另一些则衰减。衰减事件的比例在11月达到峰值，此时MJO穿越岛屿，但在1–2月较低，此时它沿澳大利亚北部移动，与岛屿地形的相互作用较少。在11月，传播型事件伴随更湿润的大气、更强的西风和东移的Walker环流。11月MJO传播在El Niño期间更为频繁，而在La Niña期间衰减，这些季节变化表明背景环流受到El Niño–Southern Oscillation的调制。

44. JC — South America Drought as a Precursor to Tropical Pacific Sea Surface Temperature Cooling

Abstract

Abstract South America has experienced notable drought conditions over recent decades. Concurrently, the adjacent tropical eastern Pacific has exhibited cooling anomalies in sea surface temperature (SST). Here, through observational analyses and climate model simulations, we reveal that terrestrial drought in central South America (CSA) acts as an emerging precursor to SST cooling in the tropical central–eastern Pacific (TCEP). Our statistical analysis identifies a robust lagged relationship whereby anomalous winter (December–February) TCEP SST cooling systematically follows reduced spring (March–May) CSA soil moisture. Employing diagnostic analyses of atmospheric and oceanic processes together with a hierarchy of climate models—including soil moisture sensitivity experiments, linear baroclinic model simulations, and fully coupled Earth system model experiments—we demonstrate a coherent mechanistic pathway in which reduced soil moisture in CSA triggers a subtropical-to-equatorial meridional precipitation dipole that disrupts Pacific zonal circulation, strengthens easterly trade winds, activates ocean–atmosphere feedbacks, and ultimately leads to cooling of TCEP SST in the subsequent winter. Our findings demonstrate a novel ocean–land–atmosphere coupling pathway modulating tropical Pacific variability, with significant implications for enhancing understanding of ocean–land–atmosphere interactions.

中文摘要

摘要 近几十年来，南美洲经历了显著的干旱状况。与此同时，相邻的热带东太平洋海表温度（SST）呈现出冷异常。本文通过观测分析和气候模式模拟，揭示南美洲中部（CSA）的陆地干旱是热带中-东太平洋（TCEP）海表温度冷化的一个新出现的先兆信号。我们的统计分析识别出一个稳健的滞后关系，即冬季（12月至2月）TCEP海表温度冷异常系统性地跟随春季（3月至5月）CSA土壤湿度的降低而出现。通过结合大气和海洋过程的诊断分析以及一系列气候模式——包括土壤湿度敏感性试验、线性斜压模式模拟和全耦合地球系统模式试验——我们展示了一条连贯的机制路径：CSA土壤湿度降低触发了一个副热带至赤道的经向降水偶极子，该偶极子扰乱了太平洋纬向环流，增强了东风信风，激活了海洋-大气反馈，并最终导致随后冬季TCEP海表温度的冷化。我们的研究结果揭示了一条调节热带太平洋变率的新颖的海洋-陆地-大气耦合路径，对于加深理解海洋-陆地-大气相互作用具有重要意义。

45. GRL — Thickness‐Dependent Thermodynamic Responses of Arctic Sea Ice to Extratropical Cyclones Based on MOSAiC Observations

Abstract

Abstract Extratropical cyclones strongly influence Arctic sea ice thermodynamics through episodic heat and moisture transport, yet their thickness‐dependent impacts remain poorly quantified. Using comprehensive observations from the Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC), we investigate how sea ice thickness (SIT) regulates thermodynamic responses during cyclones. Cyclone‐induced atmospheric perturbations propagate downward through the ice, and anomalies in conductive (), sensible (), latent (), and oceanic () heat fluxes at base all decrease with increasing SIT, indicating stronger responses in thinner ice. Among them, exhibits the strongest sensitivity to SIT, followed by , whereas and show weaker dependence because synoptic signals are progressively damped during downward propagation. These sensitivities are closely related to cyclone timing and intensity. Although cyclones exert limited immediate influence on basal ice growth, their cumulative effect during the ice growth season produces net warming of the ice, potentially favoring earlier melt onset.

中文摘要

摘要 温带气旋通过间歇性的热量和水汽输送，对北极海冰热力学产生强烈影响，然而其依赖于冰厚的效应仍缺乏定量评估。利用北极气候研究多学科漂流观测站（MOSAiC）的综合观测资料，我们研究了海冰厚度（SIT）如何调控气旋期间的热力学响应。气旋引起的大气扰动向下传播穿过冰层，底部传导热通量（）、感热通量（）、潜热通量（）及海洋热通量（）的异常均随SIT增大而减小，表明较薄冰层中的响应更强。其中，对SIT的敏感性最强，其次为，而和则表现出较弱的依赖性，因为天气尺度信号在向下传播过程中逐渐被阻尼。这些敏感性与气旋的发生时间和强度密切相关。尽管气旋对底部冰生长的直接影响有限，但其在冰生长季节的累积效应产生冰的净增温，可能有利于融冰提前开始。

46. GRL — Listening to Tsunami Waves Induced by Glacier Calving

Abstract

Abstract Processes at the ice–ocean interface play a central role in regulating the stability of marine‐terminating glaciers and ice sheets and drive ocean freshening and mixing. Iceberg calving—a mechanical loss of ice—generates ocean waves and promotes water‐mass exchange in glacierized bays. Here we show that calving and the resulting tsunami waves produce distinct audible airborne sounds that carry information on calving activity and wave properties. Directionality analysis of acoustic array measurements enables calving localization and tracking of tsunami–shoreline interactions. We further demonstrate that even single‐microphone recordings are sufficient to localize calving events using wave dispersion analysis. The rich information content of airborne sound, together with the accessibility, ease of use, and low cost of microphones, makes airborne acoustics a powerful tool for studying glacier–ocean interactions and potentially coastal wave‐energy and erosion dynamics worldwide.

中文摘要

摘要 冰–海界面过程在调控海洋性冰川与冰盖的稳定性方面发挥核心作用，并驱动海洋淡化与混合。冰山崩解——冰的机械损失——产生海洋波浪并促进冰川湾内的水团交换。本文表明，崩解及其引发的海啸波会产生独特的可听空气声，这些声音携带有关崩解活动和波浪特性的信息。对声学阵列测量的方向性分析能够实现崩解定位以及海啸–岸线相互作用的追踪。我们进一步证明，即使单麦克风记录也足以利用波频散分析定位崩解事件。空气声所携带的丰富信息，加之麦克风的可获取性、易用性和低成本，使空气声学成为研究冰川–海洋相互作用以及全球范围内潜在海岸波能与侵蚀动力学的有力工具。

47. JC — Global Climatology and Trends of the Dominant Wave-Breaking Probability

Abstract

Abstract Wave breaking is the dominant physical process responsible for the energy dissipation of ocean surface waves and is critical for exchanges of momentum, energy, and mass across the air–sea interface. Over the past two decades, extensive research efforts have been devoted to investigating the climatology and trends of wind speed and wave height in global oceans, revealing their upward trends over the past several decades. Nonetheless, research on global-scale wave-breaking statistics remains relatively limited. It is not immediately clear whether wave steepness and wave breaking have intensified because the trends of wavelength are unknown. In this paper, we first present a simplified theoretical analysis based on the empirical wind-sea fetch laws and Toba’s 3/2 power law. A climatological relation between wind-sea wave steepness and wind speed is obtained, which suggests that as a consequence of accelerating winds on a climatological time scale, wave height grows faster than wavelength does and thus results in amplified steepness and intensified wave breaking. We then conduct a thorough analysis of global climatology and trends of the dominant wave-breaking probability b T , an important proxy of wave breaking estimated empirically from a recently produced global wave hindcast over the period from 1992 to 2019. It is confirmed that in the Southern Ocean (global oceans), b T has increased by approximately 4% (2%) over the past 28 years, and these relative trends of b T are comparable to those for wind speed and wave height.

