Research@StAndrews
 
The University of St Andrews

Research@StAndrews:FullText >
Mathematics & Statistics (School of) >
Applied Mathematics >
Applied Mathematics Theses >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10023/1692
This item has been viewed 36 times in the last year. View Statistics

Files in This Item:

File Description SizeFormat
DavidMacTaggartPhDThesis.PDF4.6 MBAdobe PDFView/Open
Title: Theoretical magnetic flux emergence
Authors: MacTaggart, David
Supervisors: Hood, Alan W.
Keywords: Magnetohydrodynamics
Flux emergence
Numerical MHD
Magnetic eruptions
Issue Date: 2011
Abstract: Magnetic flux emergence is the subject of how magnetic fields from the solar interior can rise and expand into the atmosphere to produce active regions. It is the link that joins dynamics in the convection zone with dynamics in the atmosphere. In this thesis, we study many aspects of magnetic flux emergence through mathematical modelling and computer simulations. Our primary aim is to understand the key physical processes that lie behind emergence. The first chapter introduces flux emergence and the theoretical framework, magnetohydrodynamics (MHD), that describes it. In the second chapter, we discuss the numerical techniques used to solve the highly non-linear problems that arise from flux emergence. The third chapter summarizes the current literature. In the fourth chapter, we consider how changing the geometry and parameter values of the initial magnetic field can affect the dynamic evolution of the emerging magnetic field. For an initial toroidal magnetic field, it is found that its axis can emerge to the corona if the tube’s initial field strength is large enough. The fifth chapter describes how flux emergence models can produce large-scale solar eruptions. A 2.5D model of the breakout model, using only dynamic flux emergence, fails to produce any large scale eruptions. A 3D model of toroidal emergence with an overlying magnetic field does, however, produce multiple large-scale eruptions and the form of these is related to the breakout model. The sixth chapter is concerned with signatures of flux emergence and how to identify emerging twisted magnetic structures correctly. Here, a flux emergence model produces signatures found in observations. The signatures from the model, however, have different underlying physical mechanisms to the original interpretations of the observations. The thesis concludes with some final thoughts on current trends in theoretical magnetic flux emergence and possible future directions.
URI: http://hdl.handle.net/10023/1692
Type: Thesis
Publisher: University of St Andrews
Appears in Collections:Applied Mathematics Theses



This item is protected by original copyright

This item is licensed under a Creative Commons License
Creative Commons

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

DSpace Software Copyright © 2002-2012  Duraspace - Feedback
For help contact: Digital-Repository@st-andrews.ac.uk | Copyright for this page belongs to St Andrews University Library | Terms and Conditions (Cookies)