Solar Coronal Mass Ejection

One possible mechanism is the loss of equilibrium of coronal magnetic flux ropes formed gradually by large-scale surface motions. In this paper, the locations of flux rope ejections in a recently developed quasi-static global evolution model are compared with observed CME source locations over a 4.5 month period in 1999.

Using extreme ultraviolet data, the low-coronal source locations are determined unambiguously for 98 out of 330 CMEs. Our results suggest that while the gradual formation of magnetic flux ropes over weeks can account for many observed CMEs, especially at higher latitudes, there exists a second class of CMEs (at least half) for which dynamic active region flux emergence on shorter timescales must be the dominant factor.