  We present an analysis of the ionic composition of iron for two
interplanetary coronal mass ejections observed in May 21-23 2007 by the ACE and
STEREO spacecraft in the context of the magnetic structure of the ejecta flux
rope, sheath region, and surrounding solar wind flow. This analysis is made
possible due to recent advances in multispacecraft data interpolation,
reconstruction, and visualization as well as results from recent modeling of
ionic charge states in MHD simulations of magnetic breakout and flux
cancellation CME initiation. We use these advances to interpret specific
features of the ICME plasma composition resulting from the magnetic topology
and evolution of the CME. We find that in both the data and our MHD
simulations, the flux ropes centers are relatively cool, while charge state
enhancements surround and trail the flux ropes. The magnetic orientation of the
ICMEs are suggestive of magnetic breakout-like reconnection during the eruption
process, which could explain the spatial location of the observed iron
enhancements just outside the traditional flux rope magnetic signatures and
between the two ICMEs. Detailed comparisons between the simulations and data
were more complicated, but a sharp increase in high iron charge states in the
ACE and STEREO-A data during the second flux rope corresponds well to similar
features in the flux cancellation results. We discuss the prospects of this
integrated in-situ data analysis and modeling approach to advancing our
understanding of the unified CME-to-ICME evolution.
