City Research Online

Abstract

Recently, Silvers et al. (2009b), using numerical simulations, confirmed the existence of a double diffusive magnetic buoyancy instability of a layer of horizontal magnetic field produced by the interaction of a shear velocity field with a weak vertical field. Here, we demonstrate the longer term nonlinear evolution of such an instability in the simulations. We find that a quasi two-dimensional interchange instability rides (or ``surfs'') on the growing shear-induced background downstream field gradients. The region of activity expands since three-dimensional perturbations remain unstable in the wake of this upward-moving activity front, and so the three-dimensional nature becomes more noticeable with time.

Publication Type:	Article
Publisher Keywords:	instabilities; MHD; Sun: magnetic fields
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Departments:	School of Science & Technology > Mathematics

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