本期覆盖 2026-08-14 至 2026-08-21，共收录高置信度文章 23 篇，边缘相关 1 篇，待人工核实 0 篇。

本周亮点

亮点 1：Central role of Labrador Sea convection for transport of oxygen into the deep North Atlantic Ocean

期刊：Nature Geoscience ｜ DOI：https://doi.org/10.1038/s41561-026-02057-3

English summary

This study, published in Nature Geoscience, reveals the central role of Labrador Sea convection in transporting oxygen into the deep North Atlantic Ocean. Using two years of mooring data, the authors show that despite its limited contribution to density transformation, the Labrador Sea is crucial for oxygen supply to the deep limb of the Atlantic Meridional Overturning Circulation. This finding challenges previous assumptions about the region’s importance and has implications for understanding deep ocean ventilation and climate.

中文解读

这项发表在《自然·地球科学》上的研究揭示了拉布拉多海对流在向北大西洋深层输送氧气中的核心作用。通过两年的锚系观测数据，作者发现尽管拉布拉多海对密度转化的贡献有限，但它对北大西洋深层翻转环流深层的氧气供应至关重要。这一发现挑战了先前对该区域重要性的假设，对理解深层海洋通风和气候具有重要意义。

期刊：JC ｜ DOI：https://doi.org/10.1175/jcli-d-25-0460.1

English summary

This study addresses the debate over observed trends in the tropical Pacific zonal sea surface temperature gradient. The authors show that the observed strengthening trend is statistically significant under multiple null hypotheses, contrary to claims that it may be due to internal variability or observational uncertainty. This finding is important for validating climate models and understanding the response of the tropical Pacific to greenhouse gas forcing.

中文解读

这项研究解决了关于热带太平洋纬向海表温度梯度观测趋势的争论。作者表明，在多种零假设下，观测到的增强趋势具有统计显著性，这与认为该趋势可能源于内部变率或观测不确定性的观点相反。这一发现对于验证气候模式和理解热带太平洋对温室气体强迫的响应具有重要意义。

文章详览

1. 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-year 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.

中文摘要

摘要 中尺度海洋-大气耦合调节全球气候。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，通常分为单极SSTA和作为残余的各种偶极SSTA。然而，其不同的全球分布格局及其方差贡献仍未得到充分理解。对29年卫星观测数据的分析表明，偶极SSTA在气旋（反气旋）涡旋中分别占全球气旋（反气旋）涡旋诱导SSTA方差的49.3%（51.5%）。利用理想化模型，我们展示了纬向涡旋相对漂移在塑造SSTA结构中的显著作用。单极SSTA主要出现在湾流延伸体、黑潮延伸体和南极绕极流（ACC）等强东向相对漂移区域，而偶极SSTA则更常见于东海洋盆地，其中弱纬向相对漂移有利于其发展。这一发现挑战了以单极为中心的中尺度海洋-大气耦合范式，并为改进气候模式中涡旋表征提供了基准。

2. JPO — River Plume Dynamics over a Coastal Valley under Downwelling-favorable Winds

Abstract

Abstract When a river plume encounters a coastal valley, local dynamics are modified relative to those with seawater. However, the underlying dynamical processes remain poorly understood. In this study, an idealized numerical model is employed to investigate how the presence of a river plume alters the flow behavior over a coastal valley under downwelling-favorable winds. The arrival of the plume intensifies the alongshore current, weakens the cross-shore flow, and induces another upwelling–downwelling dipole within the valley. Simultaneously, the net vertical and cross-shore transport reverse from a downward-offshore pattern under seawater conditions to an upward-onshore pattern with a plume. The river plume not only amplifies the contribution of vertical vorticity diffusion but also reshapes the spatial distribution of relative vorticity changes that govern vertical motion in the valley. Compared with the dominance of relative potential vorticity advection in the no-plume case, the primary driver of cross-shore transport within the valley shifts to the joint effect of baroclinicity and topographic relief when the plume is present. These dynamical changes are linked to the combined effects of sea level anomalies associated with valley-induced coastal trapped lee waves and plume-induced spatial density variations. After wind relaxation, mesoscale instabilities develop throughout the water column, featuring longer wavelengths on the downstream side of the valley. During this stage, eddy potential energy is converted into eddy kinetic energy, part of which is subsequently transferred to the mean kinetic energy.

中文摘要

摘要 当河流羽流遇到沿海谷地时，局部动力学相对于纯海水条件会发生改变。然而，其潜在的动力学过程仍知之甚少。本研究采用理想化数值模型，探讨在顺风（下涌有利）风作用下，河流羽流的存在如何改变沿海谷地上的流动行为。羽流的到来增强了沿岸流，减弱了跨岸流，并在谷地内诱导出另一个上升流-下降流偶极子。同时，净垂直和跨岸输运从海水条件下的向下-离岸模式逆转为有羽流时的向上-向岸模式。河流羽流不仅增强了垂直涡度扩散的贡献，还重塑了控制谷地内垂直运动的相对涡度变化的空间分布。与无羽流情况下相对位势涡度平流的主导作用相比，当羽流存在时，谷地内跨岸输运的主要驱动力转变为斜压性与地形起伏的联合效应。这些动力学变化与谷地诱导的沿岸陷波相关的海平面异常及羽流引起的空间密度变化的综合效应有关。风减弱后，整个水柱中发展出中尺度不稳定，谷地下游侧呈现更长的波长。在此阶段，涡旋有效势能转化为涡旋动能，其中一部分随后转移至平均动能。

3. JPO — Forced-dissipative two-layer quasi-geostrophic 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 quasi-geostrophic (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.

中文摘要

摘要 海底地形在广泛的时间和空间尺度上影响海洋湍流。本文揭示，在热带以外区域，海洋中能量最充沛的区域具有与背景垂直切变位涡梯度方向一致的大尺度地形位涡梯度。我们利用强迫耗散双层准地转（QG）模拟，研究了这些符号和幅度各异的对齐底坡。在双层QG湍流中，小至中等底坡支持地形波增能，而中等至陡峭底坡则支持级联抑制、急流形成及表面增强的斜压波。在陡峭底坡上，由于线性波在小于地形波尺度的尺度上使流动受阻，地形波无法增能。对于支持东向（西向）地形波传播的底坡，东向指定流及涌现急流呈顺行（逆行）。逆行急流持久且自我维持，而顺行急流则为瞬态。我们通过频率-波数能量谱及考虑涌现纬向平均急流流的频散关系，证明两类急流均充当波导。对于给定底坡幅度，顺行指定流的特征长度尺度小于逆行指定流，这可通过线性波模式的多普勒频移加以解释。线性波理论亦用于预测最大诊断湍流时间尺度的长度尺度。最后，我们提出两种（未闭合的）预测纬向涡动能水平和长度尺度的方法。这些结果丰富了底坡上斜压湍流的基础理论，并为考虑地形的海洋涡旋参数化方案提供参考。

4. 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 non-dimensional parameter to predict if a system will exhibit convergent or divergent Lagrangian residual circulation. We also explore 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.

