HR: 0830h
AN: SH51C-06    [Abstracts]
TI: Magnetic Flux Emergence and the Initiation of Filament Eruptions and CMEs as Observed by the EUV Imaging Telescope on SOHO
AU: * Neupert, W M
EM: werner.neupert@noaa.gov
AF: Guest Researcher, NOAA/Space Environment Center, 325 Broadway, Boulder, CO 80305 United States
AB: Solar observations over more than twenty years (e.g., Gaizauskas and Svestka, 1987, summarizing the "Flare Build-up Study", Feynman and Martin, 1995, and more recently, Wang and Sheeley, 1999) have demonstrated that emergence of new magnetic flux in the vicinity of quiescent filament fields frequently leads to the eruption of those filaments, given polarity orientations favorable for magnetic reconnection. Concurrently, models of the interaction of such magnetic flux configurations have been developed to explain the initiation of flares (e.g., Priest and Forbes, 2002) and coronal mass ejections (Chen et al., 2002). We have used observations made in the 195 Angstrom (Fe XII) band by the EUV imaging Telescope (EIT) on SOHO to identify instances of emerging flux, indicated by new EUV emission, and subsequent eruption of a quiescent filament in a search for coronal changes that might appear as a result of merging magnetic fields. Limiting our study to quiescent filaments distant from active regions, we have identified events in which a slow increase in filament height begins shortly (a few hours) after first appearance of an EUV emission source either within or beside the filament channel. For long filaments, the apex of the rising filament appears to lie above the developing EUV source, implying that the field supporting the filament is locally interacting with the emerging field. Transient EUV features at onset of the eruptive phase include low-lying loops over the neutral line and, more rarely, localized sources apparently associated with the rising filament. No evidence of reconfiguring of an overlying corona (only faintly detected by the EIT) prior to CME initiation has been found. Our results support the hypothesis that at least in some instances the emergence of new magnetic field leads to a loss of filament equilibrium and a coronal mass ejection. This work is supported by NASA Intergovernmental Transfer W-10118 to NOAA's Space Environment Center. SOHO is a project of international cooperation between ESA and NASA.
DE: 7509 Corona
DE: 7513 Coronal mass ejections
DE: 7524 Magnetic fields
DE: 7531 Prominence eruptions
DE: 7549 Ultraviolet emissions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly