On the kinematic evolution of flare-associated CMEs

Abstract

We report a common tendency of the kinematic evolution of three flare-associated coronal mass ejections (CMEs). Their kinematic evolutions are examined using well-observed data (eruptive filaments, X-ray structures, and prominences) very close to the solar surface as well as SOHO/LASCO C2-C3 data. Their height-time data are fitted using three analytical models (exponential, power-law, and linear) to examine their kinematic behaviors. The speed and acceleration of the CMEs are then obtained from the analytical expressions of height-time data. From this analysis, it is found that the kinematic patterns of these three CMEs have a typical tendency; that is, the speed of the CMEs very close to the surface (lower corona) is approximately exponential in form, but it is nearly constant in the upper corona. The peak of the acceleration is found to occur within 2-3 solar radii and during the eruptive phase of the associated flare. It is also noted that the observed kinematic patterns are quite similar to those predicted by two flux rope emergence models: (i) a theoretical, electrodynamic model (Chen, 1996); and (ii) a numerical simulation, self-consistent, 21/2D MHD model (Wu, Guo, and Dryer, 1997).