Evaluating Southern Ocean response to wind forcing

In order to investigate how the Antarctic Circumpolar Current (ACC) respond s to changes in wind forcing, cross coherences are calculated between South ern Ocean winds and bottom pressure measurements from either side of Drake Passage. Wind stress and wind-stress curl are derived from the European Res earch Satellites (ERS) scatterometers, from the Special Sensor Microwave Im ager (SSMI), and from the European Centre for Medium-Range Weather Forecast s (ECMWF) forecast model. Winds and bottom pressure measurements both show substantial variability on all resolved time scales. Statistically signific ant coherences occur over the full range of resolved frequencies for both w ind stress and wind-stress curl. The largest number of statistically cohere nt frequencies occur between the bottom pressure at the south side of Drake Passage and wind stress. Phases are consistent with wind slightly leading bottom pressure, and strong winds driving strong transport. (C) 1999 Elsevi er Science Ltd. All rights reserved.