scholarly journals Atlantic water circulation over the Mendeleev Ridge and Chukchi Borderland from thermohaline intrusions and water mass properties

2007 ◽  
Vol 112 (C2) ◽  
Author(s):  
Rebecca A. Woodgate ◽  
Knut Aagaard ◽  
James H. Swift ◽  
William M. Smethie ◽  
Kelly K. Falkner
Keyword(s):  
Water Mass ◽  
Atlantic Water ◽  
Water Circulation ◽  
Mass Properties ◽  
Thermohaline Intrusions ◽  
Chukchi Borderland

scholarly journals Confluence and redistribution of Atlantic water in the Nansen, Amundsen and Makarov basins

2002 ◽  
Vol 20 (2) ◽  
pp. 257-273 ◽  
Author(s):  
U. Schauer ◽  
B. Rudels ◽  
E. P. Jones ◽  
L. G. Anderson ◽  
R. D. Muench ◽  
...  
Keyword(s):  
Barents Sea ◽  
Water Mass ◽  
Atlantic Water ◽  
Lomonosov Ridge ◽  
Fram Strait ◽  
The Barents Sea ◽  
Mass Properties ◽  
Anna Trough ◽  
Eurasian Basin ◽  
Canadian Basin

Abstract. The waters in the Eurasian Basin are conditioned by the confluence of the boundary flow of warm, saline Fram Strait water and cold low salinity water from the Barents Sea entering through the St. Anna Trough. Hydrographic sections obtained from RV Polarstern during the summer of 1996 (ACSYS 96) across the St. Anna Trough and the Voronin Trough in the northern Kara Sea and across the Nansen, Amundsen and Makarov basins allow for the determination of the water mass properties of the two components and the construction of a qualitative picture of the circulation both within the Eurasian Basin and towards the Canadian Basin. At the confluence north of the Kara Sea, the Fram Strait branch is displaced from the upper to the lower slope and it forms a sharp front to the Barents Sea water at depths between 100 m and greater than 1000 m. This front disintegrates downstream along the basin margin and the two components are largely mixed before the boundary current reaches the Lomonosov Ridge. Away from the continental slope, the presence of interleaving structures coherent over wide distances is consistent with low lateral shear. The return flow along the Nansen Gakkel Ridge, if present at all, seems to be slow and the cold water below a deep mixed layer there indicates that the Fram Strait Atlantic water was not covered with a halocline for about a decade. Anomalous water mass properties in the interior of the Eurasian Basin can be attributed to isolated lenses rather than to baroclinic flow cores. Eddies have probably detached from the front at the confluence and migrated into the interior of the basin. One deep (2500 m) lens of Canadian Basin water, with an anticyclonic eddy signature, must have spilled through a gap of the Lomonosov Ridge. During ACSYS 96, no clear fronts between Eurasian and Canadian intermediate waters, such as those observed further north in 1991 and 1994, were found at the Siberian side of the Lomonosov Ridge. This indicates that the Eurasian Basin waters enter the Canadian Basin not only along the continental slope but they may also cross the Lomonosov Ridge at other topographic irregularities. A decrease in salinity around 1000 m in depth in the Amundsen Basin probably originates from a larger input of fresh water to the Barents Sea. The inherent density changes may affect the flow towards the Canadian Basin.Key words. Oceanography: general (Artic and Antartic oceanography; descriptive and regional oceanography) Oceanography: physical (hydrography)

scholarly journals Latest Miocene restriction of the Mediterranean Outflow Water: a perspective from the Gulf of Cádiz

2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Zhi Lin Ng ◽  
F. Javier Hernández-Molina ◽  
Débora Duarte ◽  
Francisco J. Sierro ◽  
Santiago Ledesma ◽  
...  
Keyword(s):  
Mass Exchange ◽  
Water Mass ◽  
Atlantic Water ◽  
Meridional Overturning Circulation ◽  
Gulf Of Cadiz ◽  
Mediterranean Outflow Water ◽  
Gulf Of Cádiz ◽  
Mediterranean Outflow ◽  
The Mediterranean ◽  
Water Mass Exchange

