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Experiments with baroclinic vortex pairs in a rotating fluid

Published online by Cambridge University Press:  21 April 2006

R. W. Griffiths
Affiliation:
Research School of Earth Sciences, The Australian National University, G.P.O. Box 4, Canberra 2601, Australia
E. J. Hopfinger
Affiliation:
Institut de Mécanique, Laboratoire Associé au CNRS, Université de Grenoble, B.P. 68, 38402 St. Martin d'Hères, France

Abstract

When vortices are generated in one layer of a rotating, two-layer density stratification, the velocity field of each vortex is strongly baroclinic within a distance of order one Rossby radius from its centre. In this system there are two classes of vortex pairs: those pairs (consisting of vortices of opposite signs) for which the vortices are in the same layer, and those for which the vortices are in opposite layers. We pay particular attention to a laboratory demonstration of the properties of the latter class. These vortex pairs have the ability to transport density (or heat) in the horizontal, and provide a means for describing the release of potential energy by baroclinic instability. We also observe that interactions of real vortices and real vortex pairs differ from those computed for point vortices.

Type
Research Article
Copyright
© 1986 Cambridge University Press

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References

Aref, H. 1983 Integrable, stochastic and turbulent vortex motion in two-dimensional flows. Ann. Rev. Fluid Mech. 15, 345389.Google Scholar
Brown, G. L. & Roshko, A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775816.Google Scholar
Christiansen, J. P. & Zabusky, N. J. 1973 Instability, coalescence and fission of finite-area vortex structures. J. Fluid Mech. 61, 219243.Google Scholar
Griffiths, R. W. & Hopfinger, E. J. 1984 The structure of mesoscale turbulence and horizontal spreading at ocean fronts. Deep-Sea Res. 31, 245269.Google Scholar
Griffiths, R. W. & Linden, P. F. 1982 Laboratory experiments on fronts. Part I: Density-driven boundary currents. Geophys. Astrophys. Fluid Dyn. 19, 159187.Google Scholar
Griffiths, R. W. & Linden, P. F. 1985 Intermittent baroclinic instability and fluctuations in geophysical circulations. Nature 316, 801803.Google Scholar
Gryanik, V. M. 1983 Dynamics of singular geostraphic vortices in a two-level model of the atmosphere (or ocean). (Bull. Acad. Sci. USSR.) Atmos. Oceanic Phys. 19, 171179.Google Scholar
Hogg, N. G. & Stommel, H. M. 1985a The heton, an elementary interaction between discrete baroclinic geostrophic vortices and its implications concerning eddy heat-flow. Proc. R. Soc. Lond. A 397, 120.Google Scholar
Hogg, N. G. & Stommel, H. M. 1985b Hetonic explosions: the breakup and spread of warm pools as explained by baroclinic point vortices. J. Atmos. Sci. 42, 14651476.Google Scholar
Overman, E. A. & Zabusky, N. J. 1982 Evolution and merger of isolated vortex structures. Phys. Fluids 25, 12971305.Google Scholar
Pedlosky, J. 1979 Geophysical Fluid Dynamics. Springer. 624 pp.
Young, W. R. 1985 Some interactions between small numbers of baroclinic, geostrophic vortices. Geophys. Astrophys. Fluid Dyn. 33, 3561.Google Scholar