Submesoscale coherent vortices
From AMS Glossary
submesoscale coherent vortices
(Abbreviated SCV.) Isolated, long-lived eddies, having spatial scales smaller than mesoscale eddies; usually anticyclonic, having a geopotential maximum and stratification minimum in the center, with a velocity field having an interior maximum.
McWilliams, J. C. 1985. Submesoscale, coherent vortices in the ocean. Rev. Geophys.. 23. 165–182.