Fig. 1. Top: Spaghetti diagram of 20-day drifter trajectory segments. Colors give the mean drift direction (legend in upper-right corner). Bottom: Map of vorticity created from the spectra of 90-day drifter segments. Blue indicates predominantly cyclonic vorticity, red indicates anticyclonic vorticity. Black polygons indicate the drifter group subregions. Arrows show the mean velocity of the drifter group.