Statistical Study of CMEs with and without Distinct Low Coronal Signatures
Abstract
Taking advantage of the two viewpoints of the STEREO spacecraft, we present a statistical study of CMEs with and without distinct low coronal signatures from January 1st to August 31st, 2009. During this period, the line of sight of STEREO A and that of STEREO B are almost perpendicular and nearly a quarter of the Sun was observed by both. We identified 35 front-side (as viewed from Earth) CMEs, around half of which had no distinct low coronal signature (such as dimming, coronal wave, filament eruption, post-eruptive arcade). Study of the CME kinematics showed that in the COR2 field of view there is no obvious difference between CMEs with and without low coronal signatures. The data from COR1 and EUVI suggest that both kinds of CMEs originate from below 1.4Rsun. We conclude that the region between 1.1-1.4Rsun is very important for understanding the nascent development of CMEs. Detailed study indicates that although there may be no major low coronal signatures for half of the CMEs, there still exist some subtle changes in the low corona before or during the CME appearance. Finally, this work acknowledges that automatic space weather detection systems based on low coronal signatures totally independent of coronagraph data, may fail to detect a significant proportion of CMEs.
- Publication:
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American Astronomical Society Meeting Abstracts #216
- Pub Date:
- May 2010
- Bibcode:
- 2010AAS...21640804M