TY  - JOUR
A1  - Green, Lucie M.
A1  - Kliem, Bernhard
T1  - Flux rope formation preceding coronal mass ejection onset
N2  - We analyze the evolution of a sigmoidal (S-shaped) active region toward eruption, which includes a coronal mass ejection (CME) but leaves part of the filament in place. The X-ray sigmoid is found to trace out three different magnetic topologies in succession: a highly sheared arcade of coronal loops in its long-lived phase, a bald-patch separatrix surface (BPSS) in the hours before the CME, and the first flare loops in its major transient intensity enhancement. The coronal evolution is driven by photospheric changes which involve the convergence and cancellation of flux elements under the sigmoid and filament. The data yield unambiguous evidence for the existence of a BPSS, and hence a flux rope, in the corona prior to the onset of the CME.
Y1  - 2009
UR  - http://iopscience.iop.org/2041-8205
U6  - https://doi.org/10.1088/0004-637x/700/2/L83
SN  - 2041-8213
ER  - 
TY  - GEN
A1  - Green, Lucie M.
A1  - Kliem, Bernhard
T1  - Observations of flux rope formation prior to coronal mass ejections
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Understanding the magnetic configuration of the source regions of coronal mass ejections (CMEs) is vital in order to determine the trigger and driver of these events. Observations of four CME productive active regions are presented here, which indicate that the pre-eruption magnetic configuration is that of a magnetic flux rope. The flux ropes are formed in the solar atmosphere by the process known as flux cancellation and are stable for several hours before the eruption. The observations also indicate that the magnetic structure that erupts is not the entire flux rope as initially formed, raising the question of whether the flux rope is able to undergo a partial eruption or whether it undergoes a transition in specific flux rope configuration shortly
before the CME.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 607 
KW  - Sun: coronal mass ejections (CMEs)
KW  - Sun: activity
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-416103
SN  - 1866-8372
IS  - 607
ER  -