Articles | Volume 21, issue 6
https://doi.org/10.5194/os-21-2763-2025
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the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/os-21-2763-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
04 Nov 2025
Research article |
| 04 Nov 2025
| 04 Nov 2025
Merging of a mesoscale eddy into the Lofoten Vortex in the Norwegian Sea captured by an ocean glider and SWOT observations
Gillian M. Damerell
CORRESPONDING AUTHOR
Geophysical Institute, University of Bergen, and Bjerknes Centre for Climate Research, Bergen, Norway
Anthony Bosse
Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
Ilker Fer
Geophysical Institute, University of Bergen, and Bjerknes Centre for Climate Research, Bergen, Norway
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Cited articles
Andersson, M., Orvik, K. A., LaCasce, J. H., Koszalka, I., and Mauritzen, C.: Variability of the Norwegian Atlantic Current and associated eddy field from surface drifters, J. Geophys. Res., 116, C08032, https://doi.org/10.1029/2011JC007078, 2011. a
Asbjørnsen, H., Årthun, M., Skagseth, O., and Eldevik, T.: Mechanisms of ocean heat anomalies in the Norwegian Sea, J. Geophys. Res.-Oceans, 124, 2908–2923, https://doi.org/10.1029/2018JC014649, 2019. a
Bambrey, R. R., Reinaud, J. N., and Dritschel, D. G.: Strong interactions between two corotating quasi-geostrophic vortices, J. Fluid Mech., 592, 117–133, https://doi.org/10.1017/S0022112007008373, 2007. a
Belkin, I., Foppert, A., Rossby, T., Fontana, S., and Kincaid, C.: A double-thermostad warm-core ring of the Gulf Stream, J. Phys. Oceanogr., 50, 489–507, https://doi.org/10.1175/JPO-D-18-0275.1, 2020. a
Belonenko, T. V., Bashmachnikov, I. L., Koldunov, A. V., and Kuibin, P. A.: On the vertical velocity component in the mesoscale Lofoten vortex of the Norwegian Sea, Izv. Atmos. Ocean. Phys., 53, 641–649, https://doi.org/10.1134/S0001433817060032, 2017. a, b
Bertrand, V., E. V. Z. De Almeida, V., Le Sommer, J., and Cosme, E.: meom-group/jaxparrow: v0.2.2, Zenodo [code], https://doi.org/10.5281/zenodo.13886071, 2024. a
Bosse, A. and Fer, I.: Mean structure and seasonality of the Norwegian Atlantic front current along the Mohn Ridge from repeated glider transects, Geophys. Res. Lett., 46, 13170–13179, https://doi.org/10.1029/2019GL084723, 2019. a
Bosse, A., Testor, P., Mortier, L., Prieur, L., Taillandier, V., d'Ortenzio, F., and Coppola, L.: Spreading of Levantine Intermediate Waters by submesoscale coherent vortices in the northwestern Mediterranean Sea as observed with gliders, J. Geophys. Res.-Oceans, 120, 1599–1622, https://doi.org/10.1002/2014JC010263, 2015. a
Bosse, A., Testor, P., Houpert, L., Damien, P., Prieur, L., Hayes, D., Taillandier, V., de Madron, X. D., d'Ortenzio, F., Coppola, L., Karstensen, J., and Mortier, L.: Scales and dynamics of submesoscale coherent vortices formed by deep convection in the northwestern Mediterranean Sea, J. Geophys. Res.-Oceans, 121, 7716–7742, https://doi.org/10.1002/2016JC012144, 2016. a
Bosse, A., Fer, I., Soiland, H., and Rossby, T.: Atlantic water transformation along its poleward pathway across the Nordic Seas, J. Geophys. Res.-Oceans, 123, 6428–6448, https://doi.org/10.1029/2018JC014147, 2018. a, b
