This three-year program will construct helmet streamer solutions containing a cavity flux rope and a prominence in its closed field region. The solutions will study the initiation and propagation of coronal mass ejections by investigating their dynamical evolution due to photospheric shear motion. Using a 2 1/2 dimensional MHD code (incorporating the characteristics in the boundary conditions), the PI will construct a quasi-static helmet-streamer solution. This solution will be used to quantitatively study the equilibrium structure, force balance and energy content in detail and compare with observations. Using the helmet streamer as an initial state, the PI will also study its dynamical evolution due to photospheric shear motions. The shear is anticipated to cause the streamer to erupt impulsively, and the helmet dome, cavity and prominence will form typical three-part looplike coronal mass ejections. In all, this work will generate a more physically realistic pre-event coronal atmosphere, reveal the physical mechanisms that cause the initiation of coronal mass ejections, and address the fundamental question of the energy source of coronal mass ejections.
