Isothermal Water Mass in the Bottom Water at the Bay Mouth of Jiaozhou Bay?. Isothermal Water Mass scale and location

Based on the survey data of Jiaozhou Bay in May, June, July, August, September and October of 1980, the bottom water temperature and its horizontal distribution in Jiaozhou Bay were studied. The results showedthat the bottom water temperaturein Jiaozhou Bay rangedat a high level between 12.35℃to 25.72℃and a low level between 10.18℃to 24.58 ℃in May, June, July, August, September and October. From May to October, the bottom water temperature in Jiaozhou Bay was moderately high. In May, June, July and August, a high temperature zone formed around the waterinside the bay mouth, and the bottom water temperaturereached 12.35℃to 25.72℃.From May to August, the bottom water temperaturefirst increased in the watersinside the bay mouth, followed by the water at the bay mouth, withthe water outside the bay mouthas the end. In September and October, the temperature of the eastern coastal water outside Jiaozhou Bay ranged from 20.00℃to 24.43℃, and a high temperature zone formed around there. From September to October,the bottom water temperaturefirst decreased in the water inside the bay mouth, followed by the water at the bay mouth, with the water outside the bay mouthas the end. According to Yang Dongfang's definition of “Cryogenic Low Water Mass”, a cryogenic water mass formed in the bottom water at the bay mouthin September and extended widely among the water inside the bay mouth-at the bay mouth-in the southern part outside the bay mouthwith a temperature of 23.79℃to 23.91℃.

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Attenuated carbon sequestration by Weddell Sea dense waters over the 21st century – an assessment with FESOM-REcoM

10.5194/egusphere-egu21-6248 ◽

2021 ◽

Author(s):

Cara Nissen ◽

Ralph Timmermann ◽

Mario Hoppema ◽

Judith Hauck

Keyword(s):

Carbon Sequestration ◽

Sea Ice ◽

Continental Shelf ◽

Bottom Water ◽

Water Mass ◽

Weddell Sea ◽

Ice Shelf ◽

Deep Waters ◽

Water Formation ◽

Water Mass Transformation

Deep and bottom water formation regions have long been recognized to be efficient vectors for carbon transfer to depth, leading to carbon sequestration on time scales of centuries or more. Precursors of Antarctic Bottom Water (AABW) are formed on the Weddell Sea continental shelf as a consequence of buoyancy loss of surface waters at the ice-ocean or atmosphere-ocean interface, which suggests that any change in water mass transformation rates in this area affects global carbon cycling and hence climate. Many of the models previously used to assess AABW formation in present and future climates contained only crude representations of ocean-ice shelf interaction. Numerical simulations often featured spurious deep convection in the open ocean, and changes in carbon sequestration have not yet been assessed at all. Here, we present results from the global model FESOM-REcoM, which was run on a mesh with elevated grid resolution in the Weddell Sea and which includes an explicit representation of sea ice and ice shelves. Forcing this model with ssp585 scenario output from the AWI Climate Model, we assess changes over the 21st century in the formation and northward export of dense waters and the associated carbon fluxes within and out of the Weddell Sea. We find that the northward transport of dense deep waters (&#963;2>37.2 kg m-3 below 2000 m) across the SR4 transect, which connects the tip of the Antarctic Peninsula with the eastern Weddell Sea, declines from 4 Sv to 2.9 Sv by the year 2100. Concurrently, despite the simulated continuous increase in surface ocean CO2 uptake in the Weddell Sea over the 21st century, the carbon transported northward with dense deep waters declines from 3.5 Pg C yr-1 to 2.5 Pg C yr-1, demonstrating the dominant role of dense water formation rates for carbon sequestration. Using the water mass transformation framework, we find that south of SR4, the formation of downwelling dense waters declines from 3.5 Sv in the 1990s to 1.6 Sv in the 2090s, a direct result of the 18% lower sea-ice formation in the area, the increased presence of modified Warm Deep Water on the continental shelf, and 50% higher ice shelf basal melt rates. Given that the reduced formation of downwelling water masses additionally occurs at lighter densities in FESOM-REcoM in the 2090s, this will directly impact the depth at which any additional oceanic carbon uptake is stored, with consequences for long-term carbon sequestration.

