Thermal responses in a coronal loop maintained by wave heating mechanisms

TL;DR

This study uses 3D MHD simulations to show how wave dissipation heats coronal loops, producing impulsive, nanoflare-like temperature increases through wave interactions and energy cascades.

Contribution

It provides a detailed simulation-based demonstration of wave-driven heating mechanisms leading to coronal temperatures and impulsive heating events.

Findings

Wave energy dissipates to produce a 1-MK corona.

Wave interactions cause impulsive, localized heating.

Heating events resemble nanoflares in spatial and temporal characteristics.

Abstract

A full 3-dimensional compressible magnetohydrodynamic (MHD) simulation is conducted to investigate the thermal responses of a coronal loop to the dynamic dissipation processes of MHD waves. When the foot points of the loop are randomly and continuously forced, the MHD waves become excited and propagate upward. Then, a 1-MK temperature corona is produced naturally as the wave energy dissipates. The excited wave packets become non-linear just above the magnetic canopy, and the wave energy cascades into smaller spatial scales. Moreover, collisions between counter-propagating Alfv\'{e}n wave packets increase the heating rate, resulting in impulsive temperature increases. Our model demonstrates that the heating events in the wave-heated loops can be nanoflare-like in the sense that they are spatially localized and temporally intermittent.