Articles | Volume 19, issue 1
https://doi.org/10.5194/gmd-19-187-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-19-187-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Model experiment description paper
| 
07 Jan 2026
Model experiment description paper |
| 07 Jan 2026
| 07 Jan 2026
Assessing vertical coordinate system performance in the Regional Modular Ocean Model 6 configuration for Northwest Pacific
Inseong Chang
Division of Earth Environmental System Science, Pukyong National University, Busan, Republic of Korea
Ocean Circulation and Climate Research Department, Korea Institute of Ocean Sciences and Technology, Busan, Republic of Korea
Division of Earth Environmental System Science, Pukyong National University, Busan, Republic of Korea
Young-Gyu Park
Ocean Circulation and Climate Research Department, Korea Institute of Ocean Sciences and Technology, Busan, Republic of Korea
Hyunkeun Jin
Ocean Circulation and Climate Research Department, Korea Institute of Ocean Sciences and Technology, Busan, Republic of Korea
Gyundo Pak
Ocean Circulation and Climate Research Department, Korea Institute of Ocean Sciences and Technology, Busan, Republic of Korea
Andrew C. Ross
NOAA OAR Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA
Robert Hallberg
NOAA OAR Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA
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Michael Jacox, Dmitry Dukhovskoy, Jessie Liu, Michael Alexander, Elizabeth Drenkard, Andrew Ross, Natalie Freeman, Dillon Amaya, Steven Bograd, Allison Cluett, Nicole Lovenduski, Samuel Mogen, Mercedes Pozo Buil, Charles Stock, Wei Cheng, Albert Hermann, Liwei Jia, Nathaniel Johnson, Kelly Kearney, Colleen McHugh, and Darren Pilcher
EGUsphere, https://doi.org/10.5194/egusphere-2026-5844, https://doi.org/10.5194/egusphere-2026-5844, 2026
This preprint is open for discussion and under review for Ocean Science (OS).
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We present a new system to predict conditions in the Northeast Pacific Ocean up to one year in advance. By comparing past forecasts with ocean measurements, we show that we can accurately predict temperature and oxygen levels several months in advance. These predictions will soon be available to the public, enabling coastal communities, managers, and industries to make better proactive decisions.
Vimal Koul, Andrew C. Ross, Charles Stock, Liping Zhang, Andrew T. Wittenberg, and Thomas Delworth
Ocean Sci., 22, 3017–3036, https://doi.org/10.5194/os-22-3017-2026, https://doi.org/10.5194/os-22-3017-2026, 2026
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Predicting coastal ocean conditions years ahead has been difficult due to complex regional dynamics. This work shows we can forecast bottom temperature, oxygen, and acidity up to a decade ahead for the Northeast US Shelf. Our forecasts indicate increasing Labrador water may accelerate acidification, threatening shell-forming organisms. This provides a foundation for early warning systems to help communities and fisheries adapt proactively.
Andrew Ross, Charles Stock, Vimal Koul, Liwei Jia, Nathaniel Johnson, and Colleen McHugh
EGUsphere, https://doi.org/10.5194/egusphere-2026-5262, https://doi.org/10.5194/egusphere-2026-5262, 2026
This preprint is open for discussion and under review for Ocean Science (OS).
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This paper examines the accuracy of forecasts of ocean oxygen and acidity, both critical for the healthy functioning of fish and marine ecosystems, along the continental shelf off the Northeast U.S. coastline. The forecasts are produced using a novel numerical model able to resolve fine oceanographic details. Comparison with a reference dataset shows that the model often accurately predicts oxygen and acidity up to several months in advance.
Joseph K. Ansong, Brian K. Arbic, Romain Bourdalle-Badié, Clément Bricaud, Jérôme Chanut, Dimitris Menemenlis, Richard D. Ray, Michael Schindelegger, Alan J. Wallcraft, He Wang, Alistair J. Adcroft, Frédéric Briol, Maarten C. Buijsman, Loren Carrère, Eric P. Chassignet, Gerald Dibarboure, Robert W. Hallberg, Christopher N. Hill, Ariane Koch-Larrouy, Florent Lyard, Matthew R. Mazloff, An T. Nguyen, Nicolas Picot, Rui M. Ponte, and Jay F. Shriver
EGUsphere, https://doi.org/10.5194/egusphere-2026-5064, https://doi.org/10.5194/egusphere-2026-5064, 2026
This preprint is open for discussion and under review for Ocean Science (OS).
