Articles | Volume 22, issue 3
https://doi.org/10.5194/os-22-1545-2026
© 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/os-22-1545-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
18 May 2026
Research article | Highlight paper |
| 18 May 2026
| 18 May 2026
Internal tides–cyclonic eddy interaction and intermodal energy pathways: evidence from 3 km NEMO-AMAZON36 simulations
Fabius Kouogang
CORRESPONDING AUTHOR
CECI, Université de Toulouse, CERFACS/CNRS/IRD, Toulouse, France
Departamento de Oceanografia, Universidade Federal de Pernambuco, DOCEAN/UFPE, Recife, Brazil
Ariane Koch-Larrouy
CECI, Université de Toulouse, CERFACS/CNRS/IRD, Toulouse, France
Xavier Carton
Physical and Spatial Oceanography Laboratory, European Institute for Marine Studies, University of Western Brittany, Plouzane, France
Fernand Assene
Department of Maritime Navigation and Information System, National Advanced School of Maritime and Ocean Science and Technology (NASMOST), University of Ebolowa, Kribi, Cameroon
Guillaume Morvan
Université de Toulouse, LEGOS (CNES/CNRS/IRD/UT3), Toulouse, France
Moacyr Araujo
Departamento de Oceanografia, Universidade Federal de Pernambuco, DOCEAN/UFPE, Recife, Brazil
Related authors
Chloé Goret, Ariane Koch-Larrouy, Fabius Kouogang, Carina Regina de Macedo, Amine M'Hamdi, Jorge M. Magalhães, José Carlos Bastos da Silva, Michel Tchilibou, Camila Artana, Isabelle Dadou, Antoine Delepoulle, Simon Barbot, Maxime Ballarotta, Loren Carrère, and Alex Costa da Silva
Ocean Sci., 22, 679–698, https://doi.org/10.5194/os-22-679-2026, https://doi.org/10.5194/os-22-679-2026, 2026
Short summary
Short summary
Using high-resolution satellite measurements, we observed how eddies off the Amazon shelf modify internal solitary waves. The results show that these waves can be deflected from their path, even split into two branches, and change their geometry when interacting with different types of eddies. This work provides new insight into the ocean’s complex dynamic interactions and could help guide future predictions of ocean behavior and its effects on coastal and marine ecosystems.
Fabius Kouogang, Ariane Koch-Larrouy, Jorge Magalhaes, Alex Costa da Silva, Daphne Kerhervé, Arnaud Bertrand, Evan Cervelli, Fernand Assene, Jean-François Ternon, Pierre Rousselot, James Lee, Marcelo Rollnic, and Moacyr Araujo
Ocean Sci., 21, 1589–1608, https://doi.org/10.5194/os-21-1589-2025, https://doi.org/10.5194/os-21-1589-2025, 2025
Short summary
Short summary
New research reveals that ocean mixing off the Amazon coast peaks not only near wave origins but also 230 km offshore, where different wave paths may intersect. This overlap likely forms strong solitary waves that intensify turbulence. Based on the AMAZOMIX-2021 cruise, which collected direct turbulence measurements alongside hydrographic data, the study quantifies dissipation and the relative contributions of tidal shear and large-scale shear. This mixing helps redistribute heat and nutrients, playing a key role in climate regulation and marine ecosystems.
Amine M'hamdi, Ariane Koch-Larrouy, Isabelle Dadou, Carina Regina de Macedo, Fernand Assene, Vincent Vantrepotte, Guillaume Morvan, and Alex Costa da Silva
EGUsphere, https://doi.org/10.5194/egusphere-2026-2729, https://doi.org/10.5194/egusphere-2026-2729, 2026
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
We show that tides play a major role in structuring nutrient supply and phytoplankton variability across the Amazon shelf–offshore continuum, from the 15-day spring–neap cycle to seasonal timescales. By enhancing nitrate uplift, especially along the shelf break and internal-tide pathway, tides stimulate offshore chlorophyll growth, modulate the nitracline and deep chlorophyll maximum, and explain a large fraction of the seasonal nutrient signal.
Landry Junior Mbang Essome, Gaël Alory, Casimir Yelognissé Da-Allada, Isabelle Dadou, Roy Dorgeless Ngakala, and Guillaume Morvan
Ocean Sci., 22, 1279–1309, https://doi.org/10.5194/os-22-1279-2026, https://doi.org/10.5194/os-22-1279-2026, 2026
Short summary
Short summary
We used a high-resolution model to study how ocean currents and waves, especially coastal trapped waves, control nitrate variability in the Gabon-Congo upwelling system. This nutrient availability drives seasonal marine productivity, with the Congo River also adding significant nitrate. Our research clarifies the complex interplay of physical and biological factors, offering crucial insights for managing regional fisheries and assessing climate change impacts on this vital ecosystem.
