Simulating Coronal Mass Ejections in the Heliosphere

C. Richard DeVore

Naval Research Laboratory, Washington DC, USA

Coronal mass ejections (CMEs) are the most energetic events that occur in the heliosphere. It is widely accepted that they are driven by magnetic energy stored in the corona, triggered by one of several competing mechanisms that have been proposed for their initiation. Many CME models rely on magnetic reconnection to reconfigure the connectivity of the Sun's magnetic field to its surface so as to permit the explosive release of the previously stored excess energy. All of the models produce a coronal field that is temporarily open to the heliosphere, which then undergoes reconnection that creates the hot flare X-ray loops and Halpha ribbons, relaxes the field back toward its minimum-energy configuration, and accelerates solar energetic particles. The resulting ejecta then propagate out into the heliosphere where they interact, and may reconnect, with the ambient interplanetary magnetic field. Thus, magnetic reconnection, arguably the most universal of heliophysical processes, plays multiple roles in the initiation and evolution of coronal mass ejections. These roles will be summarized in this presentation on CME models, with detailed attention paid to their effects in our simulations of breakout coronal mass ejections originating in multipolar magnetic sources.