On the effective capacity of the dense-water reservoir for the Nordic Seas overflow : some effects of topography and wind stress
MetadataShow full item record
KeywordBottom currents; Drainage flow; Meridional overturning circulation; Ocean dynamics; Potential vorticity; Topographic effects
The overflow of the dense water mass across the Greenland–Scotland Ridge (GSR) from the Nordic Seas drives the Atlantic meridional overturning circulation (AMOC). The Nordic Seas is a large basin with an enormous reservoir capacity. The volume of the dense water above the GSR sill depth in the Nordic Seas, according to previous estimates, is sufficient to supply decades of overflow transport. This large capacity buffers overflow’s responses to atmospheric variations and prevents an abrupt shutdown of the AMOC. In this study, the authors use a numerical and an analytical model to show that the effective reservoir capacity of the Nordic Seas is actually much smaller than what was estimated previously. Basin-scale oceanic circulation is nearly geostrophic and its streamlines are basically the same as the isobaths. The vast majority of the dense water is stored inside closed geostrophic contours in the deep basin and thus is not freely available to the overflow. The positive wind stress curl in the Nordic Seas forces a convergence of the dense water toward the deep basin and makes the interior water even more removed from the overflow-feeding boundary current. Eddies generated by the baroclinic instability help transport the interior water mass to the boundary current. But in absence of a robust renewal of deep water, the boundary current weakens rapidly and the eddy-generating mechanism becomes less effective. This study indicates that the Nordic Seas has a relatively small capacity as a dense water reservoir and thus the overflow transport is sensitive to climate changes.
Author Posting. © American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 43 (2013): 418–431, doi:10.1175/JPO-D-12-087.1.
Suggested CitationArticle: Yang, Jiayan, Pratt, Lawrence J., "On the effective capacity of the dense-water reservoir for the Nordic Seas overflow : some effects of topography and wind stress", Journal of Physical Oceanography 43 (2013): 418–431, DOI:10.1175/JPO-D-12-087.1, https://hdl.handle.net/1912/5851
Showing items related by title, author, creator and subject.
Effects of an allelochemical in Phaeodactylum tricornutum filtrate on Heterosigma akashiwo : morphological, physiological and growth effects Wang, Rui; Xue, Qiaona; Wang, Jiangtao; Tan, Liju; Zhang, Qingchun; Zhao, Yue; Anderson, Donald M. (2017-08)The effects of an allelochemical extracted from the culture filtrate of diatom Phaeodactylum tricornutum on the raphidophyte Heterosigma akashiwo were investigated using a series of morphological, physiological and ...
Interactions among resource partitioning, sampling effect, and facilitation on the biodiversity effect : a modeling approach Flombaum, Pedro; Sala, Osvaldo E.; Rastetter, Edward B. (2013-08-21)Resource partitioning, facilitation, and sampling effect are the three mechanisms behind the biodiversity effect, which is depicted usually as the effect of plant-species richness on aboveground net primary production. ...
Snail grazing effects on the composition and metabolism of benthic diatom communities and subsequent effects on fish growth Connor, Michael Stewart (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1980-06)Eastern mud snails (Ilyanassa obsoleta) in densities of zero, six or twelve snails were placed in flow-through-laboratory microcosms (765 cm2) and incubated for five weeks. Other tanks were raked daily to a depth of 10 ...