An overview of flux braiding experiments

• Published in: Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences Vol. 373; no. 2042; p. 20140265
• Main Author: Wilmot-Smith, A. L.
• Format: Journal Article
• Language: English
• Published: England The Royal Society Publishing 28-05-2015
• Subjects: Corona; Magnetic Fields; Magnetic Reconnection; Review; The Sun; magnetic fields; the Sun; corona; magnetic reconnection
• ISSN: 1364-503X; 1471-2962
• DOI: 10.1098/rsta.2014.0265

In a number of papers dating back to the 1970s, Parker has hypothesized that, in a perfectly ideal environment, complex photospheric motions acting on a continuous magnetic field will result in the formation of tangential discontinuities corresponding to singular currents. I review direct numerical simulations of the problem and find that the evidence points to a tendency for thin but finite-thickness current layers to form, with thickness exponentially decreasing in time. Given a finite resistivity, these layers will eventually become important and cause the dynamical process of energy release. Accordingly, a body of work focuses on evolution under continual boundary driving. The coronal volume evolves into a highly dynamic but statistically steady state where quantities have a temporally and spatially intermittent nature and where the Poynting flux and dissipation are decoupled on short time scales. Although magnetic braiding is found to be a promising coronal heating mechanism, much work remains to determine its true viability. Some suggestions for future study are offered.