AbstractThe Mediterranean-Atlantic water mass exchange provides the ideal setting for deciphering the role of gateway evolution in ocean circulation. However, the dynamics of Mediterranean Outflow Water (MOW) during the closure of the Late Miocene Mediterranean-Atlantic gateways are poorly understood. Here, we define the sedimentary evolution of Neogene basins from the Gulf of Cádiz to the West Iberian margin to investigate MOW circulation during the latest Miocene. Seismic interpretation highlights a middle to upper Messinian seismic unit of transparent facies, whose base predates the onset of the Messinian salinity crisis (MSC). Its facies and distribution imply a predominantly hemipelagic environment along the Atlantic margins, suggesting an absence or intermittence of MOW preceding evaporite precipitation in the Mediterranean, simultaneous to progressive gateway restriction. The removal of MOW from the Mediterranean-Atlantic water mass exchange reorganized the Atlantic water masses and is correlated to a severe weakening of the Atlantic Meridional Overturning Circulation (AMOC) and a period of further cooling in the North Atlantic during the latest Miocene.

Paleoceanographic evolution of the SW Svalbard margin (76°N) since 20,000 14C yr BP

2007 ◽  
Vol 67 (1) ◽  
pp. 100-114 ◽  
Author(s):  
Tine L. Rasmussen ◽  
Erik Thomsen ◽  
Marta A. Ślubowska ◽  
Simon Jessen ◽  
Anders Solheim ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Mass ◽  
Atlantic Water ◽  
Subsurface Water ◽  
Planktic Foraminifera ◽  
Surface Conditions ◽  
Polar Surface ◽  
Warm Core ◽  
Heinrich Event ◽  
Benthic Environment

AbstractTwo cores from the southwestern shelf and slope of Storfjorden, Svalbard, taken at 389 m and 1485 m water depth have been analyzed for benthic and planktic foraminifera, oxygen isotopes, and ice-rafted debris. The results show that over the last 20,000 yr, Atlantic water has been continuously present on the southwestern Svalbard shelf. However, from 15,000 to 10,000 14C yr BP, comprising the Heinrich event H1 interval, the Bølling–Allerød interstades and the Younger Dryas stade, it flowed as a subsurface water mass below a layer of polar surface water. In the benthic environment, the shift to interglacial conditions occurred at 10,000 14C yr BP. Due to the presence of a thin upper layer of polar water, surface conditions remained cold until ca. 9000 14C yr BP, when the warm Atlantic water finally appeared at the surface. Neither extensive sea ice cover nor large inputs of meltwater stopped the inflow of Atlantic water. Its warm core was merely submerged below the cold polar surface water.

Eddy-permitting simulations of the sub-polar North Atlantic: impact of the model bias on water mass properties and circulation

2010 ◽  
Vol 60 (5) ◽  
pp. 1177-1192 ◽  
Author(s):  
Jieshun Zhu ◽  
Entcho Demirov ◽  
Fred Dupont ◽  
Daniel Wright
Keyword(s):  
North Atlantic ◽  
Water Mass ◽  
Model Bias ◽  
Mass Properties

Moored Observations of Currents and Water Mass Properties between Talaud and Halmahera Islands at the Entrance of the Indonesian Seas

2021 ◽  
Vol 51 (12) ◽  
pp. 3557-3572
Keyword(s):  
Water Mass ◽  
Low Frequency ◽  
Maximum Velocity ◽  
Boreal Winter ◽  
Indonesian Seas ◽  
Seasonal Movement ◽  
Tropical Water ◽  
The Pacific ◽  
Mass Properties ◽  
Channel Velocity

AbstractThe currents and water mass properties at the Pacific entrance of the Indonesian seas are studied using measurements of three subsurface moorings deployed between the Talaud and Halmahera Islands. The moored current meter data show northeastward mean currents toward the Pacific Ocean in the upper 400 m during the nearly 2-yr mooring period, with the maximum velocity in the northern part of the channel. The mean transport between 60- and 300-m depths is estimated to be 10.1–13.2 Sv (1 Sv ≡ 106 m3 s−1) during 2016–17, when all three moorings have measurements. The variability of the along-channel velocity is dominated by low-frequency signals (periods > 150 days), with northeastward variations in boreal winter and southwestward variations in summer in the superposition of the annual and semiannual harmonics. The current variations evidence the seasonal movement of the Mindanao Current retroflection, which is supported by satellite sea level and ocean color data, showing a cyclonic intrusion into the northern Maluku Sea in boreal winter whereas a leaping path occurs north of the Talaud Islands in summer. During Apri–July, the moored CTDs near 200 m show southwestward currents carrying the salty South Pacific Tropical Water into the Maluku Sea.

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