Solar and interplanetary signatures of intense geomagnetic storms during 1997-2000

Abstract

During the ascending phase of the recent solar cycle, the solar and interplanetary signatures of coronal mass ejections (CMEs) observed by Large Angle Spectrometric Coronagraphs (LASCO) aboard SOHO, have been examined. These CMEs were responsible for causing intense geomagnetic storms (Dst ≤ -100 nT) on the earth. In this paper, the relationship of these CMEs with halos, long-duration events, flares and eruptive prominences have been studied. In addition, investigation of the role of the initial expansion speeds of halos in determining the time of their arrival at the earth has also been made.