November 2, 2010, 2:00 pm - 3:00 pm

November 2, 2010, 2:00 pm - 3:00 pm

Ionic Composition Structure in 2.5D MHD CME Simulations

B. J. Lynch (Space Sciences Laboratory, UC Berkeley)

I present a comparison of ionic charge state composition structure of axisymmetric CMEs initiated via the flux cancellation mechanism and the magnetic breakout mechanism. The flux cancellation CME simulation is run using the Predictive Science Inc.'s Magnetohydrodynamics-on-A-Sphere (MAS) Code and the magnetic breakout CME simulation is run on A Research Code (ARC7) developed at GSFC by Allred and MacNeice (2010). Both MHD simulations include field-aligned thermal conduction, radiative losses, and coronal heating terms that give rise to steady-state solar wind and streamer solutions. The energy equation is sufficiently complex to calculate reasonable densities and temperatures associated with eruptive flare heating and CME formation. I systematically track a number of Lagrangian plasma parcels through the simulation data and can calculate the coronal temperature history of the plasma associated with the CME. We can then integrate the continuity equation for the various charge states associated with heavy ion species assuming they act as passive tracers in the MHD flow and using the plasma temperature and density in the determination of the ionization and recombination rates. Thus, we are able to calculate a 2D spatial distribution of commonly measured ionic charge state ratios, e.g. C⁶⁺/C⁵⁺, O⁷⁺/O⁶⁺, Si¹²⁺/Si¹¹⁺, and Fe^>=16+/Fe_total, over the cross section of the CME flux rope and the surrounding plasma. I will discuss the role of flare heating in determining the ionic charge state structure of CMEs.