North Brazil Current Ring Collisions With the Lesser Antilles
Abstract
The earth's largest ocean rings are spawned near 8°N in the western tropical Atlantic from the equator-crossing North Brazil Current (NBC). NBC rings, which can exceed 450 km in diameter and 2000 m in vertical extent, translate northwestward parallel to the South American coastline until they collide with the Lesser Antilles in the southeastern Caribbean Sea. The rings entrain filaments of nutrient- and sediment-rich Amazon and Orinoco River discharge, impact the distribution of icthyoplankton, and pose a physical threat to expanding offshore oil and gas exploration. The six rings generated annually are also responsible for up to one-third of the equatorial-to-subtropical mass and heat transport associated with the Atlantic meridional overturning circulation, a fundamental component of the earth climate system. Recent RAFOS float and surface drifter trajectories illustrate the translation and structural evolution of several NBC rings and enable the determination of the downstream fate of South Atlantic water trapped within the ring core. These results indicate that NBC rings do not enter the Caribbean Sea intact as simulated by numerical ocean models but are instead sheared apart through topographic interaction along the eastern flank of the Lesser Antilles.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFMOS52D0249F
- Keywords:
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- 4512 Currents;
- 4520 Eddies and mesoscale processes;
- 4576 Western boundary currents