中文摘要

摘要 河口浮力物质的汇聚具有重要意义，因为它能促进颗粒间的相互作用，涉及捕食者-猎物动态、营养获取及污染物暴露等方面。汇聚通常与河口的横向输运相关联。传统上，在潮汐平均框架下，汇聚的一个常见机制是由横向密度梯度引起的差异平流。近期，一种依赖于时间的拉格朗日汇聚机制已被提出，并在一个具有恒定密度和科里奥利力的高度理想化河口模型中进行了测试。该机制发现，横向流动中的相位偏移可导致拉格朗日余流，并进而引发横向汇聚。在此，我们探讨了在潮汐分辨的理想化河口模型中，欧拉与拉格朗日汇聚的联合效应及其竞争关系。研究发现，在高和低垂直涡粘系数情况下，欧拉平均流均驱动物质向河道中心汇聚。然而，横向相位传播的方向从高垂直涡粘系数下的发散转变为低垂直涡粘系数下的汇聚，从而相对于仅考虑欧拉流的情况改变了整体汇聚速率。我们建议使用一个无量纲参数来预测系统将表现出汇聚还是发散的拉格朗日余流。此外，我们还探讨了拉格朗日余流对宽度、深度变化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，因为它们能控制浮力颗粒的汇聚速率，并可能改变其相对于欧拉平均流的运动轨迹。

5. 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-day) 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. 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 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.

中文摘要

摘要 部分马登–朱利安振荡（MJO）事件在海洋大陆上空维持增强对流并传播至西太平洋，而其他事件则在海洋大陆附近减弱。利用卫星反演的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月的月际变率。根据海洋大陆上空20–100天季节内对流的振幅，将事件划分为传播型（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大陆南部和澳大利亚北部，限制了与海洋大陆地形及其屏障效应的相互作用。背景态（>100天）合成分析显示，11月P型与D型差异更强，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路径沃克环流上升支的东移。ENSO分层分析表明，在11月，P型事件在厄尔尼诺期间更频繁发生，而D型事件在拉尼娜期间更频繁发生。这种ENSO依赖性与其间P型事件相对于D型事件沃克环流上升支的东移一致。当ENSO由Niño-4海表温度异常定义时，这种分离最为显著。这些结果表明，ENSO相关的背景环流调制有助于决定11月MJO事件是否能在海洋大陆上空维持对流。

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

Abstract

Abstract Wave breaking is the dominant physical process responsible for 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 timescale, 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 波浪破碎是控制海洋表面波能量耗散的主要物理过程，对海气界面的动量、能量和质量交换至关重要。过去二十年间，大量研究致力于调查全球海洋风速和波高的气候态及趋势，揭示了它们在近几十年来的上升趋势。然而，关于全球尺度波浪破碎统计的研究仍相对有限。由于波长的趋势未知，波浪陡度和波浪破碎是否加剧尚不明确。本文首先基于经验风浪风区定律和Toba的3/2幂律，提出了一种简化的理论分析。得到了风浪陡度与风速之间的气候态关系，表明在气候时间尺度上，随着风速加速，波高的增长速度快于波长，从而导致陡度增大和波浪破碎加剧。随后，我们对1992年至2019年间最新生成的全球波浪后报数据中经验估计的重要波浪破碎代理指标——主导波破碎概率b_T，进行了全面的全球气候态和趋势分析。结果证实，在过去28年中，南大洋（全球海洋）的b_T增加了约4%（2%），且b_T的相对趋势与风速和波高的趋势相当。

7. GRL — Satellite Altimetry Reveals an Eddy Train Along the Ross Sea Shelf Break

Abstract

Abstract Oceanic circulation along the Antarctic shelf break regulates heat and material exchanges between the continental shelf and the open ocean, playing a crucial role in ice shelf melting and global overturning circulation. However, the circulation remains poorly understood due to limited observations. By combining the Surface Water and Ocean Topography (SWOT) mission with traditional AVISO altimetry, this study identifies an eddy train along the shelf break of the Ross Sea, which consists of alternating cyclonic and anticyclonic circulations with spatial scales of ∼100 km. A notable phase reversal of the eddy train occurred around 2014, coinciding with a broader climate variability of the Southern Ocean. SWOT reveals sea surface height amplitudes of the eddy train roughly twice those from AVISO, while current reanalysis products fail to reproduce this feature, highlighting the need for improved observations and modeling to better resolve Antarctic shelf‐region dynamics. Plain Language The ocean circulations around the Antarctic shelf break, where the shallow continental shelf meets the deep open ocean, regulate heat and material exchange between the shelf and open ocean. This exchange is critical for the formation of dense shelf water and ice shelf melt, thereby impacting the global overturning circulation and sea level rise. However, this region remains poorly understood due to limited observations. Using data from new‐generation SWOT and traditional AVISO satellites, we investigated ocean circulations at the Ross Sea shelf break. We discovered a chain of ∼100 km circulations along the shelf break with alternating clockwise and counterclockwise rotations. Around 2014, their pattern shifted dramatically, aligning with broader climate changes in the Southern Ocean. Existing ocean reanalysis products fail to reproduce these features, highlighting the need for improved observations such as SWOT to enhance our understanding of Antarctic currents and their climatic impacts.

中文摘要

摘要 南极陆架坡折处的海洋环流调节着大陆架与开阔大洋之间的热量和物质交换，在冰架融化和全球翻转环流中发挥着关键作用。然而，由于观测数据有限，对该环流的认识仍不充分。本研究结合地表水与海洋地形（SWOT）任务与传统AVISO测高数据，在罗斯海陆架坡折处识别出一列涡旋列车，由空间尺度约100公里的交替气旋式和反气旋式环流组成。约在2014年前后，该涡旋列车发生了显著的相位反转，与南大洋更广泛的气候变率相吻合。SWOT揭示的涡旋列车海面高度振幅约为AVISO观测结果的两倍，而现有的再分析产品未能重现这一特征，凸显了改进观测和模拟以更好地解析南极陆架区域动力学的必要性。通俗摘要 南极陆架坡折处（浅层大陆架与深层开阔大洋交汇处）的海洋环流调节着陆架与开阔大洋之间的热量和物质交换。这种交换对稠密陆架水的形成和冰架融化至关重要，进而影响全球翻转环流和海平面上升。然而，由于观测数据有限，该区域仍认识不足。利用新一代SWOT和传统AVISO卫星数据，我们研究了罗斯海陆架坡折处的海洋环流。我们发现沿陆架坡折存在一系列约100公里尺度的环流，呈顺时针和逆时针交替旋转。约在2014年前后，其格局发生显著转变，与南大洋更广泛的气候变化相一致。现有的海洋再分析产品未能重现这些特征，凸显了改进观测（如SWOT）以增强我们对南极海流及其气候影响认识的必要性。

8. GRL — Ocean Mixing Regimes Set Heat and Buoyancy Fluxes From the Arctic’s Atlantic Water Layer

Abstract

Abstract Quantifying Arctic Ocean mixing is important for understanding the Arctic climate system. Direct mixing measurements cannot robustly characterize mixing on a pan‐Arctic scale, while indirect estimates based on parameterizations must be made with care; multiple mixing mechanisms including double diffusion, internal wave breaking and molecular mixing must be independently considered. In this work, we use observations from Ice‐Tethered Profilers and ship‐based measurements to: (a) Characterize the prevalence of select mixing regimes in the Atlantic Water thermocline across the Arctic Ocean; (b) Provide statistical descriptions of sector‐ and regime‐specific estimates of heat and buoyancy fluxes and implied diffusivities based on regime‐specific parameterizations; and (c) Quantify the relative contribution of select mixing regimes to net heat and buoyancy transports. Results detail important geographical differences in mixing regime prevalence and the significance of regime relative contributions that can provide useful insight into differing controls on stratification and the fate of Atlantic Water heat.

