Acceleration and expansion of interplanetary coronal mass ejections

NAKWACKI, M.S.; DÉMOULIN, P.; DASSO, S.; MANDRINI, C.H.

Montreal

Congreso; 37th COSPAR Scientific Assembly; 2008

COSPAR

Coronal mass ejections (CMEs) are solar eruptions that release huge amounts of magnetized plasma into the interplanetary medium. When a CME is observed in the interplanetary space, it is called an ICME (interplanetary coronal mass ejection). These heliospheric counterparts can be identified from the surrounding solar wind because of their particular characteristics. In their travel from the Sun, ICMEs expand and accelerate. However, from single spacecraft observations, expansion and acceleration cannot be distinguished from each other. In this work, we take a new approach to study the acceleration and expansion of ICMEs, which is based on the assumption of a self-similar expansion with a different rate in each direction. To decouple the effects of expansion and acceleration, we use multi-spacecraft observations.