Abstract

The 1998 January 21 halo coronal mass ejection was launched from high southern latitudes in association with a filament disappearance observed by the Nobeyama Radioheliograph. Signatures of the initial destabilization of the filament were observed by the Extreme-ultraviolaet Imaging Telescope (EIT) on board the SOHO spacecraft and by the Soft X-ray Telescope (SXT) on board Yohkoh. The Wind/WAVES experiment observed a type II burst in the 600-300 kHz range. The data coverage for this event is unusually high and we make use of it to understand the origin and evolution of the eruption. We address several issues based on these data: (i) relation between filament eruption and arcade formation beneath the filament, (ii) comparison between the hot arcade formation in X-rays and EUV, (iii) relation between the filament eruption and the white light CME, (iv) relation between the CME and the interplanetary shock inferred from the WAVES data. A summary of near-surface activities associated with the eruption can be seen in the Figure 1. Figure 1. SOHO/MDI longitudinal magnetogram, with radio filament (white contours) and X-ray emission (enclosed by dark lines) are overlaid. The thick white line from E to W is the neutral line over which the eruption took place. North is to the top and east is to the left. F is the location where the filament split at the time of eruption.