Chromospheric and coronal heating and jet acceleration due to reconnection driven by flux cancellation. I. At a three-dimensional current sheet

TL;DR

This paper extends the theory of magnetic reconnection driven by flux cancellation to a three-dimensional axisymmetric current sheet, explaining energy release and jet acceleration in the solar atmosphere.

Contribution

It develops a 3D analytical model of reconnection at a current sheet, advancing beyond previous 2D models to better understand solar atmospheric phenomena.

Findings

Energy release occurs in two phases involving separator formation and flux cancellation.

Reconnection heats plasma and accelerates jets during the process.

The model explains observed solar jet and heating phenomena.

Abstract

Context. The recent discovery of much greater magnetic flux cancellation taking place at the photosphere than previously realised has led us in our previous works to suggest magnetic reconnection driven by flux cancellation as the cause of a wide range of dynamic phenomena, including jets of various kinds and solar atmospheric heating. Aims. Previously, the theory considered energy release at a two-dimensional current sheet. Here we develop the theory further by extending it to an axisymmetric current sheet in three dimensions without resorting to complex variable theory. Methods. We analytically study reconnection and treat the current sheet as a three-dimensional structure. We apply the theory to the cancellation of two fragments of equal but opposite flux that approach each another and are located in an overlying horizontal magnetic field. Results. The energy release occurs in two phases. During Phase 1, a separator is formed and reconnection is driven at it as it rises to a maximum height and then moves back down to the photosphere, heating the plasma and accelerating a plasma jet as it does so. During Phase 2 the fluxes cancel in the photosphere and accelerate a mixture of cool and hot plasma upwards.