2014/11/30 by Dmitri Uzdensky, Dmitri A. Uzdensky, Nuno Loureiro +1 · 3 citations
Physics and Astronomy · #Context (archaeology) #Current (fluid) #Current sheet #Geology #Instability #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Magnetic field #Magnetic reconnection #Magnetohydrodynamics #Mechanics #Physics #Plasmoid #Resistive touchscreen #Solar and Space Plasma Dynamics #Tearing #astro-ph.HE #astro-ph.SR #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.1103/physrevlett.116.105003
published as Phys. Rev. Lett. 116, 105003 (2016) · 5 pages, no figures; accepted for publication in Physical Review Letters
arxiv created 2016/02/19 · openalex publication_date 2016/03/09 · arxiv updated 2016/03/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The recent realization that Sweet-Parker current sheets are violently unstable to the secondary tearing (plasmoid) instability implies that such current sheets cannot occur in real systems. This suggests that, in order to understand the onset of magnetic reconnection, one needs to consider the growth of the tearing instability in a current layer as it is being formed. Such an analysis is performed here in the context of nonlinear resistive magnetohydrodynamics for a generic time-dependent equilibrium representing a gradually forming current sheet. It is shown that two onset regimes, single-island and multi-island, are possible, depending on the rate of current sheet formation. A simple model is used to compute the criterion for transition between these two regimes, as well as the reconnection onset time and the current sheet parameters at that moment. For typical solar corona parameters, this model yields results consistent with observations.