34th Solar Physics Division Meeting, June 2003
Session 5 Coronal Mass Ejections I
Poster, Monday, June 16, 2003, 3:30-5:00pm, Mezzanine

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[5.05] Signatures of Large Scale Coronal Eruptive Activity, Associated Flares, and Propagating Chromospheric Disturbances

K. S. Balasubramaniam, A. A. Pevtsov (NSO/SP), D. F. Neidig, E. W. Cliver (AFRL/VSBXS), C. A. Young (EER Systems, NASA/GSFC), S. F. Martin (Helio Research), A. L. Kiplinger (Univ. Colorado)

Analyses of multi-wavelength data sets on 2002 December 19 at approximately 2150 UT show evidence of a large-scale, transequatorial coronal eruption associated with simultaneous flares in active regions in both hemispheres. The coronal manifestations (based on EIT, LASCO, and TRACE images) include a large coronal dimming, an opening/restructuring of magnetic fields, the formation of a transient coronal hole, and a halo CME. In the chromosphere, ISOON H-alpha images show distant flare precursor brightenings and several sympathetic flares. Originating near the main flare is a rapidly propagating (800 km/s), narrowly channeled disturbance detectable as a sequential brightening of numerous pre-existing points in the H-alpha chromospheric network. This disturbance is not a chromospheric Moreton wave, but it does produce a temporary activation of a transequatorial filament. This filament does not erupt nor do any other filaments in the vicinity. MDI magnetograms show that the brightened network points are all of the same polarity (the dominant polarity among the points in the disturbance's path), suggesting that the affected field lines extend into the corona where they are energized in sequence as the eruption tears away.

Three other similar eruptive events (non-transequatorial) that we studied, while they are less impressive, show most of the same phenomena including distant sympathetic flares and a propagating disturbance showing close adherence to the monopolarity rule. Two of these events do include filament eruptions near the main flare. We conclude that the observations of these four events are consistent with large scale coronal eruptive activity that triggers nearly simultaneous surface activity of various forms separated by distances on the same scale as the coronal structures themselves. A filament eruption at the main flare site appears not to be a necessity in this type of eruptive activity.


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Bulletin of the American Astronomical Society, 35 #3
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