Carina Regina de Macedo, Ariane Koch-Larrouy, José Carlos Bastos da Silva, Jorge Manuel Magalhães, Fernand Assene, Manh Duy Tran, Isabelle Dadou, Amine M'Hamdi, Trung Kien Tran, and Vincent Vantrepotte
Ocean Sci., 22, 871–892, https://doi.org/10.5194/os-22-871-2026, https://doi.org/10.5194/os-22-871-2026, 2026
Short summary
Short summary
We investigated how ocean tides influence marine phytoplankton along the North Brazilian coast. Using satellite data from 2005 to 2021, we found that tides can either enhance or reduce phytoplankton growth on the continental shelf. Offshore, internal tides stimulate primary production along their pathways. These results improve our understanding of how tidal processes shape marine life in tropical coastal regions.
Chloé Goret, Ariane Koch-Larrouy, Fabius Kouogang, Carina Regina de Macedo, Amine M'Hamdi, Jorge M. Magalhães, José Carlos Bastos da Silva, Michel Tchilibou, Camila Artana, Isabelle Dadou, Antoine Delepoulle, Simon Barbot, Maxime Ballarotta, Loren Carrère, and Alex Costa da Silva
Ocean Sci., 22, 679–698, https://doi.org/10.5194/os-22-679-2026, https://doi.org/10.5194/os-22-679-2026, 2026
Short summary
Short summary
Using high-resolution satellite measurements, we observed how eddies off the Amazon shelf modify internal solitary waves. The results show that these waves can be deflected from their path, even split into two branches, and change their geometry when interacting with different types of eddies. This work provides new insight into the ocean’s complex dynamic interactions and could help guide future predictions of ocean behavior and its effects on coastal and marine ecosystems.
Axel Tassigny, Stef L. Bardoel, Thomas Valran, Samuel Viboud, Louis Gostiaux, Joël Sommeria, Lucie Bordois, Xavier Carton, and Maria Eletta Negretti
Ocean Sci., 22, 459–500, https://doi.org/10.5194/os-22-459-2026, https://doi.org/10.5194/os-22-459-2026, 2026
Short summary
Short summary
This study uses a realistic laboratory model to reveal how tides and topography shape the exchange of waters at the Strait of Gibraltar. The experiments show when, where and why strong dilution occurs, and how and why conditions change between spring and neap tides. The results give new insight into a complex passage that links the Atlantic and Mediterranean, improving our ability to understand and predict its behavior.
Fernand Assene, Ariane Koch-Larrouy, Carina Regina de Macedo, Isabelle Dadou, Michel Tchilibou, Guillaume Morvan, Damien Allain, Simon Barbot, Alex Costa da Silva, Jérôme Chanut, Vincent Vantrepotte, Florent Lyard, Edward Zaron, and Trung-Kien Tran
EGUsphere, https://doi.org/10.5194/egusphere-2026-557, https://doi.org/10.5194/egusphere-2026-557, 2026
Short summary
Short summary
We examine temperature (T) variability at two semidiurnal and one fortnightly frequencies in North Brazil using satellite-observed and modeled temperatures. Semidiurnal T variability is weak offshore but peaks over the shelf due to barotropic mixing. Below 100 m, internal tide (IT)-driven mixing causes strong T variability (0.6–2 °C). T fortnightly maximums (~0.15 °C) appear along IT pathways, showing their key role.
Perrine Bauchot, Ariane Koch-Larrouy, Michel Tchilibou, Loren Carrère, Fabrice Hernandez, Guillaume Morvan, and Jérôme Chanut
EGUsphere, https://doi.org/10.5194/egusphere-2026-93, https://doi.org/10.5194/egusphere-2026-93, 2026
Short summary
Short summary
The Vitória–Trindade Ridge off the Brazilian coast is a hotspot for internal tides, which drive energy and nutrients exchanges in the ocean. Using satellite data and a high-resolution ocean model, we study what influences these small waves in this region. We show that internal tides are generated more strongly in summer and lose energy faster in winter. Ocean eddies may also affect their fate. These results are essential for understanding oceanic energy pathways and refine model predictions.
Amine M'hamdi, Ariane Koch-Larrouy, Alex Costa da Silva, Isabelle Dadou, Carina Regina de Macedo, Anthony Bosse, Vincent Vantrepotte, Habib Micaël Aguedjou, Trung-Kien Tran, Pierre Testor, Laurent Mortier, Arnaud Bertrand, Pedro Augusto Mendes de Castro Melo, James Lee, Marcelo Rollnic, and Moacyr Araujo
Ocean Sci., 21, 2873–2894, https://doi.org/10.5194/os-21-2873-2025, https://doi.org/10.5194/os-21-2873-2025, 2025
Short summary
Short summary
In the ocean off the Amazon shelf, internal waves caused by tides move water layers up and down and mix them. Using an underwater glider and satellites, we found internal tides redistribute chlorophyll from the deep chlorophyll maximum upward to the surface and downward to depth. Turbulent chlorophyll fluxes supply about 38 % of surface chlorophyll, and total chlorophyll increases by 14–29 % during strong tides, potentially affecting the marine food web.
