34th Solar Physics Division Meeting, June 2003
Session 23 Coronal Mass Ejections II
Oral, Thursday, June 19, 2003, 11:00am-12:00noon, Auditorium

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[23.03] Rapid Evolution of Magnetic Fields Associated with Flares and CMEs

H. Wang (Big Bear Solar Observatory)

Recent BBSO and MDI magnetograph observations demonstrate more and more evidences of rapid changes of photospheric magnetic fields associated with the core regions of flares and CMEs. The signatures of such changes include (1) sudden imbalanced flux increase; (2) sudden formation of new penumbra; (3) sudden sunspot disappearances; (4) rapid increases of transverse field strength and magnetic shear; (5) sudden expansion of sunspots. The time scales of the changes are from 10 minutes to one hour, and the changes are permanent. We explain the observations by the following possible models of flare/CME triggering: (1) rapid magnetic reconnection and subsequent submergence; (2) emergence of twisted and inclined flux tubes and (3) impulsive emergence and detachment of magnetic ``bubbles" or U-shaped ropes.


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Bulletin of the American Astronomical Society, 35 #3
© 2003. The American Astronomical Soceity.