中文摘要

摘要 量化北冰洋混合过程对于理解北极气候系统至关重要。直接混合测量无法在泛北极尺度上稳健表征混合特征，而基于参数化的间接估算需谨慎处理；必须独立考虑包括双扩散、内波破碎及分子混合在内的多种混合机制。本研究利用冰系浮标观测及船基测量数据，旨在：(a) 刻画北冰洋大西洋水温跃层中特定混合机制的出现频率；(b) 基于各机制特定参数化方案，提供分区及机制特定的热量与浮力通量及其隐含扩散系数的统计描述；(c) 量化选定混合机制对净热量与浮力输运的相对贡献。结果详述了混合机制分布的重要地理差异及其相对贡献的显著性，为理解层结控制因素及大西洋水热量的归宿提供了有益见解。

9. GRL — Sea Surface Temperature Feedbacks and Convective Organization Mediate the Tropical Circulation Response to Aerosols

Abstract

Abstract Coupling between aerosols, atmospheric circulation, and tropical sea surface temperature (SST) patterns is an important part of anthropogenic influence on climate but is not well understood. Using idealized, cloud‐resolving simulations with a slab ocean, we examine the hydrologic and circulation responses to uniform and spatially varying aerosol enhancement. The equilibrium responses are decomposed into forcings attributable to aerosol‐cloud interactions and feedbacks associated with SST gradient adjustment. Aerosol enhancement within convective regimes forces an increase in deep convective mass flux but has only a modest, feedback‐driven impact on large‐scale circulation. Enhancement within subsiding regimes does not affect convective mass flux but strengthens the large‐scale circulation through direct forcing and SST gradient feedbacks; the forcing component is explained by changes in low‐level buoyancy and convective organization. These results highlight the mediating roles of convective organization and SST patterns in aerosol‐cloud‐circulation coupling on long timescales.

中文摘要

摘要 气溶胶、大气环流与热带海表温度（SST）格局之间的耦合是人为影响气候的重要组成部分，但尚未被充分理解。利用理想化的云解析模拟并结合板式海洋，我们考察了均匀及空间变化的气溶胶增强对水文和环流的响应。平衡响应被分解为可归因于气溶胶-云相互作用的强迫以及与SST梯度调整相关的反馈。对流区内的气溶胶增强迫使深对流质量通量增加，但对大尺度环流的影响仅为适度的、由反馈驱动的效应。下沉区内的增强不影响对流质量通量，但通过直接强迫和SST梯度反馈增强了大尺度环流；强迫分量可通过低层浮力和对流组织的变化来解释。这些结果突显了对流组织和SST格局在长时间尺度上气溶胶-云-环流耦合中的中介作用。

10. JC — Southern Ocean Latent Heat Flux Variability Driven by Oceanic Meso- and Submesoscale Motions

Abstract

Abstract Latent heat flux (LHF) is a primary pathway for ocean–atmosphere exchange of heat and moisture, yet the influence of sea surface temperature variability at fine scales (≤100 km) on LHF variability, particularly over the Southern Ocean, remains poorly understood. Here, we quantify the scale-dependent drivers of LHF variability using a year-long, global, fully coupled ocean–atmosphere simulation with kilometer-scale resolution. Annual-mean LHF in eddy-rich regions reaches ≈215 W m −2 , approximately 3 times larger than in eddy-poor regions. Spectral analyses show that ocean mesoscale [ ] and submesoscale [ ] variability accounts for up to ≈80% of the total LHF variance in eddy-rich sectors, but as little as 10% in eddy-poor regions, and increases proportionally with eddy kinetic energy and sea surface temperature (SST) variance. We also find that strong submesoscale SST fronts (≈5°C over 10 km) force a localized secondary circulation that extends well above the marine boundary layer into the midtroposphere. Comparison with the fifth generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis (ERA5) shows that fine ocean scales, responsible for about 17% of the ocean-driven LHF variance in the simulation, are largely unresolved in the reanalysis, leading to a muted atmospheric response lacking any secondary circulation. Despite a strong heterogeneity in LHF variability, the atmospheric dynamics are mostly uniform across the domain, suggesting a nonlocal atmospheric response to ocean forcing. These results highlight the potential for ocean meso- and submesoscales, commonly underresolved in climate models and reanalysis, to influence Southern Ocean air–sea coupling and atmosphere both locally and remotely. Significance Statement The Southern Ocean plays a key role in regulating Earth’s climate by exchanging heat and moisture with the atmosphere. Using a groundbreaking, high-resolution global simulation of the ocean and atmosphere down to kilometer scale, we show that small ocean features—eddies and sharp temperature fronts tens to just a few kilometers wide—dominate latent heat flux variability in energetic regions. These fine ocean structures can trigger strong, narrow updrafts that reach up to the midtroposphere. This small-scale atmospheric response is largely missing from widely used, coarser reanalyses and climate models. Because these fine-scale ocean processes can influence the atmosphere locally and remotely, properly representing them is essential for improving climate projections and weather forecasts.

中文摘要

摘要 潜热通量（LHF）是海洋与大气之间热量和水分交换的主要途径，然而，细尺度（≤100 km）海表温度变率对LHF变率的影响，尤其是在南大洋区域，仍知之甚少。本文利用一项为期一年、全球、千米级分辨率的全耦合海洋-大气模拟，量化了LHF变率的尺度依赖性驱动因素。涡旋丰富区域的年平均LHF可达约215 W m⁻²，约为涡旋贫乏区域的3倍。谱分析表明，海洋中尺度[ ]和次中尺度[ ]变率在涡旋丰富区域可占LHF总方差的约80%，而在涡旋贫乏区域仅占约10%，且其贡献随涡旋动能和海表温度（SST）方差的增加而按比例增大。我们还发现，强烈的次中尺度SST锋面（10公里内约5°C）会强迫产生局地次级环流，该环流可延伸至海洋边界层以上，直达对流层中层。与第五代欧洲中期天气预报中心大气再分析（ERA5）的对比显示，在模拟中约占海洋驱动LHF方差17%的细海洋尺度，在再分析资料中基本未被解析，导致大气响应减弱且缺乏次级环流。尽管LHF变率存在强烈的不均匀性，但大气动力学在整个区域内基本一致，表明大气对海洋强迫存在非局地响应。这些结果凸显了在气候模式和再分析中通常分辨率不足的海洋中尺度和次中尺度过程，可能对南大洋海气耦合及大气产生局地和远程影响的潜力。意义声明 南大洋通过与大气的热量和水分交换，在调节地球气候中发挥着关键作用。利用一项开创性的、覆盖全球的高分辨率海洋-大气模拟（分辨率精细至千米级），我们表明，小型海洋特征——涡旋和宽度仅数公里至数十公里的尖锐温度锋面——主导了能量活跃区域的潜热通量变率。这些细尺度海洋结构可触发强烈的窄幅上升气流，直达对流层中层。这种小尺度大气响应在广泛使用的较粗分辨率再分析和气候模式中基本缺失。由于这些细尺度海洋过程可对大气产生局地和远程影响，正确表征它们对于改进气候预测和天气预报至关重要。

