The stability of free and forced planetary waves in a $ beta$-channel is investigated with a barotropic model. The forced waves at equilibrium result from a constant mean-zonal wind interacting with a finite-amplitude topography. / The frequencies of all infinitesimal perturbations to the equilibrium flows are determined numerically as a function of the flow parameters. The results are interpreted using a truncated spectral model and related to those of previous studies with infinite $ beta$-planes. In contrast to some earlier analytical studies we find that unstable long waves $(L sb{x}$ $>$ $L sb{y})$ exist under superresonant conditions. We also report on the existence of an interesting travelling topographic instability. / The linear instability of a weakly non-zonal flow is investigated numerically and analytically (via WKB theory). The theory reproduces the qualitative nature of the numerically-determined fastest-growing mode. / Nonlinear integrations, involving many degrees of freedom, reveal that initially-infinitesimal disturbances may grow explosively to finite-amplitude. The longer-term integrations are interpreted using a statistical mechanical model.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75433 |
| Date | January 1987 |
| Creators | Fyfe, John |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Meteorology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000550425, proquestno: AAINL44304, Theses scanned by UMI/ProQuest. |
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