Fabius Kouogang, Ariane Koch-Larrouy, Jorge Magalhaes, Alex Costa da Silva, Daphne Kerhervé, Arnaud Bertrand, Evan Cervelli, Fernand Assene, Jean-François Ternon, Pierre Rousselot, James Lee, Marcelo Rollnic, and Moacyr Araujo
Ocean Sci., 21, 1589–1608, https://doi.org/10.5194/os-21-1589-2025, https://doi.org/10.5194/os-21-1589-2025, 2025
Short summary
Short summary
New research reveals that ocean mixing off the Amazon coast peaks not only near wave origins but also 230 km offshore, where different wave paths may intersect. This overlap likely forms strong solitary waves that intensify turbulence. Based on the AMAZOMIX-2021 cruise, which collected direct turbulence measurements alongside hydrographic data, the study quantifies dissipation and the relative contributions of tidal shear and large-scale shear. This mixing helps redistribute heat and nutrients, playing a key role in climate regulation and marine ecosystems.
Michel Tchilibou, Simon Barbot, Loren Carrere, Ariane Koch-Larrouy, Gérald Dibarboure, and Clément Ubelmann
Ocean Sci., 21, 1469–1486, https://doi.org/10.5194/os-21-1469-2025, https://doi.org/10.5194/os-21-1469-2025, 2025
Short summary
Short summary
MIOST24 (Multivariate Inversion of Ocean Surface Topography 2024) annual and monthly internal tide (IT) atlases, based on 25 years of altimetry data and an updated wavelength database, are presented for the Indo-Philippine archipelago and the Amazon shelf. The atlases show monthly IT variability and a better correction of IT in altimetry data than with MIOST22 (MIOST 2022) and HRET (High-Resolution Empirical Tide). The results support the development of a global MIOST24.
Fernand Assene, Ariane Koch-Larrouy, Isabelle Dadou, Michel Tchilibou, Guillaume Morvan, Jérôme Chanut, Alex Costa da Silva, Vincent Vantrepotte, Damien Allain, and Trung-Kien Tran
Ocean Sci., 20, 43–67, https://doi.org/10.5194/os-20-43-2024, https://doi.org/10.5194/os-20-43-2024, 2024
Short summary
Short summary
Twin simulations, with and without tides, are used to assess the impact of internal tides (ITs) on ocean temperature off the Amazon mouth at a seasonal scale. We found that in the surface layers, ITs and barotropic tides cause a cooling effect on sea surface temperature, subsequently leading to an increase in the net heat flux between the atmosphere and ocean. Vertical mixing is identified as the primary driver, followed by vertical and horizontal advection.
Carina Regina de Macedo, Ariane Koch-Larrouy, José Carlos Bastos da Silva, Jorge Manuel Magalhães, Carlos Alessandre Domingos Lentini, Trung Kien Tran, Marcelo Caetano Barreto Rosa, and Vincent Vantrepotte
Ocean Sci., 19, 1357–1374, https://doi.org/10.5194/os-19-1357-2023, https://doi.org/10.5194/os-19-1357-2023, 2023
Short summary
Short summary
We focus on the internal solitary waves (ISWs) off the Amazon shelf, their velocity, and their variability in seasonal and tidal cycles. The analysis is based on a large remote-sensing data set. The region is newly described as a hot spot for ISWs with mode-2 internal tide wavelength. The wave activity is higher during spring tides. The mode-1 waves located in the region influenced by the North Equatorial Counter Current showed a velocity/wavelength 14.3 % higher during the boreal summer/fall.
Djoirka Minto Dimoune, Florence Birol, Fabrice Hernandez, Fabien Léger, and Moacyr Araujo
Ocean Sci., 19, 251–268, https://doi.org/10.5194/os-19-251-2023, https://doi.org/10.5194/os-19-251-2023, 2023
Short summary
Short summary
Altimeter-derived currents are used here to revisit the seasonal and interannual variability of all surface currents involved in the western tropical Atlantic circulation. A new approach based on the calculation of the current strengths and core positions is used to investigate the relationship between the currents, the remote wind variability, and the tropical Atlantic modes. The results show relationships at the seasonal and interannual timescale depending on the location of the currents.
Edward D. Zaron, Tonia A. Capuano, and Ariane Koch-Larrouy
Ocean Sci., 19, 43–55, https://doi.org/10.5194/os-19-43-2023, https://doi.org/10.5194/os-19-43-2023, 2023
Short summary
Short summary
Phytoplankton in the upper ocean are food for fish and are thus economically important to humans; furthermore, phytoplankton consume nutrients and generate oxygen by photosynthesis, just like plants on land. Vertical mixing in the ocean is responsible for transporting nutrients into the sunlit zone of the surface ocean. We used remotely sensed data to quantify the influence of tidal mixing on phytoplankton through an analysis of ocean color, which we interpret as chlorophyll concentration.
Michel Tchilibou, Ariane Koch-Larrouy, Simon Barbot, Florent Lyard, Yves Morel, Julien Jouanno, and Rosemary Morrow
Ocean Sci., 18, 1591–1618, https://doi.org/10.5194/os-18-1591-2022, https://doi.org/10.5194/os-18-1591-2022, 2022
Short summary
Short summary
This high-resolution model-based study investigates the variability in the generation, propagation, and sea height signature (SSH) of the internal tide off the Amazon shelf during two contrasted seasons. ITs propagate further north during the season characterized by weak currents and mesoscale eddies and a shallow and strong pycnocline. IT imprints on SSH dominate those of the geostrophic motion for horizontal scales below 200 km; moreover, the SSH is mainly incoherent below 70 km.
