Accession Number : ADA181561

Title :   The Merging of Isolated Lenses.

Descriptive Note : Technical rept.,

Corporate Author : FLORIDA STATE UNIV TALLAHASSEE DEPT OF OCEANOGRAPHY

Personal Author(s) : Nof, Doron

PDF Url : ADA181561

Report Date : Apr 1986

Pagination or Media Count : 61

Abstract : Interaction of two isolated lens-like eddies is examined with the aid of an inviscid nonlinear model. The barotropic layer in which the lenses are embedded is infinitely deep so that there is no interaction between the eddies unless their edges touch each other. It is assumed that the latter is brought about by a mean flow which relaxes after pushing the eddies against each other and forming a 'figure eight' structure. Using arguments based on continuity and conservation of energy along the eddies edge it is shown that, once a 'figure eight' shape is established, intrusions along the eddies' peripheries are generated. These intrusions resemble 'arms' or 'tentacles' and their structure gives the impression that one vortex is 'hugging' the other. As time goes on the tentacles become longer and longer and, ultimately, the eddies are entirely converted into very long spiral-like tentacles. These spiraled tentacles are adjacent to each other so that the final result is a single vortex containing the fluid of two parent eddies. Because of the inherent nonlinearity and the fact that the problem is three dimensional (x, y, t), the complete details of the above process cannot be described analytically. It is, however, possible to show analytically that the intrusions and tentacles are inevitable.

Descriptors :   *EDDIES(FLUID MECHANICS), *OCEAN CURRENTS, BAROMETRIC PRESSURE, LAYERS, EDGES, INTRUSION, ISOLATION, LENSES, FLOW, MEAN, VORTICES, ENERGY CONSERVATION, TOUCH, INVISCID FLOW, MATHEMATICAL MODELS, NONLINEAR SYSTEMS

Subject Categories : Physical and Dynamic Oceanography
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE