MEPS 472:27-44 Supplementary Downloads

Video 1
What happens to particles near LCS? Attracting and repelling Lagrangian coherent structures (LCS) are mapped by identifying regions in the fluid where particles initially close to one another are maximally stretched out in both backward and forward time. To motivate this conceptually, here we show the evolution of particle trajectories on and near attracting (blue) and repelling (red) LCS for the model run shown in other figures. On model day 33 blue particles are initialized in a dense 100 by 100 grid (this appears as a single dot) on four saddle points and integrated forward in time. The blue particles stretch out in forward time along the attracting LCS, also shown in blue in the background field. Similarly, red particles are initialized at the end of the movie (day 46) and integrated backward in time, where they stretch out along the repelling LCS (red curves); viewed in forward time these red particles converge onto the saddle points where they were initialized. Particles on both the forward and backward LCS stay on LCS as they move with the fluid. Particles in green are initialized nearby the LCS at the same initial densities as the groups of red and blue particles; these move along and towards the blue attracting LCS, but do not stretch out to the same degree as the red and blue particle sets.

Video 2
Time series of larval density (all age classes) for the model run shown in figures. Particle density is binned to 1 km2 and shown in a log scale to facilitate visualization of the wide range of densities.