HR: 15:25h
AN: OS13D-08    [Abstracts]
TI: Caribbean Current and Eddies as Observed by Surface Drifters
AU: * Richardson, P L
EM: prichardson@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AB: Recent satellite-tracked surface drifter trajectories were analyzed to describe the mean currents and eddies in the Caribbean Sea. The structure of the Caribbean Current and its variability were determined from high-resolution « degree maps of the mean velocity and eddy kinetic energy. Looping drifter trajectories were used to identify discrete cyclones and anticyclones, and their characteristics were described and related to the structure of the mean flow. The translation rate of eddies in different areas was found to be similar to the mean velocity of the local background flow fields suggesting that the eddies were largely advected by the background flow. Ten energetic anticyclones translated westward at 13 cm/sec in the Venezuela and Colombia Basins. These anticyclones tended to lie in two bands, centered near 15§N and 17§N, coinciding with two jets of the Caribbean Current. The northern weaker jet contains water primarily from the North Atlantic, the southern stronger jet contains water from the tropical and South Atlantic. The anticyclones are thought to have formed in the eastern Caribbean from the anticyclonic vorticity derived from North Brazil Current rings. The ring vorticity enters the eastern Caribbean through island passages and is probably amplified by the anticyclonic shear on the northern side of the jets. Southwest of Cuba a cyclone-anticyclone pair was observed to slowly (~ 2 cm/sec) translate westward into the Yucatan Current. The cyclone was tracked for 10.5 months with four drifters, making it the longest-tracked of the Caribbean eddies.
DE: 4243 Marginal and semienclosed seas
DE: 4512 Currents
DE: 4520 Eddies and mesoscale processes
DE: 4532 General circulation
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting