Deciphering the pathways for the deep limb of the Meridional Overturning Circulation
For the past 50 years it has been assumed that the principal pathway for the deep limb of the Atlantic Meridional Overturning Circulation (AMOC) is the Deep Western Boundary Current (DWBC). However, recent observations of Lagrangian floats have shown that the DWBC is not necessarily a unique, dominant, or continuous pathway for these deep waters. A significant portion of the deep water export from the subpolar to the subtropical gyres follows a pathway through the interior of the Newfoundland and subtropical basins, which is constrained by the western boundary and the western flank of the Mid-Atlantic Ridge. The hypothesis that deep eddy-driven recirculation gyres are a mechanism for partitioning the deep limb of the AMOC into the DWBC and this interior pathway is investigated here. Eulerian and Lagrangian analyses of the output of ocean general circulation models at eddy-resolving, eddy-permitting, and non-eddy permitting resolutions are used to test this hypothesis. Eddy-driven recirculation gyres, simulated in the eddy-resolving and eddy-permitting models and similar to recirculations inferred from hydrographic data, are shown to shape the export pathways of deep water from the subpolar to the subtropical gyres. © 2011 Elsevier Ltd.
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Related Subject Headings
- Oceanography
- 3708 Oceanography
- 3103 Ecology
- 0602 Ecology
- 0405 Oceanography
- 0402 Geochemistry
Citation
Published In
DOI
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Oceanography
- 3708 Oceanography
- 3103 Ecology
- 0602 Ecology
- 0405 Oceanography
- 0402 Geochemistry