Cited articles
Aguedjou, H. M. A., Dadou, I., Chaigneau, A., Morel, Y., and Alory, G.: Eddies in the tropical Atlantic Ocean and their seasonal variability, Geophys. Res. Lett., 46, 12156–12164, https://doi.org/10.1029/2019GL083925, 2019.
Aguedjou, H. M. A., Chaigneau, A., Dadou, I., Morel, Y., Pegliasco, C., Da-Allada, C. Y., and Baloïtcha, E.: What can we learn from observed temperature and salinity isopycnal anomalies at eddy generation sites? Application in the tropical Atlantic Ocean, J. Geophys. Res.-Oceans, 126, e2021JC017630, https://doi.org/10.1029/2021JC017630, 2021.
Alford, M. H. and Zhao, Z.: Global patterns of low-mode internal-wave propagation. Part I: Energy and energy flux, J. Phys. Oceanogr., 37, 1829–1848, https://doi.org/10.1175/jpo3085.1, 2007.
Alford, M. H., Simmons, H. L., Marques, O. B., and Girton, J. B.: Internal tide attenuation in the North Pacific, Geophys. Res. Lett., 46, 8205–8213, https://doi.org/10.1029/2019GL082648, 2019.
Assene, F., Koch-Larrouy, A., Dadou, I., Tchilibou, M., Morvan, G., Chanut, J., Costa da Silva, A., Vantrepotte, V., Allain, D., and Tran, T.-K.: Internal tides off the Amazon shelf – Part 1: The importance of the structuring of ocean temperature during two contrasted seasons, Ocean Sci., 20, 43–67, https://doi.org/10.5194/os-20-43-2024, 2024.
Barbot, S., Lyard, F., Tchilibou, M., and Carrere, L.: Background stratification impacts on internal tide generation and abyssal propagation in the western equatorial Atlantic and the Bay of Biscay, Ocean Sci., 17, 1563–1583, https://doi.org/10.5194/os-17-1563-2021, 2021.
Barnier, B., Reynaud, T., Beckmann, A., Böning, C., Molines, J.-M., Barnard, S., and Jia, Y.: On the seasonal variability and eddies in the North Brazil Current: Insights from model intercomparison experiments, Prog. Oceanogr., 48, 195–230, https://doi.org/10.1016/S0079-6611(01)00005-2, 2001.
Bella, A., Lahaye, N., and Tissot, G.: Internal tide energy transfers induced by mesoscale circulation and topography across the North Atlantic, J. Geophys. Res.-Oceans, 129, e2024JC020914, https://doi.org/10.1029/2024JC020914, 2024.
Brandt, P., Rubino, A., and Fischer, J.: Large-amplitude internal solitary waves in the North Equatorial Countercurrent, J. Phys. Oceanogr., 32, 1567–1573, https://doi.org/10.1175/1520-0485(2002)032<1567:LAISWI>2.0.CO;2, 2002.
Buijsman, M. C., Legg, S., and Klymak, J.: Double-ridge internal tide interference and its effect on dissipation in Luzon Strait, J. Phys. Oceanogr., 42, 1337–1356, https://doi.org/10.1175/jpo-d-11-0210.1, 2012.
Cao, A., Guo, Z., Wang, S., Guo, X., and Song, J.: Incoherence of the M2 and K1 internal tides radiated from the Luzon Strait under the influence of looping and leaping Kuroshio, Prog. Oceanogr., 206, 102850, https://doi.org/10.1016/j.pocean.2022.102850, 2022.
Chen, J., Zhu, X.-H., Wang, M., Zheng, H., Zhao, R., Nakamura, H., and Yamashiro, T.: Incoherent signatures of internal tides in the Tokara Strait modulated by the Kuroshio, Prog. Oceanogr., 206, 102863, https://doi.org/10.1016/j.pocean.2022.102863, 2022.
Clément, L., Frajka-Williams, E., Sheen, K. L., Brearley, J. A., and Garabato, A. N.: Generation of internal waves by eddies impinging on the western boundary of the North Atlantic, J. Phys. Oceanogr., 46, 1067–1079, https://doi.org/10.1175/JPO-D-14-0241.1, 2016.
de Macedo, C. R., Koch-Larrouy, A., da Silva, J. C. B., Magalhães, J. M., Lentini, C. A. D., Tran, T. K., Rosa, M. C. B., and Vantrepotte, V.: Spatial and temporal variability in mode-1 and mode-2 internal solitary waves from MODIS-Terra sun glint off the Amazon shelf, Ocean Sci., 19, 1357–1374, https://doi.org/10.5194/os-19-1357-2023, 2023.
Delpech, A., Cravatte, S., Marin, F., Morel, Y., Gronchi, E., and Kestenare, E.: Observed tracer fields structuration by middepth zonal jets in the tropical Pacific, J. Phys. Oceanogr., 50, 281–304, https://doi.org/10.1175/JPO-D-19-0132.1, 2020.