11. JC — Diverse Impacts of Eastern Pacific and Central Pacific ENSO on Australian Spring Rainfall and Associated Southern Hemisphere Large-Scale Circulation

Abstract

Abstract Despite extensive research on the eastern Pacific (EP) and central Pacific (CP) El Niño–Southern Oscillation (ENSO) impacts on Australia’s climate, the physical mechanisms by which these two ENSO types influence Australian rainfall remain poorly understood. Here, we examine EP/CP ENSO’s influences on Australian spring rainfall and Southern Hemisphere large-scale circulation using updated observations and reanalysis for 1950–2024. EP ENSO induces regionally dispersed rainfall anomalies, mainly concentrated in the Northern Territory, Murray–Darling basin, and southwest Western Australia—the latter, an area traditionally considered less affected by ENSO. In contrast, CP ENSO forces a continental-scale rainfall response across northern and eastern Australia. These diverse impacts arise from changes in moisture transport and surface evaporation modulated by anomalous large-scale circulation. EP El Niño exhibits stronger covariability with positive Indian Ocean dipole (IOD) and is accompanied by a Rossby wave train emanating from the tropical Indian Ocean that anchors an equivalent-barotropic anticyclonic anomaly south of Australia, suggesting the role of the Indian Ocean in mediating EP El Niño’s impacts. CP El Niño tends to decouple with IOD and features westward-shifted enhanced equatorial Pacific convection, causing a zonally elongated Pacific–South America pattern with a low pressure anomaly extending closer to the Australian east coast. La Niña events generally produce opposite responses, but CP La Niña asymmetrically exerts stronger impacts with more widespread rainfall increases. Differences in tropical Rossby wave source, together with extratropical transient eddy feedback, explain distinct large-scale circulation anomalies that drive different rainfall patterns. These results advance the understanding of the diversity of ENSO teleconnections in the Southern Hemisphere.

中文摘要

摘要 尽管已有大量研究探讨东太平洋（EP）和中部太平洋（CP）厄尔尼诺-南方涛动（ENSO）对澳大利亚气候的影响，但这两类ENSO事件影响澳大利亚降水的物理机制仍知之甚少。本文利用1950—2024年更新的观测资料和再分析数据，考察了EP/CP ENSO对澳大利亚春季降水及南半球大尺度环流的影响。EP ENSO引发区域分散的降水异常，主要集中在北领地、墨累-达令流域和西澳大利亚西南部——后者传统上被认为受ENSO影响较小的地区。相比之下，CP ENSO在澳大利亚北部和东部引发大陆尺度的降水响应。这些不同影响源于异常大尺度环流调节的水汽输送和地表蒸发的改变。EP厄尔尼诺与正印度洋偶极子（IOD）表现出更强的协变性，并伴随从热带印度洋传播出的罗斯贝波列，在澳大利亚南部锚定一个等效正压反气旋异常，表明印度洋在调节EP厄尔尼诺影响中发挥作用。CP厄尔尼诺倾向于与IOD解耦，其特征是赤道太平洋对流增强且西移，导致太平洋-南美型遥相关模式呈纬向延伸，低压异常更接近澳大利亚东海岸。拉尼娜事件通常产生相反的响应，但CP拉尼娜不对称地施加更强影响，降水增加范围更广。热带罗斯贝波源差异，连同中纬度瞬变涡旋反馈，解释了驱动不同降水格局的独特大尺度环流异常。这些结果增进了对南半球ENSO遥相关多样性的理解。

12. JC — Classification and Dynamic Origins of Interannual Variability of the Basinwide Extreme High-Temperature Events in the Yangtze River Basin

Abstract

Abstract Utilizing k -means clustering analysis, these extensive basinwide extreme high-temperature (EHT) (EHTBW) events over the Yangtze River basin are classified into three distinct categories, including the middle–lower-reaches type (MLR-type) (i.e., EHT primarily in the middle and lower reaches), the all-reaches type (AR-type) (i.e., EHT in all reaches), and the upper-reach type (UR-type) (i.e., EHT mainly in the upper reach). The MLR-type occurs most frequently, accounting for 51.88% of all EHTBW events, followed by the AR-type with 36.41% and the UR-type with 11.71%. The MLR-type is related to a ridge extending from the anomalous anticyclone over Northeast Asia, which induces subsidence and adiabatic heating, resulting in EHT in the middle and lower reaches. It is influenced primarily by the La Niña–like sea surface temperature (SST) anomalies that generate a dipole pattern of convection with negative anomalies over the tropical central Pacific and positive anomalies over the tropical Atlantic. The AR-type is associated with an elongated anomalous anticyclone that stretches from South Asia to East Asia, leading to both enhanced adiabatic and diabatic heating anomalies and thus EHT across the entire basin. It is largely affected by the positive SST anomalies over the North Atlantic via eastward-propagating Eurasian teleconnection, as well as the dipole SST anomalies over the tropical Pacific through poleward-propagating teleconnection. The UR-type is related to a meridional dipole pattern characterized by an anomalous anticyclone over Northeast Asia and an anomalous cyclone over the Philippine Sea, which favors EHT in the upper reach through local divergence. It is mainly induced by positive SST anomalies over the northwestern Atlantic and tropical central and eastern Pacific through distinct atmospheric teleconnections. Significance Statement Extreme high-temperature events in the Yangtze River basin are not all alike. This study classifies them into three spatially distinct types: middle–lower-reaches type (MLR-type), all-reaches type (AR-type), and upper-reach type (UR-type). Each type is driven by different combinations of tropical and extratropical SST anomalies and atmospheric teleconnections. By revealing the distinct oceanic drivers of each type, our study provides a physical basis for improving seasonal prediction and developing region-dependent adaptation strategies in one of China’s most vulnerable regions for extreme high temperatures.

中文摘要

摘要 利用k均值聚类分析，长江流域广泛的流域性极端高温（EHT）事件被划分为三种不同类型，包括中下游型（MLR型）（即高温主要发生在中下游地区）、全流域型（AR型）（即高温遍布全流域）以及上游型（UR型）（即高温主要出现在上游地区）。其中，MLR型发生频率最高，占所有EHTBW事件的51.88%，其次是AR型占36.41%，UR型占11.71%。MLR型与东北亚异常反气旋延伸出的高压脊相关，该脊引发下沉运动和绝热加热，导致中下游地区出现极端高温。其主要受类似拉尼娜的海表温度（SST）异常影响，这些异常在热带中太平洋形成负异常对流偶极子，在热带大西洋形成正异常对流。AR型与从南亚延伸至东亚的拉长异常反气旋相关联，导致绝热和非绝热加热异常均增强，从而在全流域引发极端高温。该类型主要受北大西洋正SST异常通过向东传播的欧亚遥相关，以及热带太平洋偶极子SST异常通过向极传播的遥相关共同影响。UR型与经向偶极子模式相关，其特征为东北亚异常反气旋和菲律宾海异常气旋，通过局地辐散有利于上游地区出现极端高温。该类型主要由西北大西洋及热带中、东太平洋的正SST异常通过不同的大气遥相关过程诱发。意义声明 长江流域的极端高温事件并非千篇一律。本研究将其划分为三种空间上截然不同的类型：中下游型（MLR型）、全流域型（AR型）和上游型（UR型）。每种类型由热带和温带SST异常及大气遥相关的不同组合驱动。通过揭示每种类型独特的海洋驱动因素，本研究为提升季节预测能力及制定针对中国最易受极端高温影响区域之一的区域差异化适应策略提供了物理基础。

