Automated detection of coherent Lagrangian vortices in two-dimensional   unsteady flows
  Coherent boundaries of Lagrangian vortices in fluid flows have recently been identified as closed orbits of line fields associated with the Cauchy-Green strain tensor. Here we develop a fully automated procedure for the detection of such closed orbits in large-scale velocity data sets. We illustrate the power of our method on ocean surface velocities derived from satellite altimetry. 
Daniel Karrasch, Florian Huhn, George Haller
math.DS cs.GR physics.ao-ph physics.flu-dyn