Other
Scientific paper
Jun 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006spd....37.0827s&link_type=abstract
American Astronomical Society, SPD meeting #37, #8.27; Bulletin of the American Astronomical Society, Vol. 38, p.235
Other
Scientific paper
It is well known that during a two-ribbon flare the two footpoint ribbons, residing in opposite magnetic polarities, expand outward and away from each other. However, the shear motion of the footpoints along the direction parallel to the magnetic inversion line has only been examined by several authors in some individual two-ribbon flares. This motion, also described as shear change of the footpoints, is interpreted by a magnetic field model with a highly sheared inner and less sheared outer magnetic field configuration during the pre-flare phase, and the cessation of the shear change during the impulsive phase is interpreted as a splitting of the envelope of the highly sheared core field. We have made a statistical investigation of the EUV footpoint shear motion along the direction parallel to the magnetic inversion line in two-ribbon flares, using the high spatial resolution data obtained in 1998-2005 by Transition Region and Coronal Explorer (TRACE). For this study we identified 52 well-observed X- and M- class two-ribbon flares which fit our criteria: (1) most portions of the two ribbons are inside the field of view (FOV); (2) TRACE obtained several images during the rise and impulsive phase, from which we can see the two ribbons and their evolution clearly; (3) limb flares, which make the two ribbons and their evolution unable to be seen are not considered. Our preliminary results are: a) 87% (45 out of 52 of these flares (Type I flare) show shear change of footpoints and ribbon separation; b) in most Type I flares, the cessation of shear change is 1-2 minutes earlier than the end of the impulsive phase; c) there is no obvious ribbon separation in those 7 flares (Type II flare) which have no shear change of the conjugate footpoints.
Golub Leon
Su Yingna
van Ballegooijen Adriaan A.
No associations
LandOfFree
Magnetic Shear Change in Solar Flares 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 Magnetic Shear Change in Solar Flares, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic Shear Change in Solar Flares will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1328627