Accession Number:

ADA218656

Title:

Geostrophic Vortex Dynamics

Descriptive Note:

Doctoral thesis,

Corporate Author:

WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Personal Author(s):

Report Date:

1988-10-01

Pagination or Media Count:

225.0

Abstract:

By generalizing the method of contour dynamics to the quasigeostrophic two layer model, we have proposed and solved a number of fundamental problems in the dynamics of rotating and stratified vorticity fields. A variety of rotating and translating potential vorticity equilibria V- states in one and two layers have been obtained, shedding new light on potential vorticity dynamics in the geostrophic context. In particular, the equivalent barotropic model is shown to be a singular limit of the two-layer model for scales large compared to the radius of deformation. The question of coalescence of two vortices in the same layer merger and in different layers alignment is studied in detail. Critical initial separation distances for coalescence are numerically established as functions of the radius of deformation and the relative thickness of the layers at rest. The connection between coalescence and the existence of stable rotating doubly-connected V- states is shown to be an illuminating generalization of the Euler results. The question of filamentation of two-dimensional vorticity interfaces is addressed from a new geometrical perspective. The analysis of the topology of the stream function in a frame of reference rotating with the instantaneous angular velocity of the vorticity distribution the corotating frame is shown to yield new powerful insights on the nonlinear evolution of the vorticity field. Theses. AW

Subject Categories:

  • Physical and Dynamic Oceanography
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE