The control of the Southern Hemisphere Westerlies on the position of the Subtropical Front

• DOI: 10.1002/jgrc.20407
• Publication Date: 2013-10-12T01:34:07Z
• Authors: Agatha M. De Boer; Robert M. Graham; Matthew D. Thomas; Karen E. Kohfeld
• Keywords: Westerlies

[1] In recent years the latitudinal position of Subtropical Front (STF) has emerged as a key parameter in global climate. A poleward positioned front is thought to allow greater salt flux from Indian Atlantic Ocean and so drive stronger Meridional Overturning Circulation. Here common view that STF aligns with zero wind stress curl (WSC) challenged. Based on climatologies Orsi et al. (1995), Belkin Gordon (1996), Graham De Boer (2013), satellite scatterometry winds, we find WSC contour lies average ∼10°, ∼8°, ∼5° for three climatologies, respectively. The circulation region between Gyres not forced by but rather strong bottom pressure torque result interaction Antarctic Circumpolar Current ocean floor topography. actual control crucially dependent whether regarded simply surface water mass boundary or dynamical front. For Agulhas Leakage problem, southern so-called Super Gyre may be most relevant property this cannot easily identified observations.