The sinking of warm-core rings.

Abstract

Examines the dynamics of a warm core ring that becomes denser than the surrounding fluid. The model consists of three layers, a shallow upper layer or mixed layer, an infinitely deep bottom layer and a zero potential vorticity layer (ring itself). Initially the ring is lighter (but more saline) than the shallow mixed layer, but is cooled to become heavier. Fluid is assumed Boussinesq. Constructs analytic solutions for both a surfaced ring and a submerged ring. Presents typical interface and velocity profiles, and calculates the trajectory of a mixed layer parcel during ring submergence. The model predicts that overwashing is complete when the ring sinks (through the overwashing layer is thin near the centre). Distinguishes between cooling the ring and warming the environmental fluid. Accounts for the formation of streamers and the entrainment of organisms.