Articles | Volume 22, issue 2
https://doi.org/10.5194/os-22-1003-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/os-22-1003-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
25 Mar 2026
Research article |
| 25 Mar 2026
| 25 Mar 2026
Atlantic Water flow through Fram Strait to the Arctic Ocean measured by repeated glider transects
Vår Dundas
Geophysical Institute, University of Bergen, and Bjerknes Centre for Climate Research, Bergen, Norway
now at: Nansen Environmental and Remote Sensing Center, Bergen, Norway
Geophysical Institute, University of Bergen, and Bjerknes Centre for Climate Research, Bergen, Norway
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Ice shelves in the Amundsen Sea are thinning rapidly as ocean currents bring warm water into cavities beneath the floating ice. We use 2-year-long mooring records and 16-year-long model simulations to describe the hydrography and circulation near the ice front between Siple and Carney Islands. We find that temperatures here are lower than at neighboring ice fronts and that the transport of heat toward the cavity is governed by wind stress over the Amundsen Sea continental shelf.
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Cited articles
Aagaard, K., Foldvik, A., and Hillman, S. R.: The West Spitsbergen Current- Disposition and water mass transformation, J. Geophys. Res., 92, 3778–3784, 1987. a
Busecke, J., Gregor, L., Balwada, D., Thomsen, S., Giddy, I. S., Rollo, C., and tjryankeogh: GliderToolsCommunity/GliderTools: v2021.05.26, Zenodo [code], https://doi.org/10.5281/zenodo.4815417, 2021. a
Dale, D., Christl, M., Vockenhuber, C., Macrander, A., Ólafsdóttir, S., Middag, R., and Casacuberta, N.: Tracing Ocean Circulation and Mixing From the Arctic to the Subpolar North Atlantic Using the 129I-236U Dual Tracer, J. Geophys. Res., 129, e2024JC021211, https://doi.org/10.1029/2024JC021211, 2024. a
Eriksen, C. C., Osse, T. J., Light, R. D., Wen, T., Lehman, T. W., Sabin, P. L., Ballard, J. W., and Chiodi, AM.: 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, b
Fer, I., Peterson, A. K., and Nilsen, F.: Atlantic Water Boundary Current Along the Southern Yermak Plateau, Arctic Ocean, J. Geophys. Res., 128, e2023JC019645, https://doi.org/10.1029/2023JC019645, 2023. a
Fer, I., Brakstad, A., Damerell, G. M., and Elliott, F.: Physical oceanography data from Seaglider missions west of Svalbard, October 2020 – February 2023, Norwegian Marine Data Centre [data set], https://doi.org/10.21335/NMDC-1222822416, 2025. a, b, c, d
Frank, L., Albretsen, J., Skogseth, R., Nilsen, F., and Jonassen, M. O.: Mechanisms of warm-water intrusions onto the West Spitsbergen Shelf during winter, Ocean Sci., 21, 2419–2442, https://doi.org/10.5194/os-21-2419-2025, 2025. a, b
Global Ocean Gridded L4 Sea Surface Heights And Derived Variables Reprocessed 1993 Ongoing: E.U. Copernicus Marine Service Information (CMEMS), Marine Data Store (MDS) [data set], https://doi.org/10.48670/moi-00148, 2024. a, b, c
Gregor, L., Ryan-Keogh, T. J., Nicholson, S.-A., du Plessis, M., Giddy, I., and Swart, S.: GliderTools: A Python Toolbox for Processing Underwater Glider Data, Front. Mar. Sci., 6, 1–13, https://doi.org/10.3389/fmars.2019.00738, 2019. a, b
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, b, c
Hofmann, Z., von Appen, W.-J., and Wekerle, C.: Seasonal and Mesoscale Variability of the Two Atlantic Water Recirculation Pathways in Fram Strait, J. Geophys. Res., 126, e2020JC017057, https://doi.org/10.1029/2020JC017057, 2021. a, b, c, d
Huang, J., Pickart, R. S., Chen, Z., and Huang, R. X.: Role of air-sea heat flux on the transformation of Atlantic Water encircling the Nordic Seas, Nat. Commun., 14, 141, https://doi.org/10.1038/s41467-023-35889-3, 2023. a
Ingvaldsen, R. B., Assmann, K. M., Primicerio, R., Fossheim, M., Polyakov, I. V., and Dolgov, A. V.: Physical manifestations and ecological implications of Arctic Atlantification, Nat. Rev. Earth Environ., 2, 874–889, https://doi.org/10.1038/s43017-021-00228-x, 2021. a
Jakobsson, M., Mayer, L. A., Bringensparr, C., Castro, C. F., Mohammad, R., Johnson, P., Ketter, T., Accettella, D., Amblas, D., An, L., Arndt, J. E., Canals, M., and Casamor, J. L.: The International Bathymetric Chart of the Arctic Ocean Version 4.0, Sci. Data, 7, https://doi.org/10.1038/s41597-020-0520-9, 2020. a, b
Kolås, E. H., Koenig, Z., Fer, I., Nilsen, F., and Marnela, M.: Structure and Transport of Atlantic Water North of Svalbard From Observations in Summer and Fall 2018, J. Geophys. Res., 125, e2020JC016174, https://doi.org/10.1029/2020jc016174, 2020. a, b
