Evolution of the Coronal Magnetic Configurations Including a Current-Carrying Flux Rope in Response to the Change in the Background Field

TL;DR

This study uses numerical simulations to analyze how the equilibrium height and stability of a current-carrying flux rope in the solar corona depend on background magnetic fields and initial conditions, revealing factors influencing eruptions.

Contribution

It provides new insights into flux rope behavior by incorporating realistic plasma environments and higher resolution, highlighting the impact of background field strength and initial radius on eruptions.

Findings

Flux rope equilibrium height follows a power-law with background field strength.

Weaker background fields facilitate flux rope escape and eruption.

Larger initial radius increases likelihood of eruption.

Abstract

We investigate equilibrium height of the flux rope, and its internal equilibrium in a realistic plasma environment by carrying out numerical simulations of the evolution of systems including a current-carrying flux rope. We find that the equilibrium height of the flux rope is approximately a power-law function of the relative strength of the background field. Our simulations indicate that the flux rope can escape more easily from a weaker background field. This further confirms the catastrophe in the magnetic configuration of interest can be triggered by decrease of strength of the background field. Our results show that it takes some time to reach internal equilibrium depending on the initial state of the flux rope. The plasma flow inside the flux rope due to the adjustment for the internal equilibrium of the flux rope remains small and does not last very long when the initial state of the flux rope commences from the stable branch of the theoretical equilibrium curve. This work also confirms the influence of the initial radius of flux rope on its evolution, the results indicate that the flux rope with larger initial radius erupts more easily. In addition, by using the realistic plasma environment and much higher resolution in our simulations, we notice some different characters compared to previous studies in Forbes (1990).