ON THE INTERNAL STRUCTURE OF THE MAGNETIC FIELD IN MAGNETIC CLOUDS AND INTERPLANETARY CORONAL MASS EJECTIONS: WRITHE VERSUS TWIST
In this study, we test the flux rope paradigm by performing a "blind" reconstruction of the magnetic field structure of a simulated interplanetary coronal mass ejection (ICME). The ICME is the result of a magnetohydrodynamic numerical simulation and does not exhibit much magnetic twist, but appears to have some characteristics of a magnetic cloud, due to a writhe in the magnetic field lines. We use the Grad–Shafranov technique with simulated spacecraft measurements at two different distances and compare the reconstructed magnetic field with that of the ICME in the simulation. While the reconstructed magnetic field is similar to the simulated one as seen in two dimensions, it yields a helically twisted magnetic field in three dimensions. To further verify the results, we perform the reconstruction at three different position angles at every distance point, and all results are found to be in agreement. This work demonstrates that the current paradigm of associating magnetic clouds with flux ropes may have to be revised.
The Astrophysical Journal
Digital Object Identifier (DOI)
N. Al-Haddad, I. I. Roussev, C. Möstl, C. Jacobs, N. Lugaz, S. Poedts, and C. J. Farrugia. ON THE INTERNAL STRUCTURE OF THE MAGNETIC FIELD IN MAGNETIC CLOUDS AND INTERPLANETARY CORONAL MASS EJECTIONS: WRITHE VERSUS TWIST. Astrophysical Journal Letters. 738:L18-L18. 2011