Articles | Volume 14, issue 1
https://doi.org/10.5194/os-14-1-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/os-14-1-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
02 Jan 2018
Research article |
| 02 Jan 2018
Bathymetry and oceanic flow structure at two deep passages crossing the Lomonosov Ridge
Göran Björk
CORRESPONDING AUTHOR
Department of Marine Sciences, University of Gothenburg, Gothenburg 405 30, Sweden
Martin Jakobsson
Department of Geological Sciences, Stockholm University, Stockholm 106 91, Sweden
Karen Assmann
Department of Marine Sciences, University of Gothenburg, Gothenburg 405 30, Sweden
Leif G. Andersson
Department of Marine Sciences, University of Gothenburg, Gothenburg 405 30, Sweden
Johan Nilsson
Bolin Centre for Climate Research, Stockholm University, Stockholm 106 91, Sweden
Department of Meteorology, Stockholm University, Stockholm 106 91, Sweden
Christian Stranne
Department of Geological Sciences, Stockholm University, Stockholm 106 91, Sweden
Center for Coastal and Ocean Mapping, University of New Hampshire, New Hampshire 03824, USA
Larry Mayer
Center for Coastal and Ocean Mapping, University of New Hampshire, New Hampshire 03824, USA
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We use data crossing Herald Canyon in the Chukchi Sea collected in 2008 and 2014 together with numerical modelling to investigate the circulation in the western Chukchi Sea. A large fraction of water from the Chukchi Sea enters the East Siberian Sea south of Wrangel Island and circulates in an anticyclonic direction around the island. To assess the differences between years, we use numerical modelling results, which show that high-frequency variability dominates the flow in Herald Canyon.
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Recent data suggest that a 1 km thick ice shelf extended over the glacial Arctic Ocean during MIS 6, about 140 000 years ago. Here, we theoretically analyse the development and equilibrium features of such an ice shelf. The ice shelf was effectively dammed by the Fram Strait and the mean ice-shelf thickness was controlled primarily by the horizontally integrated mass balance. Our results can aid in resolving some outstanding questions of the state of the glacial Arctic Ocean.
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We use data collected in 2014 to show that the outflow of nutrient-rich water occurs much further to the west than has been reported in the past. We suggest that this is due to much less summer sea-ice coverage in the northwestern East Siberian Sea than in the past decades. Further, our data support a more complicated flow pattern in the region where the Mendeleev Ridge reaches the shelf compared to the general cyclonic circulation within the individual basins as suggested historically.
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Julia Muchowski, Martin Jakobsson, Lars Umlauf, Lars Arneborg, Bo Gustafsson, Peter Holtermann, Christoph Humborg, and Christian Stranne
Ocean Sci., 19, 1809–1825, https://doi.org/10.5194/os-19-1809-2023, https://doi.org/10.5194/os-19-1809-2023, 2023
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We show observational data of highly increased mixing and vertical salt flux rates in a sparsely sampled region of the northern Baltic Sea. Co-located acoustic observations complement our in situ measurements and visualize turbulent mixing with high spatial resolution. The observed mixing is generally not resolved in numerical models of the area but likely impacts the exchange of water between the adjacent basins as well as nutrient and oxygen conditions in the Bothnian Sea.
Jonathan Wiskandt, Inga Monika Koszalka, and Johan Nilsson
The Cryosphere, 17, 2755–2777, https://doi.org/10.5194/tc-17-2755-2023, https://doi.org/10.5194/tc-17-2755-2023, 2023
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Understanding ice–ocean interactions under floating ice tongues in Greenland and Antarctica is a major challenge in climate modelling and a source of uncertainty in future sea level projections. We use a high-resolution ocean model to investigate basal melting and melt-driven circulation under the floating tongue of Ryder Glacier, northwestern Greenland. We study the response to oceanic and atmospheric warming. Our results are universal and relevant for the development of climate models.
Johan Nilsson, Eef van Dongen, Martin Jakobsson, Matt O'Regan, and Christian Stranne
The Cryosphere, 17, 2455–2476, https://doi.org/10.5194/tc-17-2455-2023, https://doi.org/10.5194/tc-17-2455-2023, 2023
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We investigate how topographical sills suppress basal glacier melt in Greenlandic fjords. The basal melt drives an exchange flow over the sill, but there is an upper flow limit set by the Atlantic Water features outside the fjord. If this limit is reached, the flow enters a new regime where the melt is suppressed and its sensitivity to the Atlantic Water temperature is reduced.
Gabriel West, Darrell S. Kaufman, Martin Jakobsson, and Matt O'Regan
Geochronology, 5, 285–299, https://doi.org/10.5194/gchron-5-285-2023, https://doi.org/10.5194/gchron-5-285-2023, 2023
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We report aspartic and glutamic acid racemization analyses on Neogloboquadrina pachyderma and Cibicidoides wuellerstorfi from the Arctic Ocean (AO). The rates of racemization in the species are compared. Calibrating the rate of racemization in C. wuellerstorfi for the past 400 ka allows the estimation of sample ages from the central AO. Estimated ages are older than existing age assignments (as previously observed for N. pachyderma), confirming that differences are not due to taxonomic effects.
Jaclyn Clement Kinney, Karen M. Assmann, Wieslaw Maslowski, Göran Björk, Martin Jakobsson, Sara Jutterström, Younjoo J. Lee, Robert Osinski, Igor Semiletov, Adam Ulfsbo, Irene Wåhlström, and Leif G. Anderson
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We use data crossing Herald Canyon in the Chukchi Sea collected in 2008 and 2014 together with numerical modelling to investigate the circulation in the western Chukchi Sea. A large fraction of water from the Chukchi Sea enters the East Siberian Sea south of Wrangel Island and circulates in an anticyclonic direction around the island. To assess the differences between years, we use numerical modelling results, which show that high-frequency variability dominates the flow in Herald Canyon.
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Observations in the Nordic Seas have shown a general warming and an increase in sea surface height over the last few decades. However, our results reveal that the sea surface heights and heat content in the decade following the mid-2000s have not risen much or even stagnated. This is most prominent in the eastern Nordic Seas, where waters of Atlantic origin dominate. We conclude that this stagnation is possibly a consequence of decreased heat transport from the subpolar North Atlantic.
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Malin Ödalen, Jonas Nycander, Andy Ridgwell, Kevin I. C. Oliver, Carlye D. Peterson, and Johan Nilsson
Biogeosciences, 17, 2219–2244, https://doi.org/10.5194/bg-17-2219-2020, https://doi.org/10.5194/bg-17-2219-2020, 2020
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In glacial periods, ocean uptake of carbon is likely a key player for achieving low atmospheric CO2. In climate models, ocean biological uptake of carbon (C) and phosphorus (P) are often assumed to occur in fixed proportions.
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Francesco Muschitiello, Matt O'Regan, Jannik Martens, Gabriel West, Örjan Gustafsson, and Martin Jakobsson
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In this study we present a new marine chronology of the last ~30 000 years for a sediment core retrieved from the central Arctic Ocean. Our new chronology reveals substantially faster sedimentation rates during the end of the last glacial cycle, the Last Glacial Maximum, and deglaciation than previously reported, thus implying a substantial re-interpretation of paleoceanographic reconstructions from this sector of the Arctic Ocean.
Zhongshi Zhang, Qing Yan, Ran Zhang, Florence Colleoni, Gilles Ramstein, Gaowen Dai, Martin Jakobsson, Matt O'Regan, Stefan Liess, Denis-Didier Rousseau, Naiqing Wu, Elizabeth J. Farmer, Camille Contoux, Chuncheng Guo, Ning Tan, and Zhengtang Guo
Clim. Past Discuss., https://doi.org/10.5194/cp-2020-38, https://doi.org/10.5194/cp-2020-38, 2020
Manuscript not accepted for further review
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Whether an ice sheet once grew over Northeast Siberia-Beringia has been debated for decades. By comparing climate modelling with paleoclimate and glacial records from around the North Pacific, this study shows that the Laurentide-Eurasia-only ice sheet configuration fails in explaining these records, while a scenario involving the ice sheet over Northeast Siberia-Beringia succeeds. It highlights the complexity in glacial climates and urges new investigations across Northeast Siberia-Beringia.
Kelly A. Hogan, Martin Jakobsson, Larry Mayer, Brendan T. Reilly, Anne E. Jennings, Joseph S. Stoner, Tove Nielsen, Katrine J. Andresen, Egon Nørmark, Katrien A. Heirman, Elina Kamla, Kevin Jerram, Christian Stranne, and Alan Mix
The Cryosphere, 14, 261–286, https://doi.org/10.5194/tc-14-261-2020, https://doi.org/10.5194/tc-14-261-2020, 2020
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Glacial sediments in fjords hold a key record of environmental and ice dynamic changes during ice retreat. Here we use a comprehensive geophysical survey from the Petermann Fjord system in NW Greenland to map these sediments, identify depositional processes and calculate glacial erosion rates for the retreating palaeo-Petermann ice stream. Ice streaming is the dominant control on glacial erosion rates which vary by an order of magnitude during deglaciation and are in line with modern rates.
