Modification and pathways of Southern Ocean Deep Waters in the Scotia Sea

Garabato, Alberto C. Naveira; Heywood, Karen J.; Stevens, David P.

doi:10.1016/s0967-0637(01)00071-1

Cited by 161 publications

(128 citation statements)

References 35 publications

Supporting

Mentioning

108

Contrasting

Order By: Relevance

“…It lies directly downstream of Orkney Passage, the main gap in the South Scotia Ridge through which AABW flows into the Scotia Sea (Naveira Garabato et al 2002b;Nowlin and Zenk 1988), and a sufficient distance downstream of the AABW source regions for the substantial seasonal signal in outflow speed and properties (Gordon et al 2010) to be largely eroded. AABW is always present at the southern end of the section, typically occupying the bottom 500-1000 m of the water column south of the Polar Front (Fig.…”

Section: Freshening Of Aabwmentioning

confidence: 99%

“…First, a change in the balance of the rates of AABW export through the different deep passages in the South Scotia Ridge, where thermohaline characteristics differ on isopycnals (Naveira Garabato et al 2002a), could result in modified AABW properties north of the ridge. In the absence of sustained observations across all of the passages, assessing variations in export routes is difficult.…”

Section: Freshening Of Aabwmentioning

confidence: 99%

“…In the absence of sustained observations across all of the passages, assessing variations in export routes is difficult. Nonetheless, the analysis of a recent repeat of a section of hydrographic and velocity measurements along the South Scotia Ridge in 2010 [L. Jullion et al (2013), manuscript in preparation] shows no evidence of significant change relative to a section occupation in 1999 (Naveira Garabato et al 2002b). Perturbations in wind forcing are also thought to influence the export of AABW over the Scotia Ridge (Jullion et al 2010) on interannual and longer time scales.…”

Section: Freshening Of Aabwmentioning

confidence: 99%

“…The WSDW formed near the Larsen ice shelves (LIS) in the western Weddell Sea (Fig. 1b) is generally lighter and fresher than the AABW formed farther south (Fahrbach et al 1995;Gordon et al 2001;Huhn et al 2008;Gordon et al 2010) and is preferentially exported toward the Scotia Sea through several deep gaps in the South Scotia Ridge (SSR; Naveira Garabato et al 2002b). …”

mentioning

confidence: 99%

See 3 more Smart Citations

Decadal Freshening of the Antarctic Bottom Water Exported from the Weddell Sea

et al. 2013

View full text Add to dashboard Cite

Recent decadal changes in Southern Hemisphere climate have driven strong responses from the cryosphere. Concurrently, there has been a marked freshening of the shelf and bottom waters across a wide sector of the Southern Ocean, hypothesized to be caused by accelerated glacial melt in response to a greater flux of warm waters from the Antarctic Circumpolar Current onto the shelves of West Antarctica. However, the circumpolar pattern of changes has been incomplete: no decadal freshening in the deep layers of the Atlantic sector has been observed. In this study, the authors document a significant freshening of the Antarctic Bottom Water exported from the Weddell Sea, which is the source for the abyssal layer of the Atlantic overturning circulation, and trace its possible origin to atmospheric-forced changes in the ice shelves and sea ice on the eastern flank of the Antarctic Peninsula that include an anthropogenic component. These findings suggest that the expansive and relatively cool Weddell gyre does not insulate the bottom water formation regions in the Atlantic sector from the ongoing changes in climatic forcing over the Antarctic region.

show abstract

Section: Freshening Of Aabwmentioning

confidence: 99%

Section: Freshening Of Aabwmentioning

confidence: 99%

Section: Freshening Of Aabwmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Decadal Freshening of the Antarctic Bottom Water Exported from the Weddell Sea

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The ALBATROSS (Antarctic large-scale box analysis and the role of the Scotia Sea) project 21 was designed to quantify the¯ow of water into and out of the Scotia Sea, particularly the deep, dense water that is formed in the Weddell Sea and provides the cold layers at the bottom of much of the world ocean. A quasi-synoptic box of densely spaced stations measuring temperature, salinity and current velocity was completed around the Scotia Sea (Fig.…”

mentioning

confidence: 99%

High mixing rates in the abyssal Southern Ocean

Heywood

Garabato

Stevens

2002

Nature

104

107

View full text Add to dashboard Cite

Mixing of water masses from the deep ocean to the layers above can be estimated from considerations of continuity in the global ocean overturning circulation. But averaged over ocean basins, diffusivity has been observed to be too small to account for the global upward flux of water, and high mixing intensities have only been found in the restricted areas close to sills and narrow gaps. Here we present observations from the Scotia Sea, a deep ocean basin between the Antarctic peninsula and the tip of South America, showing a high intensity of mixing that is unprecedented over such a large area. Using a budget calculation over the whole basin, we find a diffusivity of (39 +/_ 10) x 104 m2 s-1, averaged over an area of 7 x 105 km2. The Scotia Sea is a basin with a rough topography, situated just east of the Drake passage where the strong flow of the Antarctic Circumpolar Current is constricted in width. The high basin-wide mixing intensity in this area of the Southern Ocean may help resolve the question of where the abyssal water masses are mixed towards the surface

show abstract

Deep boundary current disintegration in Drake Passage

Brearley

Sheen

Garabato

et al. 2014

Geophysical Research Letters

View full text Add to dashboard Cite

The fate of a deep boundary current that originates in the Southeast Pacific and flows southward along the continental slope of South America is elucidated. The current transports poorly ventilated water of low salinity (a type of Pacific Deep Water, PDW), into Drake Passage. East of Drake Passage, the boundary current breaks into fresh anticyclonic eddies, nine examples of which were observed in mooring data from December 2009 to March 2012. The observed eddies appear to originate mainly from a topographic separation point close to 60°W, have typical diameters of 20-60 km and accompanying Rossby numbers of 0.1-0.3. These features are likely to be responsible for transporting PDW meridionally across the Antarctic Circumpolar Current, explaining the near homogenization of Circumpolar Deep Water properties downstream of Drake Passage. This mechanism of boundary current breakdown may constitute an important process in the Southern Ocean overturning circulation.

show abstract

Modification and pathways of Southern Ocean Deep Waters in the Scotia Sea

Cited by 161 publications

References 35 publications

Decadal Freshening of the Antarctic Bottom Water Exported from the Weddell Sea

Decadal Freshening of the Antarctic Bottom Water Exported from the Weddell Sea

High mixing rates in the abyssal Southern Ocean

Deep boundary current disintegration in Drake Passage

Contact Info

Product

Resources

About