Large scale structures and changes associated with the 'halo' CME on May 2, 1998

Silja Pohjolainen

Abstract

We present initial results of an analysis of observations leading up to and during the 'halo' coronal mass ejection (CME) of May 2, 1998 detected by SOHO LASCO. This event was associated with a large eruptive flare, whose initial stages were observed by Yohkoh. We examine the development of large-scale structures seen with the Yohkoh SXT and the Nancay radioheliograph. These reveal changes in large-scale structures (connected to dimmings and Moreton waves -- seen in SOHO EIT images) as well as jets and other ejecta. The small scale development during the flare is observed in the Yohkoh SXT and HXT data, and in the SOONSPOT H-alpha images. In this work we examine the causal relation between the flare, the inferred coronal shock wave, the small-scale and large-scale structural changes, and the CME.

Authors: S. Pohjolainen, J.I. Khan, D. Maia, M. Pick and N.

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