The Parker Scenario for Coronal Heating as an MHD Turbulence Problem

TL;DR

This paper investigates the Parker coronal heating model using high-resolution RMHD simulations, revealing anisotropic turbulence, current sheet formation, and magnetic field line behavior consistent with observations.

Contribution

It provides a detailed numerical study of MHD turbulence in coronal loops, connecting turbulence regimes to heating rates and observable magnetic field line structures.

Findings

Turbulent cascade dominated by magnetic energy

Current sheets elongated along the magnetic field

Magnetic field lines slightly bent, matching observations

Abstract

The Parker or field line tangling model of coronal heating is investigated through long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics (RMHD). Slow photospheric motions induce a Poynting flux which saturates by driving an anisotropic turbulent cascade dominated by magnetic energy and characterized by current sheets elongated along the axial magnetic field. Increasing the value of the axial magnetic field different regimes of MHD turbulence develop with a bearing on coronal heating rates. In physical space magnetic field lines at the scale of convection cells appear only slightly bended in agreement with observations of large loops of current (E)UV and X-ray imagers.