Contact Info
Department of Applied Mathematics
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext. 32700
Fax: 519-746-4319
PDF files require Adobe Acrobat Reader
MS Teams (please email amgrad@uwaterloo.ca for the meeting link)
Jonathan Tessier | Applied Mathematics, University of Waterloo
Jets, Vortices and Turbulence in Quasi-Geostrophic Magnetohydrodynamics
In this thesis, we model the dynamics of the solar tachocline and the Earth's molten core using a shallow, rapidly rotating, and electrically conducting fluid on an f-plane. We explore the effects of a strong uniform magnetic field with and without a weak free-surface in three different physical problems. We start with large coherent vortices to build an understanding of the local interactions between the field and vortical structures. Magnetic field lines are expelled from the vortex cores for weaker fields and vortices are disrupted for stronger ones, along with a generation of small scale features in the potential vorticity. Including a weak free-surface makes the flow more compact and inhibits the field-induced anisotropy. We then study freely-decaying turbulence using the shape of the energy spectra and the spectral energy fluxes. Kinetic energy is sent to smaller length scales while magnetic energy moves to larger scales for increasing field strength. In the mid to large wavenumbers, the downscale transfer of energy is due to the Lorentz force. Including a free-surface adds an additional downscale transfer at smaller wavenumbers, provided the field is weak enough. Finally, we study the linear stability and nonlinear evolution of an unstable Bickley jet. The field and free-surface are confirmed to be individually stabilizing to the jet and the combined effects show increased stability.
Contact Info
Department of Applied Mathematics
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Phone: 519-888-4567, ext. 32700
Fax: 519-746-4319
PDF files require Adobe Acrobat Reader
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is co-ordinated within the Office of Indigenous Relations.