TOPOLOGICAL STUDY OF TORSIONAL SPINE MAGNETIC RECONNECTION AT NULL POINT

Abstract

The spine is an isolated field line which approaches the null (or recedes from it), so called torsional spine reconnection occurs when field lines in the vicinity of the fan rotate, with current becoming concentrated along the spine so that nearby field lines undergo rotational slippage. In of these region, the spine and fan are perpendicular and there is no flux transfer across spine or fan. The geometry of the current layers within which torsional spine reconnection occur is strongly dependent on the symmetry of the magnetic field. Torsional spine reconnection occurs in a narrow tube around the spine, with elliptical crosssection when the fan eigenvalues are different. The eccentricity of the ellipse increases as the degree of asymmetry increases, with the short axis of the ellipse being along the strong field direction. The spatiotemporal peak current, and the peak reconnection rate attained, are found not to depend strongly on the degree of asymmetry.