Do chaotic field lines cause fast reconnection in coronal loops?
arXiv:2208.06965 · doi:10.1063/5.0120512
Abstract
Over the past decade, Boozer has argued that three-dimensional (3D) magnetic reconnection fundamentally differs from two-dimensional (2D) reconnection due to the fact that the separation between any pair of neighboring field lines almost always increases exponentially over distance in a 3D magnetic field. According to Boozer, this feature makes 3D field-line mapping chaotic and exponentially sensitive to small non-ideal effects; consequently, 3D reconnection can occur without intense current sheets. We test Boozer's theory via ideal and resistive reduced magnetohydrodynamic simulations of the Boozer-Elder coronal loop model driven by sub-Alfvenic footpoint motions [A. H. Boozer and T. Elder, Physics of Plasmas 28, 062303 (2021)]. Our simulation results significantly differ from their predictions. The ideal simulation shows that Boozer and Elder under-predict the intensity of current density due to missing terms in their reduced model equations. Furthermore, resistive simulations of varying Lundquist numbers show that the maximal current density scales linearly rather than logarithmically with the Lundquist number.
14 pages, 9 figures. Accepted for publication in Physics of Plasmas
References in corpus (13)
- Generalized Squashing Factors for Covariant Description of Magnetic Connectivity in the Solar Corona
- Magnetic reconnection in the era of exascale computing and multiscale experiments
- Coronal Heating, Weak MHD Turbulence and Scaling Laws
- Plasmoid Instability in Evolving Current Sheets and Onset of Fast Reconnection
- Ideal Internal Kink Modes in a Line-tied Screw Pinch
- Rapid Change of Field Line Connectivity and Reconnection in Stochastic Magnetic Fields
- Do Potential Fields Develop Current Sheets Under Simple Compression or Expansion?
- Current singularities in line-tied three-dimensional magnetic fields
- Effects of Line-tying on Magnetohydrodynamic Instabilities and Current Sheet Formation
- Magnetic reconnection and thermal equilibration
- Example of exponentially enhanced magnetic reconnection driven by a spatially-bounded and laminar ideal flow
- Local analysis of fast magnetic reconnection
- Judgment of paradigms for magnetic reconnection in coronal loops