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On the formation and propagation of nonlinear internal boluses across a shelf break

Published online by Cambridge University Press:  19 April 2007

SUBHAS K. VENAYAGAMOORTHY  and
OLIVER B. FRINGER
SUBHAS K. VENAYAGAMOORTHY
Affiliation:
Environmental Fluids Mechanics Laboratory, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA
OLIVER B. FRINGER
Affiliation:
Environmental Fluids Mechanics Laboratory, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA
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Abstract

High-resolution two- and three-dimensional numerical simulations are performed of first-mode internal gravity waves interacting with a shelf break in a linearly stratified fluid. The interaction of nonlinear incident waves with the shelf break results in the formation of upslope-surging vortex cores of dense fluid (referred to here as internal boluses) that propagate onto the shelf. This paper primarily focuses on understanding the dynamics of the interaction process with particular emphasis on the formation, structure and propagation of internal boluses onshelf. A possible mechanism is identified for the excitation of vortex cores that are lifted over the shelf break, from where (from the simplest viewpoint) they essentially propagate as gravity currents into a linearly stratified ambient fluid.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 577 , 25 April 2007 , pp. 137 - 159
Copyright
Copyright © Cambridge University Press 2007

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