Didden, N. and Schott, F.: Eddies in the North Brazil Current retroflection region observed by Geosat altimetry, J. Geophys. Res., 98, 20121, https://doi.org/10.1029/93JC01184, 1993.
Duda, T. F., Lin, Y.-T., Buijsman, M., and Newhall, A. E.: Internal tidal modal ray refraction and energy ducting in baroclinic Gulf Stream currents, J. Phys. Oceanogr., 48, 1969–1993, https://doi.org/10.1175/JPO-D-18-0031.1, 2018.
Dunphy, M. and Lamb, K. G.: Focusing and vertical mode scattering of the first mode internal tide by mesoscale eddy interaction, J. Geophys. Res.-Oceans, 119, 523–536, https://doi.org/10.1002/2013JC009293, 2014.
Dunphy, M., Ponte, A. L., Klein, P., and Le Gentil, S.: Low-mode internal tide propagation in a turbulent eddy field, J. Phys. Oceanogr., 47, 649–665, https://doi.org/10.1175/JPO-D-16-0099.1, 2017.
Ernst, P. A., Subrahmanyam, B., Morel, Y., Trott, C. B., and Chaigneau, A.: Subsurface eddy detection optimized with potential vorticity from models in the Arabian Sea, J. Atmos. Ocean. Techn., 40, 677–700, https://doi.org/10.1175/JTECH-D-22-0050.1, 2023.
Ertel, H.: On hydrodynamic eddy theorems, Phys. Z., 43, 526–529, 1942.
Fan, L., Sun, H., Yang, Q., and Li, J.: Numerical investigation of interaction between anticyclonic eddy and semidiurnal internal tide in the northeastern South China Sea, Ocean Sci., 20, 241–264, https://doi.org/10.5194/os-20-241-2024, 2024.
Fassoni-Andrade, A. C., Durand, F., Azevedo, A., Bertin, X., Santos, L. G., Khan, J. U., Testut, L., and Moreira, D. M.: Seasonal to interannual variability of the tide in the Amazon estuary, Cont. Shelf Res., 255, 104945, https://doi.org/10.1016/j.csr.2023.104945, 2023.
Fratantoni, D. M. and Glickson, D. A.: North Brazil Current Ring generation and evolution observed with SeaWiFS, J. Phys. Oceanogr., 32, 1058–1074, https://doi.org/10.1175/1520-0485(2002)032<1058:NBCRGA>2.0.CO;2, 2002.
Gabioux, M., Vinzon, S. B., Paiva, A. M.: Tidal propagation over fluid mud layers on the Amazon shelf, Cont. Shelf Res., 25, 113–125, https://doi.org/10.1016/j.csr.2004.09.001, 2005.
Garrett, C. and Kunze, E.: Internal tide generation in the deep ocean, Annu. Rev. Fluid Mech., 39, 57–87, https://doi.org/10.1146/ANNUREV.FLUID.39.050905.110227, 2007.
Gerkema, T. and Zimmerman, J. T. F.: An introduction to internal waves, Lecture Notes, Royal Netherlands Institute for Sea Research, 2008.
Goret, C., Koch-Larrouy, A., Kouogang, F., de Macedo, C. R., M’Hamdi, A., Magalhães, J., da Silva, J. C. B., Tchilibou, M., Artana, C., Dadou, I., Delepoulle, A., Barbot, S., Ballarotta, M., Carrère, L., and Costa da Silva, A.: Internal solitary waves refraction and diffraction from interaction with eddies off the Amazon Shelf from SWOT, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-3933, 2025.
Guo, Z., Wang, S., Cao, A., Xie, J., Song, J., and Guo, X.: Refraction of the M2 internal tides by mesoscale eddies in the South China Sea, Deep-Sea Res. Pt. I, 192, 103946, https://doi.org/10.1016/j.dsr.2022.103946, 2023.
Huang, X., Wang, Z., Zhang, Z., Yang, Y., Zhou, C., Yang, Q., Zhao, W., and Tian, J.: Role of mesoscale eddies in modulating the semidiurnal internal tide: Observation results in the northern South China Sea, J. Phys. Oceanogr., 48, 1749–1768, https://doi.org/10.1175/JPO-D-17-0238.1, 2018.
Johnston, T. M. S. and Merrifield, M. A.: Internal tide scattering at the Line Islands Ridge, J. Geophys. Res., 108, 3365, https://doi.org/10.1029/2003JC001844, 2003.
Kelly, S. M.: The vertical mode decomposition of surface and internal tides in the presence of a free surface and arbitrary topography, J. Phys. Oceanogr., 46, 3777–3788, https://doi.org/10.1175/JPO-D-16-0131.1, 2016.
Kelly, S. M. and Nash, J. D.: Internal-tide generation and destruction by shoaling internal tides, Geophys. Res. Lett., 37, L23611, https://doi.org/10.1029/2010GL045598, 2010.
