Three-Dimensional Geometry of Magnetic Reconnection Induced by Ballooning Instability in a Generalized Harris Sheet

TL;DR

This paper reveals the first detailed 3D geometry of magnetic reconnection caused by ballooning instability in a generalized Harris sheet, highlighting its unique spatial structure and evolution.

Contribution

It uncovers the intrinsically three-dimensional nature of magnetic reconnection induced by ballooning instability, advancing understanding beyond traditional 2D models.

Findings

Reconnection occurs only in a 3D geometry.

Quasi-separatrix layers evolve over time.

Connects 3D reconnection to natural and laboratory plasmas.

Abstract

We report for the first time the intrinsically three-dimensional (3D) geometry of the magnetic reconnection process induced by ballooning instability in a generalized Harris sheet. The spatial distribution and structure of the quasi-separatrix layers, as well as their temporal emergence and evolution, indicate that the associated magnetic reconnection can only occur in a 3D geometry, which is irreducible to that of any two-dimensional reconnection process. Such a finding provides a new perspective to the long-standing controversy over the substorm onset problem, and elucidates the combined roles of reconnection and ballooning instabilities. It also connects to the universal presence of 3D reconnection processes previously discovered in various natural and laboratory plasmas.