Dynamic Topology and Flux Rope Evolution During Non-linear Tearing of 3D Null Point Current Sheets

  title={Dynamic Topology and Flux Rope Evolution During Non-linear Tearing of 3D Null Point Current Sheets},
  author={Peter F. Wyper and David I. Pontin},
  journal={arXiv: Plasma Physics},
In this work the dynamic magnetic field within a tearing-unstable three-dimensional (3D) current sheet about a magnetic null point is described in detail. We focus on the evolution of the magnetic null points and flux ropes that are formed during the tearing process. Generally, we find that both magnetic structures are created prolifically within the layer and are non-trivially related. We examine how nulls are created and annihilated during bifurcation processes, and describe how they evolve… 

Implosive Collapse about Magnetic Null Points: A Quantitative Comparison between 2D and 3D Nulls

Null collapse is an implosive process whereby MHD waves focus their energy in the vicinity of a null point, forming a current sheet and initiating magnetic reconnection. We consider, for the first

A three-dimensional model of spiral null pair to form ion-scale flux ropes in magnetic reconnection region observed by Cluster

The magnetic structure and topology of the three-dimensional magnetic reconnection region are significantly dynamic and complex. Small-scale flux ropes and magnetic null points are frequently


This work investigates fragmentation in high-resolution simulations of jets in the closed-field corona using the embedded-bipole model, and suggests that this repeated tearing process should occur at the separatrix surface between the two flux systems in all jets.

Twisted versus braided magnetic flux ropes in coronal geometry. II. Comparative behaviour.

Aims. Sigmoidal structures in the solar corona are commonly associated with magnetic flux ropes whose magnetic field lines are twisted about a mutual axis. Their dynamical evolution is well studied,

On the Spontaneous Generation of Three-dimensional Magnetic Nulls

Three-dimensional magnetic nulls relate to magnetic topology, and are propitious for triggering solar coronal transients. Although abundant in nature, their generation is not established. This paper

Proton acceleration at tearing coronal null-point current sheets

Context. Non-thermal particle acceleration in the solar corona is thought to constitute a substantial part of the energy budget of explosive events such as solar flares. One well-established

In-situ observations of flux ropes formed in association with a pair of spiral nulls in magnetotail plasmas

Signatures of secondary islands are frequently observed in the magnetic reconnection regions of magnetotail plasmas. In this paper, magnetic structures with the secondary-island signatures observed


We use kinetic particle-in-cell and MHD simulations supported by an observational data set to investigate magnetic reconnection in clusters of null points in space plasma. The magnetic configuration


It has been established that the Sweet–Parker current layer in high Lundquist number reconnection is unstable to the super-Alfvénic plasmoid instability. Past two-dimensional magnetohydrodynamic

Braided magnetic fields: equilibria, relaxation and heating

We examine the dynamics of magnetic flux tubes containing non-trivial field line braiding (or linkage), using mathematical and computational modelling, in the context of testable predictions for the



Steady state reconnection at a single 3D magnetic null point

Aims. We systematically stress a rotationally symmetric 3D magnetic null point by advecting the opposite footpoints of the spine axis in opposite directions. This stress eventually concentrates in

Current sheet formation in quasi-separatrix layers and hyperbolic flux tubes

In 3D magnetic field configurations, quasi-separatrix layers (QSLs) are defined as volumes in which field lines locally display strong gradients of connectivity. Considering QSLs both as the

Topological Evolution of a Fast Magnetic Breakout CME in Three Dimensions

We present the extension of the magnetic breakout model for CME initiation to a fully three-dimensional, spherical geometry. Given the increased complexity of the dynamic magnetic field interactions

Heating and activity of the solar corona: 3. Dynamics of a low beta plasma with three‐dimensional null points

We investigate the self-consistent nonlinear evolution of an initially force-free three-dimensional magnetic field subjected to stress on two boundaries. The results illustrate how complicated

Current accumulation at an asymmetric 3D null point caused by generic shearing motions

Context. Here we investigate the dynamical evolution of the reconnection process at an initially linear 3D null point that is stressed by a localised shear motion across the spine axis. The

Current structure and nonideal behavior at magnetic null points in the turbulent magnetosheath

The Poincaré index indicates that the Cluster spacecraft tetrahedron entraps a number of 3‐D magnetic nulls during an encounter with the turbulent magnetosheath. Previous researchers have found

Interchange Slip-Running Reconnection and Sweeping SEP Beams

We present a new model to explain how particles (solar energetic particles; SEPs), accelerated at a reconnection site that is not magnetically connected to the Earth, could eventually propagate along

Kinetic simulations of the coupling between current instabilities and reconnection in thin current sheets

Abstract. We investigate the coupling between current and tearing instability modes of a thin current sheet using the particle code GISMO. We identify pure tearing modes (kx≠ 0), instabilities in the

Three‐dimensional magnetic reconnection without null points: 1. Basic theory of magnetic flipping

In two or three dimensions, magnetic reconnection may occur at neutral points and is accompanied by the transport of magnetic field lines across separatrices, the field lines (or flux surfaces in

Kinematic reconnection at a magnetic null point: fan-aligned current

Magnetic reconnection at a three-dimensional null point is a natural extension of the familiar two-dimensional X-point reconnection. A model is set up here for reconnection at a null point with