Detection of Coherent Oceanic Structures via Transfer Operators.

• Published in: Physical Review Letters
• Main Authors: Froyland, Gary, Padberg, Kathrin, England, Matthew H., Tréguier, Anne-Marie
• Other Authors: School of Mathematics and statistics Sydney, The University of Sydney, Fakultat fur elektrotechnik, Informatik und Mathematik, Universitat Paderhom, Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Southern Ocean
• Online Access: https://hal.science/hal-00270767; https://doi.org/10.1103/PhysRevLett.98.224503

International audience 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.