Magnetic reconnection during eruptive magnetic flux ropes

Aims. We perform a three-dimensional (3D) high resolution numerical simulation in isothermal magnetohydrodynamics to study the magnetic reconnection process in a current sheet (CS) formed during an eruption of a twisted magnetic flux rope (MFR). Because the twist distribution violates the Kruskal-Sh...

Full description

Saved in:
Bibliographic Details
Published in:Astronomy and astrophysics (Berlin) 2017-08, Vol.604, p.L7
Main Authors: Mei, Z. X., Keppens, R., Roussev, I. I., Lin, J.
Format: Article
Language:English
Subjects:
Bifurcations
Computational fluid dynamics
Computer simulation
Coronal mass ejection
Distortion
Finite element method
Fluctuations
instabilities
Magnetic flux
magnetic reconnection
Magnetohydrodynamic turbulence
Magnetohydrodynamics
magnetohydrodynamics (MHD)
Mathematical models
Stability
Substructures
Sun: coronal mass ejections (CMEs)
Sun: flares
Symbiosis
Tearing
Tips
Turbulence
Two dimensional models
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Aims. We perform a three-dimensional (3D) high resolution numerical simulation in isothermal magnetohydrodynamics to study the magnetic reconnection process in a current sheet (CS) formed during an eruption of a twisted magnetic flux rope (MFR). Because the twist distribution violates the Kruskal-Shafranov condition, the kink instability occurs, and the MFR is distorted. The centre part of the MFR loses its equilibrium and erupts upward, which leads to the formation of a 3D CS underneath it. Methods. In order to study the magnetic reconnection inside the CS in detail, mesh refinement has been used to reduce the numerical diffusion and we estimate a Lundquist number S = 104 in the vicinity of the CS. Results. The refined mesh allows us to resolve fine structures inside the 3D CS: a bifurcating sheet structure signaling the 3D generalization of Petschek slow shocks, some distorted-cylindrical substructures due to the tearing mode instabilities, and two turbulence regions near the upper and the lower tips of the CS. The topological characteristics of the MFR depend sensitively on the observer’s viewing angle: it presents as a sigmoid structure, an outwardly expanding MFR with helical distortion, or a flare-CS-coronal mass ejection symbiosis as in 2D flux-rope models when observed from the top, the front, or the side.
ISSN:0004-6361
1432-0746
DOI:10.1051/0004-6361/201731146