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The features of Antarctic Bottom Water in the fracture zones at 7-10 deg. N of the Mid-Atlantic ridge

10.5194/egusphere-egu2020-19271 ◽

2020 ◽

Author(s):

Valentina Volkova ◽

Alexander Demidov ◽

Fedor Gippius

Keyword(s):

Bottom Water ◽

Historical Data ◽

Water Mass ◽

Main Task ◽

Bottom Relief ◽

Antarctic Bottom Water ◽

Fracture Zones ◽

Mid Atlantic Ridge ◽

Proper Estimation ◽

The Antarctic

Despite the fact that there are numerous estimates of the Antarctic Bottom Water (AABW) formation and transport, its evolution and distribution pathways are still debatable (Morozov E.G. et al., 2010).The main task of this work was to identify the structure and transport of deep and bottom water mass of the fracture zones (7 40', Vernadsky and Doldrums). The research is based on new data (multibeam bottom relief, temperature, salinity, velocity) obtained during the research cruise on the RV "Akademik Nikolaj Strakhov" in October-November 2019 and WODB18 historical data.The main result of the research is proper estimation of the AABW and LNADW transport, which takes into consideration the influence of fracture zone morphometry. Accordingly, the preliminary circulation scheme of water masses is obtained.

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Water masses in the Atlantic Ocean: characteristics and distributions

Ocean Science ◽

10.5194/os-17-463-2021 ◽

2021 ◽

Vol 17 (2) ◽

pp. 463-486

Author(s):

Mian Liu ◽

Toste Tanhua

Keyword(s):

Atlantic Ocean ◽

Deep Water ◽

Bottom Water ◽

Water Mass ◽

Sea Water ◽

Weddell Sea ◽

Water Masses ◽

Global Ocean ◽

Intermediate Water ◽

The North

Abstract. A large number of water masses are presented in the Atlantic Ocean, and knowledge of their distributions and properties is important for understanding and monitoring of a range of oceanographic phenomena. The characteristics and distributions of water masses in biogeochemical space are useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples. Here, we define the characteristics of the major water masses in the Atlantic Ocean as source water types (SWTs) from their formation areas, and map out their distributions. The SWTs are described by six properties taken from the biased-adjusted Global Ocean Data Analysis Project version 2 (GLODAPv2) data product, including both conservative (conservative temperature and absolute salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) properties. The distributions of these water masses are investigated with the use of the optimum multi-parameter (OMP) method and mapped out. The Atlantic Ocean is divided into four vertical layers by distinct neutral densities and four zonal layers to guide the identification and characterization. The water masses in the upper layer originate from wintertime subduction and are defined as central waters. Below the upper layer, the intermediate layer consists of three main water masses: Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Water (MW). The North Atlantic Deep Water (NADW, divided into its upper and lower components) is the dominating water mass in the deep and overflow layer. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW). The Antarctic Bottom Water (AABW) is the only natural water mass in the bottom layer, and this water mass is redefined as Northeast Atlantic Bottom Water (NEABW) in the north of the Equator due to the change of key properties, especially silicate. Similar with NADW, two additional water masses, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea region in order to understand the origin of AABW.

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Formation and Migration of Hot Water Mass in the Waterbody of Jiaozhou Bay

2019 4th International Conference on Mechanical, Control and Computer Engineering (ICMCCE) ◽

10.1109/icmcce48743.2019.00021 ◽

2019 ◽

Author(s):

Dongfang Yang ◽

Longlei Zhang ◽

Dong Yang ◽

Qi Wang ◽

Haixia Li

Keyword(s):

Water Mass ◽

Jiaozhou Bay ◽

Hot Water ◽

And Migration

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Evidence for northward expansion of Antarctic Bottom Water mass in the Southern Ocean during the last glacial inception

Paleoceanography ◽

10.1029/2008pa001603 ◽

2009 ◽

Vol 24 (1) ◽

pp. n/a-n/a ◽

Cited By ~ 51

Author(s):

Aline Govin ◽

Elisabeth Michel ◽

Laurent Labeyrie ◽

Claire Waelbroeck ◽

Fabien Dewilde ◽

...

