Accueil > Actualités > Séminaires > Séminaire de Sanjeeva Balasuriya au LMD-ENS


Titre : Flow barriers and flux in unsteady geophysical flows
Nom du conférencier : Sanjeeva Balasuriya
Son affiliation : University of Adelaide
Laboratoire organisateur : LMD
Date et heure : 17-07-2014 14h30
Lieu : Salle 235 A, 29 Rue d'Ulm
Résumé :

How does one define the boundary of the ozone hole, an oceanic eddy, or Jupiter's Great Red Spot? These occur in geophysical flows which are unsteady (nonautonomous), that is, which change with time, and therefore any boundary must as well. In steady (autonomous) flows, defining flow boundaries is straightforward: one first finds fixed points of the flow, and then determines entities in space which are attracted to or repelled from these points as time progresses. These are respectively the stable and unstable manifolds of the fixed points, and can be shown to partition space into regions of different types of flow. This talk will focus on the required modifications to this idea for determining and manipulating flow barriers in the more realistic unsteady context.