Ocean Modelling最新文献

{"title":"Three-dimensional structure reconstruction of ocean mesoscale eddies based on physical process modeling and data-driven machine learning","authors":"Penghao Wang ,&nbsp;Kefeng Mao ,&nbsp;Xi Chen ,&nbsp;Ming Li ,&nbsp;Yuhang Zhu ,&nbsp;Hongchen Li ,&nbsp;Jiahao Wang ,&nbsp;Kefeng Liu ,&nbsp;Yangjun Wang","doi":"10.1016/j.ocemod.2025.102558","DOIUrl":"10.1016/j.ocemod.2025.102558","url":null,"abstract":"<div><div>To address the challenge of obtaining ocean mesoscale eddies' refined three-dimensional (3D) structure, we propose a novel 3D structure reconstruction model that combines physical process models with data-driven machine learning. First, based on the universal structure of mesoscale eddies, the 3D density structure of eddies is reconstructed using satellite observations and individual Argo profile observations. These eddy density profiles, along with eddy elements (polarity, eddy center, and radius) and sea surface elements (temperature, salinity, and dynamic height), serve as input data to construct a data-driven machine learning algorithm, which can reconstruct the 3D temperature and salinity structure of the eddies. Using observations of oceanic mesoscale cyclonic and anticyclonic eddies in the northwest Pacific Ocean, we demonstrate that both types of eddies' reconstructed temperature, salinity, and density structures align well with the observations. The root mean square errors (RMSEs) for the anticyclonic eddy are 0.361 °C, 0.0271 PSU, and 0.0570 kg/m³, and for the cyclonic eddy, they are 0.372 °C, 0.0904 PSU, and 0.144 kg/m³, respectively. The correlation coefficients exceed 0.98. Compared to multi-source fusion data (ARMOR 3D) and dynamical statistics data (MODAS), the reconstructed 3D structure from this study shows the closest alignment with observed structures. Furthermore, incorporating physical process model inputs significantly enhances the accuracy of the data-driven machine learning reconstruction of the eddy thermohaline structure, reducing the RMSEs by &gt;40 % and 60 %, respectively.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102558"},"PeriodicalIF":3.1,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neural Synthetic Profiles from Remote Sensing and Observations (NeSPReSO) — Reconstructing temperature and salinity fields in the Gulf of Mexico","authors":"Jose R. Miranda ,&nbsp;Olmo Zavala-Romero ,&nbsp;Luna Hiron ,&nbsp;Eric P. Chassignet ,&nbsp;Bulusu Subrahmanyam ,&nbsp;Thomas Meunier ,&nbsp;Robert W. Helber ,&nbsp;Enric Pallas-Sanz ,&nbsp;Miguel Tenreiro","doi":"10.1016/j.ocemod.2025.102550","DOIUrl":"10.1016/j.ocemod.2025.102550","url":null,"abstract":"<div><div>Accurate circulation modeling in the Gulf of Mexico (GoM) is hampered by the limited availability of in-situ subsurface data, leading to inaccuracies in subsurface representations. These inaccuracies diminish the reliability of ocean models and constrain the duration of dependable forecasts. This study introduces NeSPReSO (Neural Synthetic Profiles from Remote Sensing and Observations), a data-driven method to efficiently and accurately estimate subsurface temperature and salinity profiles using satellite-derived surface data. This provides an alternative to conventional synthetic data generation techniques.</div><div>Principal Component Analysis (PCA) is applied to extract the main features of temperature and salinity profiles of an Argo dataset. Then, a neural network is trained to predict these principal features using inputs such as time, location, and satellite-derived absolute dynamic topography alongside sea surface temperature and salinity. The model, evaluated using additional Argo profiles and glider data collected in the Gulf of Mexico, over-performs other traditional synthetic data generation methods, such as the Gravest Empirical Modes (GEM), Multiple Linear Regression (MLR) and Improved Synthetic Ocean Profile (ISOP), in terms of root mean square error and bias. Our findings indicate that our method effectively captures the main variations of subsurface fields, and that synthetic profiles generated by the model align well with actual observations, accurately capturing key features such as thermoclines, haloclines, and temperature-salinity structure of the region. This new method will be implemented in GoM data assimilative models and is expected to improve the accuracy of modeled subsurface currents.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102550"},"PeriodicalIF":3.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disentangling wavy and vortical motions in concurrent snapshots of the sea surface height and velocity","authors":"Chuanyin Wang ,&nbsp;Zhiyu Liu ,&nbsp;Hongyang Lin ,&nbsp;Cesar Rocha ,&nbsp;Qinghua Yang ,&nbsp;Dake Chen ,&nbsp;Junbin Gong","doi":"10.1016/j.ocemod.2025.102556","DOIUrl":"10.1016/j.ocemod.2025.102556","url":null,"abstract":"<div><div>Wide-swath satellite missions, such as Surface Water and Ocean Topography (SWOT) and Ocean Dynamics and Sea Exchanges with the Atmosphere (ODYSEA), will provide quasi-concurrent observations of the two-dimensional sea surface height and velocity. Thanks to their high spatial resolution, the spatial features of both vortical and wavy oceanic motions are expected to be captured by these observations. A natural question is whether one can disentangle vortical and wavy motions in these snapshot observations. This issue has attracted some efforts, but crucial progress remains to be made. Here, assuming that only a single concurrent snapshot of the sea surface height and velocity is available, we pursue a dynamical approach for disentangling vortical and wavy motions. This is realized by noting that wavy motions do not induce potential vorticity anomalies. A proof-of-concept application using an output of a realistic high-resolution numerical simulation suggests that the proposed approach is simple and efficient, and is particularly useful for separating wavy and vortical motions in observations by wide-swath satellite missions.