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Significant role of the North Icelandic Jet in the formation of Denmark Strait overflow water


The Denmark Strait overflow water is the largest dense water plume from the Nordic seas to feed the lower limb of the Atlantic Meridional Overturning Circulation. Its primary source is commonly thought to be the East Greenland Current. However, the recent discovery of the North Icelandic Jet—a deep-reaching current that flows along the continental slope of Iceland—has called this view into question. Here we present high-resolution measurements of hydrography and velocity north of Iceland, taken during two shipboard surveys in October 2008 and August 2009. We find that the North Icelandic Jet advects overflow water into the Denmark Strait and constitutes a pathway that is distinct from the East Greenland Current. We estimate that the jet supplies about half of the total overflow transport, and infer that it is the primary source of the densest overflow water. Simulations with an ocean general circulation model suggest that the import of warm, salty water from the North Icelandic Irminger Current and water-mass transformation in the interior Iceland Sea are critical to the formation of the jet. We surmise that the timescale for the renewal of the deepest water in the meridional overturning cell, and its sensitivity to changes in climate, could be different than presently envisaged.

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Figure 1: Flow through the Denmark Strait.
Figure 2: Hydrographic properties along the Látrabjarg line near the sill as measured during the October 2008 survey.
Figure 3: Flow of dense water upstream of the Denmark Strait.
Figure 4: Model circulation and hydrography.


  1. Nansen, F. Das Bodenwasser und die Abkühlung des Meeres. Int. Rev. Gesamten Hydrobiol. Hydrogr. 5, 1–42 (1912).

    Article  Google Scholar 

  2. Swift, J. H., Aagaard, K. & Malmberg, S-A. The contribution of the Denmark Strait overflow to the deep North Atlantic. Deep-Sea Res. 27A, 29–42 (1980).

    Article  Google Scholar 

  3. Swift, J. H. & Aagaard, K. Seasonal transitions and water mass formation in the Iceland and Greenland seas. Deep-Sea Res. 28A, 1107–1129 (1981).

    Article  Google Scholar 

  4. Mauritzen, C. Production of dense overflow waters feeding the North Atlantic across the Greenland–Scotland Ridge. Part 1: Evidence for a revised circulation scheme. Deep-Sea Res. I 43, 769–806 (1996).

    Article  Google Scholar 

  5. Eldevik, T. et al. Observed sources and variability of Nordic seas overflow. Nature Geosci. 2, 406–410 (2009).

    Article  Google Scholar 

  6. Jónsson, S. & Valdimarsson, H. A new path for the Denmark Strait overflow water from the Iceland Sea to Denmark Strait. Geophys. Res. Lett. 31, L03305 (2004).

    Article  Google Scholar 

  7. Jónsson, S. The Circulation in the Northern Part of the Denmark Strait and its Variability. ICES Report CM-1999/L:06 (ICES, 1999).

  8. Dickson, R. R. & Brown, J. The production of North Atlantic deep water: Sources, rates and pathways. J. Geophys. Res. 99, 12319–12341 (1994).

    Article  Google Scholar 

  9. Girton, J. B., Sanford, T. B. & Käse, R. H. Synoptic sections of the Denmark Strait overflow. Geophys. Res. Lett. 28, 1619–1622 (2001).

    Article  Google Scholar 

  10. Rudels, B., Fahrbach, E., Meincke, J., Budéus, G. & Eriksson, P. The East Greenland Current and its contribution to the Denmark Strait overflow. ICES J. Mar. Sci. 59, 1133–1154 (2002).

    Article  Google Scholar 

  11. Rudels, B. et al. 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 (2005).

    Article  Google Scholar 

  12. Spall, M. A. & Price, J. F. Mesoscale variability in Denmark Strait: The PV outflow hypothesis. J. Phys. Oceanogr. 28, 1598–1623 (1998).

    Article  Google Scholar 

  13. Pickart, R. S., Torres, D. J. & Fratantoni, P. S. The East Greenland Spill Jet. J. Phys. Oceanogr. 35, 1037–1053 (2005).

    Article  Google Scholar 

  14. Magaldi, M. G., Haine, T. W. N. & Pickart, R. S. On the nature and variability of the East Greenland Spill Jet: A case study in summer 2003. J. Phys. Oceanogr. (in the press).

