Pub Date : 2025-10-31DOI: 10.1016/j.ocemod.2025.102649
Rui Li , Kejian Wu , Qingxiang Liu , Jin Liu , Shang-Min Long , Jian Sun , Alexander V. Babanin
The effect of the small-scale ocean surface waves on large-scale ocean climate has been usually neglected. The Stokes drift-induced water transport has the potential to contribute to ocean heat transport and the wave-induced heat transport (WHT) in the global ocean is quantified for the first time in this research. The magnitude of wave-induced water transport is found to be comparable to Ekman transport in the global ocean. Notably, both of the zonal and meridional surface Stokes drift exhibit a strong correlation with the El Niño-Southern Oscillation and Indian Ocean Dipole (IOD). We found that there is an anomalous increase in wave-induced heat transport towards the equator during El Niño events in the Pacific Ocean. Additionally, an increase in eastward WHT appears during eastern-type El Niño events. Moreover, the zonal WHT anomalies co-vary with IOD phases. The large-scale climate modes drive the ocean wave large-scale anomalies, and then the abnormal WHT leads to redistribution of global ocean heat, even exceeding the heat transport induced by Ekman transport.
{"title":"The wave-induced heat transport in the global ocean","authors":"Rui Li , Kejian Wu , Qingxiang Liu , Jin Liu , Shang-Min Long , Jian Sun , Alexander V. Babanin","doi":"10.1016/j.ocemod.2025.102649","DOIUrl":"10.1016/j.ocemod.2025.102649","url":null,"abstract":"<div><div>The effect of the small-scale ocean surface waves on large-scale ocean climate has been usually neglected. The Stokes drift-induced water transport has the potential to contribute to ocean heat transport and the wave-induced heat transport (WHT) in the global ocean is quantified for the first time in this research. The magnitude of wave-induced water transport is found to be comparable to Ekman transport in the global ocean. Notably, both of the zonal and meridional surface Stokes drift exhibit a strong correlation with the El Niño-Southern Oscillation and Indian Ocean Dipole (IOD). We found that there is an anomalous increase in wave-induced heat transport towards the equator during El Niño events in the Pacific Ocean. Additionally, an increase in eastward WHT appears during eastern-type El Niño events. Moreover, the zonal WHT anomalies co-vary with IOD phases. The large-scale climate modes drive the ocean wave large-scale anomalies, and then the abnormal WHT leads to redistribution of global ocean heat, even exceeding the heat transport induced by Ekman transport.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102649"},"PeriodicalIF":2.9,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465783","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}
Pub Date : 2025-10-30DOI: 10.1016/j.ocemod.2025.102644
Zhuoyue Li , Haibao Hu , Chen Chen , Zhan Wang , Zhongliang Xie , Peng Du
The density distribution scheme determines the characteristics of internal solitary waves (ISWs). Based on three typical density distributions, ISWs are modeled in two-layer, three-layer, and continuous-density systems, while also considering the effect of background shear currents. ISWs are generated using high-level Green–Naghdi (HLGN) and Dubreil-Jacotin-Long (DJL) theories, which serve as initial conditions for the computational fluid dynamics (CFD) flume. In all systems, linear background shear currents can significantly affect the ISW properties, such as wave profiles, induced velocity, propagation speed, and energy distribution. Positive-vorticity background shear currents pycnocline thinning, whereas negative-vorticity currents result in thickening. The ISW shear strength is evaluated by the average rate of change of horizontal velocity at the pycnocline. In the two-layer system, positive-vorticity currents reduce the ISW shear effect, whereas the opposite occurs with negative-vorticity currents. The conclusions for the three-layer and continuous-density systems are in contrast to those of the two-layer system. This indicates that consideration or neglect of the pycnocline thickness may lead to opposite conclusions regarding the effects of background shear currents on the ISW shear effect. Furthermore, the influence of the nonlinear background shear currents is discussed. For most properties, the effects of nonlinear currents are consistent with those of linear currents, although they are generally weak.
