20 years of ACE data: how superposed epoch analysis reveal generic features in interplanetary CME profiles

Florian Regnault

Hosted by Institut d'Astrophysique Spatiale (IAS), France on November 5, 2020


Interplanetary Coronal Mass Ejections (ICMEs) result from the reconfiguration of magnetic fields in our star’s atmosphere. These large-scale magnetized structures propagate in the interplanetary medium where they can be probed by spacecraft. Depending on their speed, ICMEs may accumulate enough solar wind plasma to form a turbulent sheath ahead of them. They therefore consist of two main substructures : a sheath and a magnetic ejecta (ME). The magnetic ejecta is the main body of an ICME where the magnetic field is more intense and with less variance than that of the ambient solar wind. We present a statistical study using the superposed epoch analysis technique on a catalog of around 400 ICMEs where we consider the profiles of the physical parameters of the ICMEs (the magnetic field intensity, the speed, temperature, …) seen at 1 AU by the ACE spacecraft. We analyze the effects of the relative speed of ICMEs compared with the ambient solar wind to extract possible interactions between both.

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