ON ATLANTIC WATER INFLOW TO ARCTIC OCEAN: UNIQUE ARGO BUOY TRIP ACROSS ATLANTIC AND BARENTS SEA

The Arctic Ocean has been receiving&#160;more of the warm and saline Atlantic Water in the past&#160;decades. This water mass enters the Arctic Ocean via two Arctic gateways: the Barents Sea Opening and the Fram Strait.&#160;Here, we focus on the fractionation of Atlantic Water at these two gateways using a Lagrangian approach based on satellite-derived geostrophic velocities.&#160;Simulated particles are released at 70N at the inner and outer branch of the North Atlantic current system&#160;in the Nordic Seas. The trajectories toward the Fram Strait and Barents Sea Opening&#160;are found to be&#160;largely steered by the bottom topography and there is an indication of an&#160;anti-phase relationship in the number of particles reaching the gateways. There is, however, a significant&#160;cross-over of particles from the outer branch to the inner branch and into the Barents Sea, which is&#160;found to be related to high eddy kinetic energy between the branches. This cross-over may be important for Arctic climate variability.

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Bio‐optical Properties of Surface Waters in the Atlantic Water Inflow Region off Spitsbergen (Arctic Ocean)

Journal of Geophysical Research Oceans ◽

10.1029/2018jc014529 ◽

2019 ◽

Vol 124 (3) ◽

pp. 1964-1987 ◽

Cited By ~ 5

Author(s):

Piotr Kowalczuk ◽

Sławomir Sagan ◽

Anna Makarewicz ◽

Justyna Meler ◽

Karolina Borzycka ◽

...

Keyword(s):

Optical Properties ◽

Arctic Ocean ◽

Surface Waters ◽

Atlantic Water ◽

Water Inflow

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Transformation of Atlantic Water in the Barents Sea in winter: overview of “Transarctika-2019” cruise results

10.5194/egusphere-egu2020-11531 ◽

2020 ◽

Author(s):

Vladimir Ivanov ◽

Ivan Frolov ◽

Kirill Filchuk

Keyword(s):

Characteristic Feature ◽

Sea Ice ◽

Arctic Ocean ◽

Water Column ◽

Barents Sea ◽

Atlantic Water ◽

The Arctic ◽

The Barents Sea ◽

Open Sea ◽

The Arctic Ocean

In the recent few years the topic of accelerated sea ice loss, and related changes in the vertical structure of water masses in the East-Atlantic sector of the Arctic Ocean, including the Barents Sea and the western part of the Nansen Basin, has been in the foci of multiple studies. This region even earned the name the &#8220;Arctic warming hotspot&#8221;, due to the extreme retreat of sea ice and clear signs of change in the vertical hydrographic structure from the Arctic type to the sub-Arctic one. A gradual increase in temperature and salinity in this area has been observed since the mid-2000s. This trend is hypothetically associated with a general decrease in the volume of sea ice in the Arctic Ocean, which leads to a decrease of ice import in the Barents Sea, salinization, weakening of density stratification, intensification of vertical mixing and an increase of heat and salt fluxes from the deep to the upper mixed layer. The result of such changes is a further reduction of sea ice, i.e. implementation of positive feedback, which is conventionally refereed as the &#8220;atlantification. Due to the fact that the Barents Sea is a relatively shallow basin, the process of atlantification might develop here much faster than in the deep Nansen Basin. Thus, theoretically, the hydrographic regime in the northern part of the Barents Sea may rapidly transform to a &#8220;Nordic Seas &#8211; wise&#8221;, a characteristic feature of which is the year-round absence of the ice cover with debatable consequences for the climate and ecosystem of the region and adjacent land areas. Due to the obvious reasons, historical observations in the Barents Sea mostly cover the summer season. Here we present a rare oceanographic data, collected during the late winter - early spring in 2019. Measurements were occupied at four sequential oceanographic surveys from the boundary between the Norwegian Sea and the Barents Sea &#8211; the so called Barents Sea opening to the boundary between the Barents Sea and the Kara Sea. Completed hydrological sections allowed us to estimate the contribution of the winter processes in the Atlantic Water transformation at the end of the winter season. Characteristic feature of the observed transformation is the homogenization of the near-to-bottom part of the water column with remaining stratification in the upper part. A probable explanation of such changes is the dominance of shelf convection and cascading of dense water over the open sea convection. In this case, complete homogenization of the water column does not occur, since convection in the open sea is impeded by salinity and density stratification, which is maintained by melting of the imported sea ice in the relatively warm water. The study was supported by RFBR grant # 18-05-60083.

