Energy of Alfven waves generated during magnetic reconnection

TL;DR

This paper introduces a new method to quantify Alfven wave energy during magnetic reconnection, demonstrating its reliability through 2D MHD simulations and analyzing energy conversion rates.

Contribution

A novel method for measuring Alfven wave energy during magnetic reconnection is proposed and validated with simulation data.

Findings

Alfven wave regions coincide with bent magnetic and flow lines.

Magnetic energy mainly converts to thermal energy during reconnection.

Maximum Alfven wave energy conversion rate is about 4% at peak reconnection.

Abstract

A new method for the determination of the Alfven wave energy generated during magnetic reconnection is introduced and used to analyze the results from two-dimensional MHD simulations. It is found that the regions with strong Alfven wave perturbations almost coincide with that where both magnetic-field lines and flow-stream lines are bent, suggesting that this method is reliable for identifying Alfven waves. The magnetic energy during magnetic reconnection is mainly transformed into the thermal energy. The conversion rate to Alfven wave energy from the magnetic energy is strongly correlated to the magnetic reconnection rate. The maximum conversion rate at the time with the peak reconnection rate is found to be only about 4% for the cases with the plasma beta=0.01,0.1, and 1.0.