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Abstract

The large-scale volume, heat, and freshwater ocean transports in the Southern Hemisphere are investigated
using time-averaged output from a seasonless, high-resolution general circulation model. The ocean
circulation is realistic, and property transports are comparable to observations. The Antarctic Circumpolar
Current (ACC) carries 144 Sv (Sv 106 m3 s1) of water eastward across Drake Passage, increasing to 155
Sv south of Australia because of the Indonesian Throughflow (ITF). There is a clear Indo-Pacific gyre
around Australia exchanging 10 Sv, 0.9 PW of heat, and 0.2 Sv of freshwater through the ITF, and there
is a 9-Sv leakage from the Tasman Sea to the Indian Ocean. The transport of heat and freshwater by eddies
is localized to the upper 1000 m of the water column and specific regions, such as western boundary
currents, confluences, and the subantarctic front (SAF). Eddy transport of heat and freshwater is negligible
in gyre interiors and south of the SAF but is vital across the northern edge of the ACC, in particular at the
Agulhas Retroflection where eddies accomplish almost 100% of the net ocean heat and 60% of the
southward freshwater transport. The eddy transport is almost zero across the latitude of Drake Passage
while in a quasi-Lagrangian frame eddy transports are significant across the ACC but surprisingly are still
smaller than the mean transport of heat. Mean and eddy property transport divergences are found to be
strongly compensating in areas of high eddy activity. This is caused by increased baroclinic instability in
strong mean flows, which induces an opposing eddy transport. This relationship is observed to be stronger
in the case of horizontal heat transport than in corresponding horizontal freshwater transports.

Item Type:	Article
Authors/Creators:	Meijers, AJ and Bindoff, NL and Roberts, JL
Journal or Publication Title:	Journal of Physical Oceanography
Publisher:	American Meteorological Society
ISSN:	0022-3670
DOI / ID Number:	10.1175/JPO3012.1
Additional Information:	Copyright 2007 AMS. Full copyright information is available at http://www.ametsoc.org/pubs/copyrightinfo/AMS_Copyright_Policy_2001_final.pdf
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