13. JC — Long-Term Extended Projection of Global Land Monsoon Precipitation Beyond 2100 under a Low-Emission Scenario

Abstract

Abstract Global land monsoon precipitation (GLMP) profoundly impacts the water resources and societal development of two-thirds of the world population. While the future change in GLMP by 2100 has been assessed, it remains unclear how it will change beyond the twenty-first century. Here, using model simulations from CMIP5/CMIP6 long-term extension experiments under the low-emission scenario RCP2.6/shared socioeconomic pathway 1-2.6 (SSP1-2.6), we analyze the GLMP changes from 2100 up to 2300. The results show that under the extended RCP2.6/SSP1-2.6 scenario, South Asia and North America both partly reverse their pre-2100 responses by the late twenty-third century. Over South Asia, the post-2100 decline offsets about 29% of the wetting projected for the late twenty-first century relative to the historical period. This decline is mainly driven by post-2100 cooling and the associated weakening of the thermodynamic contribution. Over North America, the post-2100 increase recovers about 39% of the drying projected for the late twenty-first century relative to the historical period. This increase is mainly driven by a strengthened dynamic contribution under declined anthropogenic forcing. The largest intermodel uncertainty is seen over Africa, where a north–south asymmetric precipitation dipole emerges as the leading mode of intermodel spread, explaining 56.28% of the total variance. This African pattern-sourced uncertainty is dynamically controlled and closely linked to shifts in the Atlantic-sector intertropical convergence zone (ITCZ), which are modulated by the Atlantic meridional sea surface temperature (SST) gradient. Our results highlight the regional monsoon difference in long-term extended projection and the important role of ocean response and its associated atmospheric circulation adjustment in shaping long-term GLMP projections beyond 2100.

中文摘要

摘要 全球陆地季风降水（GLMP）深刻影响着全球三分之二人口的水资源与社会发展。尽管至2100年GLMP的未来变化已得到评估，但其在二十一世纪之后将如何变化仍不清楚。本研究利用CMIP5/CMIP6长期延伸试验在低排放情景RCP2.6/共享社会经济路径1-2.6（SSP1-2.6）下的模式模拟，分析了2100年至2300年GLMP的变化。结果表明，在延伸的RCP2.6/SSP1-2.6情景下，南亚和北美的降水响应在二十三世纪末均部分逆转了其2100年前的趋势。在南亚，相对于历史时期，2100年后的降水减少抵消了二十一世纪末预估增湿的约29%。这一减少主要由2100年后的降温及其伴随的热力贡献减弱所驱动。在北美，相对于历史时期，2100年后的降水增加恢复了二十一世纪末预估变干的约39%。这一增加主要归因于人为强迫减弱下动力贡献的增强。最大的模式间不确定性出现在非洲，其中南北不对称的降水偶极子作为模式间差异的主导模态出现，解释了总方差的56.28%。这一源于非洲的模态不确定性受动力过程控制，并与大西洋区域热带辐合带（ITCZ）的位移密切相关，而后者受大西洋经向海表温度（SST）梯度调制。本研究结果凸显了长期延伸预估中区域季风差异，以及海洋响应及其伴随的大气环流调整在塑造2100年后长期GLMP预估中的重要作用。

14. JC — Divergent Pathways of the East Asian Subtropical Westerly Jet in Influencing Heavy Rainfall Events during the Mei-Yu Period in Flood and Drought Years

Abstract

Abstract Heavy rainfall events (HREs) during the mei-yu season are a primary focus of disaster prevention and mitigation. Based on the observations and reanalysis data, the classification of flood and drought years was determined by cumulative mei-yu precipitation. Then, the divergent pathways of the East Asian subtropical westerly jet (EASWJ) impacting the HREs, along with the causes of the anomalous jet variations, were analyzed. The flood-year HREs exhibit longer durations and higher frequency compared to drought-year events. The mid–high-latitude circulation exhibits a zonal pattern, characterized by the EASWJ center being persistently positioned at 35°–40°N, while precipitation locates northward. Jet intensity is enhanced and sustained by two factors: warm-region heating driven by low-latitude circulations and anomalous local Eliassen–Palm (E–P) flux divergence. These processes provide essential dynamic conditions for HREs development and prolonged persistence. During the drought years, the mid–high-latitude circulation exhibits a meridional pattern, characterized by a southward shift of the jet and precipitation. The EASWJ migrates southward, accompanied by the intrusion of cold air and intensifying the mei-yu front, thereby triggering HREs. Under the influence of cold air carried southward by mid–high-latitude vertical–meridional circulation and abnormal dispersion of disturbance energy, the jet strengthens. The southward migration of disturbance energy governs the shift of jet. However, the rapid southward advance of cold air reduces the temperature gradient across the jet’s northern and southern flanks. Concurrently, anomalous disturbance energy convergence weakens the EASWJ, leading to precipitation termination. Significance Statement Mei-yu heavy rainfall events (HREs) constitute a primary focus of disaster preventive and mitigation, owing to their highly catastrophic nature. Our study provides a clearer picture by discovering why the East Asian jet stream behaves differently in flood and drought mei-yu years and how these distinct behaviors trigger HREs through two separate pathways. In flood years, a stronger and persistent jet stream, driven by tropical heat and atmospheric disturbances, creates a favorable environment for heavy rainfall. In drought years, the jet shifts southward, bringing cold air that intensifies the storm front and triggers rainfall. The jet also strengthens in this regime due to active mid–high-latitude vertical–meridional circulation and abnormal disturbance energy divergence.

中文摘要

摘要 梅雨季节的强降雨事件（HREs）是防灾减灾工作的重点。基于观测和再分析资料，通过累计梅雨降水量划分了涝年和旱年，进而分析了东亚副热带西风急流（EASWJ）影响强降雨事件的不同路径及其异常变化的成因。涝年强降雨事件相较于旱年具有更长的持续时间和更高的发生频率。中高纬度环流呈纬向型分布，其特征为急流中心持续位于35°–40°N，降水位置偏北。急流强度增强并得以维持，受两个因素驱动：低纬度环流引起的暖区加热和局地异常Eliassen–Palm（E–P）通量辐散。这些过程为强降雨事件的发展和持续提供了必要的动力条件。在旱年，中高纬度环流呈经向型分布，其特征为急流和降水位置南移。急流向南迁移，伴随冷空气侵入并增强梅雨锋，从而触发强降雨事件。在中高纬度垂直–经向环流携带冷空气南移及扰动能量异常辐散的影响下，急流增强。扰动能量的南移主导了急流的位移。然而，冷空气的快速南侵减小了急流南北两侧的温度梯度。同时，异常扰动能量辐合削弱了急流，导致降水终止。重要声明 梅雨强降雨事件因其高度灾害性，构成防灾减灾工作的重点。本研究通过揭示东亚急流在梅雨涝年和旱年中的不同表现及其通过两条独立路径触发强降雨事件的机制，提供了更清晰的认识。在涝年，受热带热量和大气扰动驱动的更强且持续的急流，为强降雨创造了有利环境。在旱年，急流南移，携带冷空气增强风暴锋面并触发降雨。在此情形下，由于中高纬度垂直–经向环流活跃及异常扰动能量辐散，急流亦有所增强。

