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arXiv · 1406.0286

Self-similar expansion of solar coronal mass ejections: implications for Lorentz self-force driving

Prasad Subramanian·K. P. Arunbabu·Angelos Vourlidas·Adwiteey Mauriya
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Abstract

We examine the propagation of several CMEs with well-observed flux rope signatures in the field of view of the SECCHI coronagraphs aboard the STEREO satellites using the GCS fitting method of Thernisien, Vourlidas \& Howard (2009). We find that the manner in which they propagate is approximately self-similar; i.e., the ratio ($\kappa$) of the flux rope minor radius to its major radius remains approximately constant with time. We use this observation of self-similarity to draw conclusions regarding the local pitch angle ($\gamma$) of the flux rope magnetic field and the misalignment angle ($\chi$) between the current density ${\mathbf J}$ and the magnetic field ${\mathbf B}$. Our results suggest that the magnetic field and current configurations inside flux ropes deviate substantially from a force-free state in typical coronagraph fields of view, validating the idea of CMEs being driven by Lorentz self-forces.

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Prasad Subramanian, K. P. Arunbabu, Angelos Vourlidas, Adwiteey Mauriya. 2014-06-02. Self-similar expansion of solar coronal mass ejections: implications for Lorentz self-force driving. https://doi.org/10.1088/0004-637x/790/2/125

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