Martin Jakobsson, Matt O'Regan, Carl-Magnus Mörth, Christian Stranne, Elizabeth Weidner, Jim Hansson, Richard Gyllencreutz, Christoph Humborg, Tina Elfwing, Alf Norkko, Joanna Norkko, Björn Nilsson, and Arne Sjöström
Earth Surf. Dynam., 8, 1–15, https://doi.org/10.5194/esurf-8-1-2020, https://doi.org/10.5194/esurf-8-1-2020, 2020
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We studied coastal sea floor terraces in parts of the Baltic Sea using various types of sonar data, sediment cores, and video. Terraces (~1 m high, > 100 m long) are widespread in depths < 15 m and are formed in glacial clay. Our study supports an origin from groundwater flow through silty layers, undermining overlying layers when discharged at the sea floor. Submarine groundwater discharge like this may be a significant source of freshwater to the Baltic Sea that needs to be studied further.
Christian Stranne, Matt O'Regan, Martin Jakobsson, Volker Brüchert, and Marcelo Ketzer
Solid Earth, 10, 1541–1554, https://doi.org/10.5194/se-10-1541-2019, https://doi.org/10.5194/se-10-1541-2019, 2019
Martin Jakobsson, Christian Stranne, Matt O'Regan, Sarah L. Greenwood, Bo Gustafsson, Christoph Humborg, and Elizabeth Weidner
Ocean Sci., 15, 905–924, https://doi.org/10.5194/os-15-905-2019, https://doi.org/10.5194/os-15-905-2019, 2019
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The bottom topography of the Baltic Sea is analysed using the digital depth model from the European Marine Observation and Data Network (EMODnet) published in 2018. Analyses include depth distribution vs. area and seafloor depth variation on a kilometre scale. The limits for the Baltic Sea and analysed sub-basins are from HELCOM. EMODnet is compared with the previously most widely used depth model and the area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper.
Birgit Wild, Natalia Shakhova, Oleg Dudarev, Alexey Ruban, Denis Kosmach, Vladimir Tumskoy, Tommaso Tesi, Hanna Joß, Helena Alexanderson, Martin Jakobsson, Alexey Mazurov, Igor Semiletov, and Örjan Gustafsson
The Cryosphere Discuss., https://doi.org/10.5194/tc-2018-229, https://doi.org/10.5194/tc-2018-229, 2018
Revised manuscript not accepted
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The thaw and degradation of subsea permafrost on the Arctic Ocean shelves is one of the key uncertainties concerning natural greenhouse gas emissions since difficult access limits the availability of observational data. In this study, we describe sediment properties and age constraints of a unique set of three subsea permafrost cores from the East Siberian Arctic Shelf, as well as content, origin and degradation state of organic matter at the current thaw front.
Zhongshi Zhang, Qing Yan, Elizabeth J. Farmer, Camille Li, Gilles Ramstein, Terence Hughes, Martin Jakobsson, Matt O'Regan, Ran Zhang, Ning Tan, Camille Contoux, Christophe Dumas, and Chuncheng Guo
Clim. Past Discuss., https://doi.org/10.5194/cp-2018-79, https://doi.org/10.5194/cp-2018-79, 2018
Revised manuscript not accepted
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Our study challenges the widely accepted idea that the Laurentide-Eurasian ice sheets gradually extended across North America and Northwest Eurasia, and suggests the growth of the NH ice sheets is much more complicated. We find climate feedbacks regulate the distribution of the NH ice sheets, producing swings between two distinct ice sheet configurations: the Laurentide-Eurasian and a circum-Arctic configuration, where large ice sheets existed over Northeast Siberia and the Canadian Rockies.
Christian Stranne, Larry Mayer, Martin Jakobsson, Elizabeth Weidner, Kevin Jerram, Thomas C. Weber, Leif G. Anderson, Johan Nilsson, Göran Björk, and Katarina Gårdfeldt
Ocean Sci., 14, 503–514, https://doi.org/10.5194/os-14-503-2018, https://doi.org/10.5194/os-14-503-2018, 2018
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The ocean surface mixed layer depth (MLD) is an important parameter within several research disciplines, as variations in the MLD influence air–sea CO2 exchange and ocean primary production. A new method is presented in which acoustic mapping of the MLD is done remotely by means of echo sounders. This method allows for observations of high-frequency variability in the MLD, as horizontal and temporal resolutions can be increased by orders of magnitude compared to traditional in situ measurements.