{"title":"Internal solitary waves with different density distribution approximation schemes in background shear currents","authors":"Zhuoyue Li , Haibao Hu , Chen Chen , Zhan Wang , Zhongliang Xie , Peng Du","doi":"10.1016/j.ocemod.2025.102644","DOIUrl":"10.1016/j.ocemod.2025.102644","url":null,"abstract":"<div><div>The density distribution scheme determines the characteristics of internal solitary waves (ISWs). Based on three typical density distributions, ISWs are modeled in two-layer, three-layer, and continuous-density systems, while also considering the effect of background shear currents. ISWs are generated using high-level Green–Naghdi (HLGN) and Dubreil-Jacotin-Long (DJL) theories, which serve as initial conditions for the computational fluid dynamics (CFD) flume. In all systems, linear background shear currents can significantly affect the ISW properties, such as wave profiles, induced velocity, propagation speed, and energy distribution. Positive-vorticity background shear currents pycnocline thinning, whereas negative-vorticity currents result in thickening. The ISW shear strength is evaluated by the average rate of change of horizontal velocity at the pycnocline. In the two-layer system, positive-vorticity currents reduce the ISW shear effect, whereas the opposite occurs with negative-vorticity currents. The conclusions for the three-layer and continuous-density systems are in contrast to those of the two-layer system. This indicates that consideration or neglect of the pycnocline thickness may lead to opposite conclusions regarding the effects of background shear currents on the ISW shear effect. Furthermore, the influence of the nonlinear background shear currents is discussed. For most properties, the effects of nonlinear currents are consistent with those of linear currents, although they are generally weak.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102644"},"PeriodicalIF":2.9,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416783","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}
Pub Date : 2025-10-30DOI: 10.1016/j.ocemod.2025.102645
Agustinus Ribal , Brian K. Haus , Stefan Zieger , Milan Curcic
Accurate wave modeling is crucial for coastal management, navigation, and marine safety, particularly in complex coastal environments like Monterey Bay. Here, we investigated the performance of a global wave model, specifically the third-generation WAVEWATCH III model, downscaled to Monterey Bay, California, over a two-year period. We employed two different source term packages, namely ST4 and ST6, for wind input. Four distinct grids were generated, with three of them being regular grids and one being unstructured. A two-way nesting approach was applied for three grids, with resolutions in the latitude of 0.5°, 0.2°, and 0.05°, respectively. The fourth grid is unstructured, with maximum and minimum resolutions of 2 km and 0.15 km, respectively. Boundary conditions for the unstructured grids were obtained from the two-way nesting grids. Additionally, the model was forced by CFSv2 wind data with resolutions of 0.2°. This study focuses on the highest-resolution model, which utilizes an unstructured grid. Significant wave heights were validated against data from five NDBC buoys, six CDIP buoys, 22 CLASI buoy locations, eight spotter buoys, and altimeter data. Across all 41 buoy locations and altimeter data, the model exhibits excellent agreement with the measurements in terms of statistical properties. Furthermore, we observed that ST4 outperformed ST6 in terms of scatter index and Pearson’s correlation coefficient, while ST6 exhibited lower RMSE and bias. Regarding computational time, it was found that ST4 runs 25 % slower than ST6. In addition to significant wave height, wind sea, and swell were also compared based on one-dimensional wave spectra. Eleven buoys were used to validate the swell, with both ST4 and ST6 showing similar statistical performance for wind sea while ST6 should be used in swell conditions because it runs faster and gives better results.