Kelly, S. M. and Lermusiaux, P. F. J.: Internal-tide interactions with the Gulf Stream and Middle Atlantic Bight shelfbreak front, J. Geophys. Res.-Oceans, 121, 6271–6294, https://doi.org/10.1002/2016JC011639, 2016.
Kelly, S. M., Nash, J. D., and Kunze, E.: Internal-tide energy over topography, J. Geophys. Res.-Oceans, 115, C06014, https://doi.org/10.1029/2009JC005618, 2010.
Kelly, S. M., Nash, J. D., Martini, K. I., Alford, M. H., and Kunze, E.: The cascade of tidal energy from low to high modes on a continental slope, J. Phys. Oceanogr., 42, 1217–1232, https://doi.org/10.1175/jpo-d-11-0231.1, 2012.
Kelly, S. M., Lermusiaux, P. F. J., and Duda, T. F.: A coupled-mode shallow-water model for tidal analysis: Internal tide reflection and refraction by the Gulf Stream, J. Phys. Oceanogr., 46, 3747–3767, https://doi.org/10.1175/JPO-D-16-0125.1, 2016.
Kerry, C. G., Powell, B. S., and Carter, G. S.: Effects of remote generation sites on model estimates of M2 internal tides in the Philippine Sea, J. Phys. Oceanogr., 43, 187–204, https://doi.org/10.1175/jpo-d-12-081.1, 2013.
Koch-Larrouy, A., Atmadipoera, A., van Beek, P., Madec, G., Aucan, J., Lyard, F., Grelet, J., and Souhaut, M.: Estimates of tidal mixing in the Indonesian archipelago from multidisciplinary INDOMIX in-situ data, Deep-Sea Res. Pt. I, 106, 136–153, https://doi.org/10.1016/j.dsr.2015.09.007, 2015.
Kouogang, F., Koch-Larrouy, A., Magalhaes, J., Costa da Silva, A., Kerhervé, D., Bertrand, A., Cervelli, E., Assene, F., Ternon, J.-F., Rousselot, P., Lee, J., Rollnic, M., and Araujo, M.: Turbulent dissipation along contrasting internal tide paths off the Amazon shelf from AMAZOMIX, Ocean Sci., 21, 1589–1608, https://doi.org/10.5194/os-21-1589-2025, 2025.
Kunze, E.: Internal-wave-driven mixing: Global geography and budgets, J. Phys. Oceanogr., 47, 1325–1345, https://doi.org/10.1175/JPO-D-16-0141.1, 2017.
Kurian, J., Colas, F., Capet, X., McWilliams, J. C., and Chelton, D. B.: Eddy properties in the California Current System, J. Geophys. Res.-Oceans, 116, https://doi.org/10.1029/2010jc006895, 2011.
Lahaye, N., Gula, J., and Roullet, G.: Internal tide cycle and topographic scattering over the north mid-Atlantic ridge, J. Geophys. Res.-Oceans, 125, e2020JC016376, https://doi.org/10.1029/2020JC016376, 2020.
Lahaye, N., Ponte, A., Le Sommer, J., and Albert, A.: Internal tide surface signature and incoherence in the North Atlantic, Geophys. Res. Lett., 51, e2024GL108508, https://doi.org/10.1029/2024GL108508, 2024.
Le Dizes, C., Grisouard, N., Thual, O., and Mercier, M. J.: Three-dimensional modelling of internal tide generation over isolated seamounts in a rotating ocean, J. Fluid Mech., 1022, A5, https://doi.org/10.1017/jfm.2025.10647, 2025.
Li, B., Xu, M., Chen, W., Yuan, Y., Liu, Y., and Li, S.: Evolution of internal tide scattering hidden below mesoscale eddies, Prog. Oceanogr., 226, 103305, https://doi.org/10.1016/j.pocean.2024.103305, 2024.
Liao, G., Yang, C., Xu, X., Shi, X., Yuan, Y., and Huang, W.: Effects of mesoscale eddies on the internal solitary wave propagation, Acta Oceanol. Sin., 31, 26–40, https://doi.org/10.1007/s13131-012-0233-9, 2012.
Lorenz, E. N.: Available potential energy and the maintenance of the general circulation, Tellus, 7, 157–167, https://doi.org/10.1111/j.2153-3490.1955.tb01148.x, 1955.
Löb, J., Köhler, J., Mertens, C., Walter, M., Li, Z., and von Storch, J.-S.: Observations of the low-mode internal tide and its interaction with mesoscale flow south of the Azores, J. Geophys. Res.-Oceans, 125, e2019JC015879, https://doi.org/10.1029/2019JC015879, 2020.
Madec, G., Bourdallé-Badie, R., Chanut, J., Clementi, E., Coward, A., Ethé, C., Iovino, D., Lea, D., Lévy, C., Lovato, T., Martin, N., Masson, S., Mocavero, S., Rousset, C., Storkey, D., Vancoppenolle, M., Müeller, S., Nurser, G., Bell, M., and Samson, G.: NEMO ocean engine, Zenodo, https://doi.org/10.5281/zenodo.3878122, 2019.