David K. Hutchinson, Agatha M. de Boer, Helen K. Coxall, Rodrigo Caballero, Johan Nilsson, and Michiel Baatsen
Clim. Past, 14, 789–810, https://doi.org/10.5194/cp-14-789-2018, https://doi.org/10.5194/cp-14-789-2018, 2018
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The Eocene--Oligocene transition was a major cooling event 34 million years ago. Climate model studies of this transition have used low ocean resolution or topography that roughly approximates the time period. We present a new climate model simulation of the late Eocene, with higher ocean resolution and topography which is accurately designed for this time period. These features improve the ocean circulation and gateways which are thought to be important for this climate transition.
Irina I. Pipko, Svetlana P. Pugach, Igor P. Semiletov, Leif G. Anderson, Natalia E. Shakhova, Örjan Gustafsson, Irina A. Repina, Eduard A. Spivak, Alexander N. Charkin, Anatoly N. Salyuk, Kseniia P. Shcherbakova, Elena V. Panova, and Oleg V. Dudarev
Ocean Sci., 13, 997–1016, https://doi.org/10.5194/os-13-997-2017, https://doi.org/10.5194/os-13-997-2017, 2017
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The study of the outer shelf and the continental slope waters of the Eurasian Arctic seas has revealed a general trend in the surface pCO2 distribution, which manifested as an increase in pCO2 values eastward. It has been shown that the influence of terrestrial discharge on the carbonate system of East Siberian Arctic sea surface waters is not limited to the shallow shelf and that contemporary climate change impacts the carbon cycle of the Eurasian Arctic Ocean and influences air–sea CO2 flux.
Laura Gemery, Thomas M. Cronin, Robert K. Poirier, Christof Pearce, Natalia Barrientos, Matt O'Regan, Carina Johansson, Andrey Koshurnikov, and Martin Jakobsson
Clim. Past, 13, 1473–1489, https://doi.org/10.5194/cp-13-1473-2017, https://doi.org/10.5194/cp-13-1473-2017, 2017
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Continuous, highly abundant and well-preserved fossil ostracodes were studied from radiocarbon-dated sediment cores collected on the Lomonosov Ridge (Arctic Ocean) that indicate varying oceanographic conditions during the last ~50 kyr. Ostracode assemblages from cores taken during the SWERUS-C3 2014 Expedition, Leg 2, reflect paleoenvironmental changes during glacial, deglacial, and interglacial transitions, including changes in sea-ice cover and Atlantic Water inflow into the Eurasian Basin.
Matt O'Regan, Jan Backman, Natalia Barrientos, Thomas M. Cronin, Laura Gemery, Nina Kirchner, Larry A. Mayer, Johan Nilsson, Riko Noormets, Christof Pearce, Igor Semiletov, Christian Stranne, and Martin Jakobsson
Clim. Past, 13, 1269–1284, https://doi.org/10.5194/cp-13-1269-2017, https://doi.org/10.5194/cp-13-1269-2017, 2017
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Past glacial activity on the East Siberian continental margin is poorly known, partly due to the lack of geomorphological evidence. Here we present geophysical mapping and sediment coring data from the East Siberian shelf and slope revealing the presence of a glacially excavated cross-shelf trough reaching to the continental shelf edge north of the De Long Islands. The data provide direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum.
Thomas M. Cronin, Matt O'Regan, Christof Pearce, Laura Gemery, Michael Toomey, Igor Semiletov, and Martin Jakobsson
Clim. Past, 13, 1097–1110, https://doi.org/10.5194/cp-13-1097-2017, https://doi.org/10.5194/cp-13-1097-2017, 2017
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Global sea level rise during the last deglacial flooded the Siberian continental shelf in the Arctic Ocean. Sediment cores, radiocarbon dating, and microfossils show that the regional sea level in the Arctic rose rapidly from about 12 500 to 10 700 years ago. Regional sea level history on the Siberian shelf differs from the global deglacial sea level rise perhaps due to regional vertical adjustment resulting from the growth and decay of ice sheets.
