Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The three-dimensional structure of an upper ocean vortex in the tropical Pacific Ocean

Abstract

IN the equatorial Pacific Ocean, easterly trade winds and the Earth's rotation combine to drive surface currents away from the Equator, thereby causing cold nutrient-rich subsurface water to upwell. The front1 that forms between this upwelled water and warmer waters north of the Equator is sometimes visible as a spectacular "line in the sea"2 between 2° and 6° N. Westward-propagating cusp-shaped disturbances observed along this front3 have been attributed to the effect of dynamical instabilities in the system of zonal equatorial currents4–11but the connection between these phenomena remains unclear. Here we report extensive measurements from shipboard sensors, satellite and drifting buoys which reveal the three-dimensional structure of an anticyclonic eddy (or vortex) 500 km in diameter and centred at 4° N. We suggest that cusp-shaped disturbances of the front are caused by trains of large-amplitude vortices, which are driven by instability of the mean zonal shear. We show that these vortices not only play an important role in the meridional transport of heat, salt and momentum, but are also associated with regions of intense horizontal convergence along the front, where dramatic concentrations of marine life are observed.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1

    Knauss, J. A. Tellus IX, 234–237 (1957).

    ADS  Google Scholar 

  2. 2

    Yoder, J. A., Ackleson, S. G., Barber, R. T. & Balch, W. M. Nature 371, 689–692 (1994).

    ADS  Article  Google Scholar 

  3. 3

    Legeckis, R. Science 197, 1179–1181 (1977).

    ADS  CAS  Article  Google Scholar 

  4. 4

    Düing, W. et al. Nature 257, 280–284 (1975).

    ADS  Article  Google Scholar 

  5. 5

    Hansen, D. V. & Paul, C. A. J. Geophys. Res. 89, 10431–10440 (1984).

    ADS  Article  Google Scholar 

  6. 6

    Wilson, D. & Leetmaa, A. J. Phys. Oceanogr. 18, 1641–1657 (1988).

    ADS  Article  Google Scholar 

  7. 7

    Philander, G. et al. EOS 66, 154 (1985).

    ADS  Article  Google Scholar 

  8. 8

    Halpern, D., Knox, R. A. & Luther, D. S. J. Phys. Oceanogr. 18, 1514–1534 (1988).

    ADS  Article  Google Scholar 

  9. 9

    Philander, S. G. H. J. Geophys. Res. 81, 3725–3734 (1976).

    ADS  Article  Google Scholar 

  10. 10

    Cox, M. D. J. Phys. Oceanogr. 10, 1168–1186 (1980).

    ADS  Article  Google Scholar 

  11. 11

    Philander, S. G. H., Hurlin, W. J. & Pacanowski, R. C. J. Geophys. Res. 91, 14207–14211 (1986).

    ADS  Article  Google Scholar 

  12. 12

    Luther, D. S. & Johnson, E. S. J. Phys. Oceanogr. 7, 913–944 (1990).

    ADS  Article  Google Scholar 

  13. 13

    Johnson, E. S. & Luther, D. S. J. Geophys. Res. 99, 7689–7705 (1994).

    ADS  Article  Google Scholar 

  14. 14

    Pollard, R. T. Nature 323, 433–435 (1986).

    ADS  Article  Google Scholar 

  15. 15

    Niiler, P. P., Davis, R. E. & White, H. J. Deep-Sea Res. 34, 1867–1882 (1987).

    ADS  Article  Google Scholar 

  16. 16

    Smith, S. D. J. Geophys. Res. 93, 15467–15472 (1988).

    ADS  Article  Google Scholar 

  17. 17

    Liu, W. T., Katsaros, K. B. & Businger, J. A. J. Atmos. Sci. 36, 1722–1735 (1979).

    ADS  Article  Google Scholar 

  18. 18

    McPhaden, M. J. J. Geophys. Res. 101, 6337–6359 (1996).

    ADS  Article  Google Scholar 

  19. 19

    Qiao, L. & Weisberg, R. H. J. Geophys. Res. 100, 8677–8693 (1995).

    ADS  Article  Google Scholar 

  20. 20

    Chew, F. & Bushnell, M. H. J. Phys. Oceanogr. 20, 1124–1133 (1990).

    ADS  Article  Google Scholar 

  21. 21

    Donohue, K. A., thesis, Univ. Rhode Island (1996).

  22. 22

    Price, J. F., Weller, R. A. & Schudlich, R. R. Science 238, 1534–1538 (1987).

    ADS  CAS  Article  Google Scholar 

  23. 23

    Niiler, P. P. & Reynolds, R. W. J. Phys. Oceanogr. 14, 217–230 (1984).

    ADS  Article  Google Scholar 

  24. 24

    Pollard, R. T. & Regier, L. Nature 348, 227–229 (1990).

    ADS  Article  Google Scholar 

  25. 25

    Weller, R. Nature 348, 199–200 (1990).

    ADS  Article  Google Scholar 

  26. 26

    Flagg, C. N. & Smith, S. L. Deep-Sea Res. 36, 455–474 (1989).

    ADS  Article  Google Scholar 

  27. 27

    Johnson, E. S. Deep-Sea Res. (in the press).

  28. 28

    Foley, D. G. et al. Geophys. Res. Lett. (submitted).

  29. 29

    Landry, M. R., Kirshtein, J. & Constantinou, J. Deep-Sea Res. (submitted).

  30. 30

    Smith, C. R. et al. Deep-Sea Res. (submitted).

  31. 31

    Sawyer, M. & Flament, P. Deep-Sea Res. 42, (1995); cover.

  32. 32

    Perigaud, C. J. Geophys. Res. 95, 7239–7248 (1990).

    ADS  Article  Google Scholar 

  33. 33

    Miller, L., Watts, D. R. & Wimbush, M. J. Phys. Oceanogr. 15, 1759–1770 (1985).

    ADS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Flament, P., Kennan, S., Knox, R. et al. The three-dimensional structure of an upper ocean vortex in the tropical Pacific Ocean. Nature 383, 610–613 (1996). https://doi.org/10.1038/383610a0

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing