The evolution of the reconnection flux during the eruption of magnetic flux ropes

Abstract

Coronal mass ejections (CMEs) are powerful drivers of space weather, with magnetic flux ropes (MFRs) widely regarded as their primary precursors. However, the variation in the reconnection (RC) flux during the evolution of MFRs during CME eruptions remains poorly understood. In this paper, we develop a 3D magnetohydrodynamic (MHD) model that we use to explore the temporal evolution of the RC flux during the MFR evolution using both numerical simulations and observational data. Our initial coronal configuration features an isothermal atmosphere and a potential arcade magnetic field beneath which an MFR emerges at the lower boundary. As the MFR rises, we observe significant stretching and compression of the overlying magnetic field beneath it. Magnetic RC begins with the gradual formation of a current sheet, eventually culminating with the impulsive expulsion of the flux rope. We analyze the temporal evolution of RC fluxes during two successive MFR eruptions while continuously emerging the twisted flux rope through the lower boundary. We also conduct a similar analysis using observational data from the Helioseismic and Magnetic Imager and the Atmospheric Imaging Assembly for an eruptive event. Comparing our MHD simulation with observational data, we find that RC flux play a crucial role in the determination of CME kinematics. From the onset to the eruption, the rate of RC shows a monotonic variation with the acceleration. This simulation of a solar eruption provides important insights into the complex dynamics of CME initiation and progression.