Martin Jakobsson, Christof Pearce, Thomas M. Cronin, Jan Backman, Leif G. Anderson, Natalia Barrientos, Göran Björk, Helen Coxall, Agatha de Boer, Larry A. Mayer, Carl-Magnus Mörth, Johan Nilsson, Jayne E. Rattray, Christian Stranne, Igor Semiletov, and Matt O'Regan
Clim. Past, 13, 991–1005, https://doi.org/10.5194/cp-13-991-2017, https://doi.org/10.5194/cp-13-991-2017, 2017
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The Arctic and Pacific oceans are connected by the presently ~53 m deep Bering Strait. During the last glacial period when the sea level was lower than today, the Bering Strait was exposed. Humans and animals could then migrate between Asia and North America across the formed land bridge. From analyses of sediment cores and geophysical mapping data from Herald Canyon north of the Bering Strait, we show that the land bridge was flooded about 11 000 years ago.
Johan Nilsson, Martin Jakobsson, Chris Borstad, Nina Kirchner, Göran Björk, Raymond T. Pierrehumbert, and Christian Stranne
The Cryosphere, 11, 1745–1765, https://doi.org/10.5194/tc-11-1745-2017, https://doi.org/10.5194/tc-11-1745-2017, 2017
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Recent data suggest that a 1 km thick ice shelf extended over the glacial Arctic Ocean during MIS 6, about 140 000 years ago. Here, we theoretically analyse the development and equilibrium features of such an ice shelf. The ice shelf was effectively dammed by the Fram Strait and the mean ice-shelf thickness was controlled primarily by the horizontally integrated mass balance. Our results can aid in resolving some outstanding questions of the state of the glacial Arctic Ocean.
Clint M. Miller, Gerald R. Dickens, Martin Jakobsson, Carina Johansson, Andrey Koshurnikov, Matt O'Regan, Francesco Muschitiello, Christian Stranne, and Carl-Magnus Mörth
Biogeosciences, 14, 2929–2953, https://doi.org/10.5194/bg-14-2929-2017, https://doi.org/10.5194/bg-14-2929-2017, 2017
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Continental slopes north of the East Siberian Sea are assumed to hold large amounts of methane. We present pore water chemistry from the 2014 SWERUS-C3 expedition. These are among the first results generated from this vast climatically sensitive region, and they imply that abundant methane, including gas hydrates, do not characterize the East Siberian Sea slope or rise. This contradicts previous modeling and discussions, which due to the lack of data are almost entirely based assumption.
Leif G. Anderson, Göran Björk, Ola Holby, Sara Jutterström, Carl Magnus Mörth, Matt O'Regan, Christof Pearce, Igor Semiletov, Christian Stranne, Tim Stöven, Toste Tanhua, Adam Ulfsbo, and Martin Jakobsson
Ocean Sci., 13, 349–363, https://doi.org/10.5194/os-13-349-2017, https://doi.org/10.5194/os-13-349-2017, 2017
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We use data collected in 2014 to show that the outflow of nutrient-rich water occurs much further to the west than has been reported in the past. We suggest that this is due to much less summer sea-ice coverage in the northwestern East Siberian Sea than in the past decades. Further, our data support a more complicated flow pattern in the region where the Mendeleev Ridge reaches the shelf compared to the general cyclonic circulation within the individual basins as suggested historically.
Christof Pearce, Aron Varhelyi, Stefan Wastegård, Francesco Muschitiello, Natalia Barrientos, Matt O'Regan, Thomas M. Cronin, Laura Gemery, Igor Semiletov, Jan Backman, and Martin Jakobsson
Clim. Past, 13, 303–316, https://doi.org/10.5194/cp-13-303-2017, https://doi.org/10.5194/cp-13-303-2017, 2017
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The eruption of the Alaskan Aniakchak volcano of 3.6 thousand years ago was one of the largest Holocene eruptions worldwide. The resulting ash is found in several Alaskan sites and as far as Newfoundland and Greenland. In this study, we found ash from the Aniakchak eruption in a marine sediment core from the western Chukchi Sea in the Arctic Ocean. Combined with radiocarbon dates on mollusks, the volcanic age marker is used to calculate the marine radiocarbon reservoir age at that time.
