A plasma beta transition within a propagating CME leading to a magnetic substructure
Abstract
We present a study of how a sharp transition in the plasma beta within a simulated flux rope (FR) affects the distribution of toriodal flux within the obstacle. Specifically, we consider a 2.5D MHD simulation of a magnetic FR with a strong internal magnetic field and an explosive fast start. Qualitatively the overall effects show that the sharp boundary of the low-to-high plasma beta within the outer segment of a flux rope leads to layers of magnetic flux 'peeling' off the main body. This leads to an unusual flux rope morphology in the first stage of propagation, while the more traditional view of a 'pancake' shaped FR is observed as it approaches 1AU. However the simulation provides compelling evidence that at all heliocentric distances the distribution of magnetic flux away from the FR axis is not linear; with 80% of the flux occurring within 40% of the distance from the FR axis. Thus our simulation shows that the competing ideas of a pancaking structure observed remotely can coexist with a quasi-cylindrical magnetic structure seen in situ.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2013)
- Pub Date:
- June 2013
- Bibcode:
- 2013shin.confE.149S