Interaction of a Warm Ring with the Western Slope in the Gulf of Mexico

Abstract

Between November 1985 and May 1986, a warm ring encountered the western slope in the Gulf of Mexico, moved away from the slope, and began to dissipate. Before encountering the slope, the ring was quasi-circular. After encountering the slope, it became elliptically shaped with a center of circulation that changed position rapidly and erratically. The major axis of the ring rotated rapidly in a clockwise sense as the ring increased in size, most probably through interaction with two other rings in the western Gulf. During this period, neither satellite nor in situ data indicated large-scale exchange of shelf and ring water. When the ring moved eastward, then southward, away from the slope, it was observed to decrease in size by a factor of 3 to 5; the upper layer manifestation of the ring had weakened considerably. To the north of the center of the ring was a cyclonic feature which was apparently coupled to the ring and remained so throughout the period examined. The cyclone was quasi-circular and baroclinic. Its a real dimensions and position relative to the warm ring did not change appreciably.