{"title":"Global wave model performance in the vicinity of the Monterey Bay, California","authors":"Agustinus Ribal , Brian K. Haus , Stefan Zieger , Milan Curcic","doi":"10.1016/j.ocemod.2025.102645","DOIUrl":"10.1016/j.ocemod.2025.102645","url":null,"abstract":"<div><div>Accurate wave modeling is crucial for coastal management, navigation, and marine safety, particularly in complex coastal environments like Monterey Bay. Here, we investigated the performance of a global wave model, specifically the third-generation WAVEWATCH III model, downscaled to Monterey Bay, California, over a two-year period. We employed two different source term packages, namely ST4 and ST6, for wind input. Four distinct grids were generated, with three of them being regular grids and one being unstructured. A two-way nesting approach was applied for three grids, with resolutions in the latitude of 0.5°, 0.2°, and 0.05°, respectively. The fourth grid is unstructured, with maximum and minimum resolutions of 2 km and 0.15 km, respectively. Boundary conditions for the unstructured grids were obtained from the two-way nesting grids. Additionally, the model was forced by CFSv2 wind data with resolutions of 0.2°. This study focuses on the highest-resolution model, which utilizes an unstructured grid. Significant wave heights were validated against data from five NDBC buoys, six CDIP buoys, 22 CLASI buoy locations, eight spotter buoys, and altimeter data. Across all 41 buoy locations and altimeter data, the model exhibits excellent agreement with the measurements in terms of statistical properties. Furthermore, we observed that ST4 outperformed ST6 in terms of scatter index and Pearson’s correlation coefficient, while ST6 exhibited lower RMSE and bias. Regarding computational time, it was found that ST4 runs 25 % slower than ST6. In addition to significant wave height, wind sea, and swell were also compared based on one-dimensional wave spectra. Eleven buoys were used to validate the swell, with both ST4 and ST6 showing similar statistical performance for wind sea while ST6 should be used in swell conditions because it runs faster and gives better results.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102645"},"PeriodicalIF":2.9,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465784","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}
Pub Date : 2025-10-28DOI: 10.1016/j.ocemod.2025.102642
Hyungju Yoo , Haocheng Yu , Y. Joseph Zhang , Wenfan Wu , Fei Ye , Saeed Moghimi , Gregory Seroka , Zizang Yang , Edward Myers
Simulating Total Water Level (TWL) at continental scale is inherently challenging and it is often desirable to correct model bias a posteriori. Here we present a simple yet effective bias correction method for NOAA’s STOFS-3D (Three-Dimensional Surge and Tide Operational Forecast System) forecasting system. The method seeks to dynamically correct the model bias, calculated from the results from the previous 2 days, by compensating it with an adjusted non-tidal elevation boundary condition. The adjustment is spatially uniform but varies over each forecast cycle. We demonstrate that the existing 3D model bias is largely attributable to the model’s exclusion of the large-scale steric effect, and therefore the method can be effectively used to incorporate this effect into the 3D model. Assessment at over 140 NOAA stations in US east and Gulf coasts show significant reductions in biases and root-mean-square errors for the non-tidal elevation and TWL, while having a small impact on tides and surges during extreme conditions.
{"title":"A bias correction method for total water level prediction at continental scale","authors":"Hyungju Yoo , Haocheng Yu , Y. Joseph Zhang , Wenfan Wu , Fei Ye , Saeed Moghimi , Gregory Seroka , Zizang Yang , Edward Myers","doi":"10.1016/j.ocemod.2025.102642","DOIUrl":"10.1016/j.ocemod.2025.102642","url":null,"abstract":"<div><div>Simulating Total Water Level (TWL) at continental scale is inherently challenging and it is often desirable to correct model bias <em>a posteriori</em>. Here we present a simple yet effective bias correction method for NOAA’s STOFS-3D (Three-Dimensional Surge and Tide Operational Forecast System) forecasting system. The method seeks to dynamically correct the model bias, calculated from the results from the previous 2 days, by compensating it with an adjusted non-tidal elevation boundary condition. The adjustment is spatially uniform but varies over each forecast cycle. We demonstrate that the existing 3D model bias is largely attributable to the model’s exclusion of the large-scale steric effect, and therefore the method can be effectively used to incorporate this effect into the 3D model. Assessment at over 140 NOAA stations in US east and Gulf coasts show significant reductions in biases and root-mean-square errors for the non-tidal elevation and TWL, while having a small impact on tides and surges during extreme conditions.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102642"},"PeriodicalIF":2.9,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516668","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}
Pub Date : 2025-10-28DOI: 10.1016/j.ocemod.2025.102643
Fei Ye , Y. Joseph Zhang , Haocheng Yu , Felicio Cassalho , Julio Zyserman , Soroosh Mani , Saeed Moghimi , Hyungju Yoo , Greg Seroka , Zizang Yang , Edward Myers
