Klaus Galsgaard's PhD Thesis Page

Research topics

For my PhD thesis I did numerical MHD experiments, primarily with the purpose to try to obtain a qualitative understanding of the heating and flare activity of the solar corona. The general reason for these phenomena appear to be processes that allow energy to be temporarily stored in the coronal magnetic field, from which it is then occasionally released in bursty events.

This work involves trying to understand the dynamical reaction of complex field topologies to boundary driving. The short version of the story is that---as originally pointed out by Parker--- no matter what (for example how low the resistivity is), the work done on the magnetic field has to be dissipated. Thus the plasma is forced to find configurations where the stored free magnetic energy can be dissipated into heat (and presumably particle acceleration in a plasma such as the coronal one, where collisions are rare). Our results demonstrate that this happens by the formation of an ensemble of non-stationary current sheet fragments.

The modelling is performed by running a newly developed 3D MHD code on whatever available computer. The data analysis is done using IDL and NAG Explorer.

My PhD thesis was written under the supervision of Åke Nordlund.

Papers from my PhD

 * The Heating and Activity of the Solar Corona: I. Boundary Shearing of an Initially Homogeneous Magnetic Field (9 Mb) (JGR, 101, 13445-13460, 1996)
 * The Heating and Activity of the Solar Corona: II. Kink Instability in a Flux Tube (27 Mb) (JGR, 102, 219-230, 1997)
 * The Heating and Activity of the Solar Corona: III. Dynamics of a Low Beta Plasma with 3D Null Points (24 Mb) (JGR, 102, 231-248, 1997)
 * The Heating and Activity of the Solar Corona: IV. Investigation of Numerical Avalanches in a 3D Vector Field (A&A, 315, 312-318, 1996)
 * A 3D MHD Code for Parallel Computers -- Only on the www!
There is also a of the thesis summary, but this expands to 80 Mb colour PostScript, so be careful.
Klaus Galsgaard / e-mail

Last update 010301