Topographic control of Southern Ocean gyres and the Antarctic Circumpolar Current: a barotropic perspective

In the Southern Ocean the Antarctic Circumpolar Current is significantly steered by large topographic features, and sub-polar gyres form in their lee. The geometry of topographic features in the Southern Ocean is highly variable, but the influence of this variation on the large-scale flow is poorly understood. Using idealised barotropic simulations of a zonal channel with a meridional ridge, it is found that the ridge geometry is important for determining the net zonal volume transport. A relationship is observed between ridge width and volume transport that is determined by the form stress generated by the ridge. Gyre formation is also highly reliant on the ridge geometry. A steep ridge allows gyres to form within regions of unblocked geostophic ( f /H) contours, with an increase in gyre strength as the ridge width is reduced. These relationships between ridge width, gyre strength, and net zonal volume transport emerge in order to simultaneously satisfy the conservation of momentum and vorticity.

Details

Publication status:
Published
Author(s):
Authors: Patmore, Ryan D., Holland, Paul R. ORCIDORCID record for Paul R. Holland, Munday, David R. ORCIDORCID record for David R. Munday, Naveira Garabato, Alberto C., Stevens, David P., Meredith, Michael P. ORCIDORCID record for Michael P. Meredith

On this site: Dave Munday, Michael Meredith, Paul Holland, Ryan Patmore
Date:
1 December, 2019
Journal/Source:
Journal of Physical Oceanography / 49
Page(s):
3221-3244
Digital Object Identifier (DOI):
https://doi.org/10.1175/JPO-D-19-0083.1