Magalhaes, J. M., da Silva, J. C. B., Buijsman, M. C., and Garcia, C. A. E.: Effect of the North Equatorial Counter Current on the generation and propagation of internal solitary waves off the Amazon shelf (SAR observations), Ocean Sci., 12, 243–255, https://doi.org/10.5194/os-12-243-2016, 2016.
Mathur, M., Carter, G. S., and Peacock, T.: Topographic scattering of the low-mode internal tide in the deep ocean, J. Geophys. Res.-Oceans, 119, 2165–2182, https://doi.org/10.1002/2013JC009152, 2014.
Morel, Y., Gula, J., and Ponte, A.: Potential vorticity diagnostics based on balances between volume integral and boundary conditions, Ocean Model., 138, 23–35, https://doi.org/10.1016/j.ocemod.2019.04.004, 2019.
Morel, Y., Morvan, G., Benshila, R., Renault, L., Gula, J., and Auclair, F.: An “objective” definition of potential vorticity: Generalized evolution equation and application to the study of coastal upwelling instability, Ocean Model., 186, 102287, https://doi.org/10.1016/j.ocemod.2023.102287, 2023.
Nakamura, N.: Modified Lagrangian-mean diagnostics of the stratospheric polar vortices. Part I. Formulation and analysis of GFDL SKYHI GCM, J. Atmos. Sci., 52, 2096–2108, https://doi.org/10.1175/1520-0469(1995)052<2096:MLMDOT>2.0.CO;2, 1995.
Nash, J. D., Kelly, S. M., Shroyer, E. L., Moum, J. N., and Duda, T. F.: The unpredictable nature of internal tides on continental shelves, J. Phys. Oceanogr., 42, 1981–2000, https://doi.org/10.1175/JPO-D-12-028.1, 2012.
Okubo, A.: Horizontal dispersion of floatable particles in vicinity of velocity singularities such as convergence, Deep-Sea Res., 17, 445, https://doi.org/10.1016/0011-7471(70)90059-8, 1970.
Pereira, A. F., Castro, B. M., Calado, L., and da Silveira, I. C. A.: Numerical simulation of M2 internal tides in the South Brazil Bight and their interaction with the Brazil Current, J. Geophys. Res., 112, C04009, https://doi.org/10.1029/2006JC003673, 2007.
Rainville, L. and Pinkel, R.: Propagation of low-mode internal waves through the ocean, J. Phys. Oceanogr., 36, 1220–1236, https://doi.org/10.1175/JPO2924.1, 2006.
Savage, A. C., Waterhouse, A. F., and Kelly, S. M.: Internal tide nonstationarity and wave–mesoscale interactions in the Tasman Sea, J. Phys. Oceanogr., 50, 2931–2951, https://doi.org/10.1175/JPO-D-19-0283.1, 2020.
Silva, A. C., Bourles, B., and Araujo, M.: Circulation of the thermocline salinity maximum waters off the Northern Brazil as inferred from in situ measurements and numerical results, Ann. Geophys., 27, 1861–1873, https://doi.org/10.5194/angeo-27-1861-2009, 2009.
Siyanbola, O. Q., Buijsman, M. C., Delpech, A., Barkan, R., Pan, Y., and Arbic, B. K.: Interactions of remotely generated internal tides with the U. S. West Coast continental margin, J. Geophys. Res.-Oceans, 129, e2023JC020859, https://doi.org/10.1029/2023JC020859, 2024.
Small, J.: A nonlinear model of the shoaling and refraction of interfacial solitary waves in the ocean. Part II: Oblique refraction across a continental slope and propagation over a seamount, J. Phys. Oceanogr., 31, 3184–3199, https://doi.org/10.1175/1520-0485(2001)031<3184:ANMOTS>2.0.CO;2, 2001.
Tchilibou, M., Gourdeau, L., Lyard, F., Morrow, R., Koch Larrouy, A., Allain, D., and Djath, B.: Internal tides in the Solomon Sea in contrasted ENSO conditions, Ocean Sci., 16, 615–635, https://doi.org/10.5194/os-16-615-2020, 2020.
Tchilibou, M., Koch-Larrouy, A., Barbot, S., Lyard, F., Morel, Y., Jouanno, J., and Morrow, R.: Internal tides off the Amazon shelf during two contrasted seasons: interactions with background circulation and SSH imprints, Ocean Sci., 18, 1591–1618, https://doi.org/10.5194/os-18-1591-2022, 2022.
Vic, C., Naveira Garabato, A. C., Green, J. M., Waterhouse, A. F., Zhao, Z., Melet, A., de Lavergne, C., Buijsman, M. C., and Stephenson, G. R.: Deep-ocean mixing driven by small-scale internal tides, Nat. Commun., 10, 2099, https://doi.org/10.1038/s41467-019-10149-5, 2019.
Wang, W., Li, J., and Huang, X.: Semidiurnal internal tide interference in the northern South China Sea, J. Marine Sci. Eng., 12, 811, https://doi.org/10.3390/jmse12050811, 2024.
Wang, X., Peng, S., Liu, Z., Huang, R. X., Qian, Y.-K., and Li, Y.: Tidal mixing in the South China Sea: An estimate based on the internal tide energetics, J. Phys. Oceanogr., 46, 107–124, https://doi.org/10.1175/JPO-D-15-0082.1, 2016.
