Heating of coronal loops: weak MHD turbulence and scaling laws

TL;DR

This paper investigates the nonlinear dynamics of coronal loops using high-resolution simulations, revealing different regimes of anisotropic MHD turbulence that influence coronal heating processes.

Contribution

It provides new insights into the turbulence regimes in coronal loops and their impact on heating rates through detailed numerical simulations.

Findings

Identification of multiple turbulence regimes with varying spectral indexes.

Spectral power laws range from Kolmogorov-like to steeper spectra.

Implications for coronal heating mechanisms.

Abstract

To understand the nonlinear dynamics of the Parker scenario for coronal heating, long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry are carried out. A loop is modeled as a box extended along the direction of the strong magnetic field $B_0$ in which the system is embedded. At the top and bottom plates, which represent the photosphere, velocity fields mimicking photospheric motions are imposed. We show that the nonlinear dynamics is described by different regimes of MHD anisotropic turbulence, with spectra characterized by intertial range power laws whose indexes range from Kolmogorov-like values ($\sim 5/3$) up to $\sim 3$. We briefly describe the bearing for coronal heating rates.