Brakstad, A., Gebbie, G., Våge, K., Jeansson, E., and Òlafsdóttir, S. R.: Formation and pathways of dense water in the Nordic Seas based on a regional inversion, Prog. Oceanogr., 212, 102981, https://doi.org/10.1016/j.pocean.2023.102981, 2023. a
Broomé, S., Chafik, L., and Nilsson, J.: Mechanisms of decadal changes in sea surface height and heat content in the eastern Nordic Seas, Ocean Sci., 16, 715–728, https://doi.org/10.5194/os-16-715-2020, 2020. a
Carton, X., Ciani, D., Verron, J., Reinaud, J., and Sokolovskiy, M.: Vortex merger in surface quasi-geostrophy, Geophys. Astro. Fluid, 110, 1–22, https://doi.org/10.1080/03091929.2015.1120865, 2016. a, b
CNES: AVISO/DUACS, 2024. SWOT Level-3 SSH Expert (v2.0.1), AVISO+ [data set], https://doi.org/10.24400/527896/A01-2023.018, 2024. a
Damerell, G. M., Heywood, K. J., Thompson, A. F., Binetti, U., and Kaiser, J.: The vertical structure of upper ocean variability at the Porcupine Abyssal Plain during 2012–2013, J. Geophys. Res., 121, 3075–3089, https://doi.org/10.1002/2015JC011423, 2016. a
Damerell, G. M., Fer, I., Brakstad, A., and Elliott, F.: Physical oceanography data from Seaglider missions in the Lofoten Basin, Norwegian Sea, January–November 2023, Norwegian Marine Data Centre [data set], https://doi.org/10.21335/NMDC-440347600, 2024. a, b
de Marez, C., Carton, X., L'Hégaret, P., Meunier, T., Stegner, A., Le Vu, B., and Morvan, M.: Oceanic vortex mergers are not isolated but influenced by the beta-effect and surrounding eddies, Sci. Rep.-UK, 10, 2897, https://doi.org/10.1038/s41598-020-59800-y, 2020. a
de Marez, C., Le Corre, M., and Gula, J.: The influence of merger and convection on an anticyclonic eddy trapped in a bowl, Ocean Model., 167, 101874, https://doi.org/10.1016/j.ocemod.2021.101874, 2021. a, b
Dibarboure, G., Anadon, C., Briol, F., Cadier, E., Chevrier, R., Delepoulle, A., Faugère, Y., Laloue, A., Morrow, R., Picot, N., Prandi, P., Pujol, M.-I., Raynal, M., Tréboutte, A., and Ubelmann, C.: Blending 2D topography images from the Surface Water and Ocean Topography (SWOT) mission into the altimeter constellation with the Level-3 multi-mission Data Unification and Altimeter Combination System (DUACS), Ocean Sci., 21, 283–323, https://doi.org/10.5194/os-21-283-2025, 2025. a
Dritschel, D. G.: Vortex merger in rotating stratified flows, J. Fluid Mech., 455, 83–101, https://doi.org/10.1017/S0022112001007364, 2002. a
Dugstad, J., Fer, I., LaCasce, J., de La Lama, M. S., and Trodahl, M.: Lateral heat transport in the Lofoten Basin: near-surface pathways and subsurface exchange, J. Geophys. Res.-Oceans, 124, 2992–3006, https://doi.org/10.1029/2018JC014774, 2019. a
d'Ovidio, F., Pascual, A., Wang, J., Doglioli, A. M., Jing, Z., Moreau, S., Grégori, G., Swart, S., Speich, S., Cyr, F., Legresy, B., Chao, Y., Fu, L., and Morrow, R. A.: Frontiers in fine-scale in situ studies: opportunities during the SWOT fast sampling phase, Front. Mar. Sci., 6, 168, https://doi.org/10.3389/fmars.2019.00168, 2019. a
Eriksen, C. C., Osse, T. J., Light, R. D., Wen, T., Lehman, T. W., Sabin, P. L., Ballard, J. W., and Chiodi, A. M.: Seaglider: a long-range autonomous underwater vehicle for oceanographic research, IEEE J. Oceanic Eng., 26, 424–436, https://doi.org/10.1109/48.972073, 2001. a
