Nonlinear Evolution of Axisymmetric Twisted Flux Tubes in the Solar Tachocline
Abstract
We numerically study the evolution of magnetic fields and fluid flows in a thin spherical shell. We take the initial field to be a latitudinally confined, predominantly toroidal flux tube. For purely toroidal, untwisted flux tubes, we recover previously known radial-shredding instabilities, and show further that in the nonlinear regime these instabilities can very effectively destroy the original field. For twisted flux tubes, also including a poloidal component, there are several possibilities, including the suppression of the radial-shredding instability, but also a more directly induced evolution, brought about because twisted flux tubes in general are not equilibrium solutions of the governing equations.
- Publication:
-
Solar Physics
- Pub Date:
- December 2009
- DOI:
- 10.1007/s11207-009-9447-1
- arXiv:
- arXiv:0909.3809
- Bibcode:
- 2009SoPh..260..251H
- Keywords:
-
- Interior;
- tachocline;
- Instabilities;
- Magnetohydrodynamics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- final version as published in journal