Keyword(s):

Southern Ocean ◽

Bottom Water ◽

Water Mass ◽

Antarctic Bottom Water ◽

Last Glacial ◽

Northward Expansion ◽

The Last Glacial

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Millennial changes in North Atlantic oxygen concentrations

Biogeosciences ◽

10.5194/bg-13-211-2016 ◽

2016 ◽

Vol 13 (1) ◽

pp. 211-221 ◽

Cited By ~ 6

Author(s):

B. A. A. Hoogakker ◽

D. J. R. Thornalley ◽

S. Barker

Keyword(s):

Ocean Circulation ◽

North Atlantic ◽

Bottom Water ◽

Water Mass ◽

Intermediate Depth ◽

Northeast Atlantic ◽

The North ◽

Cold Events ◽

The North Atlantic ◽

Oxygen Concentrations

Abstract. Glacial–interglacial changes in bottom water oxygen concentrations [O2] in the deep northeast Atlantic have been linked to decreased ventilation relating to changes in ocean circulation and the biological pump (Hoogakker et al., 2015). In this paper we discuss seawater [O2] changes in relation to millennial climate oscillations in the North Atlantic over the last glacial cycle, using bottom water [O2] reconstructions from 2 cores: (1) MD95-2042 from the deep northeast Atlantic (Hoogakker et al., 2015) and (2) ODP (Ocean Drilling Program) Site 1055 from the intermediate northwest Atlantic. The deep northeast Atlantic core MD95-2042 shows decreased bottom water [O2] during millennial-scale cool events, with lowest bottom water [O2] of 170, 144, and 166 ± 17 µmol kg−1 during Heinrich ice rafting events H6, H4, and H1. Importantly, at intermediate depth core ODP Site 1055, bottom water [O2] was lower during parts of Marine Isotope Stage 4 and millennial cool events, with the lowest values of 179 and 194 µmol kg−1 recorded during millennial cool event C21 and a cool event following Dansgaard–Oeschger event 19. Our reconstructions agree with previous model simulations suggesting that glacial cold events may be associated with lower seawater [O2] across the North Atlantic below ∼ 1 km (Schmittner et al., 2007), although in our reconstructions the changes are less dramatic. The decreases in bottom water [O2] during North Atlantic Heinrich events and earlier cold events at the two sites can be linked to water mass changes in relation to ocean circulation changes and possibly productivity changes. At the intermediate depth site a possible strong North Atlantic Intermediate Water cell would preclude water mass changes as a cause for decreased bottom water [O2]. Instead, we propose that the lower bottom [O2] there can be linked to productivity changes through increased export of organic material from the surface ocean and its subsequent remineralization in the water column and the sediment.

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Winter study of Antarctic zone of the Southern Ocean (to the 25-th anniversary of the Soviet-Russian-American drift station “Weddell-1”)

Океанология ◽

10.31857/s0030-1574592308-310 ◽

2019 ◽

Vol 59 (2) ◽

pp. 308-310

Author(s):

N. N. Antipov ◽

N. V. Bagriantsev ◽

А. I. Danilov ◽

А. V. Klepikov

Keyword(s):

Bottom Water ◽

Water Mass ◽

Ice Formation ◽

Western Boundary ◽

Boundary Current ◽

Antarctic Sea Ice ◽

Circulation Patterns ◽

First Time ◽

Drift Station ◽

Remote Part

The information concern oceanographic investigations in 1980-90 within Antarctic sea-ice formation area together with “International oceanographic study of Antarctic Zone” ( “iAnZone”) program is given. The supreme component of these investigations became the soviet-american winter expedition “Ice Station Weddell-1” (ISW-1), supported by “Academic Fedorov”(SU), “Nathaniel Palmer” (US) and drift station (3.02.92–9.06.92). The water mass structure and circulation patterns in most remote part of the Weddell Gyre, including Western boundary current parameters and bottom water from the shelf were for the first time defined.

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