Kolås, E. H., Baumann, T. M., Skogseth, R., Koenig, Z., and Fer, I.: Circulation and Hydrography in the Northwestern Barents Sea: Insights From Recent Observations and Historical Data (1950–2022), J. Geophys. Res., 129, e2023JC020211, https://doi.org/10.1029/2023JC020211, 2024. a, b
Manley, T. O.: Branching of Atlantic Water within the Greenland- Spitsbergen passage: An estimate of recirculation, J. Geophys. Res., 100, 20627–20634, 1995. a
Marnela, M., Rudels, B., Houssais, M.-N., Beszczynska-Möller, A., and Eriksson, P. B.: Recirculation in the Fram Strait and transports of water in and north of the Fram Strait derived from CTD data, Ocean Sci., 9, 499–519, https://doi.org/10.5194/os-9-499-2013, 2013. a
McPherson, R. A., Wekerle, C., and Kanzow, T.: Shifts of the Recirculation Pathways in Central Fram Strait Drive Atlantic Intermediate Water Variability on Northeast Greenland Shelf, J. Geophys. Res., 128, e2023JC019915, https://doi.org/10.1029/2023JC019915, 2023. a
Mork, K. A. and Skagseth, Ø.: A quantitative description of the Norwegian Atlantic Current by combining altimetry and hydrography, Ocean Sci., 6, 901–911, https://doi.org/10.5194/os-6-901-2010, 2010. 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
Polyakov, I. V., Pnyushkov, A. V., Charette, M., Cho, K.-H., Jung, J., Kipp, L., Muilwijk, M., Whitmore, L., Yang, E. J., and Yoo, J.: Atlantification advances into the Amerasian Basin of the Arctic Ocean, Sci. Adv., 11, eadq7580, https://doi.org/10.1126/sciadv.adq7580, 2025. a
Quadfasel, D., Gascard, J. C., and Koltermann, K. P.: Large-scale oceanography in Fram Strait during the 1984 Marginal Ice-Zone Experiment, J. Geophys. Res., 92, 6719–6728, 1987. a
Rudels, B.: Arctic Ocean circulation, processes and water masses: A description of observations and ideas with focus on the period prior to the International Polar Year 2007–2009, Prog. Oceanogr., 132, 22–67, https://doi.org/10.1016/j.pocean.2013.11.006, 2015. a
Rudels, B., Björk, J., Nilsson, J., Winsor, P., Lake, I., and Nohr, C.: The interaction between waters from the Arctic Ocean and the Nordic Seas north of Fram Strait and along the East Greenland Current: results from the Arctic Ocean-02 Oden expedition, J. Mar. Syst., 55, 1–30, https://doi.org/10.1016/j.jmarsys.2004.06.008, 2005. a, b
Rudnick, D. L.: Ocean research enabled by underwater gliders, Annu. Rev. Mar. Sci., 8, 519–541, https://doi.org/10.1146/annurev-marine-122414-033913, 2016. a, b
Schauer, U., Fahrbach, E., Østerhus, S., and Rohardt, G.: Arctic warming through the Fram Strait: Oceanic heat transport from 3 years of measurements, J. Geophys. Res., 109, 206026, https://doi.org/10.1029/2003JC001823, 2004. a
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., E. Inall, M., Ishii, M., Ito, S.-i., 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., P. Meredith, M., 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., 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, https://doi.org/10.3389/fmars.2019.00422, 2019. a
von Appen, W.-J., Schauer, U., Hattermann, T., and Beszczynska-Möller, A.: Seasonal Cycle of Mesoscale Instability of the West Spitsbergen Current, J. Phys. Oceanogr., 46, 1231–1254, https://doi.org/10.1175/jpo-d-15-0184.1, 2016. a
Walczowski, W.: Atlantic Water in the Nordic Seas: Properties, Variability, Climatic Importance, Springer Cham, https://doi.org/10.1007/978-3-319-01279-7, 2013. a
Walczowski, W., Piechura, J., Osinski, R., and Wieczorek, P.: The West Spitsbergen Current volume and heat transport from synoptic observations in summer, Deep-Sea Res. Pt. I, 52, 1374–1391, 2005. a
Waskom, M. L.: seaborn: statistical data visualization, Journal of Open Source Software, 6, 3021, https://doi.org/10.21105/joss.03021, 2021. a
Short summary
We used ocean gliders to measure separate circulation branches of warm Atlantic water flowing into the Arctic through a key passage west of Svalbard. Over three years, gliders revealed that two main current branches together carry about five million m3 s-1 northward, with large variations linked to wind patterns. These currents influence Arctic ice and climate. Our study shows gliders can capture changes missed by traditional methods, and year-round missions are needed for a complete picture.
We used ocean gliders to measure separate circulation branches of warm Atlantic water flowing...
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