Bottom Water Circulation in the Western North Atlantic

Speer, Kevin G. and McCartney, Michael S. (1992) Bottom Water Circulation in the Western North Atlantic Journal of Physical Oceanography, 22 (1). pp. 83-92. DOI 10.1175/1520-0485(1992)022<0083:BWCITW>2.0.CO;2.

[img]
Preview
Text
1520-0485(1992)022_0083_bwcitw_2.0.co;2.pdf - Published Version

Download (720Kb) | Preview

Supplementary data:

Abstract

Antarctic Bottom Water flows into the western North Atlantic across the equator, shifting from the western side to the eastern side of the trough between the American continents and the Mid-Atlantic Ridge as it continues north. This is puzzling because such large-scale motion is thought to be controlled by dynamics that disallows an eastern boundary current. Previous explanations for the transposition involve a (necessarily small-scale) density current that changes sides because of the change in sign of rotation across the equator, or a topographic effect that changes the sign of the effective mean vorticity gradient and thus requires an eastern boundary current. Here an alternative explanation for the overall structure of bottom flow is given.

A source of mass to a thin bottom layer is assumed to upwell uniformly across its interface into a less dense layer at rest. A simple formula for the magnitude of the upwelling and thickness of the layer is derived that depends on the source strength to the bottom layer. For a strong enough source, the bottom layer thickness is zero along a grounding curve that separates the bottom water from the western boundary and confines it to the east. A band of recirculating interior flow occurs, supplied by an isolated northern and western boundary current. Similar structures appear to exist in the Antarctic Bottom Water of the western North Atlantic.

Document Type: Article
Research affiliation: OceanRep > Institute for Marine Science Kiel
Refereed: Yes
DOI etc.: 10.1175/1520-0485(1992)022<0083:BWCITW>2.0.CO;2
ISSN: 0022-3670
Date Deposited: 09 Mar 2018 12:59
Last Modified: 09 Mar 2018 12:59
URI: http://eprints.uni-kiel.de/id/eprint/42209

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...