Francois Lekien, Kayo Ide, Stephen Wiggins
California Institute of Technology
lekien@caltech.edu
(Abstract received 08/01/2000 for session C)
ABSTRACT
We study the influence of eddies detaching from a jet on intergyre transport in a model consisting of a three layer quasigeostrophic flow in a square domain subject to a sinusoidal in space (constant in time) wind stress that leads to the double gyre configuration. We use techniques from dynamical systems theory to study intergyre transport. In particuliar distinguished hyperbolic trajectories (DHT's) along with their stable and unstable manifolds are computed in order to implement the technique of lobe dynamics. An unstable manifold associated with a DHT on the western boundary and a stable manifold associated with a DHT on the eastern boundary are computed. These manifolds control intergyre transport. The influence of detached eddies on intergyre transport can then be determined by studying their influence on these stable and unstable manifolds. These eddies also have associated DHT's with their own stable and unstable manifolds. These are computed in order to understand their interaction with the unstable and stable manifolds on the boundaries controlling intergyre transport as well as to study the flux between the eddies and the main flow. Bifurcations of the stagnation points associated with the eddies complicate the computation of the DHT's. Special cases of bifurcations are studied and the issue of the existence of a DHT during a bifurcation of stagnation points is outlined.