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Centrifugal, barotropic and baroclinic instabilities of isolated ageostrophic anticyclones in the two-layer rotating shallow water model and their nonlinear saturation

Published online by Cambridge University Press:  27 November 2014

Noé Lahaye*
Affiliation:
Laboratoire de Météorologie Dynamique, UPMC-ENS, 24 rue Lhomond, 75005 Paris, France
Vladimir Zeitlin
Affiliation:
Laboratoire de Météorologie Dynamique, UPMC-ENS, 24 rue Lhomond, 75005 Paris, France Institut Universitaire de France
*
Email address for correspondence: [email protected]

Abstract

Instabilities of isolated anticyclonic vortices in the two-layer rotating shallow water model are studied at Rossby numbers up to two, with the main goal to understand the interplay between the classical centrifugal instability and other ageostrophic instabilities. We find that different types of instabilities with low azimuthal wavenumbers exist, and may compete. In a wide range of parameters, an asymmetric version of the standard centrifugal instability has larger growth rate than the latter. The dependence of the instabilities on the parameters of the flow, i.e. Rossby and Burger numbers, vertical shear and the ratios of the layers’ thicknesses and densities, is investigated. The zones of dominance of each instability are determined in the parameter space. Nonlinear saturation of these instabilities is then studied with the help of a high-resolution finite-volume numerical scheme, by using the unstable modes identified from the linear stability analysis as initial conditions. Differences in nonlinear development of the competing centrifugal and ageostrophic barotropic instabilities are evidenced. A nonlinear mechanism of axial symmetry breaking during the saturation of the centrifugal instability is displayed.

