Characteristics of an agulhas rings

Abstract

Hydrographic data, SSH from altimetry, thermosalinometer and drifters measurements were acquired along an Agulhas ring during March 2010. Hydrographic survey and drifters deployment were done 5 months after the ring formation. The ring is clearly visible from altimetry and salinity from thermosalinometer data since the surface properties in the core are different from those of the surrounding waters. The structure observed with a high geostrophic velocity of 30 cm s-1 and mass transport of 28 Sv in the surface layers, which shows a counterclockwise rotation. The trajectory is northeastward with a translation speed of 13 cm s-1, a rotating period of 8 days and a mean radius of 140 km.