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We assess how well four high-resolution global ocean models reproduce surface and internal tides compared with satellite observations. Some models produce internal tides that are too strong, but including energy loss over rough seafloor improves their accuracy. Longer model records and higher resolution also improve agreement with observations. We further identify errors in the tidal forcing of widely used MITgcm simulations that reduce the accuracy of their simulated tides.
Hong Thi My Tran, Young-Gyu Park, and Jun Myoung Choi
Ocean Sci., 22, 2533–2558, https://doi.org/10.5194/os-22-2533-2026, https://doi.org/10.5194/os-22-2533-2026, 2026
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We tracked 33 floating devices released off the Korean coast to understand how debris moves across the East/Japan Sea. Their paths showed a route toward Japan and an early split caused by ocean circulation. By comparing observations with computer simulations, we found that the best predictions combine geostrophic currents, Stoke drift, and windage, while deeper devices also require Ekman currents. Winter favored faster eastward transport and beaching, whereas summer caused wider spreading.
Dmitry S. Dukhovskoy, Theresa Cordero, Katherine Hedstrom, Michael Alexander, Michael Jacox, Robert Hallberg, Matthew Harrison, and Jessie Liu
Geosci. Model Dev., 19, 7169–7196, https://doi.org/10.5194/gmd-19-7169-2026, https://doi.org/10.5194/gmd-19-7169-2026, 2026
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Regional sea ice models often struggle to represent sea ice near model domain boundaries, where errors can accumulate over time. We implemented and tested a method that gradually adjusts simulated sea ice toward prescribed conditions while preserving a realistic evolution of the ice cover. Experiments in the Arctic and Northeast Pacific show improved sea ice simulations and ocean surface conditions, providing a practical tool for regional forecasting and research applications.
Gabriela Negrete García, Dax Matthews, Charles A. Stock, Brian Powell, Ryan R. Rykaczewski, Kisei Tanaka, Hannah Barkley, Tobias Friedrich, Jessica Y. Luo, Andrew C. Ross, and Yi-Cheng Teng
EGUsphere, https://doi.org/10.5194/egusphere-2026-1877, https://doi.org/10.5194/egusphere-2026-1877, 2026
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
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Ocean waters near the Hawaiian Islands support billions of dollars in fisheries, tourism, and coral reefs, yet managing these resources requires understanding ocean dynamics at multiple scales. We developed and tested a high-resolution ocean model for the central North Pacific against satellite data, long-term ocean monitoring, and coral temperatures. The model reliably reproduced key patterns across all scales, offering a tool for forecasting fish habitat, reef health, and ocean acidification.
Dongmin Kim, Andrew C. Ross, Sang-Ik Shin, Fabian A. Gomez, Jasmin G. John, Denis L. Volkov, Sang-Ki Lee, Michael A. Alexander, and Charles A. Stock
Ocean Sci., 22, 1987–2009, https://doi.org/10.5194/os-22-1987-2026, https://doi.org/10.5194/os-22-1987-2026, 2026
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Using high-resolution Modular Ocean Model version 6, we projected Northwest Atlantic changes under four future emission scenarios. Results show a weakening Gulf Stream reduces upwelling, causing significant shelf warming and salinification. This also leads to dynamic sea-level rise along the US East Coast, particularly in the South Atlantic Bight, with critical implications for marine ecosystems and coastal risks.
Jacob Steinberg, John Krasting, and Andrew Ross
EGUsphere, https://doi.org/10.5194/egusphere-2026-3057, https://doi.org/10.5194/egusphere-2026-3057, 2026
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We build and analyze an ensemble of year-long hindcasts of sea level in the northwest Atlantic Ocean. With a particular focus at US East Coast tide gauge stations, we reveal regional differences in simulated variability resulting from different parent and downscaled ocean model horizontal resolution. We consider differences among parent model, downscaled model, and observed variability as a function of frequency and find downscaled enhancements increase with decreasing latitude.
Meena Raju, David J. Cannon, Peter Alsip, He Wang, Jia Wang, Theresa Cordero, Robert W. Hallberg, Charles A. Stock, and Joseph A. Langan
Geosci. Model Dev., 19, 4331–4356, https://doi.org/10.5194/gmd-19-4331-2026, https://doi.org/10.5194/gmd-19-4331-2026, 2026
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This study developed the Modular Ocean Model version 6.0 coupled with Sea Ice Simulator version 2.0 for the Great Lakes, validated against observations and an operational model. This study also tested two vertical coordinate systems, z* and hybrid. The model reproduced lake physics with good skill. The hybrid vertical coordinate improved thermocline representation and preserved deep cold-water during stratification, demonstrating the model’s suitability for large freshwater systems.
