AN ACC MONITORING PROGRAM IN THE UDINTSEV FRACTURE ZONE IN THE SOUTHERN PACIFIC

Abstract

A field experiment in the Udintsev fracture zone (UFZ) in the South Pacific Ocean to monitor Antarctic Circumpolar Current (ACC), the world largest current, is in works. The UFZ, which separates the Pacific-Antarctic Ridge, is a narrow pathway for the deep ACC thus is a convenenient place to observe the meridional ACC structure. The main objective is to determine the seasonal and interannual variability of the total ACC transport purposes and to see the caracteristics of vertical current structure. Other objective is to estimate southward heat flux especially across the Southern ACC Front (SACCF). The experimental set-up is designed to use the complementarity between Lagrangian and Eulerian time-series measurements. Main tasks are the deployment of a current meter mooring array across the SACCF and of deep ARGO floats in the UFZ as well as CTD/LADCP castings. The deployment of Pressure Inverted Echo Sounder (PIES) moorings and of surface floats is also under consideration to be included.