Abstract
Magnetic reconnection is a large part in driving solar outbursts, but how to explain their sudden bursts after periods of relative calm is still not fully known. One possible explanation is the often overlooked Hall effect, in which it becomes possible to explain reconnection through a build up of energy through separated currents. More focus has come on the Hall effect in recent years, as it seems it could be a powerful driver in this area.
We build upon the pre-existing solar MHD model Bifrost, and add in the Hall term in order to investigate this. Through a modification in Ohm’s law we allow for current separation at inertial scales, and run tests for the effectiveness when compared with normal ideal MHD models. The goal of this thesis is to measure the reconnected flux from the Hall MHD model and see if it has a significant impact on reconnection rate.
Through following a tutorial laid out by Joseph D. Huba in his 2003 paper [3], we perform both a whistler wave validation test, and a reconnection setup. We found that the Hall effect indeed has a large impact on the amount of reconnected flux, which falls in line with previous investigations.
[3] Joseph D. Huba. Hall Magnetohydrodynamics - A Tutorial. In Jörg Büchner, Manfred Scholer, and Christian T. Dum, editors, Space Plasma Simulation, volume 615, pages 166–192. Springer Berlin Heidelberg, Berlin, Heidelberg, 2003. Series Title: Lecture Notes in Physics. URL: http://link.springer.com/10.1007/ 3-540-36530-3_9, doi:10.1007/3-540-36530-3_9.
Supervisor: Professor Boris Gudiksen, Institute of Theoretical Astrophysics, UiO (main-supervisor)
Intern. assessor: Professor David F. Mota, Institute of Theoretical Astrophysics, UiO
Extern. assessor: Professor Thomas Neukirch, University of St Andrews