How long do cold-core Gulf Stream rings usually last?

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Map of the North Atlantic Ocean showing major ocean currents, with warm currents like the Gulf Stream and North Atlantic Drift highlighted in pink and cold currents in blue. Arrows indicate current directions and relative speeds, connecting the eastern coasts of North America, the western coasts of Europe and Africa, and the Arctic region. — Gulf Stream Major warm and cold currents of the North Atlantic Ocean.

Cold-core Gulf Stream rings typically have a lifetime of one to two years.1

These rings are formed when meanders in the current pinch off to the south of the Gulf Stream. They are characterized by a counterclockwise rotation and diameters ranging from 200 to 300 km (124 to 186 miles). Composed of a mixture of Gulf Stream and continental slope waters, these rings generally move southwestward into the Sargasso Sea. They are more numerous than warm-core rings, with approximately 10 cold-core rings forming each year.1