  15. Köhl, A., Käse, R. H. & Stammer, D. B. Causes of changes in the Denmark Strait overflow. J. Phys. Oceanogr. 37, 1678–1696 (2007).

    Article  Google Scholar 

  16. Smith, P. C. Baroclinic instability in the Denmark Strait overflow. J. Phys. Oceanogr. 6, 355–371 (1976).

    Article  Google Scholar 

  17. Ross, C. K. Temperature–salinity characteristics of the ‘overflow’ water in Denmark Strait during ‘OVERFLOW ′73’. Rapp. P.-v. Réun.-Cons. Int. Explor. Mer. 185, 111–119 (1984).

    Google Scholar 

  18. Macrander, A., Send, U., Valdimarsson, H., Jónsson, S. & Käse, R. H. Interannual changes in the overflow from the Nordic Seas into the Atlantic Ocean through Denmark Strait. Geophys. Res. Lett. 32, L06606 (2005).

    Article  Google Scholar 

  19. Stommel, H., Bryden, H. & Mangelsdorf, P. Does some of the Mediterranean outflow come from great depth? Pure Appl. Geophys. 105, 879–889 (1973).

    Article  Google Scholar 

  20. Kinder, T. H. & Parrilla, G. Yes, some of the Mediterranean outflow does come from great depth. J. Geophys. Res. 92, 2901–2906 (1987).

    Article  Google Scholar 

  21. Hansen, B. & Østerhus, S. Faroe Bank Channel overflow 1995–2001. Prog. Oceanogr. 75, 817–856 (2007).

    Article  Google Scholar 

  22. Marshall, J., Hill, C., Perelman, L. & Adcroft, A. Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling. J. Geophys. Res. 102, 5733–5752 (1997).

    Article  Google Scholar 

  23. Spall, M. A. On the role of eddies and surface forcing in the heat transport and overturning circulation in marginal seas. J. Clim. (2011).

  24. Stefánsson, U. North Icelandic waters. Rit Fiskid. 3, 1–269 (1962).

    Google Scholar 

  25. Valdimarsson, H. & Malmberg, S-A. Near-surface circulation in Icelandic waters derived from satellite tracked drifters. Rit Fiskid. 16, 23–39 (1999).

    Google Scholar 

  26. Woodgate, R. A., Fahrbach, E. & Rohardt, G. Structure and transports of the East Greenland Current at 75° N from moored current meters. J. Geophys. Res. 104, 18059–18072 (1999).

    Article  Google Scholar 

  27. Spall, M. A. Boundary currents and watermass transformation in marginal seas. J. Phys. Oceanogr. 34, 1197–1213 (2004).

    Article  Google Scholar 

  28. Spall, M. A. Dynamics of downwelling in an eddy-resolving convective basin. J. Phys. Oceanogr. 40, 2341–2347 (2010).

    Article  Google Scholar 

  29. Egbert, G. D., Bennett, A. F. & Foreman, M. G. G. TOPEX/Poseidon tides estimated using a global inverse model. J. Geophys. Res. 99, 24821–24852 (1994).

    Article  Google Scholar 

  30. Egbert, G. D. & Erofeeva, S. Y. Efficient inverse modeling of barotropic ocean tides. J. Atmos. Oceanic Technol. 19, 183–204 (2002).

    Article  Google Scholar 

  31. Thurnherr, A. M. A practical assessment of the errors associated with full-depth LADCP profiles obtained using Teledyne RDI Workhorse Acoustic Current Dopper Profilers. J. Atmos. Oceanic Technol. 27, 1215–1227 (2010).

    Article  Google Scholar 

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The authors wish to thank B. Rudels and J. B. Girton for comments. Support for this work was provided by the US National Science Foundation and the Research Council of Norway. This is publication A351 from the Bjerknes Centre for Climate Research.

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K.V., R.S.P., H.V., S.J. and D.J.T. collected and analysed the data; M.A.S. designed and analysed the model simulations; K.V., R.S.P. and M.A.S. wrote the paper and all authors interpreted the results and clarified the implications.

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Correspondence to Kjetil Våge.

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The authors declare no competing financial interests.

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Våge, K., Pickart, R., Spall, M. et al. Significant role of the North Icelandic Jet in the formation of Denmark Strait overflow water. Nature Geosci 4, 723–727 (2011).

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