Nicole Cristine Laureanti, Enrique Curchitser, Katherine Hedstrom, Alistair Adcroft, Robert Hallberg, Matthew J. Harrison, Raphael Dussin, Sin Chan Chou, Paulo Nobre, Emanuel Giarolla, and Rosio Camayo
Geosci. Model Dev., 19, 3109–3128, https://doi.org/10.5194/gmd-19-3109-2026, https://doi.org/10.5194/gmd-19-3109-2026, 2026
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This study investigates the variability of currents in the Southwestern Atlantic Ocean using a high-resolution simulation. Particularly in the Brazil-Malvinas Confluence (BMC), it finds that the southward movement of the BMC, induced by the warming trends in the region, is balanced by northward flow from the Malvinas Current and Pacific Waves. The analysis also examines the intense northward displacement of the North Brazil Current, where inconsistencies in the simulation affect its evolution.
Inseong Chang, Young Ho Kim, Young-Gyu Park, Hyunkeun Jin, Gyundo Pak, Andrew C. Ross, and Robert Hallberg
Geosci. Model Dev., 19, 3053–3074, https://doi.org/10.5194/gmd-19-3053-2026, https://doi.org/10.5194/gmd-19-3053-2026, 2026
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This study assesses how vertical coordinate choice shapes barotropic and baroclinic tide simulations in a high-resolution, MOM6 (Modular Ocean Model version 6) regional model. Focusing on the Yellow Sea under realistic forcing and seasonal stratification, we compare z* and z*-isopycnal hybrid to quantify coordinate-dependent impacts on tidal energetics and vertical structure. The results underscore that vertical representation is critical for accurately reproducing coastal stratification and tide–stratification interactions.
Claire K. Yung, Xylar S. Asay-Davis, Alistair Adcroft, Christopher Y. S. Bull, Jan De Rydt, Michael S. Dinniman, Benjamin K. Galton-Fenzi, Daniel Goldberg, David E. Gwyther, Robert Hallberg, Matthew Harrison, Tore Hattermann, David M. Holland, Denise Holland, Paul R. Holland, James R. Jordan, Nicolas C. Jourdain, Kazuya Kusahara, Gustavo Marques, Pierre Mathiot, Dimitris Menemenlis, Adele K. Morrison, Yoshihiro Nakayama, Olga Sergienko, Robin S. Smith, Alon Stern, Ralph Timmermann, and Qin Zhou
The Cryosphere, 20, 2053–2088, https://doi.org/10.5194/tc-20-2053-2026, https://doi.org/10.5194/tc-20-2053-2026, 2026
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The second Ice Shelf-Ocean Model Intercomparison Project, ISOMIP+, compares 12 ice shelf-ocean models with a common, idealised, static configuration, aiming to assess inter-model variability. Models show similar basal melt rate patterns, ocean profiles and circulation but differ in ice-ocean boundary layer properties. Ice-ocean boundary layer representation is a key area for future work, as are realistic-domain ice sheet-ocean model intercomparisons.
Enhui Liao, Laure Resplandy, Fan Yang, Yangyang Zhao, Sam Ditkovsky, Manon Malsang, Jenna Pearson, Andrew C. Ross, Robert Hallberg, and Charles Stock
Geosci. Model Dev., 18, 6553–6596, https://doi.org/10.5194/gmd-18-6553-2025, https://doi.org/10.5194/gmd-18-6553-2025, 2025
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The northern Indian Ocean is central to the livelihoods and economies of countries that comprise about one-third of the world's population. We present a high-resolution (~10 km) ocean model that simulates seasonal and year-to-year variability in ocean, including currents, oxygen levels, and phytoplankton growth. This model is a powerful tool to study how climate change and human activities influence the northern Indian Ocean, which can be used for marine resource applications and management.
