Caribbean Current and eddies as observed by surface drifters

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Figure 1: Location diagram showing the major Caribbean basins, the surrounding countries and islands, and the 200 m (dashed) and 2000 m (dotted) depth contours. (953.0Kb)

Figure 2: Launch or start locations of 212 drifters used in this study. (1.294Mb)

Figure 3: Summary of 212 surface drifter trajectories in and near the Caribbean and over 50 drifter-years of data from the years 1986-2003. (3.371Mb)

Figure 4A: Drifter trajectories in the Panama-Colombia Gyre region. (1.532Mb)

Figure 4B: Trajectory of a drifter launched in the Panama-Colombia Gyre near 10.8ºN 75.6ºW that circled in the gyre 11 times during June 1998-July 1999. (763.5Kb)

Figure 5: Trajectories of 10 drifters that drifted through the Caribbean and exited through the Yucatan Straits. (1.527Mb)

Figure 6: Drifter locations color-coded to indicate speed. (22.97Mb)

Figure 7: Mean Velocity vectors calculated by grouping 6-hourly velocity values into ½ degree by ½ degree bins. (1.131Mb)

Figure 8: Eddy kinetic energy (cm²/sec²) estimated from drifter velocity variances in ½ degree by ½ degree bins. (1.215Mb)

Figure 9: Trajectories of 5 different drifters looping in and around anticyclone 1 during July 1999-January 2000. (784.4Kb)

Figure 10: Trajectories of two drifters looping in and around anticyclone 5. (705.8Kb)

Figure 11: Drifter trajectories in 28 cyclonic loopers (blue lines) and 29 anticyclonic loopers (red lines). (1.386Mb)

Figure 12: Trajectories of 19 cyclones (blue) and 19 anticyclones (red) inferred from looping drifter trajectories. (956.3Kb)

Figure 13: Meridional velocity profile of eastward velocity averaged by grouping individual velocities in ½ degree north-south bins in the central Caribbean (65-75ºW). (267.7Kb)

Figure 14: Locations of eastward drifter velocity components that are faster than 30 cm/sec, indicating regions of counterflows. (2.560Mb)

Figure 15: Number of looper days in the 10 main anticyclones in the eastern Caribbean. (292.7Kb)

Figure 16: Two drifters looping in a NBC ring that translated southwestward towards the islands of Guadeloupe (G), Dominica (D), and Martinique (M) during July-September 2000. (492.0Kb)

Figure 17: Summaries of four loopers in the cyclone (C) and four in the anticyclone (AC) of a cyclone-anticyclone pair southwest of Cuba, and four monthly plots of loopers in the cyclone (blue)--anticyclone (red) pair as they translated westward toward the Yucatan Current. (2.606Mb)

Date

2004-11-29

Author

Richardson, Philip L.

Metadata

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Citable URI

https://hdl.handle.net/1912/443

As published

https://doi.org/10.1016/j.dsr2.2004.11.001

Keyword

Surface drifters; Caribbean Current; Caribbean eddies; Eddies; North Brazil Current rings; Meridional overturning circulation; Intra-Americas Seas; Caribbean Sea; Colombia Basin; Venezuela Basin; Yucatan Basin; Antilles

Abstract

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 ½ 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 15ºN and 17ºN, 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.

Description

Author Posting. © The Author, 2004. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 52 (2005): 429-463, doi:10.1016/j.dsr2.2004.11.001.

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Physical Oceanography (PO)