Generation of fast magnetoacoustic waves in the corona by impulsive bursty reconnection

TL;DR

This paper simulates how impulsive bursty reconnection in the solar corona generates fast magnetoacoustic waves through plasmoid formation and coalescence, contributing to coronal heating and solar wind acceleration.

Contribution

It introduces a model linking impulsive reconnection and plasmoid dynamics to the generation of fast magnetoacoustic waves in the corona, highlighting their role in solar atmospheric processes.

Findings

Generated waves carry significant energy flux (~10^5 erg cm^-2 s^-1).

Waves are predominantly fast-mode magnetoacoustic.

Reconnection and waves interact, influencing coronal heating and solar wind.

Abstract

Fast-mode magnetohydrodynamic (MHD) waves in the solar corona are often known to be produced by solar flares and eruptive prominences. We here simulate the effect of the interaction of an external perturbation on a magnetic null in the solar corona which results in the formation of a current sheet (CS). Once the CS undergoes a sufficient extension in its length and squeezing of its width, it may go unstable to the formation of multiple impulsive plasmoids. Eventually, the plasmoids merge with one another to form larger plasmoids and/or are expelled from the sheet. The formation, motion and coalescence of plasmoids with each other and with magnetic Y-points at the outer periphery of the extended CS are found to generate wave-like perturbations. An analysis of the resultant quasi-periodic variations of pressure, density, velocity and magnetic field at certain locations in the model corona indicate that these waves are predominantly fast-mode magnetoacoustic waves. For typical coronal parameters, the resultant propagating waves carry an energy flux of $\mathrm{10^{5}~\mathrm{erg~cm^{-2}~s^{-1}}}$ to a large distance of at least 60 Mm away from the current sheet. In general, we suggest that both waves and reconnection play a role in heating the solar atmosphere and driving the solar wind and may interact with one another in a manner that we refer to as a $"$Symbiosis of WAves and Reconnection (SWAR)$"$.