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Wave-induced shear instability in the summer thermocline

Published online by Cambridge University Press:  28 March 2006

J. D. Woods
Affiliation:
Meteorological Office, Bracknell, Berks

Abstract

The fine structure of the summer thermocline in the Mediterranean Sea around Malta, investigated by a new temperature-gradient meter and by photographs of dye tracers, is summarized. The principal internal feature of the thermocline is a series of thin, laminar-flow sheets of high static stability, separated by weakly turbulent layers of only moderate density gradient and a few metres thick. A mechanism for generating the patches of turbulence observed on these thermocline sheets is established by comparing dye photographs with a theory by Miles & Howard (1964).

Type
Research Article
Copyright
© 1968 Cambridge University Press

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References

Banner, A. H. 1955 Note on a visible thermocline Science, 121, 402.Google Scholar
Bowden, K. F. 1965 Horizontal mixing in the sea due to a shearing current J. Fluid Mech. 21, 83.Google Scholar
Grant, H. L., Moilliet, A. & Vogel, W. M. 1963 Turbulent mixing in the thermocline. Pacific Naval Lab. preprint (Esquimalt D.C.) (to be published in J. Fluid Mech.).
Lafond, E. C. 1962 Internal waves in The Sea, vol. I. Ed. M. N. Hill. London: Interscience.
Linbaugh, C. & Rechnitzer, A. B. 1955 Visual detection of temperature-density discontinuities in water by diving Science. 121, 395.Google Scholar
Ludlam, F. H. 1967 Characteristics of billow clouds and their relation to clear-air turbulence Q. J. Roy. Meteor. Soc. 93, 419.Google Scholar
Miles, J. W. & Howard, L. N. 1964 Note on a heterogeneous shear flow J. Fluid Mech. 20, 311.Google Scholar
Phillips, O. M. 1966 Dynamics of the Upper Ocean. Cambridge University Press.
Proudman, J. 1953 Dynamical Oceanography. London: Methuen.
Rosenhead, L. 1932 The formation of vortices from a surface of discontinuity. Proc. Roy. Soc A 134, 17092.Google Scholar
Rouse, H. & Dodu, J. 1955 Diffusion turbulent à travers une discontinuité de densité. La Houille blanche 10° année, pp. 5229.Google Scholar
Spilhaus, A. F. 1937 A Bathythermograph. J. Mar. Res. (16), 95.Google Scholar
Taylor, G. I. 1954 Dispersion of matter in turbulent flow through a pipe. Proc. Roy. Soc A 223, 44668.Google Scholar
Thorpe, S. 1968 A method of producing a shear flow in a stratified fluid. J. Fluid Mech. (in the Press).Google Scholar
Tully, J. P. & Giovando, L. F. 1963 Seasonal temperature structure in the Eastern Sub Aretic Pacific Ocean, in Marine Distributions. Ed. M. J. Dunbar. University of Toronto Press (Canada).
Wearden, G. 1966 A temperature gradient meter. (unpublished report). Admiralty Research Laboratory, Teddington Ref. 0/30.Google Scholar
Woods, J. D. 1968 An investigation of some physical processes associated with the vertical flow of heat through the upper ocean Met. Mag. 97, 6572.Google Scholar
Woods, J. D. & Fosberry, G. G. 1966 Observations of the thermocline and transient stratifications made visible by dye. In Malta ′65. Proc. Symp. Underwater Ass. (London), p. 31.
Woods, J. D. & Fosberry, G. G. 1967 The structure of the summer thermocline, in Underwater Association Report 1966–67 (London), pp. 518.