Fer, I., Bosse, A., and Dugstad, J.: Norwegian Atlantic Slope Current along the Lofoten Escarpment, Ocean Sci., 16, 685–701, https://doi.org/10.5194/os-16-685-2020, 2020. a
Frajka-Williams, E., Eriksen, C. C., Rhines, P. B., and Harcourt, R. R.: Determining vertical water velocities from Seaglider, J. Atmos. Ocean. Tech., 28, 1641–1656, https://doi.org/10.1175/2011JTECHO830.1, 2011. a
Fu, L. L., Pavelsky, T., Cretaux, J. F., Morrow, R., Farrar, J. T., Vaze, P., Sengenes, P., Vinogradova-Shiffer, N., Sylvestre-Baron, A., Picot, N., and Dibarboure, G.: The surface water and ocean topography mission: a breakthrough in radar remote sensing of the ocean and land surface water, Geophys. Res. Lett., 51, e2023GL107652, https://doi.org/10.1029/2023GL107652, 2024. a
Garau, B., Ruiz, S., Zhang, W. G., Pascual, A., Heslop, E., Kerfoot, J., and Tintore, J.: Thermal lag correction on Slocum CTD glider data, J. Atmos. Ocean. Tech., 28, 1065–1071, https://doi.org/10.1175/JTECH-D-10-05030.1, 2011. a
Garreau, P., Dumas, F., Louazel, S., Stegner, A., and Le Vu, B.: High-resolution observations and tracking of a dual-core anticyclonic eddy in the Algerian Basin, J. Geophys. Res.-Oceans, 123, 9320–9339, https://doi.org/10.1029/2017JC013667, 2018. a
Hansen, C., Kvaleberg, E., and Samuelsen, A.: Anticyclonic eddies in the Norwegian Sea; their generation, evolution and impact on primary production, Deep-Sea Res. Pt. I, 57, 1079–1091, https://doi.org/10.1016/j.dsr.2010.05.013, 2010. a
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J.-N.: ERA5 hourly data on single levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.adbb2d47, 2023. a
IOC, SCOR, and IAPSO: The International Thermodynamic Equation of Seawater – 2010: Calculations and Use of Thermodynamic Properties, Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, UNESCO (English), 2010. a
Isachsen, P. E.: Baroclinic instability and the mesoscale eddy field around the Lofoten Basin, J. Geophys. Res., 120, 2884–2903, https://doi.org/10.1002/2014JC010448, 2015. a
Klein, P., Lapeyre, G., Siegelman, L., Qiu, B., Fu, L. L., Torres, H., Su, Z., Menemenlis, D., and Le Gentil, S.: Ocean-scale interactions from space, Earth Space Sci., 6, 795–817, https://doi.org/10.1029/2018EA000492, 2019. a
Liu, H. C., Shah, S., and Jiang, W.: On-line outlier detection and data cleaning, Comput. Chem. Eng., 28, 1635–1647, https://doi.org/10.1016/j.compchemeng.2004.01.009, 2004. a
Mason, E., Pascual, A., and McWilliams, J. C.: A new sea surface height–based code for oceanic mesoscale eddy tracking, J. Atmos. Ocean. Tech., 31, 1181–1188, https://doi.org/10.1175/JTECH-D-14-00019.1, 2014. a
Meunier, P., Ehrenstein, U., Leweke, T., and Rossi, M.: A merging criterion for two-dimensional co-rotating vortices, Phys. Fluids, 14, 2757–2766, https://doi.org/10.1063/1.1489683, 2002. a
Mooney, C. Z.: Monte Carlo Simulation. Quantitative Applications in the Social Sciences, SAGE Publications, Inc, Thousand Oaks, CA, https://doi.org/10.4135/9781412985116, 1997. a, b
Özugurlu, E., Reinaud, J. N., and Dritschel, D. G.: Interaction between two quasi-geostrophic vortices of unequal potential vorticity, J. Fluid Mech., 597, 395–414, https://doi.org/10.1017/S0022112007000018, 2008. a