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102556"},"PeriodicalIF":3.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current effects on wind generated waves near an Ocean Eddy Dipole","authors":"Nelson Violante-Carvalho ,&nbsp;Thiago de Paula ,&nbsp;Leandro Calado ,&nbsp;Felipe Marques dos Santos ,&nbsp;Luiz Mariano Carvalho ,&nbsp;Andre Luiz Cordeiro dos Santos ,&nbsp;Wilton Z. Arruda ,&nbsp;Leandro Farina","doi":"10.1016/j.ocemod.2025.102544","DOIUrl":"10.1016/j.ocemod.2025.102544","url":null,"abstract":"<div><div>Ocean eddy dipoles are among the most common mesoscale features and may be ubiquitous across the global oceans. However, wave–current interactions in their proximity have not been extensively studied. Here we examine the impact of surface currents on the wave field near an ocean eddy dipole. Using the WW3 wave model, we conducted idealized numerical simulations to assess the influence of different configurations on the spatial variability of Significant Wave Height (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span>). Additionally, a two-month hindcast of a strong dipole event in the Southwestern Atlantic Ocean was performed using three distinct surface current products: SSalto/Duacs, HYCOM NCODA and GlobCurrent. Among these, HYCOM, which incorporates ageostrophic effects, provided a more detailed representation of oceanic energy compared to GlobCurrent and SSalto/Duacs, which primarily reflect geostrophic components. The hindcast assessment employed denoised altimeter-derived <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> data, with a spatial resolution of approximately 6 km. The greatest increase in wave energy occurs in the region between the peak values of positive and negative vorticity, where the opposing surface currents reach their maximum intensity. Therefore, dipoles act as converging lenses for surface waves, channeling their refraction toward the central jet. Despite its poorer spatial and temporal resolutions, SSalto-Duacs surface current data provides more reliable <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> fields, in the study region where geostrophic dynamics are expected to be significant or even dominant. Both Absolute Dynamic Topography derived surface current inputs produce comparable effects on the wave field, with the inclusion of the Ekman component yielding no substantial enhancement. HYCOM captures a broader range of dynamical processes, essential for accurately representing the total energy, though discrepancies with SSalto/Duacs data may arise from assimilation inaccuracies and model limitations. While gridded altimetry may underestimate total current components during dipole events, it offers precise insights into their positioning and evolution, useful for specific event analysis and near real-time forecasting for marine safety.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102544"},"PeriodicalIF":3.1,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of suspended sediment variation during a landing typhoon in the Yangtze River Estuary","authors":"Jie Wang ,&nbsp;Cuiping Kuang ,&nbsp;Daidu Fan ,&nbsp;Jilong Chen ,&nbsp;Rufu Qin ,&nbsp;Dan Wang","doi":"10.1016/j.ocemod.2025.102554","DOIUrl":"10.1016/j.ocemod.2025.102554","url":null,"abstract":"<div><div>Hydrodynamic variations and suspended sediment concentration (SSC) dynamics under typhoon conditions are critical to understanding sediment transport processes in the Yangtze River Estuary (YRE). Strong winds, waves, and currents during typhoons alter water levels, flow velocities, and SSC distribution patterns, significantly affecting estuarine stratification. This study employs a validated three-dimensional coupled hydrodynamic-salinity-sediment transport model integrated with wave dynamics to investigate storm surge characteristics and SSC variations during Typhoon Muifa (September 2022). The mechanisms driving SSC changes were analyzed through wave effects and bottom shear stress (BSS). Key findings include: 1) Storm surge evolution during Typhoon Muifa transitioned from positive to negative storm surge due to the typhoon's southeast-to-northwest path, with a declining trend post-landfall. 2) Peak BSS values at NC2 (outer North Channel) reached 9.0 Pa, five times higher than normal conditions, while the maximum bottom-layer SSC at NB2 (outer North Branch) exceeded 15 kg/m³. 3) Nonlinear wave-current interactions modulated BSS magnitudes and SSC distribution. These interactions enhanced BSS in outer estuarine regions, suppressed tidal forces, and promoted sediment deposition, ultimately reducing SSC across all study sites. The results highlight distinct SSC responses to typhoon-induced dynamics, underscoring the need for further research on wave-sediment interaction mechanisms.