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Impact of Atlantic water inflow on winter cyclone activity in the Barents Sea: Insights from coupled regional climate model simulations

10.5194/egusphere-egu2020-456 ◽

2020 ◽

Author(s):

Mirseid Akperov ◽

Vladimir A. Semenov ◽

Igor I. Mokhov ◽

Wolfgang Dorn ◽

Annette Rinke

Keyword(s):

Climate Model ◽

Barents Sea ◽

Regional Climate ◽

Lower Troposphere ◽

Static Stability ◽

Atlantic Water ◽

Water Inflow ◽

Cyclone Activity ◽

The Barents Sea ◽

The Impact

The impact of the Atlantic water inflow (AW inflow) into the Barents Sea on the regional cyclone activity in winter is analyzed in 10 ensemble simulations with the coupled Arctic atmosphere-ocean-sea ice model HIRHAM-NAOSIM for the 1979&#8211;2016 period. The model shows a statistically robust connection between AW inflow and climate variability in the Barents Sea. The analysis reveals that anomalously high AW inflow leads to changed baroclinicity in the lower troposphere via changed static stability and wind shear, and thus favorable conditions for cyclogenesis in the Barents/Kara Seas. The frequency of occurrence of cyclones, but particularly of intense cyclones, is increased over the Barents Sea. Furthermore, the cyclones in the Barents Sea become larger (increased radius) and stronger (increased intensity) in response to an increased AW inflow into the Barents Sea, compared to years of anomalously low AW inflow.The authors acknowledge the support by the Russian-German project funded by the Federal Ministry of Education and Research of Germany and Ministry of Science and Higher Education of the Russian Federation (grant 05.616.21.0109 (RFMEFI61619X0109)).

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Holocene sub-centennial evolution of Atlantic water inflow and sea ice distribution in the western Barents Sea

Climate of the Past ◽

10.5194/cp-10-181-2014 ◽

2014 ◽

Vol 10 (1) ◽

pp. 181-198 ◽

Cited By ~ 41

Author(s):

S. M. P. Berben ◽

K. Husum ◽

P. Cabedo-Sanz ◽

S. T. Belt

Keyword(s):

Sea Ice ◽

Barents Sea ◽

Low Frequency ◽

Atlantic Water ◽

Water Inflow ◽

Apparent Temperature ◽

Planktic Foraminifera ◽

Neogloboquadrina Pachyderma ◽

Polar Species ◽

Surface Temperatures

Abstract. A marine sediment core (JM09-KA11-GC) from the Kveithola Trough at the western Barents Sea margin has been investigated in order to reconstruct sub-surface temperatures and sea ice distribution at a sub-centennial resolution throughout the Holocene. The relationship between past variability of Atlantic water inflow and sea ice distribution has been established by measurement of planktic foraminifera, stable isotopes and biomarkers from sea ice diatoms and phytoplankton. Throughout the early Holocene (11 900–7300 cal yr BP), the foraminiferal fauna is dominated by the polar species Neogloboquadrina pachyderma (sinistral) and the biomarkers show an influence of seasonal sea ice. Between 10 900 and 10 700 cal yr BP, a clear cooling is shown both by fauna and stable isotope data corresponding to the so-called Preboreal Oscillation. After 7300 cal yr BP, the sub-polar Turborotalita quinqueloba becomes the most frequent species, reflecting a stable Atlantic water inflow. Sub-surface temperatures reach 6 °C and biomarker data indicate mainly ice-free conditions. During the last 1100 cal yr BP, biomarker abundances and distributions show the reappearance of low-frequency seasonal sea ice and the planktic fauna show a reduced salinity in the sub-surface water. No apparent temperature decrease is observed during this interval, but the rapidly fluctuating fauna and biomarker distributions indicate more unstable conditions.

