Point-vortex application to vortex stability, evolution, and statistical equilibrium
Date
1995-06
Authors
Persing, John, author
Montgomery, Michael T., author
Journal Title
Journal ISSN
Volume Title
Abstract
The nonlinear evolution of an isolated, barotropic vortex in an infinite, frictionless domain is examined with a cloud of like-signed point-vortices. The stability of systems of point vortices is reviewed as well as the stability of continuous systems possessing a sign reversal in the radial vorticity gradient like that observed in the inner core of hurricanes. The new result is the application of point-vortices to examine the evolution of a hurricane like vortex system. Using a three-region approximation to the radial vorticity profile, the nondimensional problem can be reduced to two parameters. These are the inner radius of the vorticity maximum 8 and the tangential wind speed at this radius Vtan(8). The relaxation time scale is on the order of five circuit times, and the relaxed vorticity profile ranges from near solid-body rotation to highly monopolar profiles. The relaxation time-scale and the monopolicity of the relaxed vorticity profile show some correlation to the strength of the linear instability in the initial system, although a more thorough examination of the parameter space is proposed to obtain a complete understanding of the processes involved in the relaxation.
Description
June 1995.
Also issued as John Persing's thesis (M.S.) -- Colorado State University, 1995.
Also issued as John Persing's thesis (M.S.) -- Colorado State University, 1995.
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Subject
Hurricanes -- Mathematical models
Vortex-motion -- Mathematical models