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Short-circuiting of the overturning circulation in the Antarctic Circumpolar Current

Nature volume 447, pages 194–197 (2007)Cite this article

Abstract

The oceanic overturning circulation has a central role in the Earth’s climate system and in biogeochemical cycling1,2, as it transports heat, carbon and nutrients around the globe and regulates their storage in the deep ocean. Mixing processes in the Antarctic Circumpolar Current are key to this circulation, because they control the rate at which water sinking at high latitudes returns to the surface in the Southern Ocean3,4,5,6,7,8. Yet estimates of the rates of these processes and of the upwelling that they induce are poorly constrained by observations. Here we take advantage of a natural tracer-release experiment—an injection of mantle helium from hydrothermal vents into the Circumpolar Current near Drake Passage9—to measure the rates of mixing and upwelling in the current’s intermediate layers over a sector that spans nearly one-tenth of its circumpolar path. Dispersion of the tracer reveals rapid upwelling along density surfaces and intense mixing across density surfaces, both occurring at rates that are an order of magnitude greater than rates implicit in models of the average Southern Ocean overturning4,5,6,7,8. These findings support the view that deep-water pathways along and across density surfaces intensify and intertwine as the Antarctic Circumpolar Current flows over complex ocean-floor topography, giving rise to a short circuit of the overturning circulation in these regions.

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Figure 1: Large-scale distribution of primordial 3 He in the deep Southeast Pacific and Southwest Atlantic.
Figure 2: Downstream evolution of the primordial 3 He distribution in density coordinates.
Figure 3: Distribution of primordial 3 He and streamfunction along the Scotia Sea rim.

References

  1. Rahmstorf, S. Ocean circulation and climate during the past 120,000 years. Nature 419, 207–214 (2002)

    Article  ADS  CAS  Google Scholar 

  2. Sarmiento, J. L., Gruber, N., Brzezinski, M. & Dunne, J. P. High-latitude controls of thermocline nutrients and low latitude biological productivity. Nature 427, 56–60 (2004)

    Article  ADS  CAS  Google Scholar 

  3. Marshall, D. Subduction of water masses in an eddying ocean. J. Mar. Res. 55, 201–222 (1997)

    Article  Google Scholar 

  4. Gnanadesikan, A. A simple predictive model for the structure of the oceanic pycnocline. Science 283, 2077–2079 (1999)

    Article  ADS  CAS  Google Scholar 

  5. Speer, K., Rintoul, S. R. & Sloyan, B. The diabatic Deacon cell. J. Phys. Oceanogr. 30, 3212–3222 (2000)

    Article  ADS  MathSciNet  Google Scholar 

  6. Marshall, J. & Radko, T. Residual-mean solutions for the Antarctic Circumpolar Current and its associated overturning circulation. J. Phys. Oceanogr. 33, 2341–2354 (2003)

    Article  ADS  Google Scholar 

  7. Bryden, H. L. & Cunningham, S. A. How wind forcing and air–sea heat exchange determine the meridional temperature gradient and stratification for the Antarctic Circumpolar Current. J. Geophys. Res. 108 3275 doi: 1029/2001/JC001296 (2003)

    Article  ADS  Google Scholar 

  8. Olbers, D. & Visbeck, M. A model of the zonally averaged stratification and overturning in the Southern Ocean. J. Phys. Oceanogr. 35, 1190–1205 (2005)

    Article  ADS  Google Scholar 

  9. Well, R., Roether, W. & Stevens, D. P. An additional deep-water mass in Drake Passage as revealed by 3He data. Deep-Sea Res. I 50, 1079–1098 (2003)

    Article  CAS  Google Scholar 

  10. Wunsch, C. & Ferrari, R. Vertical mixing, energy, and the general circulation of the oceans. Annu. Rev. Fluid Mech. 36, 281–314 (2004)

    Article  ADS  MathSciNet  Google Scholar 

  11. Toggweiler, J. R. & Samuels, B. On the ocean’s large-scale circulation near the limit of no vertical mixing. J. Phys. Oceanogr. 28, 1832–1852 (1998)

    Article  ADS  Google Scholar 

  12. Webb, D. J. & Suginohara, N. Vertical mixing in the ocean. Nature 409, 37 (2001)

    Article  ADS  CAS  Google Scholar 

  13. Naveira Garabato, A. C., Polzin, K. L., King, B. A., Heywood, K. J. & Visbeck, M. Widespread intense turbulent mixing in the Southern Ocean. Science 303, 210–213 (2004)

    Article  ADS  CAS  Google Scholar 

  14. Kunze, E., Firing, E., Hummon, J. M., Chereskin, T. K. & Thurnherr, A. M. Global abyssal mixing inferred from lowered ADCP shear and CTD strain profiles. J. Phys. Oceanogr. 36, 1553–1576 (2006)

    Article  ADS  Google Scholar 

  15. Ledwell, J. R., Watson, A. J. & Law, C. S. Mixing of a tracer in the pycnocline. J. Geophys. Res. 103, 21499–21529 (1998)

