Impacts of wind stress on the Antarctic Circumpolar Current fronts and associated subduction
Article first published online: 14 JUN 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 11, June 2011
How to Cite
2011), Impacts of wind stress on the Antarctic Circumpolar Current fronts and associated subduction, Geophys. Res. Lett., 38, L11605, doi:10.1029/2011GL047668., , , and (
- Issue published online: 14 JUN 2011
- Article first published online: 14 JUN 2011
- Manuscript Accepted: 9 MAY 2011
- Manuscript Revised: 7 MAY 2011
- Manuscript Received: 4 APR 2011
- Antacrtic Circumpolar Current;
- Southern Ocean;
- wind stress
 Recent studies suggest that the overturning circulation in the Antarctic Circumpolar Current (ACC) region shows a weak sensitivity to overlying wind stress changes, due to balancing of changes in the eddy-induced and Eulerian mean transports. Using an eddy-permitting coupled climate model, we analyze the response of the ACC transport, and associated water mass subduction rates, in response to an idealized poleward shift and intensification of the westerlies. As in previous studies, we find a small increase in the net ACC transport, and a poleward shift in the mean position of the ACC flow. However, the ACC is restructured, with the Subantarctic Front (SAF) and Polar Front (PF) branches shifting poleward by between 0.9° and 2.5° of latitude, resulting in a weaker ACC flow in both the SAF and PF zones. The wind stress anomaly drives a stronger northward Ekman transport of cool surface waters, deepening the winter mixed layer and causing a 12.7 Sv increase in the subduction of Subantarctic Mode Water (SAMW) north of the SAF zone and a 6.5 Sv increase in the subduction of Antarctic Intermediate Water (AAIW) within the SAF and PF zones. Our results suggest that changes in the wind stress restructure the Southern Ocean large-scale circulation, including the flow of the ACC in its primary jets, and that this affects the formation rates of SAMW and AAIW in this complex region.