Wang, Y. and Legg, S.: Enhanced dissipation of internal tides in a mesoscale baroclinic eddy, J. Phys. Oceanogr., 53, 2533–2550, https://doi.org/10.1175/JPO-D-22-0205.1, 2023.
Wang, Y., Xu, Z., Hibiya, T., Yin, B., and Wang, F.: Radiation path of diurnal internal tides in the northwestern Pacific controlled by refraction and interference, J. Geophys. Res.-Oceans, 126, e2020JC016972, https://doi.org/10.1029/2020JC016972, 2021.
Wang, Y., Curchitser, E., Legg, S., and Kang, D.: Internal tide interactions with submesoscale and mesoscale eddies in the tropical western Atlantic, J. Phys. Oceanogr., 55, 1277–1296, https://doi.org/10.1175/JPO-D-24-0201.1, 2025.
Waterhouse, A. F., Kelly, S. M., Zhao, Z., MacKinnon, J. A., Nash, J. D., Simmons, H., and Pinkel, R.: Observations of the Tasman Sea internal tide beam, J. Phys. Oceanogr., 48, 1283–1297, https://doi.org/10.1175/JPO-D-17-0116.1, 2018.
Weiss, J.: The dynamics of enstrophy transfer in 2-dimensional hydrodynamics, Physica D, 48, 273–294, https://doi.org/10.1016/0167-2789(91)90088-Q, 1991.
Winters, K. B. and D'Asaro, E. A.: Diascalar flux and the rate of fluid mixing, J. Fluid Mech., 317, 179–193, https://doi.org/10.1017/S0022112096000717, 1996.
Wunsch, C. and Ferrari, R.: Vertical mixing, energy, and the general circulation of the oceans, Annu. Rev. Fluid Mech., 36, 281–314, https://doi.org/10.1146/annurev.fluid.36.050802.122121, 2004.
Xu, A., Yu, F., and Nan, F.: Study of subsurface eddy properties in northwestern Pacific Ocean based on an eddy-resolving OGCM, Ocean Dynam., 69, 463–474, https://doi.org/10.1007/s10236-019-01255-5, 2019.
Xu, Z., Liu, K., Yin, B., Zhao, Z., Wang, Y., and Li, Q.: Longrange propagation and associated variability of internal tides in the South China Sea, J. Geophys. Res.-Oceans, 121, 8268–8286, https://doi.org/10.1002/2016JC012105, 2016.
Xu, Z., Wang, Y., Liu, Z., McWilliams, J. C., and Gan, J.: Insight into the dynamics of the radiating internal tide associated with the Kuroshio current, J. Geophys. Res.-Oceans, 126, e2020JC017018, https://doi.org/10.1029/2020JC017018, 2021.
Zhang, Z., Wang, W., and Qiu, B.: Oceanic mass transport by mesoscale eddies, Science, 345, 322–324, https://doi.org/10.1126/science.1252418, 2014.
Zhao, Z.: Internal tide radiation from the Luzon Strait, J. Geophys. Res.-Oceans, 119, 5434–5448, https://doi.org/10.1002/2014JC010150, 2014.
Zhao, Z.: The global mode-1 S2 internal tide, J. Geophys. Res.-Oceans, 122, 8794–8812, https://doi.org/10.1002/2017JC013112, 2017.
Zhao, Z.: The global mode-2 M2 internal tide, J. Geophys. Res.-Oceans, 123, 7725–7746, https://doi.org/10.1029/2018JC014475, 2018.
Zhao, Z., Alford, M. H., MacKinnon, J. A., and Pinkel, R.: Long-range propagation of the semidiurnal internal tide from the Hawaiian Ridge, J. Phys. Oceanogr., 40, 713–736, https://doi.org/10.1175/2009JPO4207.1, 2010.
Zaron, E. D. and Egbert, G. D.: Time-variable refraction of internal tides at the Hawaiian Ridge, J. Phys. Oceanogr., 44, 538–557, https://doi.org/10.1175/JPO-D-12-0238.1, 2014.
Editorial statement
This study shows that the fate of internal tide energy is not uniform but is dictated by interactions with mesoscale eddies features, affecting the intensity and distribution of energy flux. The study finds that the specific response of an internal tide—whether it propagates freely or deviates—is dually controlled by the internal tide vertical modal structure, and the ocean state it encounters together with its associated background conditions. In additions, it is also found that the redistribution of energy via intermodal transfers is governed by a hierarchy of synergistic interactions between the topographic features and the background flow of the ocean state.
This study shows that the fate of internal tide energy is not uniform but is dictated by...
Short summary
Our research investigates how large waves travel deep within the ocean. Using a detailed computer model, we show that when these deep waves meet giant ocean circulation, their path is dramatically changed. They can be bent off course, split apart, or stopped completely. An underwater mountain works with this circulation to transfer the wave energy between different ocean layers. Understanding this process is vital because it controls ocean mixing.
Our research investigates how large waves travel deep within the ocean. Using a detailed...