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The Arctic Ocean Seasonal Cycles of Heat and Freshwater Fluxes: Observation-Based Inverse Estimates

Journal of Physical Oceanography ◽

10.1175/jpo-d-17-0239.1 ◽

2018 ◽

Vol 48 (9) ◽

pp. 2029-2055 ◽

Cited By ~ 10

Author(s):

Takamasa Tsubouchi ◽

Sheldon Bacon ◽

Yevgeny Aksenov ◽

Alberto C. Naveira Garabato ◽

Agnieszka Beszczynska-Möller ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Barents Sea ◽

Numerical Models ◽

Water Layer ◽

Atlantic Water ◽

Surface Fluxes ◽

The Arctic ◽

Bering Strait ◽

The Arctic Ocean

AbstractThis paper presents the first estimate of the seasonal cycle of ocean and sea ice heat and freshwater (FW) fluxes around the Arctic Ocean boundary. The ocean transports are estimated primarily using 138 moored instruments deployed in September 2005–August 2006 across the four main Arctic gateways: Davis, Fram, and Bering Straits, and the Barents Sea Opening (BSO). Sea ice transports are estimated from a sea ice assimilation product. Monthly velocity fields are calculated with a box inverse model that enforces mass and salt conservation. The volume transports in the four gateways in the period (annual mean ± 1 standard deviation) are −2.1 ± 0.7 Sv in Davis Strait, −1.1 ± 1.2 Sv in Fram Strait, 2.3 ± 1.2 Sv in the BSO, and 0.7 ± 0.7 Sv in Bering Strait (1 Sv ≡ 106 m3 s−1). The resulting ocean and sea ice heat and FW fluxes are 175 ± 48 TW and 204 ± 85 mSv, respectively. These boundary fluxes accurately represent the annual means of the relevant surface fluxes. The ocean heat transport variability derives from velocity variability in the Atlantic Water layer and temperature variability in the upper part of the water column. The ocean FW transport variability is dominated by Bering Strait velocity variability. The net water mass transformation in the Arctic entails a freshening and cooling of inflowing waters by 0.62 ± 0.23 in salinity and 3.74° ± 0.76°C in temperature, respectively, and a reduction in density by 0.23 ± 0.20 kg m−3. The boundary heat and FW fluxes provide a benchmark dataset for the validation of numerical models and atmospheric reanalysis products.

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Seabed erosion on the Lomonosov Ridge, central Arctic Ocean: A tale of deep draft icebergs in the Eurasia Basin and the influence of Atlantic water inflow on iceberg motion?

Paleoceanography ◽

10.1029/2003pa000985 ◽

2004 ◽

Vol 19 (3) ◽

pp. n/a-n/a ◽

Cited By ~ 59

Author(s):

Y. Kristoffersen ◽

B. Coakley ◽

W. Jokat ◽

M. Edwards ◽

H. Brekke ◽

...

Keyword(s):

Arctic Ocean ◽

Atlantic Water ◽

Water Inflow ◽

Lomonosov Ridge ◽

Central Arctic Ocean ◽

Eurasia Basin

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Arctic Ocean circulation and variability – advection and external forcing encounter constraints and local processes

Ocean Science Discussions ◽

10.5194/osd-8-2313-2011 ◽

2011 ◽

Vol 8 (6) ◽

pp. 2313-2376 ◽

Cited By ~ 2

Author(s):

