The Model Study of the Wind Stress Impact to the Interannual Variability of the Antarctic Circumpolar Current South of Australia

Abstract

The interannual variability of the Antarctic Circumpolar Current (ACC) in the region south of Australia is studied on the base of numerical simulations performed with the use of the Argo-based model for Investigation of the Global Ocean (AMIGO). The model consists of a block for variational interpolation to a regular grid of Argo floats data and a block for model hydrodynamic adjustment of variationally interpolated fields. The mean ACC transport for the period of 2005–2014 through the Australia-Antarctica section was estimated at 178±6 Sv (1 Sv = 106m3/с-1). Additional numerical experiments were carried out in order to study the contribution of the wind forcing to the interannual variability of the ACC transport: the real thermohaline fields corresponding to the particular time period were replaced by climatic ones (1) and by replacing the real wind forcing data with the climatic ones (2). Analysis of the numerical experiments results has shown that the variable wind stress forcing is the key factor determining the interannual variability of the ACC transport through the Australia-Antarctica section.