scholarly journals Variability of the Lower Circumpolar Deep Water in Drake Passage 1926–2004

2006 ◽  
Vol 33 (3) ◽  
Author(s):  
Adam Williams ◽  
Sheldon Bacon ◽  
Stuart Cunningham
Keyword(s):  
Deep Water ◽  
Drake Passage ◽  
Circumpolar Deep Water ◽  
Lower Circumpolar Deep Water

scholarly journals Bottom water warming along the pathway of lower circumpolar deep water in the Pacific Ocean

2006 ◽  
Vol 33 (23) ◽  
Author(s):  
Takeshi Kawano ◽  
Masao Fukasawa ◽  
Shinya Kouketsu ◽  
Hiroshi Uchida ◽  
Toshimasa Doi ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Deep Water ◽  
Bottom Water ◽  
Circumpolar Deep Water ◽  
The Pacific ◽  
Lower Circumpolar Deep Water ◽  
The Pacific Ocean

Deep flow in the Madagascar–Mascarene Basin over the last 150000 years

2005 ◽  
Vol 363 (1826) ◽  
pp. 81-99 ◽  
Author(s):  
I. N. McCave ◽  
T. Kiefer ◽  
D. J. R. Thornalley ◽  
H. Elderfield
Keyword(s):  
Southern Ocean ◽  
Water Flow ◽  
Deep Water ◽  
Last Interglacial ◽  
Circumpolar Deep Water ◽  
The North ◽  
Bottom Waters ◽  
Lower Circumpolar Deep Water ◽  
Sw Indian Ocean ◽  
Fast Flow

The SW Indian Ocean contains at least four layers of water masses with different sources: deep Antarctic (Lower Circumpolar Deep Water) flow to the north, midwater North Indian Deep Water flow to the south and Upper Circumpolar Deep Water to the north, meridional convergence of intermediate waters at 500–1500 m, and the shallow South Equatorial Current flowing west. Sedimentation rates in the area are rather low, being less than 1 cm ka −1 on Madagascar Ridge, but up to 4 cm ka −1 at Amirante Passage. Bottom flow through the Madagascar–Mascarene Basin into Amirante Passage varies slightly on glacial–interglacial time–scales, with faster flow in the warm periods of the last interglacial and minima in cold periods. Far more important are the particularly high flow rates, inferred from silt grain size, which occur at warm–to–cold transitions rather than extrema. This suggests the cause is changing density gradient driving a transiently fast flow. Corroboration is found in the glacial–interglacial range of benthic d 18 O which is ca. 2%, suggesting water close to freezing and at least 1.2 more saline and thus more dense glacial bottom waters than present. Significant density steps are inferred in isotope stage 6, the 5e–5d, and 5a–4 transitions. Oxygen isotope data suggest little change by mixing in glacial bottom water on their northward path. Benthic carbon isotope ratios at Amirante Passage differ from glacial Southern Ocean values, due possibly to absence of a local productivity effect present in the Southern Ocean.

Lower Circumpolar Deep Water Flow Through the SW Pacific Gateway for the Last 190 Ky: Evidence from Antarctic Diatoms

2013 ◽  
pp. 101-116 ◽  
Author(s):  
Catherine E. Stickley ◽  
Lionel Carter ◽  
I. Nick Mccave ◽  
Phil P.E. Weaver
Keyword(s):  
Water Flow ◽  
Deep Water ◽  
Circumpolar Deep Water ◽  
Sw Pacific ◽  
Lower Circumpolar Deep Water ◽  
Flow Through ◽  
Antarctic Diatoms

scholarly journals Baroclinic Transport Time Series of the Antarctic Circumpolar Current Measured in Drake Passage

2014 ◽  
Vol 44 (7) ◽  
pp. 1829-1853 ◽  
Author(s):  
María Paz Chidichimo ◽  
Kathleen A. Donohue ◽  
D. Randolph Watts ◽  
Karen L. Tracey
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
Deep Water ◽  
Antarctic Circumpolar Current ◽  
Drake Passage ◽  
Polar Front ◽  
Intermediate Water ◽  
Circumpolar Deep Water ◽  
Circumpolar Current ◽  
Baroclinic Transport