Elizabeth J. Drenkard, Charles A. Stock, Andrew C. Ross, Yi-Cheng Teng, Theresa Cordero, Wei Cheng, Alistair Adcroft, Enrique Curchitser, Raphael Dussin, Robert Hallberg, Claudine Hauri, Katherine Hedstrom, Albert Hermann, Michael G. Jacox, Kelly A. Kearney, Rémi Pagès, Darren J. Pilcher, Mercedes Pozo Buil, Vivek Seelanki, and Niki Zadeh
Geosci. Model Dev., 18, 5245–5290, https://doi.org/10.5194/gmd-18-5245-2025, https://doi.org/10.5194/gmd-18-5245-2025, 2025
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We made a new regional ocean model to assist fisheries and ecosystem managers in making decisions in the Northeast Pacific Ocean (NEP). We found that the model did well simulating past ocean conditions like temperature and nutrient and oxygen levels and can even reproduce metrics used by, and important to, ecosystem managers.
Andrew C. Ross, Charles A. Stock, Vimal Koul, Thomas L. Delworth, Feiyu Lu, Andrew Wittenberg, and Michael A. Alexander
Ocean Sci., 20, 1631–1656, https://doi.org/10.5194/os-20-1631-2024, https://doi.org/10.5194/os-20-1631-2024, 2024
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In this paper, we use a high-resolution regional ocean model to downscale seasonal ocean forecasts from the Seamless System for Prediction and EArth System Research (SPEAR) model of the Geophysical Fluid Dynamics Laboratory (GFDL). We find that the downscaled model has significantly higher prediction skill in many cases.
Andrew C. Ross, Charles A. Stock, Alistair Adcroft, Enrique Curchitser, Robert Hallberg, Matthew J. Harrison, Katherine Hedstrom, Niki Zadeh, Michael Alexander, Wenhao Chen, Elizabeth J. Drenkard, Hubert du Pontavice, Raphael Dussin, Fabian Gomez, Jasmin G. John, Dujuan Kang, Diane Lavoie, Laure Resplandy, Alizée Roobaert, Vincent Saba, Sang-Ik Shin, Samantha Siedlecki, and James Simkins
Geosci. Model Dev., 16, 6943–6985, https://doi.org/10.5194/gmd-16-6943-2023, https://doi.org/10.5194/gmd-16-6943-2023, 2023
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We evaluate a model for northwest Atlantic Ocean dynamics and biogeochemistry that balances high resolution with computational economy by building on the new regional features in the MOM6 ocean model and COBALT biogeochemical model. We test the model's ability to simulate impactful historical variability and find that the model simulates the mean state and variability of most features well, which suggests the model can provide information to inform living-marine-resource applications.
Fabian A. Gomez, Sang-Ki Lee, Charles A. Stock, Andrew C. Ross, Laure Resplandy, Samantha A. Siedlecki, Filippos Tagklis, and Joseph E. Salisbury
Earth Syst. Sci. Data, 15, 2223–2234, https://doi.org/10.5194/essd-15-2223-2023, https://doi.org/10.5194/essd-15-2223-2023, 2023
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We present a river chemistry and discharge dataset for 140 rivers in the United States, which integrates information from the Water Quality Database of the US Geological Survey (USGS), the USGS’s Surface-Water Monthly Statistics for the Nation, and the U.S. Army Corps of Engineers. This dataset includes dissolved inorganic carbon and alkalinity, two key properties to characterize the carbonate system, as well as nutrient concentrations, such as nitrate, phosphate, and silica.
Gustavo M. Marques, Nora Loose, Elizabeth Yankovsky, Jacob M. Steinberg, Chiung-Yin Chang, Neeraja Bhamidipati, Alistair Adcroft, Baylor Fox-Kemper, Stephen M. Griffies, Robert W. Hallberg, Malte F. Jansen, Hemant Khatri, and Laure Zanna
Geosci. Model Dev., 15, 6567–6579, https://doi.org/10.5194/gmd-15-6567-2022, https://doi.org/10.5194/gmd-15-6567-2022, 2022
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We present an idealized ocean model configuration and a set of simulations performed using varying horizontal grid spacing. While the model domain is idealized, it resembles important geometric features of the Atlantic and Southern oceans. The simulations described here serve as a framework to effectively study mesoscale eddy dynamics, to investigate the effect of mesoscale eddies on the large-scale dynamics, and to test and evaluate eddy parameterizations.
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Short summary
We conducted sensitivity experiments to examine how different vertical coordinates influence the representation of water masses and tides using a high-resolution regional ocean model for the Northwest Pacific. We found that the choice of vertical coordinate strongly affects the degree of artificial mixing, which in turn changes how well the model reproduces key ocean features. This highlights the importance of selecting a vertical coordinate when developing regional ocean models.
We conducted sensitivity experiments to examine how different vertical coordinates influence the...
