The Effect of Reconnection on the Structure of the Sun's Open-Closed Flux Boundary

Pontin, D.; Wyper, P.

Abstract

Global magnetic field extrapolations are now revealing the huge complexity of the Sun's corona, and in particular the structure of the boundary between open and closed magnetic flux. Moreover, recent developments indicate that magnetic reconnection in the corona likely occurs in highly fragmented current layers, and that this typically leads to a dramatic increase in the topological complexity beyond that of the equilibrium field. In this paper we use static models to investigate the consequences of reconnection at the open–closed flux boundary ("interchange reconnection") in a fragmented current layer. We demonstrate that it leads to efficient mixing of magnetic flux (and therefore plasma) from open and closed field regions. This corresponds to an increase in the length and complexity of the open–closed boundary. Thus, whenever reconnection occurs at a null point or separator of this open–closed boundary, the associated separatrix arc of the so-called S-web in the high corona becomes not a single line but a band of finite thickness within which the open–closed boundary is highly structured. This has significant implications for the acceleration of the slow solar wind, for which the interaction of open and closed field is thought to be important, and may also explain the coronal origins of certain solar energetic particles. The topological structures examined contain magnetic null points, separatrices and separators, and include a model for a pseudo-streamer. The potential for understanding both the large scale morphology and fine structure observed in flare ribbons associated with coronal nulls is also discussed.

Citation

Pontin, D., & Wyper, P. (2015). The Effect of Reconnection on the Structure of the Sun's Open-Closed Flux Boundary. Astrophysical Journal, 805(1), Article 39. https://doi.org/10.1088/0004-637x/805/1/39

• Journal Article Type: Article
• Acceptance Date: Apr 16, 2015
• Online Publication Date: May 18, 2015
• Publication Date: May 18, 2015
• Deposit Date: Oct 18, 2016
• Publicly Available Date: Mar 29, 2017
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 805
• Issue: 1
• Article Number: 39
• DOI: https://doi.org/10.1088/0004-637x/805/1/39
• Public URL: https://durham-repository.worktribe.com/output/1372399