Accurate simulation of compound flooding in the coastal transition zone requires a fully coupled hydrologic–hydrodynamic modeling system to capture the complex interactions between inland and oceanic floodwaters. Despite recent advances in fully coupled 3D modeling frameworks, significant challenges persist in resolving flow through intricate river networks, especially where small channels are poorly represented due to limitations in digital elevation models (DEMs). This study addresses these challenges by enhancing the model meshing process and evaluating coupling strategies in the lower Mississippi River region, a representative coastal transition zone with a dense and complex river network. We improve a previously developed semi-automatic meshing approach by incorporating the National Hydrography Dataset to ensure clean delineation and connectivity of small channels where DEM uncertainties often cause artificial blockages. We also assess two strategies for integrating hydrologic model outputs into the hydrodynamic domain: (1) a conventional “hand-off” method that imposes freshwater streamflows at the land boundary combined with spatially varying precipitation, and (2) an alternative scheme that distributes hydrologic outputs at every resolved channel within the hydrodynamic mesh. Results show that the enhanced mesh, combined with updated topographic data, substantially reduces domain-wide bias and improves water-level skill at inland USGS stations. The alternative coupling scheme produces results comparable to the base method, providing an extensible framework for potential future development. By improving inland channel resolution and establishing a pathway for deeper coupling with hydrologic models, this work strengthens the scientific foundation and contributes to the operational readiness of compound flood forecasting.
{"title":"Improving compound flood modeling skill in coastal transition zones","authors":"Fei Ye , Y. Joseph Zhang , Haocheng Yu , Felicio Cassalho , Julio Zyserman , Soroosh Mani , Saeed Moghimi , Hyungju Yoo , Greg Seroka , Zizang Yang , Edward Myers","doi":"10.1016/j.ocemod.2025.102643","DOIUrl":"10.1016/j.ocemod.2025.102643","url":null,"abstract":"<div><div>Accurate simulation of compound flooding in the coastal transition zone requires a fully coupled hydrologic–hydrodynamic modeling system to capture the complex interactions between inland and oceanic floodwaters. Despite recent advances in fully coupled 3D modeling frameworks, significant challenges persist in resolving flow through intricate river networks, especially where small channels are poorly represented due to limitations in digital elevation models (DEMs). This study addresses these challenges by enhancing the model meshing process and evaluating coupling strategies in the lower Mississippi River region, a representative coastal transition zone with a dense and complex river network. We improve a previously developed semi-automatic meshing approach by incorporating the National Hydrography Dataset to ensure clean delineation and connectivity of small channels where DEM uncertainties often cause artificial blockages. We also assess two strategies for integrating hydrologic model outputs into the hydrodynamic domain: (1) a conventional “hand-off” method that imposes freshwater streamflows at the land boundary combined with spatially varying precipitation, and (2) an alternative scheme that distributes hydrologic outputs at every resolved channel within the hydrodynamic mesh. Results show that the enhanced mesh, combined with updated topographic data, substantially reduces domain-wide bias and improves water-level skill at inland USGS stations. The alternative coupling scheme produces results comparable to the base method, providing an extensible framework for potential future development. By improving inland channel resolution and establishing a pathway for deeper coupling with hydrologic models, this work strengthens the scientific foundation and contributes to the operational readiness of compound flood forecasting.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102643"},"PeriodicalIF":2.9,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466587","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}
Pub Date : 2025-10-27DOI: 10.1016/j.ocemod.2025.102641
Zijian Cui , Tao Ding , Beifeng Zhou , Chujin Liang , Weifang Jin , Feilong Lin
Modern remote sensing techniques can now systematically extract coherent internal tidal signals (mode-1 and mode-2) from global sea surface height measurements. This capability arises from the accumulation of multi-source satellite altimetry data. However, the steady-state internal tides constructed by this method have limitations. They cannot fully characterize how dynamic oceanographic environmental variations influence internal tides. In realistic oceanic conditions, stratification and background currents significantly modulate the phase velocity and amplitude of internal tides. This modulation significantly enhances the energy proportion of incoherent internal tides. This study proposes applying the Gaussian beam superposition method to the Wavefront model to improve its capability in calculating internal tide energy evolution within complex oceanic environments, with validation provided by two sets of mooring observations from the northern South China Sea. The developed approach demonstrates potential for modeling time-varying patterns in global internal tide energy distribution under varying stratification and background current conditions.
