THE EDDY FIELD OF THE SOUTHEAST ATLANTIC-OCEAN - A STATISTICAL CENSUSFROM THE BENGUELA SOURCES AND TRANSPORTS PROJECT

Data collected during the Benguela Sources and Transports project were examined to determine some statistical properties of the eddy field o bserved in the Cape Basin. Seven anticyclonic eddies were encountered during the hydrographic surveys. Two of these were shown to be of Braz il Current origin (this paper and Smythe-Wright Et al. [1996]). Invert ed echosounder (IES) records of acoustic travel time were scaled to th e depth of the thermocline, represented in the Cape Basin by the 10 de grees C isotherm. These records indicate that a minimum of four to six eddies, assumed to be of Agulhas origin, entered the Cape Basin per y ear during the sampling period. They were associated with depressions in the 10 degrees C isotherm records ranging from 100 to 400 m and of a duration between 30 and 100 days. The thermocline appears to shallow appreciably after the passage of an eddy before relaxing to the local mean. Estimates of the heat and salt contents of the hydrographically surveyed eddies indicated that the mean available heat and salt anoma lies of the eddies were 0.55 x 10(20) J and 3.5 x 10(12) kg, respectiv ely. Extrapolating the hydrographic data to the eddies detected in the IES record shows the eddy field responsible for the transfer of 2.2 t o 3.3 x 10(20) J yr(-1) (0.007 PW), 14 to 21 x 10(12) kg salt yr(-1), and 2.6 to 3.8 x 10(6) m(3) s(-1).