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Turbulent diffusion in Lake Huron

Published online by Cambridge University Press:  28 March 2006

G. T. Csanady
Affiliation:
Department of Mechanical Engineering, University of Windsor, Ontario, Canada
Present address: University of Waterloo, Waterloo, Ontario.

Abstract

The diffusion of small floating objects and of fluorescent dyehas been studied at Douglas Point, Lake Huron. The dispersal of floating objects was complicated by surface confluences, slicks and windrows, which under certain circumstances could completely reverse the diffusion process. In the absence of such disturbing effects, however, the dispersal of floating objects exhibited an increase in rate of growth with the size of the diffusing cloud, characteristic of relative turbulent diffusion. A similar conclusion holds with regard to the diffusion of dye perpendicular to the mean current. Along the direction of the current the diffusion of dye was accelerated by the changes of current velocity with depth, much as in a pipe or channel. In the vertical, diffusion was very slow, the effective diffusivity being barely 10 times the molecular constant. Even in the horizontal the effective diffusivities describing relative diffusion were much less than values typical of the lower atmosphere or of the ocean (only of order 103 times the molecular diffusivity). A study of the meandering of the dye plume showed that this was a more important agency than relative diffusion in dispersing the dye over a large area.

Type
Research Article
Copyright
© 1963 Cambridge University Press

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References

Batchelor, G. K. 1949 Diffusion in a field of homogeneous turbulence. I. Eulerian analysis. Aust. J. Sci. Res. A, 2, 437.Google Scholar
Batchelor, G. K. 1952a Diffusion in a field of homogeneous turbulence. II. The relative motion of particles. Proc. Camb. Phil. Soc., 48, 345362.Google Scholar
Batchelor, G. K. 1952b The effect of homogeneous turbulence on material lines and surfaces. Proc. Roy. Soc. A, 213, 349366.Google Scholar
Csanady, G. T., Ellenton, H. K. & Deane, R. E. 1962 Slicks of Lake Huron. Nature, Lond., 196, 1305.Google Scholar
Csanady, G. T. & Ellenton, H. K. 1962 Douglas Point Project, 1962 Annual Report Great Lakes Institute, University of Toronto.
Deacon, E. L. 1962 Aerodynamic roughness of the sea. J. Geophys. Res., 67, 31573172.Google Scholar
Elder, J. W. 1959 The dispersion of marked fluid in turbulent shear flow. J. Fluid Mech., 5, 544560.Google Scholar
Ellison, T. H. 1959 A note on the velocity profile and longitudinal mixing in a broad, open channel. J. Fluid Mech., 8, 3340.Google Scholar
Gifford, F. A. 1959 Statistical properties of a fluctuating plume dispersion model. Adv. Geophys., 6, 117137.Google Scholar
Gifford, F. A. 1960 Peak to average concentration ratios according to a fluctuating plume dispersion model. Int. J. Air Poll., 3, 253260.Google Scholar
Langmuir, I. 1938 Surface motion of water induced by wind. The Collected Works of Irving Langmuir, vol. 10, p. 67. London: Pergamon Press, 1961.
Pritchard, D. W. & Carpenter, J. H. 1960 Measurements of turbulent diffusion in estuaries and inshore waters. Report, Chesapeake Bay Institute, Johns Hopkins University.
Richardson, L. F. 1926 Atmospheric diffusion shown on a distance-neighbour graph. Proc. Roy. Soc. A, 110, 709.Google Scholar
Richardson, L. F. & Stommel, H. 1948 J. Meteorol, 5, 238.
Saffman, P. G. 1960 On the effect of the molecular diffusivity in turbulent diffusion. J. Fluid Mech., 8, 273283.Google Scholar
Smith, F. B. 1957 The diffusion of smoke from a continuous elevated point source into a turbulent atmosphere. J. Fluid Mech., 2, 4976.Google Scholar
Taylor, G. I. 1954 The dispersion of matter in turbulent flow through a pipe. Proc. Roy. Soc. A, 223, 446467.Google Scholar