Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T02:06:43.366Z Has data issue: false hasContentIssue false

The vortex instability pathway in stratified turbulence

Published online by Cambridge University Press:  18 January 2013

Michael L. Waite*
Affiliation:
Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
*
Email address for correspondence: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The parameter regime of strong stable density stratification and weak rotation is an important one in geophysical fluid dynamics. These conditions exist at intermediate length scales in the atmosphere and ocean (mesoscale and sub-mesoscale, respectively), and turbulence here links large-scale quasi-geostrophic motions with small-scale dissipation. While major advances in the theory of stratified turbulence have been made over the last few decades, many open questions remain, particularly about the nature of the energy cascade. Recent numerical experiments and analysis by Augier, Chomaz & Billant (J. Fluid Mech., vol. 713, 2012, pp. 86–108) present a remarkably vivid illustration of the nonlinear interactions that drive such turbulence. They consider a columnar vortex dipole, which naturally three-dimensionalizes under the influence of strong stratification. Kelvin–Helmholtz instabilities subsequently transfer energy directly to small scales, where the flow transitions into three-dimensional turbulence. This direct link between large and small scales is quite distinct from the usual picture of a turbulent cascade, in which nonlinear interactions are local in scale. But how important is this mechanism in the atmosphere and ocean?

Type
Focus on Fluids
Copyright
©2013 Cambridge University Press

References

Augier, P. & Billant, P. 2011 Onset of secondary instabilities on the zigzag instability in stratified fluids. J. Fluid Mech. 682, 120131.CrossRefGoogle Scholar
Augier, P., Chomaz, J.-M. & Billant, P. 2012 Spectral analysis of the transition to turbulence from a dipole in stratified fluids. J. Fluid Mech. 713, 86108.CrossRefGoogle Scholar
Billant, P. & Chomaz, J.-M. 2000 Experimental evidence for a new instability of a vertical columnar vortex pair in a strongly stratified fluid. J. Fluid Mech. 418, 167188.CrossRefGoogle Scholar
Bretherton, F. P. 1969 Waves and turbulence in stably stratified fluids. Radio Sci. 4, 12791287.CrossRefGoogle Scholar
Brethouwer, G., Billant, P., Lindborg, E. & Chomaz, J.-M. 2007 Scaling analysis and simulation of strongly stratified turbulent flows. J. Fluid Mech. 585, 343368.CrossRefGoogle Scholar
Deloncle, A., Billant, P. & Chomaz, J.-M. 2008 Nonlinear evolution of the zigzag instability in stratified fluids: a shortcut on the route to dissipation. J. Fluid Mech. 599, 229239.CrossRefGoogle Scholar
Herring, J. R. & Métais, O. 1989 Numerical experiments in forced stably stratified turbulence. J. Fluid Mech. 202, 97115.CrossRefGoogle Scholar
Laval, J.-P., McWilliams, J. C. & Dubrulle, B. 2003 Forced stratified turbulence: successive transitions with Reynolds number. Phys. Rev. E 68, 036308.CrossRefGoogle ScholarPubMed
Lilly, D. K. 1983 Stratified turbulence and the mesoscale variability of the atmosphere. J. Atmos. Sci. 40, 749761.2.0.CO;2>CrossRefGoogle Scholar
Lindborg, E. 2006 The energy cascade in a strongly stratified fluid. J. Fluid Mech. 550, 207242.CrossRefGoogle Scholar
Riley, J. J. & Lelong, M.-P. 2000 Fluid motions in the presence of strong stable stratification. Annu. Rev. Fluid Mech. 32, 613657.CrossRefGoogle Scholar
Waite, M. L. 2011 Stratified turbulence at the buoyancy scale. Phys. Fluids 23, 066602.CrossRefGoogle Scholar
Waite, M. L. & Bartello, P. 2004 Stratified turbulence dominated by vortical motion. J. Fluid Mech. 517, 281308.CrossRefGoogle Scholar
Waite, M. L. & Smolarkiewicz, P. K. 2008 Instability and breakdown of a vertical vortex pair in a strongly stratified fluid. J. Fluid Mech. 606, 239273.CrossRefGoogle Scholar