Abstract
In the Bay of Biscay, large anticyclonic vortices (called swoddies) have been observed to form surface-intensified tripoles. Here we idealize this process in a two-layer quasi-geostrophic model. First, we compute the growth rate of elliptic disturbances on circular baroclinic vortices. Such perturbed vortices, either with a continuous or a piecewise-constant potential vorticity profile, are then used as initial conditions for nonlinear simulations in a numerical quasi-geostrophic model at high Reynolds number. Finite-amplitude evolutions yield baroclinic dipoles in the case of strong instability, but also uniformly rotating states, such as surface-intensified or arch-shaped tripoles and orthogonal elliptical vortices, when the instability is moderate. These baroclinic tripoles are novel stationary solutions of the stratified geostrophic dynamics. Their long-term evolution is naturally stable, though an asymmetric breaking into a monopole and a dipole can be induced by increased dissipation or by beta-effect.
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References
Carton, X.J. and Legras, B. (1994) The life-cycle of tripoles in two-dimensional incompressible flows, J. Fluid Mech., Vol. no. 267, pp.53–82.
Carton, X.J. and Mc Williams, J.C. (1989) Barotropic and baroclinic instabilities of axisymmetric vortices in a quasi-geostrophic model. In: Mesoscale/ Synoptic Coherent Structures in Geophysical Turbulence, Vol. no. 50, Ed. J.C.J. Nihoul & B.M. Jamart, Elsevier, pp.225–244.
Carton, X.J. and Mc Williams, J.C. (1996) Nonlinear oscillatory evolution of a baroclinically unstable vortex, Dyn. Atmos. Oceans, Vol. no. 24, pp.207–214.
Corréard, S.M. and X.J. Carton (1997) Vertical alignment of geostrophic vortices: On the influence of the initial distribution of potential vorticity, to appear in Proceedings of the IUTAM/SIMFLOW Symposium, Lyngby, Denmark, Kluwer Acad. Publ.
Dritschel, D.G. and Saravanan, R. (1994) Three-dimensional quasi-geostrophic contour dynamics, with an application to stratospheric vortex dynamics, Q.J.R. Meteorol. Soc. Vol. no. 120, pp.1267–1297.
Hopfinger, E.J. and van Heijst, G.J.F. (1993) Vortices in rotating fluids. Ann. Rev. Fluid Mech., Vol. no. 25, pp.241–289.
Morel, Y.G. (1995) Etude des déplacements et de la dynamique des tourbillons géophysiques; application aux meddies. Thèse de Doctorat de l’Université Joseph Fourier — Grenoble 1, 155 pp.
Morel, Y.C. and Carton, X.J. (1994) Multipolar vortices in two-dimensional incompressible flows. J. Fluid Mech., Vol. no. 267, pp.23–51.
Pingree, R.D. and LeCann, B. (1992) Three anticyclonic Slope Water Oceanic eDDIES (SWODDIES) in the Southern Bay of Biscay in 1990, Deep-Sea Res., Vol. no. 39, 7/8, pp.1147–1175.
Polvani, L.M. and Carton, X.J. (1990) The tripole: a new coherent vortex structure of incompressible two-dimensional flows. Geophys. Astrophys. Fluid Dyn., Vol. no. 51, pp.87–102.
Sokolovskyi, M. (1989) O vstrechnom stolknovenii raspredelennykh khetonov. Doklady Akademii Nauk SSSR, Vol. no. 306, pp.198–202.
Wu, H.M., Overman II, E.A. & Zabusky, N.J. (1984) Steady-state solutions of the Euler equations in two dimensions: Rotating and translating V-States with limiting cases. I. Numerical algorithms and results. J. Comp. Phys., Vol. no. 53 pp.42–71.
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Carton, X.J., Corréard, S.M. (1999). Baroclinic Tripolar Geostrophic Vortices. In: Sørensen, J.N., Hopfinger, E.J., Aubry, N. (eds) IUTAM Symposium on Simulation and Identification of Organized Structures in Flows. Fluid Mechanics and Its Applications, vol 52. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4601-2_16
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DOI: https://doi.org/10.1007/978-94-011-4601-2_16
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