Show simple item record

contributor authorBorn, Andreas
contributor authorStocker, Thomas F.
date accessioned2017-06-09T17:20:32Z
date available2017-06-09T17:20:32Z
date copyright2014/01/01
date issued2013
identifier issn0022-3670
identifier otherams-83509.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4226742
description abstracthe cyclonic circulation of the Atlantic subpolar gyre is a key mechanism for North Atlantic climate variability on a wide range of time scales. It is generally accepted that it is driven by both cyclonic winds and buoyancy forcing, yet the individual importance and dynamical interactions of the two contributions remain unclear. The authors propose a simplified four-box model representing the convective basin of the Labrador Sea and its shallow and deep boundary current system, the western subpolar gyre. Convective heat loss drives a baroclinic flow of relatively light water around the dense center. Eddy salt flux from the boundary current to the center increases with a stronger circulation, favors the formation of dense waters, and thereby sustains a strong baroclinic flow, approximately 10%?25% of the total. In contrast, when the baroclinic flow is not active, surface waters may be too fresh to convect, and a buoyancy-driven circulation cannot develop. This situation corresponds to a second stable circulation mode. A hysteresis is found for variations in surface freshwater flux and the salinity of the near-surface boundary current. An analytical solution is presented and analyzed.
publisherAmerican Meteorological Society
titleTwo Stable Equilibria of the Atlantic Subpolar Gyre
typeJournal Paper
journal volume44
journal issue1
journal titleJournal of Physical Oceanography
identifier doi10.1175/JPO-D-13-073.1
journal fristpage246
journal lastpage264
treeJournal of Physical Oceanography:;2013:;Volume( 044 ):;issue: 001
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record