The connectivity of eddy variability in the Caribbean Sea, the Gulf of Mexico, and the Atlantic Ocean

A set of numerical simulations is used to investigate the connectivity of m esoscale variability in the Atlantic Ocean, the Caribbean, and the Gulf of Mexico. The primitive equation models used for these simulations have a fre e surface and realistic coastline geometry including a detailed representat ion of the Lesser Antilles island are. Two simulations have 1/4 degrees res olution and include a 5.5-layer reduced gravity and a 6-layer model with re alistic bottom topography. Both are wind forced and include the global ther mohaline circulation. The third simulation is from a 1/2 degrees linear win d-driven model. In the two nonlinear numerical simulations, potential vorti city from decaying rings shed by the North Brazil Current retroflection can be advected through the Lesser Antilles. This potential vorticity acts as a finite amplitude perturbation for mixed barotropic and internal mode baro clinic instabilities, which amplify mesoscale features in the Caribbean. Th e eddies associated with the Caribbean Current are primarily anticyclonic a nd transit a narrow corridor across the Caribbean basin along an axis at 14 degrees to 15 degrees N with an average speed of 0.15 m/s. It takes them a n average of 10 months to transit from the Lesser Antilles to the Yucatan C hannel. Along the way, many of the eddies intensify greatly. The amount of intensification depends substantially on the strength of the Caribbean Curr ent and is greatest during a multiyear period when the current is anomalous ly strong owing to interannual variation in the wind forcing. Some Caribbea n eddies squeeze through the Yucatan Channel into the Gulf of Mexico, where they can influence the timing of Loop Current eddy-shedding events. There is a significant correlation of 0.45 between the Loop Current eddy shedding and the eddies near the Lesser Antilles with a time Zag of ii months. Howe ver, Caribbean eddies show no statistically significant net influence on th e mean eddy-shedding period nor on the size and strength of shed eddies in the Gulf of Mexico. Additionally, no significant correlation is found betwe en eddy shedding in the Gulf of Mexico and transport variations in the Flor ida Straits, although transport fluctuations in the Florida Straits at 27 d egrees N and the Yucatan Channel and showed a correlation of about 0.7 with a lag of 15 days. The linear solution exhibited a multiyear anomaly in the strength of the Caribbean circulation that was concentrated in the central and eastern Caribbean due to a multiyear anomaly in the wind field over th e basin. In the nonlinear simulation this anomaly extended into the western Caribbean and across the entire Gulf of Mexico. This westward extension re sulted from the nonlinearity and instability of the Caribbean Current, the westward propagation of the eddies, and the passage of Caribbean eddies thr ough the Yucatan Channel into the Gulf of Mexico.