Tracking and Understanding the Trajectory of CMEs From Birth to Late Stage

We present a detailed observational study of the trajectory of coronal mass ejections (CMEs) from their onset continuously to the late stage of evolution in the outer corona. The 3-D trajectory of CMEs, along with their sizes, kinematics and internal magnetic structure, determines the full global state of a CME and how it evolves in the interplanetary space. These properties are essential for understanding their evolution, their interaction with the interplanetary magnetic field and plasma, and ultimately their geoeffectiveness and space weather consequences. Changes of the CME trajectory, often referred to as deflection or channeling, have been observed mostly in the outer corona and/or for events that originate near the solar limb. Measurements of the early trajectory of CMEs that originate near the center of the solar disk are rare, due to the limitation of coronagraphic observations. However, these CMEs are of particular interest since they are mor likely to hit the Earth and the likelihood of hitting is sensitive to the trajectory. Here we present a novel technique for determining CME trajectories near the solar surface, which employs SDO/AIA observations and is based on the shape of coronal waves driven by the CME expansion. We further use STEREO/COR1 and COR2 observations, in combination with SOHO/LASCO data, to determine the 3D trajectory of CMEs in the inner and outer corona, respectively. This study addresses the following two main questions: (1) What are the rise directions of CMEs right after the onset of the eruption and how do they change as a function of height above the solar surface? (2) Are deviations from a radial trajectory caused primarily by the deflection of the CME at coronal holes or by the magnetic properties of the CME's source region?