{"title":"Application of Gaussian beam superposition method in the Wavefront model for internal tides","authors":"Zijian Cui , Tao Ding , Beifeng Zhou , Chujin Liang , Weifang Jin , Feilong Lin","doi":"10.1016/j.ocemod.2025.102641","DOIUrl":"10.1016/j.ocemod.2025.102641","url":null,"abstract":"<div><div>Modern remote sensing techniques can now systematically extract coherent internal tidal signals (mode-1 and mode-2) from global sea surface height measurements. This capability arises from the accumulation of multi-source satellite altimetry data. However, the steady-state internal tides constructed by this method have limitations. They cannot fully characterize how dynamic oceanographic environmental variations influence internal tides. In realistic oceanic conditions, stratification and background currents significantly modulate the phase velocity and amplitude of internal tides. This modulation significantly enhances the energy proportion of incoherent internal tides. This study proposes applying the Gaussian beam superposition method to the Wavefront model to improve its capability in calculating internal tide energy evolution within complex oceanic environments, with validation provided by two sets of mooring observations from the northern South China Sea. The developed approach demonstrates potential for modeling time-varying patterns in global internal tide energy distribution under varying stratification and background current conditions.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102641"},"PeriodicalIF":2.9,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416901","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}
Pub Date : 2025-10-15DOI: 10.1016/j.ocemod.2025.102640
Hao Yin , Jie Su , Jiping Liu , Mingfeng Wang
Snow density plays crucial roles in snow and sea ice thermodynamics. However, current coupled global climate models typically rely on empirical constants for snow properties in sea ice model components, limiting our understanding of how snow processes influence snow and sea ice evolution. To address this, we implemented a layered snow density parameterization in the Los Alamos Sea Ice Model (CICE), which explicitly considers strain compaction, wind-driven compaction, and fresh snow deposition. Compared to the control run, our experiments show that this scheme reduces wintertime positive bias in snow depth and cold bias in snow temperature in the Arctic. The reduction in winter conductivity heat loss accounts for the improvement in temperature biases, resulting in an enhanced net surface energy gain in the winter. Eighty-five percent of this additional energy gain is attributed solely to the density-dependent variation of the snow thermal conductivity over the Arctic. Further spatiotemporal analysis reveals distinct seasonal difference in the drivers of snow depth and density changes. Wind compaction and snowfall emerge as competing processes in winter, while ablation dominates during June and July. Their contributions to pan-Arctic multi-year mean snow density change are +0.161 (wind compaction), -0.198 (snowfall), +0.016 (strain compaction), +0.012 (phase changes), and -0.003 (snow-ice) kg·m-3·hr-1. The corresponding rates of snow depth changes are -0.095, +0.277, -0.020, -0.103, and -0.009 cm·day-1.
{"title":"Impacts of a layered snow density evolution scheme on Arctic snow and sea ice simulation in the CICE sea ice model","authors":"Hao Yin , Jie Su , Jiping Liu , Mingfeng Wang","doi":"10.1016/j.ocemod.2025.102640","DOIUrl":"10.1016/j.ocemod.2025.102640","url":null,"abstract":"<div><div>Snow density plays crucial roles in snow and sea ice thermodynamics. However, current coupled global climate models typically rely on empirical constants for snow properties in sea ice model components, limiting our understanding of how snow processes influence snow and sea ice evolution. To address this, we implemented a layered snow density parameterization in the Los Alamos Sea Ice Model (CICE), which explicitly considers strain compaction, wind-driven compaction, and fresh snow deposition. Compared to the control run, our experiments show that this scheme reduces wintertime positive bias in snow depth and cold bias in snow temperature in the Arctic. The reduction in winter conductivity heat loss accounts for the improvement in temperature biases, resulting in an enhanced net surface energy gain in the winter. Eighty-five percent of this additional energy gain is attributed solely to the density-dependent variation of the snow thermal conductivity over the Arctic. Further spatiotemporal analysis reveals distinct seasonal difference in the drivers of snow depth and density changes. Wind compaction and snowfall emerge as competing processes in winter, while ablation dominates during June and July. Their contributions to pan-Arctic multi-year mean snow density change are +0.161 (wind compaction), -0.198 (snowfall), +0.016 (strain compaction), +0.012 (phase changes), and -0.003 (snow-ice) kg·m<sup>-3</sup>·hr<sup>-1</sup>. The corresponding rates of snow depth changes are -0.095, +0.277, -0.020, -0.103, and -0.009 cm·day<sup>-1</sup>.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102640"},"PeriodicalIF":2.9,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416782","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}
Pub Date : 2025-10-15DOI: 10.1016/j.ocemod.2025.102639
Dongliang Shen, Xiaofeng Li
The Oceanic responses to Super Typhoon Bolaven (2023) in the Northwest Pacific Ocean are simulated and investigated by the Regional Ocean Modeling System (ROMS) integrated with a Machine Learning (ML) based ocean vertical mixing parameterization (OVMP) scheme. Traditional OVMP schemes, such as MY25 and KPP, underestimate the ocean vertical mixing processes under typhoon condition. To address this limitation, vertical eddy viscosity (Km) data were generated under Typhoon Bolaven using the high-resolution Parallelized Large Eddy Simulation Model (PALM) and used to train a XGBoost-based ML model. This XGBoost model is used to form a ML-based OVMP scheme and integrated into ROMS model via Forpy coupler. The results indicate that ROMS-ML coupled model can significantly improve the simulations of sea surface temperature (SST) cooling and subsurface thermal structure compared to traditional OVMP schemes. The ML-based OVMP scheme estimates stronger ocean vertical mixing under Typhoon Bolaven, enhancing the upper-oean heat redistribution and aligning more closely with the satellite and in-situ observations. Thermodynamic analyses reveal that the temperature cooling in the upper ocean is primarily driven by strong ocean vertical mixing, latent heat loss, and vertical advection. Notably, the structure of the North Pacific Subtropical Mode Water (STMW) was altered by Typhoon Bolaven, with reductions in its area and thickness, suggesting a weakened heat reservoir and potential impact on regional climate buffering. Momentum energy analyses confirm that vertical viscosity is the dominant contributor to oceanic energy input during Typhoon Bolaven, promoting local eddy generation and associated cooling. Moreover, additional diagnostics under Typhoon Haikui (2023) indicate that while the ML-based OVMP scheme captures localized cooling more accurately than traditional schemes, it tends to overestimate vertical mixing in regions with complex circulation and steep bathymetry. Overall, this study highlights the potential of physics-informed ML approaches in improving the accuracy of ocean simulations under extreme weather events, offering a promising pathway for improving coupled atmosphere–ocean prediction systems under climate change with more frequent super typhoons.
