Forced magnetic reconnection and plasmoid coalescence: I - MHD Simulations
arXiv:1901.02392 · doi:10.1051/0004-6361/201833565
Abstract
Forced magnetic reconnection, a reconnection event triggered by external perturbation, should be ubiquitous in the solar corona. Energy released during such cases can be much greater than that which was introduced by the perturbation. It is unclear how the properties of the external perturbation and the initial current sheet affect the reconnection region properties, and thereby the reconnection dynamics and energy release profile. We investigate the effect of the form of the external perturbation and initial current sheet on the evolution of the reconnection region and the energy release process. Chiefly we explore the non-linear interactions between multiple, simultaneous perturbations, which represent more realistic scenarios. Future work will use these results in test particle simulations to investigate particle acceleration over multiple reconnection events. Simulations are performed using Lare2d, a 2.5D Lagrangian-remap solver for the visco-resistive MHD equations. The model of forced reconnection is extended to include superpositions of sinusoidal driving disturbances, including localised Gaussian perturbations. A transient perturbation is applied to the boundaries of a region containing a force-free current sheet. The simulation domain is sufficiently wide to allow multiple magnetic islands to form and coalesce. Island coalescence contributes significantly to energy release and involves rapid reconnection. Long wavelength modes in perturbations dominate the evolution, without the presence of which reconnection is either slow, as in the case of short wavelength modes, or the initial current sheet remains stable, as in the case of noise perturbations. Multiple perturbations combine in a highly non-linear manner: reconnection is typically faster than when either disturbance is applied individually, with multiple low-energy events contributing to the same total energy release.
arXiv comment13 pages (including appendix)
References in corpus (22)
- Reconnection in a Weakly Stochastic Field
- An Observational Overview of Solar Flares
- Instability of current sheets and formation of plasmoid chains
- Fast Reconnection in High-Lundquist-Number Plasmas Due to Secondary Tearing Instabilities
- Numerical Tests of Fast Reconnection in Weakly Stochastic Magnetic Fields
- Imaging coronal magnetic-field reconnection in a solar flare
- Scaling laws of resistive magnetohydrodynamic reconnection in the high-Lundquist-number, plasmoid-unstable regime
- 25 Years of Self-Organized Criticality: Solar and Astrophysics
- Recent Advances in Understanding Particle Acceleration Processes in Solar Flares
- From coronal observations to MHD simulations, the building blocks for 3D models of solar flares
- Spontaneous current-layer fragmentation and cascading reconnection in solar flares: I. Model and analysis
- Turbulent Magnetohydrodynamic Reconnection Mediated by the Plasmoid Instability
- Statistics of Reconnection-Driven Turbulence
- Reconnection Studies Under Different Types of Turbulence Driving
- Self-generated turbulence in magnetic reconnection
- Magnetohydrodynamic Turbulence in the Plasmoid-Mediated Regime
- Three-dimensional Spontaneous Magnetic Reconnection
- Extended theory of the Taylor problem in the plasmoid-unstable regime
- Reconnection and particle acceleration in interacting flux ropes -- II. 3D effects on test particles in magnetically dominated plasmas
- How Anomalous Resistivity Accelerates Magnetic Reconnection
- Evolution of 3-dimensional Relativistic Current Sheets and Development of Self-Generated Turbulence
- Reconnection in weakly stochastic B-fields in 2D
Cited by in corpus (8)
- On the observations of rapid forced reconnection in the solar corona
- Evolution, structure and topology of self-generated turbulent reconnection layers
- HFQPOs and discoseismic mode excitation in eccentric, relativistic discs. II. Magnetohydrodynamic simulations
- HFQPOs and discoseismic mode excitation in eccentric, relativistic discs. I. Hydrodynamic simulations
- Oscillatory reconnection and waves driven by merging magnetic flux ropes in solar flares
- Merging plasmoids and nanojet-like ejections in a coronal current sheet
- Energy distribution and substructure formation in astrophysical MHD simulations
- The prominence driven forced reconnection in the solar corona and associated plasma dynamics