MHD Numerical Simulation of Interdependent Flares and CMEs

Abstract

Using time-dependent resistive magnetohydrodynamic simulations, we study a flux rope eruption caused by magnetic reconnection with implication in coexistent flare-CME events. Without the resistance the flux rope system presents a double catastrophe. We use the first catastrophic state as the initial condition, in which an isolated flux rope coexists with two current sheets: a vertical one below and a transverse one above the flux rope. The flux rope erupts when reconnection starts in the current sheets, and the flux rope dynamics depends on the reconnection sequence in the two current sheets. We obtain three cases: reconnection occurs (1) simultaneously in the two current sheets, (2) first in the transverse one and then in the vertical, and (3) in an order opposite to case 2. Such a model exhibits characteristics of both magnetic breakout model for CME initiation and standard flare model. We argue that both breakout-like and tether-cutting reconnections may be important for CME eruptions.