Numerical Simulation of Earth Directed CMEs with an Advanced Two-Temperature Coronal Model

MANCHESTER IV, WARD B.; VAN DER HOLST, BARTHOLOMEUS; FRAZIN, RICHARD A.; ALBERTO M. VASQUEZ; TOTH, GABOR; GOMBOSI, TAMAS

San Francisco, California, EEUU

Congreso; AGU Fall Meeting 2010; 2010

AGU

We present progress on modeling Earth-directed CMEs including the December 12, 2008 CME and the May 13, 2005 campaign event from initiation to heliospheric propagation. Our earlier work on the 2005 event followed the CME to the orbit of Saturn employing the coronal model of Cohen et al. (2007), which relies on a spatially varying adiabatic index (gamma) to produce the bimodal solar wind. This model was able to reproduce several features of the observed event, but suffered from artifacts of the artificially thermodynamics. We will examine results of a recent simulation performed with a new two-temperature solar corona model developed at the University of Michigan. This model employs heat conduction for both ion and electron species, constant adiabatic index (=5/3), and includes Alfven waves to drive the solar wind. The model includes SOHO/MDI magnetogram data to calculate the coronal field, and also uses SOHO/EIT observations to specify the density and temperature at the coronal boundary by the Differential Emission Measure Tomography (DEMT) method. The Wang-Sheeley-Arge empirical model is used to determi ne the Alfven wave pressure necessary to produce the observed solar wind speeds. We find that the new model is much better able to reproduce the solar wind densities, and also correctly captures the compression at the CME-driven shock due to the fixed adiabatic index.