The 2D magnetohydrostatic configurations leading to flares or quiescent filament eruptions
Abstract
To investigate the cause of flares and quiescent filament eruptions the quasistatic evolution of a magnetohydrostatic (MHS) model was studied. The results lead to a proposal that: the sudden disruption of an activeregion filament field configuration and the accompanying flare result from the lack of a neighboring equilibrium state as magnetic shear is increased above the critical value; and a quiescent filament eruption is due to an ideal MHD kink instability of a highly twisted detached flux tube formed by the increase of plasma current flowing along the length of the filament. A numerical solution was developed for the 2D MHS equation for the selfconsistent equilibrium of a filament and overlying coronal magnetic field. Increase of the poloidal current causes increase of magnetic shear. As shear increases past a critical point, there is a discontinuous topological change in the equilibrium configuration. It was proposed that the lack of a neighboring equilibrium triggers a flare. Increase of the axial current results in a detached tube with enough helical twist to be unstable to ideal MHD kink modes. It was proposed that this is the condition for the eruption of a quiescent filament.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 May 1988
 Bibcode:
 1988STIN...8825423A
 Keywords:

 Magnetohydrodynamic Stability;
 Numerical Analysis;
 Poloidal Flux;
 Solar Flares;
 Astronomical Models;
 Topology;
 Solar Physics