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Magnetic Reconnection in a Sheared Magnetic Flux Tube: Slippage Versus Tearing
Author(s) -
Kuniyoshi Hidetaka,
Hesse Michael,
Norgren Cecilia,
Tenfjord Paul,
Kwagala Norah Kaggwa
Publication year - 2021
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2021ja029236
Subject(s) - slippage , physics , tearing , magnetic reconnection , mechanics , instability , magnetic flux , flux tube , resistive touchscreen , magnetohydrodynamic drive , magnetohydrodynamics , flux (metallurgy) , classical mechanics , magnetic field , materials science , quantum mechanics , electrical engineering , metallurgy , composite material , thermodynamics , engineering
Abstract The process of magnetic reconnection in a flux tube can occur in a time‐stationary fashion as slippage reconnection or in a time‐dependent manner based on, for example, the tearing instability. However, it is not well known under which conditions a system can sustain slippage reconnection. Likewise, it is unclear whether systems can exhibit slippage reconnection and time‐dependent reconnection simultaneously. In order to investigate these questions, we employ a set of 3D magnetohydrodynamic simulation. Using these simulations, we model a twisted flux tube with a spatially localized resistive region in the center of the simulation box, and an applied driver on one end plane of the simulation box. As a result, the Poynting flux injected at the boundary propagates to the resistive region and dissipates there. If the driver is nearly circular, we find a predominance of slippage reconnection, which decouples the applied driver entirely from one half of the flux tube. Second, a tearing‐like instability occurs with slippage reconnection in the resistive region when the resistivity is strong enough and the cross section of the flux tube, as defined by the shape of the applied velocity perturbation, is elliptical enough. In this case we find the surprising feature that magnetic field perturbation generated by the tearing‐like instability radiates away from the resistive region to influence the entire flux tube shape.