Three-Dimensional Numerical Studies of the Magnetic Topology and Pre-Eruption Conditions for the Halloween Storms from 2003: Computational Challenges Posed by Extreme Space Weather Events

The coronal mass ejections (CMEs), and the solar energetic particle (SEP) events associated with them, are of particular importance for Space Weather since they endanger human life in outer space and pose major hazards for spacecraft in the inner Solar System. The Halloween Storms from 2003 were the most powerful solar events ever recorded. These storms broke all-time records for extreme amount of: peak X-ray intensity (>X28); CME speed ( ∼2700km/s); concentration of energetic CMEs in interplanetary space; concentration of interplanetary radio bursts; SEP flux (33,000pfu); interplanetary CME magnetic field ( ∼60nT); geo-impact magnetic field (-465nT); and solar wind speed ( ∼2000km/s). About one third of the total particle radiation emitted by the Sun in the last decade in the deadly 30-50MeV energy range came from these storms, even though the solar activity cycle was well past its maximum. We present preliminary results of a recent numerical investigation of the global magnetic topology and pre-eruption conditions of the active regions that spawned the extreme CME events from last year. We employed the BATS-R-US code to perform global, fully compressional, 3-D numerical MHD computations. High quality magnetic data from MDI are used to drive the MHD simulations. We discuss the obtained numerical results and the computational challenges faced in modeling CME events of that high magnitude. This study is a prerequisite of a more detailed investigation of the series of events associated with the Halloween Storms.