Leif G. Anderson, Jörgen Ek, Ylva Ericson, Christoph Humborg, Igor Semiletov, Marcus Sundbom, and Adam Ulfsbo
Biogeosciences, 14, 1811–1823, https://doi.org/10.5194/bg-14-1811-2017, https://doi.org/10.5194/bg-14-1811-2017, 2017
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Waters with very high pCO2, nutrients and low oxygen concentrations were observed along the continental margin of the East Siberian Sea and well out into the deep Makarov and Canada basins during the SWERUS-C3 expedition in 2014. This water had a low saturation state with respect to calcium carbonate, down to less than 0.8 for calcite and 0.5 for aragonite, and is traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean in the western Fram Strait.
Erik Gustafsson, Christoph Humborg, Göran Björk, Christian Stranne, Leif G. Anderson, Marc C. Geibel, Carl-Magnus Mörth, Marcus Sundbom, Igor P. Semiletov, Brett F. Thornton, and Bo G. Gustafsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-115, https://doi.org/10.5194/bg-2017-115, 2017
Preprint withdrawn
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In this study we quantify key carbon cycling processes on the East Siberian Arctic Shelf. A specific aim is to determine the pathways of terrestrial organic carbon (OC) supplied by rivers and coastline erosion – and particularly to what extent degradation of terrestrial OC contributes to air-sea CO2 exchange. We estimate that the shelf is a weak CO2 sink, although this sink is considerably reduced mainly by degradation of eroded OC and to a lesser extent by degradation of riverine OC.
Jörg Schwinger, Nadine Goris, Jerry F. Tjiputra, Iris Kriest, Mats Bentsen, Ingo Bethke, Mehmet Ilicak, Karen M. Assmann, and Christoph Heinze
Geosci. Model Dev., 9, 2589–2622, https://doi.org/10.5194/gmd-9-2589-2016, https://doi.org/10.5194/gmd-9-2589-2016, 2016
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We present an evaluation of the ocean carbon cycle stand-alone configuration of the Norwegian Earth System Model. A re-tuning of the ecosystem parameterisation improves surface tracer fields between versions 1 and 1.2 of the model. Focus is placed on the evaluation of newly implemented parameterisations of the biological carbon pump (i.e. the sinking of particular organic carbon). We find that the model previously underestimated the carbon transport into the deep ocean below 2000 m depth.
M. Löfverström, R. Caballero, J. Nilsson, and J. Kleman
Clim. Past, 10, 1453–1471, https://doi.org/10.5194/cp-10-1453-2014, https://doi.org/10.5194/cp-10-1453-2014, 2014
M. Berger, J. Brandefelt, and J. Nilsson
Clim. Past, 9, 969–982, https://doi.org/10.5194/cp-9-969-2013, https://doi.org/10.5194/cp-9-969-2013, 2013
F. O. Nitsche, K. Gohl, R. D. Larter, C.-D. Hillenbrand, G. Kuhn, J. A. Smith, S. Jacobs, J. B. Anderson, and M. Jakobsson
The Cryosphere, 7, 249–262, https://doi.org/10.5194/tc-7-249-2013, https://doi.org/10.5194/tc-7-249-2013, 2013
Related subject area
Approach: In situ Observations | Depth range: All Depths | Geographical range: Deep Seas: Arctic Ocean | Phenomena: Current Field
Problems with estimation and interpretation of oceanic heat transport – conceptual remarks for the case of Fram Strait in the Arctic Ocean
U. Schauer and A. Beszczynska-Möller
Ocean Sci., 5, 487–494, https://doi.org/10.5194/os-5-487-2009, https://doi.org/10.5194/os-5-487-2009, 2009
Cited articles
Aksenov, Y., Ivanov, V. V., Nurser, A. J. G., Bacon, S., Polyakov, I. V.,
Coward, A. C., Naveira-Garabato, A. C., and Beszczynska-Moeller, A.: The
Arctic Circumpolar Boundary Current, J. Geophys. Res., 116, C09017,
https://doi.org/10.1029/2010JC006637, 2011.
Anderson, L. G., Björk, G., Holby, O., Jones, E. P., Kattner, G.,
Koltermann, K. P., Liljebladh, B., Lindergren, R., Rudels, B., and Swift, J.:
Water masses and circulation in the Eurasian basin: results from the Oden 91
expedition, J. Geophys. Res., 99, 3273–3283, https://doi.org/10.1029/93JC02977, 1994.
Biastoch, A., Treude, T., Rüpke, L. H., Riebesell, U., Roth, C., Burwicz,
E. B., Park, W., Latif, M., Böning, C. W., Madec, G., and Wallmann, K.:
Rising Arctic Ocean temperatures cause gas hydrate destabilization and ocean
acidification, Geophys. Res. Lett., 38, L08602, https://doi.org/10.1029/2011GL047222,
2011.