中文摘要

摘要 波浪破碎是导致海洋表面波能量耗散的主要物理过程，对于海气界面间的动量、能量和质量交换至关重要。过去二十年间，大量研究工作致力于探究全球海洋风速与波高的气候态特征及趋势，揭示了其在过去数十年间呈上升趋势。然而，针对全球尺度波浪破碎统计特征的研究仍相对有限。由于波长的趋势尚不明确，波浪陡度与波浪破碎是否已经加剧尚不能立即确定。本文首先基于经验风浪风区规律与Toba的3/2幂律，提出了一种简化的理论分析。获得了风浪陡度与风速之间的气候态关系，该关系表明，在气候时间尺度上，由于风速加速，波高的增长速度大于波长的增长速度，从而导致陡度增大、波浪破碎加剧。随后，我们对主导波浪破碎概率b_T的全球气候态及趋势进行了全面分析，b_T是基于近期生成的1992年至2019年全球波浪后报数据经验估算的波浪破碎的重要代用指标。研究证实，在南大洋（全球海洋）中，b_T在过去28年间增加了约4%（2%），且b_T的这些相对趋势与风速和波高的趋势相当。

48. JC — Winter wave extremes in the Nordic seas - dependence on NAO and cyclone characteristics

Abstract

Abstract Extreme wave events in the North Atlantic have been linked to the North Atlantic Oscillation (NAO), though the connection varies spatially and the related synoptic-scale mechanisms remain unclear. We quantify how the winter NAO affects both the occurrence and magnitude of significant wave height extremes, defined here as seasonal winter maxima, in the Nordic seas and the North Sea. We show that this relationship exhibits pronounced spatial variability, with more and higher wave extremes in the Norwegian Sea during positive NAO, a weaker influence in the western North Sea, and reduced wave extremes in the southern Barents Sea. By linking extreme wave events to synoptic-scale processes, we demonstrate that this spatial variability arises from differences in cyclone characteristics and wave growth mechanisms. We find that most wave extremes occur in connection with cyclones. However, wave extremes in the Norwegian Sea and the western North Sea exhibit substantial differences in cyclone pathways, intensity, translation speed, and development. Extreme wave heights in the Norwegian Sea are associated with running fetch conditions, i.e., cyclones moving close to the group velocity of the waves. In contrast, in the western North Sea and southern Barents Sea, wave growth is fetch-limited due to land interaction and sea ice, with extreme waves primarily generated by northerly winds in the rear of cyclones. These differences in cyclone characteristics help reconcile the regionally varying relationship between extreme waves and the NAO, demonstrating that the influence of large-scale atmospheric patterns on wave extremes depends critically on regional wave growth characteristics.

中文摘要

极端波浪事件在北大西洋与北大西洋涛动（NAO）存在关联，但这种关联在空间上存在差异，且相关的天气尺度机制仍不明确。本文量化了冬季NAO如何影响北欧海域和北海区域有效波高极端事件的发生频率与量级，此处极端事件定义为冬季季节最大值。研究表明，这一关系呈现出显著的空间变异性：在NAO正位相期间，挪威海出现更多且更高的波浪极端事件，北海西部影响较弱，而巴伦支海南部波浪极端事件减少。通过将极端波浪事件与天气尺度过程相联系，我们证明这种空间变异性源于气旋特征和波浪成长机制的差异。研究发现，大多数波浪极端事件与气旋有关。然而，挪威海和北海西部的波浪极端事件在气旋路径、强度、移动速度和发展过程方面存在显著差异。挪威海的极端波高与移动风区条件有关，即气旋以接近波浪群速度的速度移动。相比之下，在北海西部和巴伦支海南部，由于陆地相互作用和海冰的影响，波浪成长受风区限制，极端波浪主要由气旋后部的偏北风产生。气旋特征的这些差异有助于调和极端波浪与NAO之间区域变化的关系，表明大尺度大气环型对波浪极端事件的影响在很大程度上取决于区域波浪成长特征。

