Invited review abstract

Large-scale development of CMEs
Tibor Török


The large-scale evolution of coronal mass ejections (CMEs) typically consists of three distinct phases: an initiation phase, often observed as the slow rise of a filament or
prominence, a phase of rapid expansion and acceleration of the ejecta to velocities ranging from a few hundred to more than 3000 km/s in the inner corona, and a final propagation phase through interplanetary space at approximately constant velocity. Also, erupting filaments and CME cores are sometimes
observed to undergo a significant rotation about their rise direction (of 100 degrees and more) in the course of their acceleration phase. Since the velocity and magnetic orientation of CMEs upon their arrival at Earth strongly affect their geoeffectiveness, we have to understand which physical
mechanisms govern the amount of acceleration and rotation in the early evolution of CMEs. In this talk, I will review theoretical models and numerical simulations of CMEs in light of what we can learn about these mechanisms.