Tracking CME substructure evolution through the solar wind

Future coronagraphs and heliospheric imagers, in particular those to be launched on the PUNCH mission, will have the capability to track the evolution of CME substructures as the CME moves through and interacts with the solar wind. We present analysis using polarization data obtained from forward modeling simulations of CMEs in the corona and inner heliosphere. We use these data to track the evolution of substructures in three dimensions, and consider the diagnostic potential of internal substructure vs structure at the front of the CME. In particular, we develop methods for extracting information about chirality of CME magnetic flux ropes from polarization data.