{"title":"Simulating oceanic responses to Super Typhoon Bolaven (2023) in the Northwest Pacific Ocean using a numerical model coupled with machine learning-based ocean vertical mixing parameterization","authors":"Dongliang Shen, Xiaofeng Li","doi":"10.1016/j.ocemod.2025.102639","DOIUrl":"10.1016/j.ocemod.2025.102639","url":null,"abstract":"<div><div>The Oceanic responses to Super Typhoon Bolaven (2023) in the Northwest Pacific Ocean are simulated and investigated by the Regional Ocean Modeling System (ROMS) integrated with a Machine Learning (ML) based ocean vertical mixing parameterization (OVMP) scheme. Traditional OVMP schemes, such as MY25 and KPP, underestimate the ocean vertical mixing processes under typhoon condition. To address this limitation, vertical eddy viscosity (Km) data were generated under Typhoon Bolaven using the high-resolution Parallelized Large Eddy Simulation Model (PALM) and used to train a XGBoost-based ML model. This XGBoost model is used to form a ML-based OVMP scheme and integrated into ROMS model via Forpy coupler. The results indicate that ROMS-ML coupled model can significantly improve the simulations of sea surface temperature (SST) cooling and subsurface thermal structure compared to traditional OVMP schemes. The ML-based OVMP scheme estimates stronger ocean vertical mixing under Typhoon Bolaven, enhancing the upper-oean heat redistribution and aligning more closely with the satellite and in-situ observations. Thermodynamic analyses reveal that the temperature cooling in the upper ocean is primarily driven by strong ocean vertical mixing, latent heat loss, and vertical advection. Notably, the structure of the North Pacific Subtropical Mode Water (STMW) was altered by Typhoon Bolaven, with reductions in its area and thickness, suggesting a weakened heat reservoir and potential impact on regional climate buffering. Momentum energy analyses confirm that vertical viscosity is the dominant contributor to oceanic energy input during Typhoon Bolaven, promoting local eddy generation and associated cooling. Moreover, additional diagnostics under Typhoon Haikui (2023) indicate that while the ML-based OVMP scheme captures localized cooling more accurately than traditional schemes, it tends to overestimate vertical mixing in regions with complex circulation and steep bathymetry. Overall, this study highlights the potential of physics-informed ML approaches in improving the accuracy of ocean simulations under extreme weather events, offering a promising pathway for improving coupled atmosphere–ocean prediction systems under climate change with more frequent super typhoons.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102639"},"PeriodicalIF":2.9,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324806","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}
Langmuir turbulence in shallow-water coastal environments can reach the seafloor, developing into Langmuir supercells, which enhance size and mixing intensity. Two fundamental issues in coastal Langmuir turbulence remain unclear: (i) the energy cycle of the turbulence under different circumstances, and (ii) its effect on vertical mixing. We investigate these issues using large eddy simulations, considering aligned and opposing wind-wave and current directions. Results show that Langmuir supercells possess an intense full-column, narrow-band energetic mode, distinct from Langmuir turbulence in the energy spectrum. This mode occurs with aligned wind/wave and current directions but disappears when they oppose. In the latter case, only Langmuir and shear turbulence exist near surface and bottom boundaries; moreover, despite no stratification in simulations, their intensities are suppressed by a mid-layer barrier that limits surface-bottom interaction. When Langmuir supercells are present, the surface-bottom exchange of momentum is highly asymmetric between upwelling and downwelling limbs. Strong connections between surface and bottom turbulence, as indicated by the vortex-tube-connection events, can only be found in upwelling regions. As a result, the upwelling motions contribute considerably more to the momentum flux than the downwelling motions. All these results indicate that, despite the windrow pattern on the ocean surface from near-surface wind-wave interaction, whether full-column supercells can be activated or suppressed depends on different interactions between near-surface wind-wave forcing and near-bottom shear forcing. Once Langmuir supercells are activated, they differ significantly from Langmuir turbulence from the perspectives of energy and momentum transport; therefore, they cannot be simply treated as a “full column” version of Langmuir turbulence.
{"title":"The role of longitudinal alignment between surface and bottom forcing on the full-column turbulence mixing in the coastal ocean","authors":"Jiahao Huang , Marcelo Chamecki , Qing Li , Bicheng Chen","doi":"10.1016/j.ocemod.2025.102637","DOIUrl":"10.1016/j.ocemod.2025.102637","url":null,"abstract":"<div><div>Langmuir turbulence in shallow-water coastal environments can reach the seafloor, developing into Langmuir supercells, which enhance size and mixing intensity. Two fundamental issues in coastal Langmuir turbulence remain unclear: (i) the energy cycle of the turbulence under different circumstances, and (ii) its effect on vertical mixing. We investigate these issues using large eddy simulations, considering aligned and opposing wind-wave and current directions. Results show that Langmuir supercells possess an intense full-column, narrow-band energetic mode, distinct from Langmuir turbulence in the energy spectrum. This mode occurs with aligned wind/wave and current directions but disappears when they oppose. In the latter case, only Langmuir and shear turbulence exist near surface and bottom boundaries; moreover, despite no stratification in simulations, their intensities