Large (roughly 300 km diameter) anticyclonically rotating eddies found in the slope waters to the north of the Gulf Stream, containing Sargasso Sea water in their core. They persist for several months, being trapped in the region between the Gulf Stream and the continental slope, occasionally interacting with the Gulf Stream and getting destroyed in the process. A warm-core ring is formed from a large-amplitude Gulf Stream meander that pinches off to the north, trapping relatively warm Sargasso Sea water from south of the Gulf Stream within its circumferential current. Compare cold-core rings; see Gulf Stream rings.