We study the transport of particles in a general, two-dimensional, incompressible flow in the presence of a transient eddy, i.e., a bounded set of closed streamlines with a finite time of existence. Using quantities obtained from Eulerian observations, we provide explicit conditions for the existence of a hyperbolic structure in the flow, which induces mixing between the eddy and its environment. Our results can be used directly to study finite-time transport in numerically or experimentally generated vector fields with general time dependence.

back to list of publications.