A three-dimensional model study of warm core ring interaction with continental shelf and slope

The interaction of warm core rings with a western wall and shelf/slope is examined with a three-dimensional primitive-equation model. The model ring is initialized with an axisymmetric Gaussian-type anticyclonic eddy placing far from the coastal boundary to allow the ring to freely propagate towards the wall and shelf/slope. The ring initially propagates steadily to the southwest at about 3 km/day under the combined planetary β and nonlinear effects. When colliding with a wall, the ring adjusts into a ‘D’ shape and moves poleward under primarily the image effect. When colliding with a shelf and slope, the ring however becomes stalled and bounces on and off the shelf/slope with little net movement. Small cyclones marked by strong upwelling are generated near the shelfbreak. Cyclones and anticyclones also are spawned at the periphery of the ring. Satellite SST images and concurrent ADCP transects are used to illustrate the strong interaction of a Gulf Stream warm ring (99B) with the Middle Atlantic Bight.