The Nd isotopic composition in the Barents Sea, Nansen Basin and Fram Strait: Water mass exchange between the Arctic and Atlantic Ocean

2006 ◽  
Vol 70 (18) ◽  
pp. A17
Author(s):  
P.S. Andersson ◽  
D. Porcelli ◽  
M. Frank ◽  
G. Björk
2020 ◽  
Author(s):  
Léon Chafik ◽  
Sara Broomé

<p>The Arctic Ocean has been receiving more of the warm and saline Atlantic Water in the past decades. This water mass enters the Arctic Ocean via two Arctic gateways: the Barents Sea Opening and the Fram Strait. Here, we focus on the fractionation of Atlantic Water at these two gateways using a Lagrangian approach based on satellite-derived geostrophic velocities. Simulated particles are released at 70N at the inner and outer branch of the North Atlantic current system in the Nordic Seas. The trajectories toward the Fram Strait and Barents Sea Opening are found to be largely steered by the bottom topography and there is an indication of an anti-phase relationship in the number of particles reaching the gateways. There is, however, a significant cross-over of particles from the outer branch to the inner branch and into the Barents Sea, which is found to be related to high eddy kinetic energy between the branches. This cross-over may be important for Arctic climate variability.</p>


2019 ◽  
Vol 47 (4) ◽  
pp. 62-75
Author(s):  
L. L. Demina ◽  
A. S. Solomatina ◽  
G. A. Abyzova

Zooplankton plays a Central role in the transfer of matter and energy from primary producers to high trophic organisms, and zooplankton serves as an essential component of sedimentary material that supplies organic matter to the bottom of marine basins. The paper presents new data on the distribution of a number of heavy metals (Cd, Co, Cr, Cu, Mo, Ni, Pb) and As in the Calanus zooplankton collected in July–August 2017 in the North-Eastern, Eastern and Central parts of the Barents Sea. It is shown that the spatial distribution of metals in zooplankton organisms is influenced by both biotic ecosystem factors associated with bioproductivity and hydrological and geochemical parameters of the habitat (North Polar Front). In the zooplankton of the Arctic water mass to the South-East of Franz Josef Land, there was an increased content of essential heavy metals Cu, Zn and Cr in comparison with the coastal and Atlantic water masses. Zooplankton from the Central part of the sea (Atlantic water mass), where phytoplankton production is reduced, is characterized by the lowest concentrations of most elements (Ni, Cu, Zn, As and Pb). The highest concentrations were found for both essential heavy metals (Zn and Cu) and toxic metalloid As, which may indicate non-selective bioaccumulation of trace elements by copepods.


Ocean Science ◽  
2013 ◽  
Vol 9 (1) ◽  
pp. 147-169 ◽  
Author(s):  
B. Rudels ◽  
U. Schauer ◽  
G. Björk ◽  
M. Korhonen ◽  
S. Pisarev ◽  
...  

Abstract. The circulation and water mass properties in the Eurasian Basin are discussed based on a review of previous research and an examination of observations made in recent years within, or parallel to, DAMOCLES (Developing Arctic Modeling and Observational Capabilities for Long-term Environmental Studies). The discussion is strongly biased towards observations made from icebreakers and particularly from the cruise with R/V Polarstern 2007 during the International Polar Year (IPY). Focus is on the Barents Sea inflow branch and its mixing with the Fram Strait inflow branch. It is proposed that the Barents Sea branch contributes not just intermediate water but also most of the water to the Atlantic layer in the Amundsen Basin and also in the Makarov and Canada basins. Only occasionally would high temperature pulses originating from the Fram Strait branch penetrate along the Laptev Sea slope across the Gakkel Ridge into the Amundsen Basin. Interactions between the Barents Sea and the Fram Strait branches lead to formation of intrusive layers, in the Atlantic layer and in the intermediate waters. The intrusion characteristics found downstream, north of the Laptev Sea are similar to those observed in the northern Nansen Basin and over the Gakkel Ridge, suggesting a flow from the Laptev Sea towards Fram Strait. The formation mechanisms for the intrusions at the continental slope, or in the interior of the basins if they are reformed there, have not been identified. The temperature of the deep water of the Eurasian Basin has increased in the last 10 yr rather more than expected from geothermal heating. That geothermal heating does influence the deep water column was obvious from 2007 Polarstern observations made close to a hydrothermal vent in the Gakkel Ridge, where the temperature minimum usually found above the 600–800 m thick homogenous bottom layer was absent. However, heat entrained from the Atlantic water into descending, saline boundary plumes may also contribute to the warming of the deeper layers.