B. Rudels

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Ocean Circulation ◽

Barents Sea ◽

Atlantic Water ◽

The Arctic ◽

Fram Strait ◽

Intermediate Layers ◽

The Arctic Ocean ◽

Almost All

Abstract. The first hydrographic data from the Arctic Ocean, the section from the Laptev Sea to the passage between Greenland and Svalbard obtained by Nansen on the drift by Fram 1893–1896, aptly illustrate the main features of Arctic Ocean oceanography and indicate possible processes active in transforming the water masses in the Arctic Ocean. Many, perhaps most, of these processes were identified already by Nansen, who put his mark on almost all subsequent research in the Arctic Ocean. Here we shall revisit some key questions and follow how our understanding has evolved from the early 20th century to present. What questions, if any, can now be regarded as solved and which remain still open? Five different but connected topics will be discussed: (1) The low salinity surface layer and the storage and export of freshwater. (2) The vertical heat transfer from the Atlantic water to sea ice and to the atmosphere. (3) The circulation and mixing of the two Atlantic inflow branches. (4) The formation and circulation of deep and bottom waters in the Arctic Ocean. (5) The exchanges through Fram Strait. Foci will be on the potential effects of increased freshwater input and reduced sea ice export on the freshwater storage and residence time in the Arctic Ocean, on the deep waters of the Makarov Basin and on the circulation and relative importance of the two inflows, over the Barents Sea and through Fram Strait, for the distribution of heat in the intermediate layers of the Arctic Ocean.

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Atlantic Water properties, transport, and water mass transformation north of Svalbard from one-year-long mooring observations

10.5194/egusphere-egu21-2505 ◽

2021 ◽

Author(s):

Zoé Koenig ◽

Kjersti Kalhagen ◽

Eivind Kolås ◽

Ilker Fer ◽

Frank Nilsen ◽

...

Keyword(s):

Arctic Ocean ◽

Water Layer ◽

Atlantic Water ◽

Water Inflow ◽

The Arctic ◽

Short Time Scale ◽

The Arctic Ocean ◽

Explained Variance ◽

One Year ◽

Counter Current

North of Svalbard is a key region for the Arctic Ocean heat and salt budget as it is the gateway for one of the main branches of Atlantic Water to the Arctic Ocean. As the Atlantic Water layer advances into the Arctic, its core deepens from about 250 m depth around the Yermak Plateau to 350 m in the Laptev Sea, and gets colder and less saline due to mixing with surrounding waters. The complex topography in the region facilitates vertical and horizontal exchanges between the water masses and, together with strong shear and tidal forcing driving increased mixing rates, impacts the heat and salt content of the Atlantic Water layer that will circulate around the Arctic Ocean.In September 2018, 6 moorings organized in 2 arrays were deployed across the Atlantic Water Boundary current for more than one year (until November 2019), within the framework of the Nansen Legacy project to investigate the seasonal variations of this current and the transformation of the Atlantic Water North of Svalbard. The Atlantic Water inflow exhibits a large seasonal signal, with maxima in core temperature and along-isobath velocities in fall and minima in spring. Volume transport of the Atlantic Water inflow varies from 0.7 Sv in spring to 3 Sv in fall. An empirical orthogonal function analysis of the daily cross-isobath temperature sections reveals that the first mode of variation (explained variance ~80%) is the seasonal cycle with an on/off mode in the temperature core. The second mode (explained variance ~ 15%) corresponds to a short time scale (less than 2 weeks) variability in the onshore/offshore displacement of the temperature core. On the shelf, a counter-current flowing westward is observed in spring, which transports colder (~ 1&#176;C) and fresher (~ 34.85 g kg-1) water than Atlantic Water (&#952; > 2&#176;C and SA > 34.9 g kg-1). The processes driving the dynamic of the counter-current are under investigation. At greater depth (~1000 m) on the offshore part of the slope, a bottom-intensified current is noticed that seems to covary with the wind stress curl. Heat loss of the Atlantic Water between the two mooring arrays is maximum in winter reaching 250 W m-2 when the current is the largest and the net radiative flux from the atmosphere to the ocean is the smallest (only 50 W m-2 compared to about 400 W m-2 in summer).

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