Pseudo-Streamer Magnetic Topologies in the 2010 August 1-2 CMEs

We upgrade our previous source-surface model of the background magnetic field in the 2010 August 1-2 sympathetic CMEs to a more accurate thermodynamic MHD model of the solar corona. For this new model, we verify our earlier results on the structure of the large-scale magnetic field, making a similar topological analysis of the field as before. We identify the similarities and differences between the two configurations, particularly, for the eruptive regions with three pseudo-streamers that we have found before. The new study confirms that all these pseudo-streamers indeed contain vertical separatrix surfaces located between two adjacent disconnected coronal holes. Of special interest to us are the magnetic null points and separator field lines belonging to such separatrix surfaces. We reassert our earlier hypothesis that magnetic reconnection at these nulls and separators likely plays a key role in establishing a physical connection between the successive eruptions observed by SDO and STEREO. The results obtained provide further validation of our recent simplified MHD model of sympathetic eruptions (Török et al. 2011). Work supported by NASA's Heliophysics Theory and SR&T programs, and SHINE NSF Grant AGS-1156119.