15. JC — Observed Trends in the Tropical Pacific Zonal Sea Surface Temperature Gradient Are Statistically Significant Based on Multiple Null Hypotheses

Abstract

Abstract Climate conditions worldwide are influenced by the mean and variability of the tropical Pacific zonal sea surface temperature (SST) gradient. How this gradient responds to greenhouse gas forcing is, therefore, critical for accurate future climate projections. The nature of the response, however, remains debated: Historical model simulations favor a weakening trend, whereas observational records from the same period are characterized by a strengthening trend. To explain this model–observation discrepancy, some attribute the observed trend to internal variability or observational uncertainties, while others suggest that models may inaccurately simulate the radiatively forced response. Past studies have analyzed different trend intervals and observational datasets, potentially contributing to conflicting conclusions about whether observations reflect the forced response. We present a comprehensive analysis of observed zonal SST gradient trends and their statistical significance. We estimate observed trends over all 20-yr or longer intervals within the 1870–2024 period and subsequently evaluate these trends against a series of null hypotheses using bootstrapped ensembles of various statistical, conceptual, and geophysical models. Our analysis reveals that both strengthening and weakening trends are observed, depending on the analyzed intervals; however, intervals extending into the twenty-first century, particularly those since 1950 or those over a century or longer, exhibit statistically significant strengthening trends, suggesting that such trends are unlikely to have emerged from internal variability alone. This finding has implications for the historical and probable near-term transient responses, indicating they are likely radiatively forced. We confirm these findings with multiple observational datasets, demonstrating that data uncertainties minimally influence our conclusions. Significance Statement The response of the tropical Pacific Ocean to radiative forcing, such as greenhouse gas forcing, remains highly debated: Climate models’ historical forcing experiments generally simulate a weakening trend in the west–east sea surface temperature gradient, while observations so far estimate a strengthening trend. Past studies, regardless of which response they supported, used different trend intervals and observational data. This study analyzes all multidecadal or longer trends in the observed gradient and their associated statistical significance across multiple datasets. Although both strengthening and weakening trends are present in observations, we find the emergence of statistically significant strengthening trends over multidecadal and centennial-scale intervals extending into the past several decades likely reflects the influence of historical radiative forcings.

中文摘要

摘要 全球气候状况受到热带太平洋纬向海表温度（SST）梯度的平均值及其变率的影响。因此，该梯度对温室气体强迫的响应方式对于准确预测未来气候至关重要。然而，响应的性质仍存在争议：历史模型模拟倾向于显示减弱趋势，而同期观测记录则表现为增强趋势。为解释这一模型与观测之间的差异，一些研究者将观测到的趋势归因于内部变率或观测不确定性，而另一些则认为模型可能未能准确模拟辐射强迫响应。以往研究分析了不同的趋势区间和观测数据集，这可能导致了关于观测是否反映强迫响应的相互矛盾的结论。我们提出了对观测到的纬向SST梯度趋势及其统计显著性的综合分析。我们估算了1870年至2024年间所有20年或更长区间的观测趋势，并随后利用多种统计、概念和地球物理模型的引导重采样集合，将这些趋势与一系列零假设进行对比评估。分析显示，根据所分析的区间不同，观测中既存在增强趋势也存在减弱趋势；然而，延伸至二十一世纪的区间，特别是自1950年以来或长达一个世纪或更长的区间，表现出统计上显著的增强趋势，这表明此类趋势不太可能仅由内部变率产生。这一发现对历史及可能近期瞬态响应具有启示意义，表明它们很可能受到辐射强迫的影响。我们通过多个观测数据集确认了这些发现，证明数据不确定性对我们的结论影响极小。意义声明 热带太平洋对辐射强迫（如温室气体强迫）的响应仍存在高度争议：气候模型的历史强迫实验通常模拟出东西向海表温度梯度的减弱趋势，而观测至今估计为增强趋势。以往研究，无论支持哪种响应，均使用了不同的趋势区间和观测数据。本研究分析了观测梯度中所有多年代或更长时间尺度的趋势及其在多个数据集中的统计显著性。尽管观测中同时存在增强和减弱趋势，但我们发现，在过去几十年延伸的多年代和百年尺度区间内出现的统计显著增强趋势，可能反映了历史辐射强迫的影响。

16. GRL — Tropical Eastern Pacific Decadal Variability Drives Atlantic Multidecadal Variability: Two Distinct Pathways

Abstract

Abstract Using a tropical Pacific pacemaker experiment, we demonstrate that the tropical eastern Pacific (TEP) decadal sea surface temperature (SST) variability influences the Atlantic Multidecadal Variability (AMV) through two pathways. The TEP induces a North Atlantic SST tripole response that peaks 1 year later, primarily via modulation of net surface heat flux. The subpolar SST anomalies associated with this tripole response subsequently influence the strength of North Atlantic deep water formation and the Atlantic Meridional Overturning Circulation, ultimately leading to a monopole SST response in the North Atlantic about one decade later. The tripole and monopole responses account for 40% and 59% of the TEP‐forced AMV signal, respectively. The TEP‐forced AMV explains approximately 30% of the variance in the internal AMV, thus substantially modulating the phase transitions and intensity of the historical AMV. This identified TEP forcing should be carefully considered to improve simulations and predictions of the AMV.

中文摘要

摘要 通过热带太平洋加速实验，我们证明热带东太平洋（TEP）年代际海表温度（SST）变率通过两条路径影响大西洋多年代际变率（AMV）。TEP引发北大西洋SST三极型响应，峰值出现在1年后，主要通过净表面热通量的调节实现。与此三极型响应相关的副极地SST异常随后影响北大西洋深层水形成的强度及大西洋经向翻转环流，最终在约十年后导致北大西洋出现单极型SST响应。三极型和单极型响应分别占TEP强迫AMV信号的40%和59%。TEP强迫的AMV解释了内部AMV方差的约30%，从而显著调节了历史AMV的相位转换和强度。这一识别的TEP强迫应被仔细考虑，以改进AMV的模拟和预测。

17. GRL — Historical and Projected Antarctic Sea Ice Trends Across High‐Resolution Coupled Model Hierarchies

  • 作者：Mitchell Bushuk, David B. Bonan, Stephen M. Griffies, William Gregory, Yongfei Zhang, Bill Hurlin, Yan‐Ting Chen, Thomas Rackow, Helge F. Goessling
  • 发表日期：2026-08-20
  • DOI：https://doi.org/10.1029/2026gl124043

Abstract

Abstract Coupled climate models generally simulate a decline in Antarctic sea ice extent (SIE) over the satellite period, failing to capture the observed near‐zero trend. Recent work has suggested that high‐resolution ocean models could ameliorate this issue via improved representation of mesoscale ocean processes, which may delay simulated Antarctic SIE decline. We investigate this hypothesis using two high‐resolution hierarchies of coupled climate models developed at GFDL and NCAR, which span atmospheric resolutions of 0.25–1 and ice‐ocean resolutions of 0.1–1, as well as three generations of Coupled Model Intercomparison Project (CMIP) models. Across the high‐resolution hierarchies and CMIP ensembles, we find no clear relationship between ocean and atmospheric resolution and Antarctic SIE trends over both the satellite period and the remainder of the 21st century. Climate models that reproduce observed trends in individual ensemble members are those that exhibit large amplitude multi‐decadal Southern Ocean climate variability.