Orvik, K. A. and Niiler, P.: Major pathways of Atlantic water in the northern North Atlantic and Nordic Seas toward Arctic, Geophys. Res. Lett., 29, 1896, https://doi.org/10.1029/2002GL015002, 2002. a, b, c
Pavia, E. G. and Cushman-Roisin, B.: Merging of frontal eddies, J. Phys. Oceanogr., 20, 1886–1906, https://doi.org/10.1175/1520-0485(1990)020<1886:MOFE>2.0.CO;2, 1990. a
Pegliasco, C., Delepoulle, A., Mason, E., Morrow, R., Faugère, Y., and Dibarboure, G.: META3.1exp: a new global mesoscale eddy trajectory atlas derived from altimetry, Earth Syst. Sci. Data, 14, 1087–1107, https://doi.org/10.5194/essd-14-1087-2022, 2022. a
Penven, P., Halo, I., Pous, S., and Marié, L.: Cyclogeostrophic balance in the Mozambique Channel, J. Geophys. Res.-Oceans, 119, 1054–1067, https://doi.org/10.1002/2013JC009528, 2014. a
Poulain, P. M., WarnVarnas, A., and Niiler, P. P.: Near-surface circulation of the Nordic seas as measured by Lagrangian drifters, J. Geophys. Res.-Oceans, 101, 18237–18258, https://doi.org/10.1029/96JC00506, 1996. a
Raj, R. P., Johannessen, J. A., Eldevik, T., Nilsen, J. E. O., and Halo, I.: Quantifying mesoscale eddies in the Lofoten Basin, J. Geophys. Res.-Oceans, 121, 4503–4521, https://doi.org/10.1002/2016JC011637, 2016. a
Reinaud, J. N. and Dritschel, D. G.: The merger of vertically offset quasi-geostrophic vortices, J. Fluid Mech., 469, 287–315, https://doi.org/10.1017/S0022112002001854, 2002. a
Richards, C. G. and Straneo, F.: Observations of water mass transformation and eddies in the Lofoten Basin of the Nordic Seas, J. Phys. Oceanogr., 45, 1735–1756, https://doi.org/10.1175/JPO-D-14-0238.1, 2015. a
Rossby, T., Ozhigin, V., Ivshin, V., and Bacon, S.: An isopycnal view of the Nordic Seas hydrography with focus on properties of the Lofoten Basin, Deep-Sea Res. Pt. I, 56, 1955–1971, https://doi.org/10.1016/j.dsr.2009.07.005, 2009a. a
Rossby, T., Prater, M. D., and Soiland, H.: Pathways of inflow and dispersion of warm waters in the Nordic Seas, J. Geophys. Res.-Oceans, 114, C04011, https://doi.org/10.1029/2008JC005073, 2009b. a, b, c
Rykova, T. and Oke, P. R.: Stacking of EAC eddies observed from Argo, J. Geophys. Res.-Oceans, 127, e2022JC018679, https://doi.org/10.1029/2022JC018679, 2022. a
Segtnan, O. H., Furevik, T., and Jenkins, A. D.: Heat and freshwater budgets of the Nordic seas computed from atmospheric reanalysis and ocean observations, J. Geophys. Res.-Oceans, 116, C11003, https://doi.org/10.1029/2011JC006939, 2011. a
Søiland, H., Chafik, L., and Rossby, T.: On the long-term stability of the Lofoten Basin Eddy, J. Geophys. Res.-Oceans, 121, 4438–4449, https://doi.org/10.1002/2016JC011726, 2016. a, b, c, d
Testor, P., de Young, B., Rudnick, D. L., Glenn, S., Hayes, D., Lee, C. M., Pattiaratchi, C., Hill, K., Heslop, E., Turpin, V., Alenius, P., Barrera, C., Barth, J. A., Beaird, N., Bécu, G., Bosse, A., Bourrin, F., Brearley, J. A., Chao, Y., Chen, S., Chiggiato, J., Coppola, L., Crout, R., Cummings, J., Curry, B., Curry, R., Davis, R., Desai, K., DiMarco, S., Edwards, C., Fielding, S., Fer, I., Frajka-Williams, E., Gildor, H., Goni, G., Gutierrez, D., Haugan, P., Hebert, D., Heiderich, J., Henson, S., Heywood, K., Hogan, P., Houpert, L., Huh, S., Inall, M. E., Ishii, M., Ito, S., Itoh, S., Jan, S., Kaiser, J., Karstensen, J., Kirkpatrick, B., Klymak, J., Kohut, J., Krahmann, G., Krug, M., McClatchie, S., Marin, F., Mauri, E., Mehra, A., Meredith, M. P., Meunier, T., Miles, T., Morell, J. M., Mortier, L., Nicholson, S., O'Callaghan, J., O'Conchubhair, D., Oke, P., Pallàs-Sanz, E., Palmer, M., Park, J., Perivoliotis, L., Poulain, P. M., Perry, R., Queste, B., Rainville, L., Rehm, E., Roughan, M., Rome, N., Ross, T., Ruiz, S., Saba, G., Schaeffer, A., Schönau, M., Schroeder, K., Shimizu, Y., Sloyan, B. M., Smeed, D., Snowden, D., Song, Y. M., Swart, S., Tenreiro, M., Thompson, A., Tintore, J., Todd, R. E., Toro, C., Venables, H., Wagawa, T., Waterman, S., Watlington, R. A., and Wilson, D.: OceanGliders: a component of the integrated GOOS, Front. Mar. Sci., 6, 422, https://doi.org/10.3389/fmars.2019.00422, 2019. a
Todd, R. E., Rudnick, D. L., Mazloff, M. R., Davis, R. E., and Cornuelle, B. D.: Poleward flows in the southern California Current System: glider observations and numerical simulation, J. Geophys. Res., 116, C02026, https://doi.org/10.1029/2010JC006536, 2011. a, b
Verron, J. and Valcke, S.: Scale-dependent merging of baroclinic vortices, J. Fluid Mech., 264, 81–106, https://doi.org/10.1017/S0022112094000595, 1994. a
Viglione, G. A., Thompson, A. F., Flexas, M. M., Sprintall, J., and Swart, S.: Abrupt transitions in submesoscale structure in southern Drake Passage: glider observations and model results, J. Phys. Oceanogr., 48, 2011–2027, https://doi.org/10.1175/JPO-D-17-0192.1, 2018. a
Voet, G., Quadfasel, D., Mork, K. A., and Soiland, H.: The mid-depth circulation of the Nordic Seas derived from profiling float observations, Tellus A, 62, 516–529, https://doi.org/10.1111/j.1600-0870.2010.00444.x, 2010. a
Volkov, D. L., Kubryakov, A. A., and Lumpkin, R.: Formation and variability of the Lofoten basin vortex in a high-resolution ocean model, Deep-Sea Res. Pt. I, 105, 142–157, https://doi.org/10.1016/j.dsr.2015.09.001, 2015. a
Von Hardenberg, J., McWilliams, J., Provenzale, A., Shchepetkin, A., and Weiss, J.: Vortex merging in quasi-geostrophic flows, J. Fluid Mech., 412, 331–353, https://doi.org/10.1017/S0022112000008442, 2000. a, b
Yasuda, I. and Flierl, G. R.: Two-dimensional asymmetric vortex merger: merger dynamics and critical merger distance, Dynam. Atmos. Oceans, 26, 159–181, https://doi.org/10.1016/S0377-0265(96)00485-X, 1997. a, b
Zhang, Z. W., Miao, M. F., Qiu, B., Tian, J. W., Jing, Z., Chen, G., Chen, Z. H., and Zhao, W.: Submesoscale eddies detected by SWOT and moored observations in the Northwestern Pacific, Geophys. Res. Lett., 51, e2024GL110000, https://doi.org/10.1029/2024GL110000, 2024. a
Short summary
The Lofoten Vortex is an unusual feature in the ocean: a permanent eddy which does not dissipate as most eddies do. We have long thought that other eddies must merge into the vortex in order to maintain its heat content and energetics, but such mergers are very difficult to observe due to their transient, unpredictable nature. For the first time, we have observed a merger using an ocean glider and high-resolution satellite data and can document how the merger affects the properties of the vortex.
The Lofoten Vortex is an unusual feature in the ocean: a permanent eddy which does not dissipate...
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