CME Observations -- from Sun to Impact on Geospace

Abstract: Our Sun is an active star expelling dynamic phenomena known as coronal mass ejections (CMEs). The magnetic field configuration on the Sun and related solar wind structures affect the propagation behavior of CMEs, dominate its transit time and embedded magnetic field properties when impacting Earth. Since the conditions on the Sun constantly change, the impact of CMEs on the different regimes of geospace is quite variable and may differ significantly from event to event. This short review summarizes the different manifestations of CMEs on the Sun, their appearance in interplanetary space, and how CMEs trigger a cascade of reactions as they interact with Earth.