Publication

2007-06

English

http://archimer.ifremer.fr/doc/2007/publication-4349.pdf (0.94 Mo)

2007 The American Physical Society

Froyland G¹, Padberg K², England M¹, Treguier Anne-Marie³

1 : Univ New S Wales, Sch Math & Stat, Sydney, NSW 2052, Australia.
2 : Univ Paderborn, Fak Elektortech Informat & Math, D-33095 Paderborn, Germany.
3 : IFREMER, CNRS, F-29280 Plouzane, France.

Physical Review Letters (0031-9007) (The American Physical Society), 2007-06 , Vol. 98 , N. 22 , P. NIL_131-NIL_134

19

Engineering Sciences, Mathematics-Computer Science

Coherent nondispersive structures are known to play a crucial role in explaining transport in nonautonomous dynamical systems such as ocean flows. These structures are difficult to extract from model output as they are Lagrangian by nature and not revealed by the underlying Eulerian velocity fields. In the last few years heuristic concepts such as finite-time Lyapunov exponents have been used in an attempt to detect barriers to oceanic transport and thus identify regions that trap material such as nutrients and phytoplankton. In this Letter we pursue a novel, more direct approach to uncover coherent regions in the surface ocean using high-resolution model velocity data. Our method is based upon numerically constructing a transfer operator that controls the surface transport of particles over a short period. We apply our technique to the polar latitudes of the Southern Ocean.