Structure and Variability of the Mesoscale Circulation in the Caribbean sea as Deduced From Satellite Altimetry
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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Four years of TopexPoseidon TIP and European Remote Sensing Satellite ERS altimetry data in the Caribbean Sea are used to describe the structure and variability of the mesoscale circulation in this area. These results are compared with satellite-derived sea surface temperature SST and drifter trajectories for the same period of time. Contour maps of sea surface height anomalies made for each 10-day period TIP data reveal the formation and evolution of anticyclonic and cyclonic mesoscale features in the central part of the Caribbean Sea during the entire period studied. These features move westward at average speeds between 10 and 15 cms, growing in amplitude up to 25 Cm. Also, a quasi-permanent gyre is detected in the Golfo de los Mosquitos coast of Panarna and Colombia. The sense of rotation of this gyre is shown to be modulated seasonally. Enhanced relative clockwise and counterclockwise rotation are observed during the rainy season June-October and the drywindy season January-April, respectively. No strong mesoscale anomalies are detected in the eastern part of the Caribbean Sea where they are expected. A seasonal cycle is found in the sea level anomaly SLA derived from TIP and ERS-1 data due to steric effects. Upwelling is observed near the coast of Venezuela during the dry season. A comparison of SLA with SST is made and good correlation is observed at some locations. Drifter trajectories contemporaneous with SLA data agree well with the sense of rotation of strong features, but the drifter speeds are twice the absolute geostrophic currents calculated from SLA.
- Physical and Dynamic Oceanography