The Origin and Development of Solar Eruptive Events

Abstract:

Solar eruptive events (SEE), which consist of fast coronal mass ejections and intense flares, are the largest and most energetic form of solar activity, and are the drivers of the most destructive space weather throughout interplanetary space. Understanding the physical origin of these giant magnetic explosions is absolutely essential for any first-principles based space weather forecasting and, consequently, is a core focus of the NASA LWS Program. We describe how magnetic reconnection is responsible for the energy buildup that leads to SEEs, how it drives the explosive energy release, and how it controls the propagation of the event. Reconnection turns out to be especially important for understanding the escape of high-energy particles into the heliosphere. A key issue for numerical simulation of SEEs is the effect of the resistivity model used by the simulation, because the onset and subsequent development of reconnection inherently dependent on the effective resistivity. We present the latest ultra-high numerical resolution 2.5D simulations quantifying how the reconnection dynamics scale with effective resistivity. We also present 3D simulations demonstrating the complexities introduced by reconnection in a realistic 3D system. The implications of our results for interpreting observations and for developing space weather capabilities will be described.

This work was supported by the NASA LWS Strategic Capability Program.