Abstract The first multiyear continuous time series of Antarctic Circumpolar Current (ACC) baroclinic transport through Drake Passage measured by moored observations is presented. From 2007 to 2011, 19 current- and pressure-recording inverted echo sounders and 3 current-meter moorings were deployed in Drake Passage to monitor the transport during the cDrake experiment. Full-depth ACC baroclinic transport relative to the bottom has a mean strength of 127.7 ± 1.0 Sverdrups (Sv; 1 Sv ≡ 106 m3 s−1) with a standard deviation of 8.1 Sv. Mean annual baroclinic transport is remarkably steady. About 65% of the baroclinic transport variance is associated with time periods shorter than 60 days with peaks at 20 and 55 days. Nearly 28% of apparent energy in the spectrum computed from transport subsampled at the 10-day repeat cycle of the Jason altimeter results from aliasing of high-frequency signals. Approximately 80% of the total baroclinic transport is carried by the Subantarctic Front and the Polar Front. Partitioning the baroclinic transport among neutral density γn layers gives 39.2 Sv for Subantarctic Surface Water and Antarctic Intermediate Water (γn < 27.5 kg m−3), 57.5 Sv for Upper Circumpolar Deep Water (27.5 < γn < 28.0 kg m−3), 27.7 Sv for Lower Circumpolar Deep Water (28.0 < γn < 28.2 kg m−3), and 3.3 Sv for Antarctic Bottom Water (γn > 28.2 kg m−3). The transport standard deviation in these layers decreases with depth (4.0, 3.1, 2.1, and 1.1 Sv, respectively). The transport associated with each of these water masses is statistically steady. The ACC baroclinic transport exhibits considerable variability and is a major contributor to total ACC transport variability.

scholarly journals Warm Circumpolar Deep Water at the Western Getz Ice Shelf Front, Antarctica

2019 ◽  
Vol 46 (2) ◽  
pp. 870-878 ◽  
Author(s):  
K. M. Assmann ◽  
E. Darelius ◽  
A. K. Wåhlin ◽  
T. W. Kim ◽  
S. H. Lee
Keyword(s):  
Deep Water ◽  
Ice Shelf ◽  
Circumpolar Deep Water

Thermohaline suppression of Upper Circumpolar Deep Water eddies in the Ross Gyre

2021 ◽  
Author(s):  
Yana Bebieva ◽  
Kevin Speer
Keyword(s):  
Deep Water ◽  
Circumpolar Deep Water

Upper ocean salinity variabilities in the Southern Ocean responding to the recent surface salting in perspective of climate changes

2021 ◽  
Author(s):  
Ling Du ◽  
Xubin Ni
Keyword(s):  
Southern Ocean ◽  
Deep Water ◽  
Water Mass ◽  
Water Cycle ◽  
Upper Ocean ◽  
Tropical Ocean ◽  
Circumpolar Deep Water ◽  
Salinity Changes ◽  
Ocean Salinity ◽  
The Antarctic

<p>Water cycle have prevailed on upper ocean salinity acting as the climate change fingerprint in the numerous observation and simulation works. Water mass in the Southern Ocean accounted for the increasing importance associated with the heat and salt exchanges between Subantarctic basins and tropical oceans. The circumpolar deep water (CDW), the most extensive water mass in the Southern Ocean, plays an indispensable role in the formation of Antarctic Bottom Water. In our study, the observed CTDs and reanalysis datasets are examined to figure out the recent salinity changes in the three basins around the Antarctica. Significant surface salinity anomalies occurred in the South Indian/Pacific sectors south of 60ºS since 2008, which are connected with the enhanced CDW incursion onto the Antarctic continental shelf. Saltier shelf water was found to expand northward from the Antarctica coast. Meanwhile, the freshening of Upper Circumpolar Deep Water(UCDW), salting and submergence of Subantarctic Mode Water(SAMW) were also clearly observed. The modified vertical salinity structures contributed to the deepen mixed layer and enhanced intermediate stratification between SAMW and UCDW. Their transport of salinity flux attributed to the upper ocean processes responding to the recent atmospheric circulation anomalies, such as the Antarctic Oscillation and Indian Ocean Dipole. The phenomena of SAMW and UCDW salinity anomalies illustrated the contemporaneous changes of the subtropical and polar oceans, which reflected the meridional circulation fluctuation. Salinity changes in upper southern ocean (< 2000m) revealed the influence of global water cycle changes, from the Antarctic to the tropical ocean, by delivering anomalies from high- and middle-latitudes to low-latitudes oceans.</p>

scholarly journals Circulation of Circumpolar Deep Water and marine environment traced by 127I and 129I speciation in the Amundsen Sea Polynya, Antarctica

2020 ◽  
Vol 225 ◽  
pp. 106424
Author(s):  
Shan Xing ◽  
Xiaolin Hou ◽  
Keliang Shi ◽  
Ala Aldahan ◽  
Goran Possnert
Keyword(s):  
Marine Environment ◽  
Deep Water ◽  
Amundsen Sea ◽  
Circumpolar Deep Water
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