HR: 13:30h
AN: SP43C-01 INVITED     [Abstracts]
TI: Harvey Prize Lecture: The calm before the storm: the link between quiescent cavities and CMEs
AU: * Gibson, S E
EM: sgibson@ucar.edu
AF: NCAR/HAO, 3450 Mitchell Lane, Boulder, CO 80305 United States
AB: Coronal mass ejections (CMEs) are thought to be driven by magnetic energy, stored in twisted or sheared magnetic fields. Magnetic clouds, which are interplanetary manifestations of CMEs, are commonly modeled as flux ropes of twisted magnetic field. It has also become quite standard to model the erupting CME as a flux rope. However, the question of whether the flux rope is formed during the eruption, or whether the flux rope existed prior to the eruption, remains controversial. CMEs often possess a three-part morphology in white light observations of a bright front, followed by a relatively dark cavity, and lastly a bright core associated with an erupting prominence. The three-part structure of CMEs has been shown in a variety of models to be a consequence of a magnetic flux rope topology. The same physical reasons for the presence of the cavity system in eruption hold true in quiescence, and so it is significant that the three-part structure, in the form of helmet-streamer/cavity/prominence-core often exists quiescently in the corona. I will present an analysis of a few case studies of white light quiescent cavities as observed by the HAO Mauna Loa Solar Observatory Mk4 coronagraph. In particular I will consider the 3D structure and evolution of these cavities, and how these are related to CMEs. Finally, I will discuss the implications that these observations may have for the state of the corona just prior to a CME, and more generally for the nature of coronal MHD equilibria.
DE: 7509 Corona
DE: 7511 Coronal holes
DE: 7524 Magnetic fields
DE: 7531 Prominence eruptions
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly