A Statistical Study of Streamer-Associated Coronal Mass Ejections

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Sun: Coronal Mass Ejection, Sun: Helmet Streamer

Scientific paper

We have made a comprehensive statistical study on the coronal mass ejections (CMEs) associated with helmet streamers. A total number of 3810 CMEs observed by SOHO/LASCO coronagraph from 1996 to 2000 have been visually inspected. By comparing their LASCO images and running difference images, we picked out streamer-associated CMEs, which are classified into two sub-groups: Class-A events whose morphological shape seen in the LASCO running difference image is quite similar to that of the pre-existing streamer, and Class-B events whose ejections occurred in a part of the streamer. The former type of CME may be caused by the destabilization of the helmet streamer and the latter type of CME may be related to the eruption of a filament underlying the helmet streamer or narrow CMEs such as streamer puffs. We have examined the distributions of CME speed and acceleration for both classes as well as the correlation between their speed and acceleration. The major results from these investigations are as follows. First, about a quarter of all CMEs are streamer-associated CMEs. Second, their mean speed is 413 km s^{-1} for Class-A events and 371 km s^{-1} for Class-B events. And the fraction of the streamer-associated CMEs decreases with speed. Third, the speed-acceleration diagrams show that there are no correlations between two quantities for both classes and the accelerations are nearly symmetric with respect to zero acceleration line. Fourth, their mean angular width are about 60 arcdeg, which is similar to that of normal CMEs. Fifth, the fraction of streamer-associated CMEs during the solar minimum is a little larger than that during the solar maximum. Our results show that the kinematic characteristics of streamer-associated CMEs, especially Class-A events, are quite similar to those of quiescent filament-associated CMEs.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A Statistical Study of Streamer-Associated Coronal Mass Ejections does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Statistical Study of Streamer-Associated Coronal Mass Ejections, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Statistical Study of Streamer-Associated Coronal Mass Ejections will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1547858

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.