HR: 1340h
AN: SH13A-1154    [Abstracts]
TI: Force-Free Magnetic Flux Ropes in the Solar Corona
AU: * Wolfson, R
EM: wolfson@middlebury.edu
AF: Middlebury College, Department of Physics, Middlebury, VT 05753 United States
AB: Magnetic flux ropes offer a venue for storage of magnetic energy in the solar corona, energy that can contribute to eruptive events such as coronal mass ejections (CMEs). When a flux rope encircles the Sun, the associated magnetic field can store more energy than is needed to open the field fully---one of three energy-demanding tasks required for a CME. This work explores conditions necessary for the formation of energetic force-free flux ropes. We show that flux-rope formation is encouraged in sheared, force-free fields when (1) the shear is highly concentrated near the photospheric neutral line (taken to be the equator in our simple models) and (2) a strong potential field overlies the sheared field. Furthermore, the energy stored in the flux rope increases as the latitudinal extent of the sheared region diminishes. We demonstrate these properties with a new computational technique that follows force-free solution sequences through and beyond their states of maximum energy.
DE: 7509 Corona
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting