Evolution of the Coronal Magnetic Configurations Including a   Current-Carrying Flux Rope in Response to the Change in the Background Field
  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). 
Hong-Juan Wang, Si-Qing Liu, Jian-Cun Gong, Jun Lin
astro-ph.SR