Double-diffusive instabilities of a shear-generated magnetic layer

Article, Preprint English OPEN
Silvers, Lara J. ; Vasil, Geoffrey M. ; Brummell, Nicholas H. ; Proctor, Michael R. E. (2009)
  • Publisher: IOP
  • Related identifiers: doi: 10.1088/0004-637X/702/1/L14
  • Subject: Astrophysics - Solar and Stellar Astrophysics | QB
    arxiv: Physics::Fluid Dynamics | Astrophysics::Solar and Stellar Astrophysics

Previous theoretical work has speculated about the existence of double-diffusive magnetic buoyancy instabilities of a dynamically evolving horizontal magnetic layer generated by the interaction of forced vertically sheared velocity and a background vertical magnetic field. Here we confirm numerically that if the ratio of the magnetic to thermal diffusivities is sufficiently low then such instabilities can indeed exist, even for high Richardson number shear flows. Magnetic buoyancy may therefore occur via this mechanism for parameters that are likely to be relevant to the solar tachocline, where regular magnetic buoyancy instabilities are unlikely.
  • References (6)

    Cattaneo, F. & Hughes, D.W. 1988, J. Fluid. Mech., 196,323 Cline, K.S. 2003, The Formation and Evolution of Magnetic Structures in the Solar Interior, PhD Thesis, University of Colorado

    Davidson, P.A. 2004, Turbulence (Oxford: Oxford University Press) Drazin, P.G. & Reid, W.H. 2004, Hydrodynamic Stability (2nd ed.; Cambridge: Cambridge University Press)

    Gilman, P.A., ApJ, 162, 1019.

    Gough, D.O. 2007, in The Solar Tachocline, eds. D.W. Hughes & R. Rosner, & N.O. Weiss (Cambridge: Cambridge University Press) 3

    Fan, Y. & Abbett, W.P. & Fisher, G.H. 2003, ApJ, 582, 1206 Hughes, D. W. 2007, in The Solar Tachocline, eds. D.W. Hughes & R. Rosner, & N.O. Weiss (Cambridge: Cambridge University Press) 275.

    Hughes, D. W., & Weiss, N.O. 1995, J. Fluid Mech., 301, 383 Newcomb, W.A. 1961, Phys. Fluids, 4, 391

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