Dependence of Coronal Loop Heating on the Characteristics of Slow Photospheric Motions

Abstract

The Parker hypothesis (Parker (1972)) assumes that heating of coronal loops occurs due to reconnection, induced when photospheric motions braid field lines to the point of current sheet formation. In this contribution we address the question of how the nature of photospheric motions affects heating of braided coronal loops. We design a series of boundary drivers and quantify their properties in terms of complexity and helicity injection. We examine a series of long-duration full resistive MHD simulations in which a simulated coronal loop, consisting of initially uniform field lines, is subject to these photospheric flows. Braiding of the loop is continually driven until differences in behaviour induced by the drivers can be characterised. It is shown that heating is crucially dependent on the nature of the photospheric driver - coherent motions typically lead to fewer large energy release events, while more complex motions result in more frequent but less energetic heating events.

References in corpus (5)

• Convectively driven vortex flows in the Sun
• Coronal Heating, Weak MHD Turbulence and Scaling Laws
• An overview of flux braiding experiments
• The structure of current layers and degree of field line braiding in coronal loops
• The coronal energy input from magnetic braiding

Cited by in corpus (6)

• The Heating of Solar Coronal Loops by Alfven Wave Turbulence
• A solar coronal loop in a box: Energy generation and heating
• Helical Twisting Number and Braiding Linkage Number of Solar Coronal Loops
• The effects of driving time scales on heating in a coronal arcade
• Estimating the rate of field line braiding in the solar corona by photospheric flows
• Effects of Fieldline Topology on Energy Propagation in the Corona