1211.2108 (A. Isavnin et al.)

Three-dimensional evolution of erupted flux ropes from the Sun (2-20Rs) to 1AU    [PDF]

A. Isavnin, A. Vourlidas, E. K. J. Kilpua

Studying the evolution of magnetic clouds entrained in by coronal mass ejections using in-situ data is a difficult task since only a limited number of observational points is at hand. In this work we estimate the flux rope orientation first in the close vicinity of the Sun (2-20Rs) using forward modeling of STEREO/SECCHI and SOHO/LASCO coronagraph images of coronal mass ejections and then in-situ using Grad-Shafranov reconstruction of the magnetic cloud. Thus, we are able to measure changes in the orientation of the erupted flux ropes as they propagated from the Sun to 1AU. We present both techniques and use them to study 15 magnetic clouds observed during the minimum following the Solar Cycle 23 and the rise of the Solar Cycle 24. The results of our analysis agree with earlier studies showing that the flux ropes tend to deflect towards the solar equatorial plane and also experience rotation on their travel from the Sun to 1AU. However, our method allows one to deduce the evolution of the three-dimensional orientation of individual flux ropes and not as a statistical result.

View original: http://arxiv.org/abs/1211.2108