Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-06-04T11:34:33.303Z Has data issue: false hasContentIssue false

On the damping of internal gravity waves in a continuously stratified ocean

Published online by Cambridge University Press:  28 March 2006

Paul H. LeBlond
Affiliation:
Institute of Oceanography, University of British Columbia

Abstract

The problem studied here is that of the attenuation of internal waves through turbulent mixing in a weakly and exponentially stratified fluid. The equations are linearized and it is assumed that the action of turbulence can be parametrically represented by eddy mixing coefficients and that the influence of bottom friction is restricted to a thin bottom boundary layer. The simple case where there is no rotation and only one component to the stratification is first examined in detail, and the modifications caused by introducing rotation and a second component are subsequently investigated. Subject quantitatively to the choice made for the eddy coefficients, but qualitatively not strongly dependent on that choice, the following conclusions are drawn: (i) very short internal waves (length < 100 m) are strongly damped in basins of all depths; (ii) long internal waves or seiches in shallow seas (depth ≃ 100 m) will not last more than a few cycles as free oscillations; (iii) the attenuation rate for long internal tides is small enough that these should be observable very far from the coasts, but large enough to exclude the possibility of oceanic standing wave systems; (iv) for very long internal waves the damping is predominantly due to the effect of bottom friction, and the attenuation rate becomes almost independent of the actual form of the stratification present in the fluid.

Type
Research Article
Copyright
© 1966 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bowden, K. F. 1960 Phil. Mag. (Ser. 7), 41, 907.
Chandrasekhar, S. 1961 Hydrodynamic and Hydromagnetic Stability. Oxford: Clarendon Press.
Ekman, V. W. 1931 Rapp. Cons. Perm. Expl. de la Mer, 76.
Fofonoff, N. P. 1961 Physical properties of sea water. The Sea (ed. Hill). Wiley.
Glinskii, N. T. & Boguslavskii, S. G. 1963 Izv. Geophys. Ser. no. 10, 1554.
Groen, P. 1954 Publ. No. K.N.M.I. 102–63 of Koninkl. Ned. Met. Inst.
Harrison, W. J. 1908 Proc. Lond. Math. Soc. 6, 39.
Krauss, W. 1964 Kieler Meeresf. Bd. 20, p. 109.
Krauss, W. 1965 Methoden und Ergebnisse der theoretischen Ozeanographie. Bd. II. Interne Wellen. Berlin: Gebrüder Bornträger.
Lamb, H. 1932 Hydrodynamics (6th ed.). Cambridge University Press.
Leblond, P. H. 1965 Kieler Meeresf. Bd. 21.
Rattray, M. 1957 Trans. Amer. Geophys. Union, 38, 495.
Richardson, L. F. & Stommel, H. 1948 J. Mar. Res. 8, 19.
Stern, M. E. 1960 Tellus, 12, 172.
Ufford, C. W. 1947 Trans. Amer. Geophys. Union, 28, 87.
Walin, G. 1964 Tellus, 16, 389.