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

摘要

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 coronagraphs, and the HI and SMEI instruments can track their ICME counterparts through the inner heliosphere. The HI fields of view (4 -aEuro parts per thousand 90A degrees) overlap with the SMEI field of view (> 20A degrees to all sky) and, thus, both instrument sets can observe the same ICME. In this paper we present results for ICMEs observed on 24 -aEuro parts per thousand 29 January 2007, when the STEREO spacecraft were still near 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 the ENLIL MHD models. We find it encouraging that the four model runs generally were in agreement on both the kinematic evolution and appearance of the events. Because it is essential to understand the effects of projection across large distances, that are not generally crucial for events observed closer to the Sun, we discuss our analysis procedure in some detail.