边缘相关条目

命中物理海洋学关键词，但同时涉及其他学科领域，仅供参考。

  • JGR: Oceans — Seasonal to Decadal Patterns in Sea Ice and Turbidity at Arctic River Mouths（DOI: https://doi.org/10.1029/2026jc024659）
    • 命中: [核心期刊], Arctic Ocean, sea ice, freshwater
    • 排除: sediment
  • JGR: Oceans — The Transformation of Trace Metal Distributions Across the Mackenzie Shelf and Through the Northwest Passage（DOI: https://doi.org/10.1029/2026jc024398）
    • 命中: [核心期刊], mixing, Arctic Ocean, sea ice, salinity
    • 排除: sediment
  • Ocean Modelling — Future directions in oil spill modeling（DOI: https://doi.org/10.1016/j.ocemod.2026.102806）
    • 命中: [核心期刊]
    • 排除: oil spill

待人工核实

元数据缺失（摘要 / DOI / 作者），需人工核查后再纳入。

  • JGR: Oceans — Issue Information
    • 缺失项: 摘要缺失或过短; 作者列表缺失
    • 链接: 原文链接
  • Ocean Modelling — Explainable deep learning methods for medium- and long-term storm surge forecast
  • Ocean Modelling — Evaluation of the third-generation typhoon model in the Northwest Pacific operational forecasting for 2023
  • Ocean Modelling — Submesoscale dynamics in the Shallow Southern Yellow Sea. Part I: Topography dependent characteristics and distinctive seasonality
  • Ocean Modelling — The changing seasonality of mixed layer temperature in the Arctic shelf seas in response to surface heat flux forcing
  • Ocean Modelling — Scale-separated ensemble data assimilation of SWOT observations in the South China Sea
  • Ocean Modelling — Surface waves generated by a rising bubble: Analysis with impact model
  • Ocean Modelling — Numerical assessment of wave responses to wind wakes induced by an offshore wind energy area on the Scotian Shelf
  • Ocean Modelling — Lead-conditioned direct forecasting of daily air–sea interface variables over the Tropical Pacific ocean with soft physical regularization
  • Ocean Modelling — Advancing absolute regional sea level rise estimation: Methodological improvements using satellite altimetry and filtering techniques in the Baltic Sea
  • Ocean Modelling — Improving the prediction of ecosystem indicators by assimilating biogeochemical data from multiplatform observing systems
  • Ocean Modelling — Global directional wave spectra prediction based on energy-conserving deep learning
  • Ocean Modelling — Model simulation of M2 tide-induced turbulent mixing in the deepest trench on Earth
  • Ocean Modelling — Improving ENSO hindcast skill by adjusting the mean background state in a coupled general circulation model (CAS-ESM2.0)
  • Ocean Modelling — Modelling delayed bloom dynamics of Entomoneis sp. in İzmir Bay using spectral collocation
  • Ocean Modelling — Ring assistance of tracer transport across the Kuroshio Extension: observation and simulation
  • Ocean Modelling — Ice-thickness based scaling of wave attenuation in sea ice: Application and assessment of wave spectra
  • Ocean Modelling — Wave-driven circulation and transport in a tropical barrier reef system in the western Caribbean Sea with a phase-resolving model
  • Ocean Modelling — Development of a model for the wave-induced melt rate of floating icebergs with three degrees of freedom
  • Ocean Modelling — Coastal ocean influence on the Chesapeake Bay revealed by flux and tracer analyses
  • Ocean Modelling — Dynamical downscaling of future climate projections around Penghu Islands in the southern Taiwan Strait
  • Ocean Modelling — Characteristics and formation of the double-core Luzon undercurrent: Numerical modeling study
  • Ocean Modelling — Strain-dominated pathways of floating marine debris in Xiamen bay identified using Lagrangian coherent structures
  • Ocean Modelling — Editorial Board
    • 缺失项: 摘要缺失或过短; 作者列表缺失
    • 链接: 原文链接