Abstract: The genesis of solar coronal mass ejections (CMEs) is both an intellectually intriguing, fundamental unsolved problem in plasma astrophysics, and a societally relevant subject critical to space weather prediction and mitigation. Dark coronal cavities surrounding cool, dense prominence material are observed within CMEs, but also as equilibrium states in the magnetically-dominated corona. Their plasma properties as observed in their quiescent phase provide clues to the nature of such equilibria and how they may ultimately be lost during CMEs.
July 22, 2002 observations of a polar crown filament and associated cavity. Clockwise from top left: HAO MLSO Mk4 white-light coronagraph; Big Bear Solar Observatory H-alpha; SOHO/EIT 284 Angstroms; SOHO/EIT 304 Angstroms.
From Gibson et al, 2006.