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102554"},"PeriodicalIF":3.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface drifter trajectory prediction in the Gulf of Mexico using neural networks","authors":"Matthew D. Grossi ,&nbsp;Stefanie Jegelka ,&nbsp;Pierre F.J. Lermusiaux ,&nbsp;Tamay M. Özgökmen","doi":"10.1016/j.ocemod.2025.102543","DOIUrl":"10.1016/j.ocemod.2025.102543","url":null,"abstract":"<div><div>Machine learning techniques are applied to Lagrangian trajectory reconstructions, which are important in oceanography for providing guidance to search and rescue efforts, forecasting the spread of harmful algal blooms, and tracking pollutants and marine debris. This study evaluates the ability of two types of neural networks for learning ocean trajectories from nearly 250 surface drifters released during the Grand Lagrangian Deployment in the Gulf of Mexico from Jul-Oct 2012. First, simple fully connected neural networks were trained to predict an individual drifter’s trajectory over 24<!--> <!-->h and 5<!--> <!-->d time windows using only that drifter’s previous velocity time series. These networks, despite having successfully learned modeled trajectories in a previous study, failed to outperform common autoregressive models in any of the tests conducted. This was true even when drifters were pre-sorted into geospatial groups based on past trajectories and different networks were trained on each group to reduce the variability that each network had to learn. In contrast, a more sophisticated social spatio-temporal graph convolutional neural network (STN), originally developed for learning pedestrian trajectories, demonstrated greater potential due to two important features: learning spatial and temporal patterns simultaneously, and sharing information between similarly-behaving drifters to facilitate the prediction of any particular drifter. Position prediction errors averaged around 60<!--> <!-->km at day 5, roughly 20<!--> <!-->km lower than autoregression, and even better for certain subsets of drifters. The passage of Tropical Cyclone Isaac over the drifter array as a tropical storm and Category 1 hurricane provided a unique opportunity to also explore whether these models would benefit from adding wind as a predictor when making short 24<!--> <!-->h predictions. The STNs were found to not benefit from wind on average, though certain subsets of drifters exhibited slightly lower reconstruction errors at hour 24 with the addition of wind.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102543"},"PeriodicalIF":3.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new EnOI-based multiscale assimilation system for global ocean circulation model","authors":"Li Liu ,&nbsp;Xunqiang Yin ,&nbsp;Xueen Chen","doi":"10.1016/j.ocemod.2025.102551","DOIUrl":"10.1016/j.ocemod.2025.102551","url":null,"abstract":"<div><div>With advancements in observational techniques and computational technologies, multi-scale data assimilation (MS-DA) has become a significant focus in data assimilation research. Global ocean models with variable resolution grids offer advantages in specific regions, highlighting the need for MS-DA methods tailored for these models. This study develops an MS-DA system that extends the single-scale data assimilation (SS-DA) framework. It integrates a multi-grid interpolation module and uses the MPI-OM ocean model with the Ensemble Kalman Filter (EAKF) assimilation technique. The system aims to enhance computational efficiency and improve the assimilation of temperature and salinity data, particularly in the South China Sea (SCS). The MS-DA system uses a two-step assimilation process to convert high-resolution model data to lower-resolution grids and vice versa, with parallel computing to accelerate data processing. The study compares the computational performance and assimilation outcomes of MS-DA and SS-DA. Results show that the MS-DA system reduces computational time by 20 % compared to SS-DA, with minimal differences in global sea surface temperature (SST) and salinity (SSS) assimilation. However, the MS-DA system performs better in the SCS, reducing the mean absolute error (MAE) for SST and SSS by 0.01 °C and 0.01 PSU, respectively. It also improves temperature and salinity assimilation in the upper 500 m of the SCS by 1.7 % and 6.2 %, respectively. Overall, the MS-DA system offers better assimilation performance with lower computational costs, especially in high-resolution regions like the SCS.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102551"},"PeriodicalIF":3.