Type
Papers
Copyright
© 2014 Cambridge University Press 

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References

Arai, M. & Yamagata, T. 1994 Asymmetric evolution of eddies in rotating shallow water. Chaos 4 (2), 163175.Google Scholar
Arobone, E. & Sarkar, S. 2012 Evolution of a stratified rotating shear layer with horizontal shear. Part I. Linear stability. J. Fluid Mech. 703, 2948.Google Scholar
Baey, J.-M. & Carton, X. 2002 Vortex multipoles in two-layer rotating shallow-water flows. J. Fluid Mech. 460, 151175.Google Scholar
Benilov, E. S. 2003 Instability of quasi-geostrophic vortices in a two-layer ocean with a thin upper layer. J. Fluid Mech. 475, 303331.CrossRefGoogle Scholar
Benilov, E. S. 2004 Stability of vortices in a two-layer ocean with uniform potential vorticity in the lower layer. J. Fluid Mech. 502, 207232.Google Scholar
Billant, P. & Gallaire, F. 2005 Generalized Rayleigh criterion for non-axisymmetric centrifugal instabilities. J. Fluid Mech. 542, 365379.Google Scholar
Bouchut, F., Ribstein, B. & Zeitlin, V. 2011 Inertial, barotropic, and baroclinic instabilities of the Bickley jet in two-layer rotating shallow water model. Phys. Fluids 23 (12), 126601.Google Scholar
Bouchut, F. & Zeitlin, V. 2010 A robust well-balanced scheme for multi-layer shallow water equations. Discrete Continuous Dyn. Syst. 13 (4), 739758.Google Scholar
Boyd, J. P. 1987 Orthogonal rational functions on a semi-infinite interval. J. Comput. Phys. 70 (1), 6388.Google Scholar
Boyd, J. P. 2001 Chebyshev and Fourier Spectral Methods. Dover.Google Scholar
Dewar, W. K. & Killworth, P. D. 1995 On the stability of oceanic rings. J. Phys. Oceanogr. 25, 14671487.Google Scholar
Drazin, P. G. & Reid, W. H. 1981 Hydrodynamic Stability. Cambridge University Press.Google Scholar
Flór, J.-B., Scolan, H. & Gula, J. 2011 Frontal instabilities and waves in a differentially rotating fluid. J. Fluid Mech. 685, 532542.Google Scholar
Ford, R. 1994 The instability of an axisymmetric vortex with monotonic potential vorticity in rotating shallow water. J. Fluid Mech. 280, 303334.CrossRefGoogle Scholar
Gent, P. R. & McWilliams, J. C. 1986 The instability of barotropic circular vortices. Geophys. Astrophys. Fluid Dyn. 24, 209233.Google Scholar
Gula, J. & Zeitlin, V. 2014 Instabilities of shallow-water flows with vertical shear in the rotating annulus. In Modeling Atmospheric and Oceanic Flows: Insights from Laboratory Experiments and Numerical Simulations (ed. von Larcher, T. & Williams, P. D.), Geophysical Monograph Series, pp. 119138. AGU/Wiley.Google Scholar
Iga, K. 1999 Critical layer instability as a resonance between a non-singular mode and continuous modes. Fluid Dyn. Res. 25 (2), 6386.Google Scholar
Ikeda, M. 1981 Instability and splitting of mesoscale rings using a two-layer quasi-geostrophic model on a $f$ -plane. J. Phys. Oceanogr. 11, 987998.2.0.CO;2>CrossRefGoogle Scholar
Katsman, C. A., Van Der Vaart, P. C. F., Dijkstra, H. A. & De Ruijet, W. P. M. 2003 Stability of multilayer ocean vortices: a parameter study including realistic Gulf Stream and Agulhas rings. J. Phys. Oceanogr. 33, 11971218.Google Scholar
Kloosterziel, R. C., Carnevale, G. F. & Orlandi, P. 2007 Inertial instability in rotating and stratified fluids: barotropic vortices. J. Fluid Mech. 583, 379412.Google Scholar
Kloosterziel, R. C. & van Heijst, G. J. F. 1991 An experimental study of unstable barotropic vortices in a rotating fluid. J. Fluid Mech. 223, 124.Google Scholar
Lahaye, N. & Zeitlin, V. 2012 Existence and properties of ageostrophic modons and coherent tripoles in the two-layer rotating shallow water model on the $f$ -plane. J. Fluid Mech. 706, 71107.Google Scholar
Lazar, A., Stegner, A., Caldeira, R., Dong, C., Didelle, H. & Viboud, S. 2013a Inertial instability of intense stratified anticyclones. Part 2. Laboratory experiments. J. Fluid Mech. 732, 485509.Google Scholar
Lazar, A., Stegner, A. & Heifetz, E. 2013b Inertial instability of intense stratified anticyclones. Part 1. Generalized stability criterion. J. Fluid Mech. 732, 457484.Google Scholar
Le Dizès, S. & Billant, P. 2009 Radiative instability in stratified vortices. Phys. Fluids 21 (9), 096602.Google Scholar
Le Sommer, J., Medvedev, S. B., Plougonven, R. & Zeitlin, V. 2003 Singularity formation during relaxation of jets and fronts toward the state of geostrophic equilibrium. Commun. Nonlinear Sci. Numer. Simul. 8 (3–4), 415442.Google Scholar
Lin, C. C. 1945 On the stability of two-dimensional parallel flows. Parts I, II. Q. Appl. Maths 3, 117142; 218–234.Google Scholar
McWilliams, J. C. 1985 Submesoscale, coherent vortices in the ocean. Rev. Geophys. 23 (2), 165182.Google Scholar
Munk, W., Armi, L., Fischer, K. & Zachariasen, F. 2000 Spirals on the sea. Proc. R. Soc. Lond. 456 (1997), 12171280.Google Scholar
Orlandi, P. & Carnevale, G. F. 1999 Evolution of isolated vortices in a rotating fluid of finite depth. J. Fluid Mech. 381, 239269.Google Scholar
Park, J. & Billant, P. 2013 Instabilities and waves on a columnar vortex in a strongly stratified and rotating fluid. Phys. Fluids 25 (8), 086601.Google Scholar
Pedlosky, J. 1987 Geophysical Fluid Dynamics. Springer.Google Scholar
Plougonven, R. & Zeitlin, V. 2005 Lagrangian approach to geostrophic adjustment of frontal anomalies in a stratified fluid. Geophys. Astrophys. Fluid Dyn. 99 (2), 101135.Google Scholar
Potylitsin, P. G. & Peltier, W. R. 1998 Stratification effects on the stability of columnar vortices on the $f$ -plane. J. Fluid Mech. 355, 4579.Google Scholar
Rayleigh, Lord 1917 On the dynamics of revolving fluids. Proc. R. Soc. Lond. A 93, 148154.Google Scholar
Ribstein, B., Plougonven, R. & Zeitlin, V. 2014 Inertial vs baroclinic instability of the Bickley jet in continuously stratified rotating fluid. J. Fluid Mech 743, 131.Google Scholar
Ripa, P. 1992 Instability of a solid-body rotating vortex in a two-layer model. J. Fluid Mech. 242, 395417.Google Scholar
Smyth, W. D. & McWilliams, J. C. 1998 Instability of an axisymmetric vortex in a stably stratified, rotating environment. Theor. Comput. Fluid Dyn. 11 (3–4), 305322.Google Scholar
Smyth, W. D. & Peltier, W. R. 1994 Three-dimensionalization of barotropic vortices on the $f$ -plane. J. Fluid Mech. 265, 2564.Google Scholar
Stevens, D. E. & Ciesielski, P. E. 1986 Inertial instability of horizontally sheared flow away from the equator. J. Atmos. Sci. 43 (23), 28452856.Google Scholar
Thivolle-Cazat, E., Sommeria, J. & Galmiche, M. 2005 Baroclinic instability of two-layer vortices in laboratory experiments. J. Fluid Mech. 544, 6997.CrossRefGoogle Scholar
Trefethen, L. N. 2000 Spectral Methods in MATLAB. SIAM.Google Scholar
Vallis, G. K. 2006 Atmospheric and Oceanic Fluid Dynamics. Cambridge University Press.Google Scholar
Whitham, G. B. 1974 Stability of shocks. In Linear and Nonlinear Waves, sec. 8.8, Wiley-Interscience.Google Scholar
Zeitlin, V. 2007 Introduction: fundamentals of rotating shallow water model in the geophysical fluid dynamics perspective. In Nonlinear Dynamics of Rotating Shallow Water: Methods and Advances (ed. Zeitlin, V.), Edited Series on Advances in Nonlinear Science and Complexity, vol. 2, chap. 1, pp. 145. Elsevier Science.Google Scholar
Zeitlin, V. 2008 Decoupling of balanced and unbalanced motions and inertia–gravity wave emission: small versus large Rossby numbers. J. Atmos. Sci. 65, 35283542.CrossRefGoogle Scholar