Magnetic Configuration in Low Solar Atmosphere Prior to Eruptions

Details Magnetic Configuration in Low Solar Atmosphere Prior to Eruptions Magnetic Configuration in Low Solar Atmosphere Prior to Eruptions

Dec 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003agufmsh21c..01v&link_type=abstract

American Geophysical Union, Fall Meeting 2003, abstract #SH21C-01

Physics

7513 Coronal Mass Ejections, 7519 Flares, 7524 Magnetic Fields, 7531 Prominence Eruptions

Scientific paper

Vector magnetograph observations of active regions prior to large flares often show strongly sheared magnetic fields, and the associated Hα filaments show long threads parallel to the neutral line. This suggests that the filament is embedded in a horizontal flux tube that is basically untwisted. In contrast, eruptive prominences often show helical structures, suggesting a flux rope with multiple twists. To reconcile these observations, we propose a model of the pre-eruptive state in which an untwisted horizontal flux tube is held down by an overlying magnetic arcade. Unlike in previous models, electric currents flow mainly at the interface between the two flux systems. The two ends of the flux tube are anchored in the photosphere. We use 3D MHD modeling based on NSO/KP magnetograph data to demonstrate that such a system can be in stable force-free equilibrium, provided the arcade field is sufficiently strong to restrain the flux tube. A weakening of the arcade or interaction with a neighboring filament can cause loss of magnetostatic equilibrium, resulting in the eruption of part of the flux tube (Sturrock et al. 2001, ApJ 548, 492). Magnetic reconnection during the early phase of the eruption causes the arcade field to be wrapped around the filament flux, creating the unstable flux rope seen in erupting prominences. The model is applied to Hα observations of a filament obtained at the Swedish Vacuum Solar Telescope (La Palma) and TRACE observation of its eruption on June 21-22, 1998.

Affiliated with

Also associated with

No associations

Rating

Magnetic Configuration in Low Solar Atmosphere Prior to Eruptions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Magnetic Configuration in Low Solar Atmosphere Prior to Eruptions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic Configuration in Low Solar Atmosphere Prior to Eruptions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1644789