are suppressed by a mid-layer barrier that limits surface-bottom interaction. When Langmuir supercells are present, the surface-bottom exchange of momentum is highly asymmetric between upwelling and downwelling limbs. Strong connections between surface and bottom turbulence, as indicated by the vortex-tube-connection events, can only be found in upwelling regions. As a result, the upwelling motions contribute considerably more to the momentum flux than the downwelling motions. All these results indicate that, despite the windrow pattern on the ocean surface from near-surface wind-wave interaction, whether full-column supercells can be activated or suppressed depends on different interactions between near-surface wind-wave forcing and near-bottom shear forcing. Once Langmuir supercells are activated, they differ significantly from Langmuir turbulence from the perspectives of energy and momentum transport; therefore, they cannot be simply treated as a “full column” version of Langmuir turbulence.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102637"},"PeriodicalIF":2.9,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267922","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}
Pub Date : 2025-10-09DOI: 10.1016/j.ocemod.2025.102636
Julie Cheynel , Lucia Pineau-Guillou , Pascal Lazure , Marta Marcos , Florent Lyard , Nicolas Raillard
Changes in extreme sea levels, combined with the growth of coastal population, are critical factors in evaluating the risks related to coastal flooding. Thus, studying the variability and trends of storm surges, a major contributor to extreme sea levels, becomes essential for coastal protection policies. We developed in the North Atlantic the first hourly surge hindcast covering the full 20th century (1900–2015) on a 0.1°grid, and called ClimEx hindcast. We validated the hindcast against 34 long-term tide gauges. The model shows overall very good performance for surges (Root Mean Square Error of 9.3 cm on average), and good performance for extreme surges, despite an overall underestimation. To investigate the variability and trends in storm surges, we performed a non-stationary extreme value analysis on modeled and observed storm surges. The seasonality of storm surges is highly dependent on the area. The seasonal amplitude varies from typically 10 cm, to more than 40 cm in the North Sea. The storm surge season occurs around December–January in the north of the domain (above 40°N), due to winter extra-tropical cyclones, and around September–October in the south-west, due to tropical cyclones. The dependence of storm surges with the North Atlantic Oscillation extends from the coasts to the deep ocean, and is positive above 50°N and negative below. Observed storm surges show mostly non significant or small trends ( 1 mm/yr), while the model displays positive trends almost everywhere, possibly due to inhomogeneities in the atmospheric forcing dataset prior to 1950.
{"title":"A secular sea level hindcast (1900–2015) to investigate extreme surges variability and trends in the North Atlantic","authors":"Julie Cheynel , Lucia Pineau-Guillou , Pascal Lazure , Marta Marcos , Florent Lyard , Nicolas Raillard","doi":"10.1016/j.ocemod.2025.102636","DOIUrl":"10.1016/j.ocemod.2025.102636","url":null,"abstract":"<div><div>Changes in extreme sea levels, combined with the growth of coastal population, are critical factors in evaluating the risks related to coastal flooding. Thus, studying the variability and trends of storm surges, a major contributor to extreme sea levels, becomes essential for coastal protection policies. We developed in the North Atlantic the first hourly surge hindcast covering the full 20th century (1900–2015) on a 0.1°grid, and called ClimEx hindcast. We validated the hindcast against 34 long-term tide gauges. The model shows overall very good performance for surges (Root Mean Square Error of 9.3 cm on average), and good performance for extreme surges, despite an overall underestimation. To investigate the variability and trends in storm surges, we performed a non-stationary extreme value analysis on modeled and observed storm surges. The seasonality of storm surges is highly dependent on the area. The seasonal amplitude varies from typically 10 cm, to more than 40 cm in the North Sea. The storm surge season occurs around December–January in the north of the domain (above 40°N), due to winter extra-tropical cyclones, and around September–October in the south-west, due to tropical cyclones. The dependence of storm surges with the North Atlantic Oscillation extends from the coasts to the deep ocean, and is positive above 50°N and negative below. Observed storm surges show mostly non significant or small trends (<span><math><mrow><mo><</mo><mo>±</mo></mrow></math></span> 1 mm/yr), while the model displays positive trends almost everywhere, possibly due to inhomogeneities in the atmospheric forcing dataset prior to 1950.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"199 ","pages":"Article 102636"},"PeriodicalIF":2.9,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267924","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号