Photospheric Motions and Their Effects on the Corona: a Numerical Approach

TL;DR

This study uses numerical MHD simulations to explore how different photospheric motions influence the solar corona's current density, revealing rapid initial increases followed by stabilization dependent on photospheric conditions.

Contribution

It introduces a systematic numerical approach to analyze the impact of photospheric plasma motions on coronal current density, highlighting the dynamic response and stabilization behavior.

Findings

Current density rapidly increases then stabilizes.

Asymptotic current densities depend on photospheric conditions.

Stabilization occurs over hundreds of minutes.

Abstract

We perform a number of numerical simulations of the solar corona with the aim to understand how it responds to different conditions in the photosphere. By changing parameters which govern the motion of the plasma at the photosphere we study the behavior of the corona, in particular, the effects on the current density generated. An MHD code is used to run simulations, using a 20x20x20 Mm^3 box with time spans ranging from one hundred to several hundreds of minutes. All the experiments show a fast initial increase of the current density, followed by a stabilization around an asymptotic value which depends on the photospheric conditions. These asymptotic average current densities as well as the turn-over points are discussed.