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the directional distributions of the observation-based wind input and dissipation terms in a third-generation wave model","authors":"Franklin F. Ayala ,&nbsp;Rubén D. Montoya ,&nbsp;Andrés F. Osorio ,&nbsp;Alexander Babanin","doi":"10.1016/j.ocemod.2025.102542","DOIUrl":"10.1016/j.ocemod.2025.102542","url":null,"abstract":"<div><div>New observation-based directional spreading functions for the wind input term <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>i</mi><mi>n</mi></mrow></msub></math></span> and the dissipation term <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>d</mi><mi>s</mi></mrow></msub></math></span> have been investigated in third-generation wave models (WAVEWATCH III, ST6 version). In this study we evaluate bimodal directional distribution for <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>d</mi><mi>s</mi></mrow></msub></math></span> and narrower (<span><math><mrow><msup><mrow><mo>cos</mo></mrow><mrow><mn>2</mn></mrow></msup><mi>θ</mi></mrow></math></span> and <span><math><mrow><msup><mrow><mo>cos</mo></mrow><mrow><mn>4</mn></mrow></msup><mi>θ</mi></mrow></math></span>) distributions for <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>i</mi><mi>n</mi></mrow></msub></math></span>. The impact of these new directional functions on the integral wave parameters, as well as the nondirectional and directional spectra, is analyzed through a set of numerical experiments and their results are compared against buoy observations in the Caribbean Sea. Improvements in the estimation of <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> under wind-sea dominant conditions are presented. For the shape of frequency spectra, the bimodal distribution of <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>d</mi><mi>s</mi></mrow></msub></math></span> causes a weaker energy enhancement by comparison with the narrower distribution of <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>i</mi><mi>n</mi></mrow></msub></math></span>, but it generally shows a better fit than the default functions in the model. The combined effect of both modifications brings larger energy allocation around the main wave propagation direction, generating both an energy increase and a downshift at the spectral peak. These findings suggest the relevance of including realistic directional distributions and reveal the need for further studies of directional distributions of the source terms.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102542"},"PeriodicalIF":3.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The simulation of the South China Sea by the variable resolution version of the global ocean general circulation model LICOM3.0","authors":"Jiangfeng Yu ,&nbsp;Jingwei Xie ,&nbsp;Hailong Liu ,&nbsp;Pengfei Lin ,&nbsp;Zipeng Yu ,&nbsp;Jiahui Bai","doi":"10.1016/j.ocemod.2025.102549","DOIUrl":"10.1016/j.ocemod.2025.102549","url":null,"abstract":"<div><div>We develop a variable-resolution method based on the tripolar grid to achieve fine-resolution regional simulations with limited computational resources. Based on the global ocean general circulation model LICOM3.0, we select the South China Sea (SCS) as the refined area and design five experiments to assess the impact of the variable-resolution grid on oceanic simulation. The results show that the method can retain the model capacity for global ocean simulation and obtain results in the refined region comparable to the reference global high-resolution model. Improving the resolution in the SCS from 0.1° to 0.02° significantly enhances the model performance in simulating submesoscale phenomena. The model can effectively reproduce submesoscale processes generated by frontogenesis, topographic wakes, and their seasonal variation. We uncover the effect of the submesoscale vortex train near the Luzon Strait. In summer, the vortex train tends to carry positive vorticity westward into the SCS and constrain the negative vorticity along the Kuroshio Current. In winter, the vortex train is more intrusive into the SCS with enhanced filament activities.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102549"},"PeriodicalIF":3.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement in wintertime mixed layer depth simulation by CMIP6 compared to CMIP5 climate models","authors":"Tengfei Xu ,&nbsp;Shanshan Jin ,&nbsp;Xunwei Nie ,&nbsp;Zishan Qiu ,&nbsp;Hao Liu ,&nbsp;Ying Li ,&nbsp;Zexun Wei","doi":"10.1016/j.ocemod.2025.102545","DOIUrl":"10.1016/j.ocemod.2025.102545","url":null,"abstract":"<div><div>In this study, we assessed the simulated winter mixed layer depth (MLD) in the CMIP5 and CMIP6 models by comparing to Argo observations. Both the CMIP5 and CMIP6 models have well simulated the pattern of the winter MLD; however, there are large biases in the subtropical and subpolar regions, where the Subtropical Under Waters, Subtropical and Subantarctic Mode Waters, and North Atlantic Deep Water are formed. The CMIP6 models have not eliminated the simulation biases of winter MLD in subtropical and subpolar regions. However, Taylor Diagram (TD) analysis indicates that the CMIP6 models improved winter MLD simulation, showing less scatter and better TD scores than the CMIP5 simulations. Biases in the CMIP6 models were reduced by 11.60–27.55% in the subtropical to middle latitudes, and by 12.64–67.64% in the south/north subpolar Atlantic Ocean. With both the CMIP5 and CMIP6 models, the biases in winter MLD simulation are mainly attributed to inaccurate convection and stratification associated with heat/freshwater fluxes and thermohaline structures. Improving mixing parameterization is one of the most important updates in the CMIP6 models; however, it remains uncertain whether these improvements caused the winter MLD biases to decrease.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"196 ","pages":"Article 102545"},"PeriodicalIF":3.1,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}