2012 ◽  
Vol 9 (4) ◽  
pp. 2695-2747
Author(s):  
B. Rudels ◽  
U. Schauer ◽  
G. Björk ◽  
M. Korhonen ◽  
S. Pisarev ◽  
...  

Abstract. The circulation and water mass properties in the Eurasian Basin are discussed based on a review of previous research and an examination of observations made in recent years within, or parallel to, DAMOCLES (Developing Arctic Modelling and Observational Capabilities for Long-term Environmental Studies). The discussion is strongly biased towards observations made from icebreakers and particularly from the cruise with R/V Polarstern 2007 during the International Polar Year (IPY). Focus is on the Barents Sea inflow branch and its mixing with the Fram Strait inflow branch. It is proposed that the Barents Sea branch contributes not just intermediate water but also most of the Atlantic layer that is found in the Amundsen Basin and also in the Makarov and Canada basins. Only occasionally would high temperature pulses originating from the Fram Strait branch penetrate along the Laptev Sea slope across the Gakkel Ridge into the Amundsen Basin. Interactions between the Barents Sea and the Fram Strait branches lead to formation of intrusive layers, in the Atlantic layer and in the intermediate waters. The intrusion characteristics found downstream north of the Laptev Sea are similar to those observed in the Northern Nansen Basin and over the Gakkel Ridge, implying a flow from the Laptev Sea towards Fram Strait. The formation mechanisms for the intrusions at the continental slope, or in the interior of the basins if they are reformed there, have not been identified. The temperature of the deep water of the Eurasian Basin has increased in the last 10 yr rather more than expected from geothermal heating. That geothermal heating does influence the deep water column was obvious from 2007 Polarstern observations made close to a hydrothermal vent in the Gakkel Ridge, where the temperature minimum usually found above the 600–800 m thick homogenous bottom layer was absent. However, heat entrained from the Atlantic water into descending boundary plumes may also contribute to the warming of the deeper layers.


2002 ◽  
Vol 20 (2) ◽  
pp. 257-273 ◽  
Author(s):  
U. Schauer ◽  
B. Rudels ◽  
E. P. Jones ◽  
L. G. Anderson ◽  
R. D. Muench ◽  
...  

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)


2020 ◽  
Vol 12 (4) ◽  
pp. 2447-2457
Author(s):  
Sylvain Watelet ◽  
Øystein Skagseth ◽  
Vidar S. Lien ◽  
Helge Sagen ◽  
Øivind Østensen ◽  
...  

Abstract. The Barents Sea, located between the Norwegian Sea and the Arctic Ocean, is one of the main pathways of the Atlantic Meridional Overturning Circulation. Changes in the water mass transformations in the Barents Sea potentially affect the thermohaline circulation through the alteration of the dense water formation process. In order to investigate such changes, we present here a seasonal atlas of the Barents Sea including both temperature and salinity for the period 1965–2016. The atlas is built as a compilation of datasets from the World Ocean Database, the Polar Branch of the Russian Federal Research Institute of Fisheries and Oceanography and the Norwegian Polar Institute using the Data-Interpolating Variational Analysis (DIVA) tool. DIVA allows for a minimization of the expected error with respect to the true field. The atlas is used to provide a volumetric analysis of water mass characteristics and an estimation of the ocean heat and freshwater contents. The results show a recent “Atlantification” of the Barents Sea, that is a general increase in both temperature and salinity, while its density remains stable. The atlas is made freely accessible as user-friendly NetCDF files to encourage further research in the Barents Sea physics (https://doi.org/10.21335/NMDC-2058021735, Watelet et al., 2020).


2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Zhi Lin Ng ◽  
F. Javier Hernández-Molina ◽  
Débora Duarte ◽  
Francisco J. Sierro ◽  
Santiago Ledesma ◽  
...  

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.


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