Title: Magnetic-Flux Emergence into the Solar Corona
Author: Mei Zhang
Affil: High Altitude Observatory / NCAR
Email: zhm@hao.ucar.edu
Authors: B.C. Low
Abstract: Low (1997) suggested that CMEs might play a vital role in the reversal of the coronal magnetic field, through the ejection of magnetic flux out of the corona. However, no specific proposal was made for the reversal process. We examine this with a set of elementary hydromagnetic calculations to give some physical insights into how a fresh magnetic field of the opposite polarity might emerge into a corona containing a pre-existing magnetic field. The inevitable magnetic reconnection that takes place between the two magnetic-flux systems involves an expulsion of magnetic flux to infinity. This can be seen even in the geometrically simplified models adopted for our calculations to render the mathematical problems tractable. The calculations related interesting physical properties, such as flux budget, free magnetic energy and Aly limit to CMEs and field reversal.