HR: 1340h
AN: SH13A-1138    [Abstracts]
TI: A Search for Extreme Ultraviolet Signatures of CME Initation
AU: * Neupert, W M
EM: werner.neupert@noaa.gov
AF: NOAA/Space Environment Center, 325 Broadway, Boulder, CO 80305 United States
AB: Present models for the initiation of a CME involve magnetic reconnection either in a multipolar magnetic field overlying a filament channel or between emerging and existing magnetic flux in the vicinity of a filament channel. We have searched for evidence in EUV (195 Angstrom) images recorded by the EIT on SOHO and in other EUV images obtained by earlier instruments that might characterize the sites of such reconnection. No transient emission above a filament channel that might be indicative of magnetic reconnection has been found to date. We have, however, observed rapid changes in brightness or morphology of new emission regions, which represent the presence of newly emerged bipolar magnetic fields adjacent to and below filaments, just prior to and during filament eruption. In the SOHO observations these changes precede the acceleration phase of CMEs and the rapid rise of the GOES soft X-ray flux. Detecting short-lived transients with EIT is problematic because of its poor image-taking cadence (12-min) in the CME Watch mode. One instance of a transient EUV brightening preceding CME initiation has been reported (Dere et al., 1997) and earlier higher cadence observations provide several examples of short duration (1-2 min) EUV bursts in the immediate vicinity of filaments just prior to lift-off.
DE: 7513 Coronal mass ejections
DE: 7519 Flares
DE: 7524 Magnetic fields
DE: 7531 Prominence eruptions
DE: 7549 Ultraviolet emissions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting