The preceding paper (Steinolfson, this issue) describes three ambient coronal models suitable for the study of time-dependent phenomena: (1) a static corona with a dipole magnetic field, (2) a steady polytropic corona with an equatorial coronal streamer, and (3) a heated corona with an equatorial coronal streamer. We now consider the propagation of coronal mass ejections initiated in each atmosphere by an identical energy source. A localized thermal energy input at the base of closed field regions produces mass ejections that are simulated by numerical integration of the MHD equations. We show that the computed ejection in the first atmosphere listed above does not adequately represent the general characteristics of observed looplike mass ejections. The simulated ejection in a polytropic corona with a streamer does simulate some of the observed features. It is only when a heating term is added to the initial atmosphere with a streamer that all of these are reproduced. A detailed comparison between a computed mass ejection and a representative observation demonstrates that the simulation can also duplicate some of the quantitative properties (e.g., brightness level) of individual looplike ejections. ¿ American Geophysical Union 1988