CME - Open Field Coupling: Application to the escape of Flare-accelerated Particles

Magnetic reconnection in the solar atmosphere is believed to be the driver of most solar active phenomena. Therefore, the structure and dynamics of the coronal magnetic field are central to understanding solar and heliospheric activity. Important heliospheric manifestations of intense energy release linked to solar activity include the impact at the Earth of energetic particles accelerated during solar eruptions. Observationally, the magnetic configuration of active regions, where solar eruptions occur, agrees well with the standard model of eruption, consisting of a flare and a coronal mass ejection (CME). According to the standard model, particles accelerated at the flare reconnection site should remain trapped in the CME. However, flare-accelerated particles frequently reach the Earth long before the CME does. We present a 3D model that explains how flare-accelerated particles escape into the interplanetary magnetic flux tubes during a solar eruption. Our model is based on results of large-scale 3D MHD simulations of a breakout-CME erupting into the heliosphere build by an isothermal solar wind. The simulations are performed with the Adaptively Refined Mhd Solver (ARMS). We describe the multiple reconnection episodes that occur during the evolution of the event, and show how they lead to the release of flare-accelerated particles onto open field lines. Analyzing the dynamics of the reconnected flux during the eruption, we evaluate the spatial distribution and the timing of the particle beams injected into the heliosphere. We discuss the implications of results for CME/flare models and for SEPs observations. This work was supported, in part, by the NASA TR&T and SR&T Programs.