The Effect of the Relative Orientation between the Coronal Field and New Emerging Flux. I. Global Properties

Galsgaard, K.; Archontis, V.; Moreno-Insertis, F.; Hood, A. W.
Bibliographical reference

The Astrophysical Journal, Volume 666, Issue 1, pp. 516-531.

Advertised on:
9
2007
Number of authors
4
IAC number of authors
1
Citations
80
Refereed citations
71
Description
The emergence of magnetic flux from the convection zone into the corona is an important process for the dynamical evolution of the coronal magnetic field. In this paper we extend our previous numerical investigations, by looking at the process of flux interaction as an initially twisted flux tube emerges into a plane-parallel, coronal magnetic field. Significant differences are found in the dynamical appearance and evolution of the emergence process depending on the relative orientation between the rising flux system and any preexisting coronal field. When the flux systems are nearly antiparallel, the experiments show substantial reconnection and demonstrate clear signatures of a high-temperature plasma located in the high-velocity outflow regions extending from the reconnection region. However, the cases that have a more parallel orientation of the flux systems show very limited reconnection and none of the associated features. Despite the very different amount of reconnection between the two flux systems, it is found that the emerging flux that is still connected to the original tube reaches the same height as a function of time. As a compensation for the loss of tube flux, a clear difference is found in the extent of the emerging loop in the direction perpendicular to the main axis of the initial flux tube. Increasing amounts of magnetic reconnection decrease the volume, which confines the remaining tube flux.