Björk, G., Jakobsson, M., Rudels, B., Swift, J. H., Anderson, L., Darby,
D. A., Backman, J., Coakley, B., Winsor, P., Polyak, L., and Edwards, M.:
Bathymetry and deep-water exchange across the central Lomonosov Ridge at
88∘–89∘ N, Deep-Sea Res. I, 54, 1197–1208, 2007.
Björk, G., Anderson, L., Jakobsson, M., Antony, D., Eriksson, P. B.,
Eriksson, B., Hell, B., Hjalmarsson, S., Janzen, T., Jutterström, S.,
Linders, J., Löwemark, L., Marcussen, C., Olsson, K. A., Rudels, B.,
Sellén, E., and Sølvsten, M.: Flow of Canadian Basin Deep Water in the
Western Eurasian Basin of the Arctic Ocean, Deep-Sea Res. I, 57, 577–586,
https://doi.org/10.1016/j.dsr.2010.01.006, 2010.
Dmitrenko, I. A., Bauch, D., Kirillov, S. A., Koldunov, N., Minnett, P. J.,
Ivanov, V. V., Hölemann, J. A., and Timokhov, L. A.: Barents Sea upstream
events impact the properties of Atlantic water inflow into the Arctic Ocean:
Evidence from 2005 to 2006 downstream observations, Deep-Sea Res. I, 56,
513–527, https://doi.org/10.1016/j.dsr.2008.11.005, 2009.
Jakobsson, M., Nilsson, J., Anderson, L., Backman, J., Bjork, G., Cronin, T.
M., Kirchner, N., Koshurnikov, A., Mayer, L., Noormets, R., O'Regan, M.,
Stranne, C., Ananiev, R., Barrientos Macho, N., Cherniykh, D., Coxall, H.,
Eriksson, B., Floden, T., Gemery, L., Gustafsson, O., Jerram, K., Johansson,
C., Khortov, A., Mohammad, R., and Semiletov, I.: Evidence for an ice shelf
covering the central Arctic Ocean during the penultimate glaciation, Nature
Comm., 7, 1–10, https://doi.org/10.1038/ncomms10365, 2016.
Linders, J. and Björk, G.: The melt-freeze cycle of the Arctic Ocean ice
cover and its dependence on ocean stratification, J. Geophys. Res., 118,
5963–5976, https://doi.org/10.1002/jgrc.20409, 2013.
McDougall, T. J.: Double-diffusive interleaving. Part II: Finite amplitude,
steady state interleaving, J. Phys. Oceanogr., 15, 1542–1556, 1985.
Morison, J. , Kwok, R., Peralta-Ferriz, C., Alkire M., Rigor, I., Andersen,
R., and Steele, M.: Changing Arctic Ocean freshwater pathways, Nature, 481,
66–70, https://doi.org/10.1038/nature10705, 2012.
Münchow, A., Falkner, K. K., and Melling, H.: Spatial continuity of
measured seawater and tracer fluxes through Nares Strait, a dynamically wide
channel bordering the Canadian Archipelago, J. Mar. Res., 65, 759–788, 2007.
Naryshkin, G.: Bottom relief of the Arctic Ocean, bathymetric contour map,
scale 1:2 500 000, Russ. Acad. of Sci., St. Petersburg, Russia, 2001.
Nøst, O. A. and Isachsen, P. E.: The large-scale time-mean ocean
circulation in the Nordic Seas and Arctic Ocean estimated from simplified
dynamics, J. Mar. Res., 61, 175–210, https://doi.org/10.1357/002224003322005069, 2003.
Polyakov I. V., Timokhov, L. A., Alexeev, V. A., Bacon, S., Dmitrenko, I. A.,
Fortier, L., Frolov, I. E., Gascard, J.-C., Hansen, E., Ivanov, V. V., Laxon,
S., Mauritzen, C., Perovich, D., Shimada, K., Simmons, H. L., Sokolov, V. T.,
Steele, M. and Toole, J.: Arctic ocean warming contributes to reduced polar
ice cap, J. Phys. Oceanogr., 40, 2743–2756, https://doi.org/10.1175/2010JPO4339.1, 2010.