    Article  ADS  Google Scholar 

  16. Gille, S. T. Float observations of the Southern Ocean: Part 2. Eddy fluxes. J. Phys. Oceanogr. 33, 1182–1196 (2003)

    Article  ADS  Google Scholar 

  17. Stammer, D. On eddy characteristics, eddy transports, and mean flow properties. J. Phys. Oceanogr. 28, 727–739 (1998)

    Article  ADS  Google Scholar 

  18. Ferreira, D., Marshall, J. & Heimbach, P. Estimating eddy stresses by fitting dynamics to observations using a residual-mean ocean circulation model and its adjoint. J. Phys. Oceanogr. 35, 1891–1910 (2005)

    Article  ADS  Google Scholar 

  19. Olbers, D., Borowski, D., Völker, C. & Wolff, J.-O. The dynamical balance, transport and circulation of the Antarctic Circumpolar Current. Antarct. Sci. 16, 439–470 (2004)

    Article  ADS  Google Scholar 

  20. MacCready, P. & Rhines, P. B. Meridional transport across a zonal channel: Topographic localization. J. Phys. Oceanogr. 31, 1427–1439 (2001)

    Article  ADS  Google Scholar 

  21. Lee, M.-M. & Coward, A. C. Eddy mass transport in an eddy-permitting global ocean model. Ocean Model. 5, 249–266 (2003)

    Article  ADS  Google Scholar 

  22. Hallberg, R. & Gnanadesikan, A. The role of eddies in determining the structure and response of the wind-driven Southern Hemisphere overturning: Results from the MESO project. J. Phys. Oceanogr. 36, 2232–2252 (2006)

    Article  ADS  Google Scholar 

  23. Aguilar, D. A. & Sutherland, B. R. Internal wave generation from rough topography. Phys. Fluids 18 doi: 10.1063/1.2214538 (2006)

  24. Polzin, K. L. Subinertial finestructure on the continental slope / rise transition. J. Phys. Oceanogr. (submitted).

  25. Sanson, L. Z. & van Heijst, G. J. F. Ekman effects in a rotating flow over bottom topography. J. Fluid Mech. 471, 239–255 (2002)

    Article  ADS  MathSciNet  Google Scholar 

  26. Wilson, C. & Williams, R. G. When are eddy tracer fluxes directed down gradient? J. Phys. Oceanogr. 36, 189–201 (2006)

    Article  ADS  Google Scholar 

  27. Wunsch, C. The work done by the wind on the oceanic general circulation. J. Phys. Oceanogr. 28, 2332–2340 (1998)

    Article  ADS  Google Scholar 

  28. Scott, R. B. & Wang, F. Direct evidence of an oceanic inverse kinetic energy cascade from satellite altimetry. J. Phys. Oceanogr. 35, 1650–1666 (2005)

    Article  ADS  Google Scholar 

  29. Tandon, A. & Garrett, C. On a recent parameterization of mesoscale eddies. J. Phys. Oceanogr. 26, 406–411 (1996)

    Article  ADS  Google Scholar 

  30. Ledwell, J. R., Watson, A. J. & Law, C. S. Evidence for slow mixing across the pycnocline from an open-ocean tracer release experiment. Nature 364, 702–703 (1993)

    Article  ADS  Google Scholar 

  31. Jackett, D. R. & McDougall, T. J. A neutral density variable for the world's oceans. J. Phys. Oceanogr. 27, 237–263 (1997)

    Article  ADS  Google Scholar 

  32. Naveira Garabato, A. C., Stevens, D. P. & Heywood, K. J. Water mass conversion, fluxes and mixing in the Scotia Sea diagnosed by an inverse model. J. Phys. Oceanogr. 33, 2565–2587 (2003)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

A NERC Advanced Research Fellowship supported A.C.N.G. during the analysis and writing of this Letter. We gratefully acknowledge feedback from J. Ledwell and K. Polzin.

Author Contributions A.C.N.G. designed and conducted the analysis and wrote the letter. D.P.S. and A.J.W. discussed aspects of the methodology and results, and helped with the writing. W.R. provided many of the 3He data and advised on their use.

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Authors and Affiliations

  1. School of Ocean and Earth Science, National Oceanography Centre, Southampton SO14 3ZH, UK,

    Alberto C. Naveira Garabato

  2. School of Mathematics, University of East Anglia, Norwich NR4 7TJ, UK,

    David P. Stevens

  3. School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK,

    Andrew J. Watson

  4. Institut für Umweltphysik, Universität Bremen, Bremen D-28334, Germany,

    Wolfgang Roether

Authors
  1. Alberto C. Naveira Garabato
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Correspondence to Alberto C. Naveira Garabato.

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Supplementary information

Supplementary Information

This file contains Supplementary Notes containing a detailed description of the methodology, derivation of equations, and error analysis, Supplementary Figure 1 with Legend and additional references. (PDF 278 kb)

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Garabato, A., Stevens, D., Watson, A. et al. Short-circuiting of the overturning circulation in the Antarctic Circumpolar Current. Nature 447, 194–197 (2007). https://doi.org/10.1038/nature05832

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