- Series
- CDSNS Colloquium
- Time
- Wednesday, May 15, 2013 - 4:30pm for 1 hour (actually 50 minutes)
- Location
- Skiles 05
- Speaker
- Daniel Blazevski – ETH Zurich
- Organizer
- Rafael de la Llave
Building on recent work on hyperbolic barriers (generalized stable and
unstable manifolds) and elliptic barriers (generalized KAM tori) for
two-dimensional unsteady flows, we present Lagrangian descriptions of
shearless barriers (generalized nontwist KAM tori) and barriers in higher
dimensional flows. Shearless barriers (generalized nontwist KAM tori)
capture the core of Rossby waves appearing in atmospheric and oceanic
flows, and their robustness is appealing in the theory of magnetic
confinement of plasma. For three-dimensional flows, we give a description
of hyperbolic barriers as Lagrangian Coherent Structures (LCSs) that
maximally repel in the normal direction, while shear barriers are LCSs that
generate shear along the LCS and act as boundaries of Lagrangian vortices
in unsteady fluid flows. The theory is illustrated on several models.