Planetary-type Waves in the South West Indian Ocean

Article metrics


SOUTH of the latitude of the Cape of Good Hope, the Agulhas Current Stream (or at least most of it) turns back into the Indian Ocean and forms a zonal current called the Agulhas Return Current, whose mean axis of flow is approximately 38°–39°S. Near the start of its eastward flow, the Agulhas Return Current has been shown to undergo sharp changes of direction (Fig. 1a). These deflections are apparent in the analysis made by Dietrich1 and Le Pichon2. The latter shows them occurring down to the depth of the salinity maximum and draws attention to the important influence of bottom topography. They are also very evident in the study made by Darbyshire3 of data from the cruises of SAS Natal and RS Africana II, occurring in three out of the four seasons examined. The deflections all occur near a prominent topographical feature, the Agulhas Plateau, and their recurrence suggests that they are a quasi-stationary feature and possibly planetary waves caused by the rapid changes in water depth. An investigation into this possibility has been made by comparing the flow patterns deduced from hydrological data with those predicted by theory.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Dietrich, G., Veroff. des. Inst. fur Meereskunde, 27, 1 (1935).

  2. 2

    Le Pichon, X., J. Geophys. Res., 65, 12, 4061 (1960).

  3. 3

    Darbyshire, J., Deep Sea Res., 11, 781 (1964).

  4. 4

    Porter, G. H., and Rattray, jun., M., Deut. Hydr. Zeit., 17, 4, 164 (1964).

  5. 5

    Simpson, E. S. W., and Forder, E., Chart 123A (third ed.) (University of Cape Town, 1969).

  6. 6

    Shipley, A. M., and Zoutendyk, P., Univ. Cape Town, Data Report, 2 (1964).

  7. 7

    Orren, M. J., Invest. Rep. Sea Fish. S. Afr., 45 (1963).

  8. 8

    S.A. Division of Sea Fisheries, Manuscript data Africana II cruise, July 1962.

  9. 9

    Woods Hole Oceanographic Institution, Anton Bruun, Cruise, 6 (1965).

  10. 10

    Meteorological Office, Met. Office, 772 (HM Stationery Office, 1966).

  11. 11

    Tchernia, P., Le Floch, J., Lacombe, H., Bull. d'Information du Comité Central d'Oceanographique et d' Études des Côtes, 3, 10 (1951).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

HARRIS, T. Planetary-type Waves in the South West Indian Ocean. Nature 227, 1043–1044 (1970) doi:10.1038/2271043a0

Download citation

Further reading


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.