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A laboratory model of the wind-driven ocean circulation

Published online by Cambridge University Press:  29 March 2006

R. C. Beardsley
Affiliation:
Meteorology Department, Massachusetts Institute of Technology

Abstract

A simple laboratory model for the wind-driven ocean circulation is re-studied experimentally and theoretically. Introduced by Pedlosky & Greenspan (1967), the model consists of a rotating cylinder with sloping bottom, the fluid inside being driven by the steady relative rotation of the cylinder's lid. A linear theory is developed to illustrate the modification in the interior and Stewartson boundary layers caused by variation of the bottom slope from 0 to O(1); Stommel's (1948) model is obtained when the bottom slope tan α [Lt ] E¼, and the Munk & Carrier (1950) model is obtained for E¼ [Lt ] tan α [Lt ] 1 (E is the Ekman number). Measurements of the interior cross-contour ‘Sverdrup’ velocity agree well with theory when the Ekman-layer Reynolds number RE is ≈ 1 or less. The western boundarylayer azimuthal velocity agrees reasonably well with theory, although the observed variation with depth and bottom slope were not predicted. The western boundary layer shows downstream intensification when RE is increased from ≈ 1 until topographic Rossby waves appear in the transition region between western boundary layer and interior. The motion becomes unstable when a critical value of RE is reached, independent of the bottom slope, and a low-frequency two-dimensional flow oscillation is observed. A brief comparison is made with previous wind-driven ocean circulation studies.

Type
Research Article
Copyright
© 1969 Cambridge University Press

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References

Baker, D. J. 1966 A technique for the precise measurement of small fluid velocities J. Fluid Mech. 26, 573.Google Scholar
Barcilon, V. 1967 On the motion due to sources and sinks distributed along the vertical boundary of a rotating fluid J. Fluid Mech. 27, 551.Google Scholar
Beardsley, R. C. 1968 Ph.D. Thesis, M.I.T.
Bisshopp, F. E. 1966 Linearized flow in rotating systems. Technical Report, no. 2, Brown University.Google Scholar
Bryan, K. 1963 A numerical investigation of a non-linear model of a wind-driven ocean J. Atmos. Sci. 20, 594.Google Scholar
Carrier, G. F. & Robinson, A. R. 1962 On the theory of the wind-driven ocean circulation J. Fluid Mech. 12, 49.Google Scholar
Charney, J. 1955 The Gulf Stream as an inertial boundary layer Proc. natn. Acad. Sci. U.S.A. 41, 731.Google Scholar
Fofonoff, N. P. 1954 Steady flow in a frictionless homogeneous ocean J. Mar. Res. 13, 254.Google Scholar
Greenspan, H. P. 1965 On the general theory of contained rotating fluid motion J. Fluid Mech. 22, 449.Google Scholar
Ilyin, A. N. & Kamenkovich, V. M. 1963 On the influence of friction on ocean currents Dokl. Akad. Nauk SSSR, 150, 1274.Google Scholar
Lilly, D. K. 1966 On the instability of Ekman boundary flow J. Atmos. Sci. 23, 481.Google Scholar
Moore, D. W. 1963 Rossby waves in ocean circulation Deep-Sea Res. 10, 735.Google Scholar
Munk, W. H. & Carrier, G. F. 1950 The wind-driven circulation in ocean basins of various shapes Tellus, 2, 158.Google Scholar
Pedlosky, J. & Greenspan, H. P. 1967 A simple laboratory model for the oceanic circulation J. Fluid Mech. 27, 291.Google Scholar
Stommel, H. 1948 The westward intensification of wind-driven ocean currents Trans. Am. Geophys. Union, 29, 202.Google Scholar
Sverdrup, H. 1947 Wind-driven currents in a baroclinic ocean Proc. natn. Acad. Sci. U.S.A. 33, 318.Google Scholar