Hurricane Motion on a Beta Plane in an Asymmetric Balance.
Abstract
This thesis extends asymmetric balance theory (AB) to the shallow water beta plane (Beta-AB). The physical problem studied is that of vortex motion on a beta plane in the absence of environmental steering flow. To reduce the problem to its essential physics, the mathematical formulation developed is restricted to purely linear dynamics. The linear dynamics precludes wave-wave and wave-mean-flow interactions. Vortices placed in the Beta-AB model correctly develop the wavenumber one asymmetries (the 'beta' gyres) necessary for vortex self-advection. The vortices move in a northwest direction consistent with their relative strengths. Finite drift speeds are reached in all cases. Both the Beta-AB model and a linear barotropic nondivergent model are used to investigate the existence of a translating normal mode of zero frequency. If such a mode exists, the beta gyres would be expected to remain unchanged in the absence of beta forcing. When the beta forcing is discontinued, the beta gyres axisymmetrize in both models, refuting the normal mode hypothesis.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 31, 1996
- Accession Number
- ADA312186
Entities
People
- Christopher T. Nicklas
Organizations
- Air Force Institute of Technology