The Open UniversitySkip to content
 

Transport and variability of the Antarctic Circumpolar Current in Drake Passage

Cunningham, S. A.; Alderson, S. G.; King, B. A. and Brandon, M. A. (2003). Transport and variability of the Antarctic Circumpolar Current in Drake Passage. Journal of Geophysical Research: Oceans, 108(C5) pp. 1–17.

URL: http://www.agu.org/pubs/crossref/2003/2001JC001147...
DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1029/2001JC001147
Google Scholar: Look up in Google Scholar

Abstract

The baroclinic transport of the Antarctic Circumpolar Current (ACC) above 3000 m through Drake Passage is 107.3 ± 10.4 Sv and has been steady between 1975 and 2000. For six hydrographic sections (1993–2000) along the World Ocean Circulation Experiment (WOCE) line SR1b, the baroclinic transport relative to the deepest common level is 136.7 ± 7.8 Sv. The ACC transport is carried in two jets, the Subantarctic Front 53 ± 10 Sv and the Polar Front (PF) 57.5 ± 5.7 Sv. Southward of the ACC the Southern Antarctic Circumpolar Current transports 9.3 ± 2.4 Sv. We observe the PF at two latitudes separated by 90 km. This bimodal distribution is related to changes in the circulation and properties of Antarctic Bottom Water. Three realizations of the instantaneous velocity field were obtained with lowered ADCPs. From these observations we obtain near-bottom reference velocities for transport calculations. Net transport due to these reference velocities ranges from −28 to 43 Sv, consistent with previous estimates of variability. The transport in density layers shows systematic variations due to seasonal heating in near-surface layers. Volume transport-weighted mean temperatures vary by 0.40°C from spring to summer; a seasonal variation in heat flux of about 0.22 PW. Finally, we review a series of papers from the International Southern Ocean Studies Program. The average yearlong absolute transport is 134 Sv, and the standard deviation of the average is 11.2 Sv; the error of the average transport is 15 to 27 Sv. We emphasize that baroclinic variability is an important contribution to net variability in the ACC.

Item Type: Journal Article
ISSN: 0148-0227
Extra Information: Article # 8084
Keywords: Antarctic Circumpolar Current; hydrography; acoustic Doppler current profiler; transport; ADCP; Antarctica
Academic Unit/Department: Science > Environment, Earth and Ecosystems
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 10589
Depositing User: Mark Brandon
Date Deposited: 16 Apr 2008
Last Modified: 02 Dec 2010 20:07
URI: http://oro.open.ac.uk/id/eprint/10589
Share this page:

Altmetrics

Scopus Citations

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340   general-enquiries@open.ac.uk