The source and propagation of the interplanetary disturbance associated with the full‐halo coronal mass ejection on 28 October 2003

Observations of interplanetary scintillations made with the 327‐MHz four‐station system of the Solar‐Terrestrial Environment Laboratory of Nagoya University were analyzed to study the three‐dimensional properties of a transient solar wind stream associated with the 28 October 2003 full‐halo coronal mass ejection (CME). A loop‐shaped high‐density regionregion propagating at a significantly slower speed than the CME‐driven shock was identified. This feature appeared approximately the same as the structure seen in white‐light observations made simultaneously. The orientation of the loop structure was found in general agreement with the inclination of the magnetic flux rope observed at 1 AU. Therefore we propose that the origin of this loop structure included the high‐density plasma ejected from the corona in association with the 28 October 2003 CME. By comparing this loop structure with solar wind speed data, we find that the loop structure had a solar source aligned with a slow‐speed solar wind regionregion.