中文摘要

摘要 耦合气候模式通常模拟出卫星观测期间南极海冰范围（SIE）的下降趋势，却未能捕捉到观测到的近零趋势。近期研究提出，高分辨率海洋模式通过改进中尺度海洋过程的表征，可能延缓模拟的南极SIE下降，从而缓解这一问题。我们利用GFDL和NCAR开发的两套高分辨率耦合气候模式层级，其大气分辨率范围为0.25–1，海冰-海洋分辨率范围为0.1–1，以及三代耦合模式比较计划（CMIP）模式，对这一假设进行了探究。在高分辨率层级和CMIP集合中，我们未发现海洋和大气分辨率与卫星观测期间及21世纪剩余时间内南极SIE趋势之间存在明确关系。能够再现观测趋势的单个集合成员的气候模式，通常表现出大幅度的多年代际南大洋气候变率。

18. GRL — High‐ and Low‐Concentration Spiral Chlorophyll Bands Excited by Vortex Rossby Waves

Abstract

Abstract High‐concentration spiral chlorophyll bands (HSCBs) embedded in oceanic mesoscale eddies have recently been observed worldwide. They are considered to be the footprints of vortex Rossby waves (VRWs). Based on satellite observations and drifter data, we identified additional low‐concentration spiral chlorophyll bands (LSCBs). The morphological and kinematic features of the LSCBs are similar to those of the HSCBs and align with the VRW theory. Both the HSCBs and LSCBs are predominantly found in areas of weak background flow and are more easily excited during the eddy’s mature stage. Further analysis showed that the formation of HSCBs (LSCBs) is probably associated with upward (downward) motions accompanied by horizontal divergence (convergence). Finally, it was found that strong background flows will significantly suppress VRWs ( r ≤ −0.52, where r is the Pearson correlation coefficient), as manifested by the distortion and breakdown of their structure. This study improves our understanding of VRW dynamics in mesoscale eddies.

中文摘要

摘要 高浓度螺旋叶绿素带（HSCBs）嵌入海洋中尺度涡旋中的现象近期在全球范围内被观测到，被认为是涡旋罗斯贝波（VRWs）的足迹。基于卫星观测和漂流浮标数据，我们识别出了额外的低浓度螺旋叶绿素带（LSCBs）。LSCBs的形态和运动学特征与HSCBs相似，并与VRW理论相符。HSCBs和LSCBs主要出现在背景流较弱区域，且更易在涡旋成熟阶段被激发。进一步分析表明，HSCBs（LSCBs）的形成可能与伴随水平辐散（辐合）的上升（下降）运动有关。最后发现，强背景流会显著抑制VRWs（r ≤ −0.52，其中r为皮尔逊相关系数），表现为其结构的扭曲和破裂。本研究增进了我们对中尺度涡旋中VRW动力学的理解。

19. GRL — Numerical Evidence of Invariance of Turbulence Dissipation Rate in Breaking Waves

  • 作者：Umberto C. bitencourt, Saswata Basak, Grant B. Deane, M. Dale Stokes, Anqing Xuan, Han Liu, Lian Shen
  • 发表日期：2026-08-18
  • DOI：https://doi.org/10.1029/2026gl123324

Abstract

Abstract We perform direct numerical simulations to verify the hypothesis of invariance of the turbulence dissipation rate, proposed by Deane, Stokes, and Callaghan (2016, https://doi.org/10.1175/jpo‐d‐14‐0187.1 ) based on their laboratory breaking wave experiments. Our DNS data provide direct access to local viscous dissipation rates, which are difficult to measure in laboratory and field experiments. The breaking waves simulated have a wavelength of 25 cm and varying amplitudes. Despite a fivefold variation in the total energy dissipation, our results indicate the emergence of a space–time‐averaged dissipation rate between 0.49 and 0.70 W/kg. The additional energy loss accompanying an increase in wave amplitude is accommodated by an increase in the bubble plume volume, where energy dissipation is concentrated, rather than by an increase in energy dissipation rate via shear stress correlations. These findings clarify how breaking wave energetics constrain turbulence injection into the upper ocean and regulate air–sea exchange processes.

中文摘要

摘要 我们进行了直接数值模拟，以验证Deane、Stokes和Callaghan（2016，https://doi.org/10.1175/jpo‐d‐14‐0187.1）基于其实验室破碎波实验提出的湍流耗散率不变性假设。我们的DNS数据能够直接获取局部粘性耗散率，这在实验室和现场实验中难以测量。模拟的破碎波波长为25厘米，振幅各异。尽管总能量耗散存在五倍的变化，我们的结果表明，空间-时间平均耗散率介于0.49至0.70瓦/千克之间。伴随波幅增加而产生的额外能量损失，是通过增加气泡羽流体积（能量耗散集中区域）来容纳的，而非通过剪切应力相关性增加能量耗散率。这些发现阐明了破碎波能量学如何约束上层海洋中的湍流注入，并调节海-气交换过程。

20. GRL — Enhanced Subsurface Warming of the Kuroshio Revealed by Long‐Term Observations During 1965–2020

Abstract

Abstract The Kuroshio transports large amounts of heat from the tropical to extratropical Pacific, playing a crucial role in regional climate changes. However, how the temperature and heat transport changes of the Kuroshio under a warming climate remain ambiguous. In this study, based on long‐term full‐depth observations during 1965–2020, we firstly reveal that there exists an enhanced warming trend in subsurface layer of the Kuroshio. The mean and maximum subsurface warming rates reach 0.18°C per decade and 0.30°C per decade, respectively, which are much higher than those of the Kuroshio surface and global average temperature. The enhanced subsurface warming contributes 73% of the Kuroshio heat transport increase. We further indicate that the subsurface warming signals originate from sea surface warming in the downstream Kuroshio Extension region. Our findings highlight that the pronounced Kuroshio subsurface warming has considerable implications for the regional climate and ecology changes.

中文摘要

摘要 黑潮将大量热量从热带太平洋输送到温带太平洋，在区域气候变化中扮演着关键角色。然而，在气候变暖背景下，黑潮的温度和热输送变化仍不明确。本研究基于1965—2020年的长期全深度观测数据，首次揭示了黑潮次表层存在增强的变暖趋势。平均和最大次表层增温速率分别达到每十年0.18°C和每十年0.30°C，远高于黑潮表层及全球平均温度的增温速率。增强的次表层增温贡献了黑潮热输送增加的73%。我们进一步指出，次表层增温信号源于黑潮延伸体下游区域的海表增温。我们的研究结果强调，黑潮显著的次表层增温对区域气候和生态变化具有重要影响。

21. GRL — Rapid Surface Intensification of the Gulf Stream Since 2014

Abstract

Abstract The warm, swift Gulf Stream (GS) plays a key role in shaping weather and climate patterns across the North Atlantic. Using 31‐year (1993–2023) of continuous satellite altimeter observations, we identify a pronounced intensification of the free‐flowing GS after its separation from the coast beginning around 2014 and persisting thereafter, following a prolonged period (2005–2014) of weaker transport. This intensification coincides with a northward displacement and reduced meandering of the GS path, which appears to be linked to a spin‐up of the North Atlantic subtropical gyre. This gyre acceleration is largely driven by an increase in the negative wind stress curl, partially modulated by the two leading modes of atmospheric variability in the region: the North Atlantic Oscillation and the East Atlantic Pattern. Our analysis also suggests that GS intensification may have a local air–sea feedback leading to anomalous wind stress curl.

