Study of CME Propagation in the Inner Heliosphere: SOHO LAS, SMEI and STERO HI Observations of the January 2007 Events

We are investigating the geometric and kinematic characteristics of interplanetary coronal mass ejections (ICMEs) using data obtained by the LASCO coronagraphs, the Solar Mass Ejection Imager (SMEI), and the SECCHI imaging experiments on the STEREO spacecraft. The early evolution of CMEs can be tracked by the LASCO C2 and C3 and SECCHI COR1 and COR2 corona-graphs, and the HI and SMEI instruments can track their ICME counterparts through the inner heliosphere. The HI fields of view (4-90 deg) overlap with the SMEI field of view (>20 deg to all sky) and, thus, both instrument sets can observe the same ICME. We present results for ICMEs observed on 24-29 Jan 2007 when the STEREO spacecraft were still near the Earth so that both the SMEI and STEREO views of large ICMEs in the inner heliosphere coincided. These results include measurements of the structural and kinematic evolution of two ICMEs and comparisons with drive/drag kinematic, 3D tomographic reconstruction, the HAFv2 kinematic, and ENLIL MHD models. We find that the four model runs generally were in agreement on both kinematic evolution and appearance of the events. ; Published in Solar Physics, v256 p239-267, 2009.