Polyakov, I. V., Pnyushkov, A. V., and Timokhov, L. A.: Warming of the
intermediate Atlantic Water of the Arctic Ocean in the 2000s, J. Climate.,
25, 8362–8370, https://doi.org/10.1175/JCLI-D-12-00266.1, 2012.
Rainville, L. and Winsor, P.: Mixing across the Arctic Ocean: Microstructure
observations during the Beringia 2005 Expedition, Geophys. Res. Lett., 35,
L08606, https://doi.org/10.1029/2008GL033532, 2008.
Rudels, B., Friedrich, H. J., and Quadfasel, D.: The Arctic Circumpolar
Boundary Current, Deep-Sea Res. Pt. II, 46, 1023–1062,
https://doi.org/10.1016/S0967-0645(99)00015-6, 1999a.
Rudels, B., Björk, G., Muench, R. D., and Schauer, U.: Double-Diffusive
layering in the Eurasian basin of the Arctic Ocean, J. Marine Syst., 21,
3–27, 1999b.
Rudels, B., Muench, R. D., Gunn, J., Schauer, U., and Friedrich, H. J.:
Evolution of the Arctic Ocean boundary current north of the Siberian shelves,
J. Marine Syst. I, 25, 77–99, https://doi.org/10.1016/S0924-7963(00)00009-9, 2000.
Rudels, B., Schauer, U., Björk, G., Korhonen, M., Pisarev, S., Rabe, B.,
and Wisotzki, A.: Observations of water masses and circulation with focus on
the Eurasian Basin of the Arctic Ocean from the 1990s to the late 2000s,
Ocean Sci., 9, 147–169, https://doi.org/10.5194/os-9-147-2013, 2013.
Schauer, U., Rudels, B., Jones, E. P., Anderson, L. G., Muench, R. D.,
Björk, G., Swift, J. H., Ivanov, V., and Larsson, A.-M.: Confluence and
redistribution of Atlantic water in the Nansen, Amundsen and Makarov basins,
Ann. Geophys., 20, 257–273, https://doi.org/10.5194/angeo-20-257-2002, 2002.
Schauer, U., Rabe, B., and Wisotzki, A.: Physical oceanography during
POLARSTERN cruise ARK-XXVI/3 (TransArc), Alfred Wegener Institute, Helmholtz
Center for Polar and Marine Research, Bremerhaven,
https://doi.org/10.1594/PANGAEA.774181, 2012.
Sirevaag, A. and Fer, I.: Early spring oceanic heat fluxes and mixing
observed from drift stations north of Svalbard, J. Phys. Oceanogr., 39,
3049–3069, https://doi.org/10.1175/2009JPO4172.1, 2009.
Stranne, C., O'Regan, M., Dickens, G. R., Crill, P., Miller, C., Preto, P.,
and Jakobsson, M.: Dynamic simulations of potential methane release from East
Siberian continental slope sediments, Geochemistry, Geophysics, Geosystems,
17, 872–886, https://doi.org/10.1002/2015GC006119, 2016.
Westbrook, G. K., Thatcher, K. E., Rohling, E. J., Piotrowski, A. M.,
Pälike, H., Osborne, A. H., Nisbet, E. G., Minshull, T. A.,
Lanoisellé, M., James, R. H., Hühnerbach, V., Green, D., Fisher, R.
E., Crocker, A. J., Chabert, A., Bolton, C., Beszczynska-Möller, A.,
Berndt, C., and Aquilina, A.: Escape of methane gas from the seabed along the
West Spitsbergen continental margin, Geophys. Res. Lett., 36, L15608,
https://doi.org/10.1029/2009gl039191, 2009.
Woodgate, R. A., Aaagard, K., Muench, R. D., Gunn, J., Björk, G., Rudels,
B., Roach, A. T., and Schauer, U.: The Arctic Ocean boundary current along
the Eurasian slope and the adjacent Lomonosov Ridge: Water mass properties,
transports and transformation from moored instruments, Deep-Sea Res. I, 48,
1757–1792, 2001.
Short summary
This study presents detailed bathymetric data along with hydrographic data at two deep passages across the Lomonosov Ridge in the Arctic Ocean. The southern channel is relatively smooth with a sill depth close to 1700 m. Hydrographic data reveals an eastward flow in the southern part and opposite in the northern part. The northern passage is characterized by a narrow and steep ridge with a sill depth of 1470 m. Here, water exchange appears to occur in well-defined but irregular vertical layers.
This study presents detailed bathymetric data along with hydrographic data at two deep passages...
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