中文摘要

摘要 温暖而湍急的湾流（GS）在塑造北大西洋的天气和气候模式中发挥着关键作用。利用1993年至2023年连续31年的卫星测高观测数据，我们发现，在经历了一段较长时间（2005-2014年）的输运减弱之后，自由流动的湾流在脱离海岸后，自2014年前后开始出现显著的增强，并在此后持续。这一增强现象与湾流路径的北移和弯曲度减小相伴发生，似乎与北大西洋副热带环流的加速旋转有关。这种环流加速主要由负风应力旋度的增加所驱动，并部分受到该区域两种主要大气变率模态的调节：北大西洋涛动和东大西洋型。我们的分析还表明，湾流的增强可能引发局地海气反馈，导致异常的风应力旋度。

22. JC — Climatic Impacts of a Warmer Mediterranean Sea Simulated by the Fully Coupled Community Earth System Model, Version 2 (CESM2)

Abstract

Abstract This study presents a set of process-oriented sensitivity experiments using the state-of-the-art fully coupled Community Earth System Model, version 2 (CESM2), for the first time to isolate the role of Mediterranean sea surface temperature (MedSST) anomalies from regional to global scales. Ten-member ensembles of historical simulations (Control) and two Mediterranean Pacemaker experiments [Mediterranean Pacemaker (MedP) and MedP +3°C (MedP3)] are performed for the 1980–2014 period. MedP aims to achieve an accurate representation of MedSST evolution by applying bias corrections to the model-simulated fields, while MedP3 introduces a +3°C perturbation to MedP as an idealized experiment to explore the sensitivity of the climate to substantially warmer MedSSTs. The impacts of the bias correction are evaluated by comparing MedP and Control with observational-based data, while the climatic impacts of a warmer Mediterranean are assessed by comparing MedP3 with MedP. MedP improves the representation of surface temperatures over large parts of the Euro-Mediterranean region. Relatedly, there are not only improvements in precipitation patterns over Anatolia, the Balkans, and Gibraltar but also degradations in central Europe and the southern Mediterranean basin. In MedP3, warmer MedSSTs enhance upward motion and induce anomalous cyclonic surface winds, increasing atmospheric instability and intensifying precipitation. This precipitation enhancement is largely confined to the Mediterranean Sea and adjacent northern land areas, particularly the Anatolian, Italian, and Balkan peninsulas. At the hemispheric scale, MedP3 produces a Northern Hemisphere warming response. The associated interhemispheric thermal contrast shifts the intertropical convergence zone slightly northward, resulting in increased precipitation in the northern tropics. Overall, our study shows that changes in MedSSTs could have climatic impacts on both regional and global scales. Significance Statement The Mediterranean Sea is important in shaping the climate of the Mediterranean region, which is recognized as a climate change hotspot with future projections indicating significant drying. This modeling study provides valuable insights into the Mediterranean Sea’s influence on both regional and global climate systems. Results reveal that a warmer Mediterranean Sea enhances upward atmospheric motion over the region, disrupting both Hadley and Ferrel circulations. The enhanced atmospheric instability increases regional precipitation. A warmer Mediterranean Sea also heats the midlatitudes in the Northern Hemisphere. The greater temperature gradient between the polar regions and the northern midlatitudes strengthens the polar jet stream, which likely causes the intertropical convergence zone to shift slightly northward. These findings underscore the Mediterranean’s impact on regional and global atmospheric circulation and climate dynamics.

中文摘要

摘要 本研究首次利用最先进的完全耦合社区地球系统模型第二版（CESM2）开展了一系列面向过程的敏感性实验，以隔离地中海海表温度（MedSST）异常从区域到全球尺度的影响。针对1980—2014年期间，进行了十成员集合的历史模拟（控制实验）和两个地中海“起搏器”实验[地中海起搏器（MedP）和MedP+3°C（MedP3）]。MedP旨在通过对模型模拟场进行偏差校正，实现对MedSST演变的准确再现，而MedP3则在MedP基础上引入+3°C扰动，作为理想化实验以探索气候对显著变暖的MedSST的敏感性。通过将MedP和控制实验与基于观测的数据进行比较，评估了偏差校正的影响；通过将MedP3与MedP进行比较，评估了更暖地中海的气候影响。MedP改善了对欧洲-地中海地区大部分区域地表温度的再现。相应地，不仅安纳托利亚、巴尔干和直布罗陀地区的降水格局有所改善，中欧和地中海盆地南部的降水表现也有所退化。在MedP3中，更暖的MedSST增强了上升运动并诱发异常气旋性地面风，增加了大气不稳定性并加强了降水。这种降水增强主要局限于地中海及其邻近北部陆地区域，特别是安纳托利亚、意大利和巴尔干半岛。在半球尺度上，MedP3产生了北半球的增暖响应。相关的半球间热力对比使热带辐合带略微北移，导致北热带降水增加。总体而言，本研究表明MedSST的变化可能对区域和全球尺度产生气候影响。意义声明 地中海在塑造地中海地区气候方面具有重要作用，该地区被公认为气候变化热点区域，未来预测显示其将显著变干。本模拟研究为地中海对区域和全球气候系统的影响提供了宝贵见解。结果表明，更暖的地中海增强了该区域上空的上升大气运动，扰乱了哈德莱环流和费雷尔环流。增强的大气不稳定性增加了区域降水。更暖的地中海还加热了北半球中纬度地区。极地与北半球中纬度之间更大的温度梯度增强了极地急流，这可能导致热带辐合带略微北移。这些发现强调了地中海对区域和全球大气环流及气候动态的影响。

23. Nature Geoscience — Central role of Labrador Sea convection for transport of oxygen into the deep North Atlantic Ocean

  • 作者：Una Kim Miller, Jaime Palter, Ellen Park, Dariia Atamanchuk, Kristen Fogaren, Yao Fu, Johannes Karstensen, Jannes Koelling, Isabela Le Bras, Hiroki Nagao, David Nicholson, Hilary Palevsky, Meg Yoder
  • 发表日期：2026-08-17
  • DOI：https://doi.org/10.1038/s41561-026-02057-3

Abstract

Nature Geoscience, Published online: 17 August 2026; doi:10.1038/s41561-026-02057-3 The Labrador Sea plays a crucial role in transporting oxygen into the deep limb of the Atlantic Meridional Overturning Circulation, despite its limited contribution to density transformation, according to an analysis of 2 years of mooring data.

中文摘要

《自然·地球科学》，在线发表于2026年8月17日；doi:10.1038/s41561-026-02057-3。根据对两年锚系观测数据的分析，尽管拉布拉多海对密度转化的贡献有限，但其在将氧气输送到大西洋经向翻转环流深层分支中发挥着关键作用。

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。

  • GRL — Antarctic Sea‐Ice Extent Anomalies Impact Interannual Variability of Phytoplankton Chlorophyll‐a in Southern Ocean Frontal Zones（DOI: https://doi.org/10.1029/2026gl123800）
    • 命中: Southern Ocean
    • 排除: phytoplankton