Disclaimer: The following material is being kept online for archival purposes.
Although accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers.
Onset of the Magnetic Explosion in Filament-Eruption Flares and CMEs
We present three-dimensional sketches of the magnetic field before and
during filament eruptions in flares and coronal mass ejections. Before
the eruption, the overall magnetic field is a closed bipole in which the
core field (the field rooted along the bipoleís neutral line in
the photospheric magnetic flux) is strongly sheared and has oppositely
curved ìelbowsî that bulge out from the opposite ends of the
neutral line. This core-field sigmoid runs under and is pressed down
in the middle by the rest of the field in the bipole, the less-sheared
envelope field rooted outside the core field (as in the model of Antiochos,
Dahlburg, & Klimchuk 1994, ApJ, 420, L41). A filament of chromospheric-temperature
plasma is often held in the core field over the neutral line. In
a filament eruption, the core field undergoes an explosive eruption, the
frozen-in filament plasma providing a visible tracer of the erupting field.
The core-field explosion may be either confined (as in some flares) or
ejective (as in CMEs that begin together with the onset of a long-duration
two-ribbon flare). We present examples of each of these two kind
of events as observed in sequences of coronal X-ray images from the Yohkoh
SXT, and consider (1) how the explosion begins, and (2) whether confined
eruptions begin in basically the same way as ejective eruptions.
Authors: Ron Moore and Alphonse Sterling
Telephone: (256) 544-7613
Address: Code SD50
Marshall Space Flight Center
Huntsville, AL 35812
Above is background material for archival reference only.