Chaotic transport by Rossby waves in shear flow

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Physics of Fluids A; (United States)

DOI:https://doi.org/10.1063/1.858639· OSTI ID:6750201

del-Castillo-Negrete, D; Morrison, P J ^[1]

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1. Department of Physics and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)

Transport and mixing properties of Rossby waves in shear flow are studied using tools from Hamiltonian chaos theory. The destruction of barriers to transport is studied analytically, by using the resonance overlap criterion and the concept of separatrix reconnection, and numerically by using Poincare sections. Attention is restricted to the case of symmetric velocity profiles with a single maximum; the Bickley jet with velocity profile sech[sup 2] is considered in detail. Motivated by linear stability analysis and experimental results, a simple Hamiltonian model is proposed to study transport by waves in these shear flows. Chaotic transport, both for the general case and for the sech[sup 2] profile, is investigated. The resonance overlap criterion and the concept of separatrix reconnection are used to obtain an estimate for the destruction of barriers to transport and the notion of [ital banded] chaos is introduced to characterize the transport that typically occurs in symmetric shear flows. Comparison between the analytical estimates for barrier destruction and the numerical results is given. The role of potential vorticity conservation in chaotic transport is discussed. An area preserving map, termed [ital standard] [ital nontwist] map, is obtained from the Hamiltonian model. It is shown that the map reproduces the transport properties and the separatrix reconnection observed in the Hamiltonian model. The conclusions reached are used to explain experimental results on transport and mixing by Rossby waves in rotating fluids.

• DOE Contract Number: FG05-80ET53088
• OSTI ID: 6750201
• Journal Information: Physics of Fluids A; (United States), Journal Name: Physics of Fluids A; (United States) Vol. 5:4; ISSN PFADEB; ISSN 0899-8213
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FLUID FLOW
FUNCTIONS
HAMILTONIAN FUNCTION
INCOMPRESSIBLE FLOW
MIXING
OCEANIC CIRCULATION
RESONANCE
STABILITY
TRANSPORT