eCite Digital Repository

Antarctic Circumpolar Current transport and barotropic transition at Macquarie Ridge

Citation

Rintoul, SR and Sokolov, S and Williams, M and Pena-Molino, B and Rosenberg, MA and Bindoff, NL, Antarctic Circumpolar Current transport and barotropic transition at Macquarie Ridge, Geophysical Research Letters, 41, (20) pp. 7254-7261. ISSN 0094-8276 (2014) [Refereed Article]


Preview
PDF
1Mb
  

Copyright Statement

Copyright 2014 American Geophysical Union

DOI: doi:10.1002/2014GL061880

Abstract

©2014. American Geophysical Union. All Rights Reserved. Theory and numerical simulations suggest that topographic interactions are central to the dynamics of the Antarctic Circumpolar Current (ACC), but few observations are available to test these ideas. We use direct velocity measurements, satellite altimetry, and an ocean state estimate to investigate the interaction of the ACC with the Macquarie Ridge. Satellite altimeter data show that the Subantarctic Front crosses the ridge through a gap immediately north of Macquarie Island. Yearlong current meter records reveal strong deep mean flow (>-0.2-m-s-1 at 3000-m) and substantial transport (52 ± 8 × 106-m3-s-1) in the 50-km wide gap. The ACC becomes much more barotropic at the ridge. Acceleration of the deep jet is balanced by the ageostrophic along-gap pressure gradient, convergence of zonal momentum by the mean vertical velocity, and dissipation. The study helps explain how the ACC negotiates large topographic obstacles and highlights the role of local, nonlinear processes in the dynamical balance of the ACC. Key Points Antarctic Circumpolar Current velocity was measured at Macquarie RidgeThe current becomes more barotropic as it crosses the ridgeLocal nonlinear processes accelerate deep jet

Item Details

Item Type:Refereed Article
Keywords:Antarctic Circumpolar Current, barotropic, Macquarie Ridge, Southern Ocean, topographic interaction, transport
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical Oceanography
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Marine Oceanic Processes (excl. climate related)
Author:Rintoul, SR (Dr Steve Rintoul)
Author:Sokolov, S (Dr Serguei Sokolov)
Author:Pena-Molino, B (Dr Beatriz Pena-Molino)
Author:Rosenberg, MA (Mr Mark Rosenberg)
Author:Bindoff, NL (Professor Nathan Bindoff)
ID Code:97455
Year Published:2014
Web of Science® Times Cited:5
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2014-12-17
Last Modified:2015-04-21
Downloads:146 View Download Statistics

Repository Staff Only: item control page