The Evolution of a Double Diffusive Magnetic Buoyancy Instability

Silvers, L. J., Vasil, G., Brummell, N. H. & Proctor, M. (2010). The Evolution of a Double Diffusive Magnetic Buoyancy Instability. Proceedings of the International Astronomical Union, 6(S271), pp. 218-226. doi: 10.1017/S1743921311017649

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