• Floating Ice-Algal Aggregates below melting Arctic Sea Ice 

      Assmy, P; Ehn, Jens K.; Fernandez-Mendez, M; Hop, H; Katlein, C; Sundfjord, Arild; Bluhm, K; Daase, Malin; Engel, A.; Fransson, A.; Granskog, M.A.; Hudson, SR; Kristiansen, Svein; Nicolaus, M.; Peeken, I.; Renner, AHH; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Josef (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained ...
    • Hydrography, inorganic nutrients and chlorophyll a linked to sea ice cover in the Atlantic Water inflow region north of Svalbard 

      Renner, Angelika; Bailey, Allison Michelle; Reigstad, Marit; Sundfjord, Arild; Chierici, Melissa; Jones, Elizabeth Marie (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-04)
      Changes in the inflow of Atlantic Water (AW) and its properties to the Arctic Ocean bring more warm water, contribute to sea ice decline, promote borealisation of marine ecosystems, and affect biological and particularly primary productivity in the Eurasian Arctic Ocean. One of the two branches of AW inflow follows the shelf break north of Svalbard, where it dominates oceanographic conditions, ...
    • The importance of turbulent ocean–sea ice nutrient exchanges for simulation of ice algal biomass and production with CICE6.1 and Icepack 1.2 

      Duarte, Pedro; Assmy, Philip; Campbell, Karley; Sundfjord, Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-31)
      Different sea ice models apply unique approaches in the computation of nutrient diffusion between the ocean and the ice bottom, which are generally decoupled from the calculation of turbulent heat flux. A simple molecular diffusion formulation is often used. We argue that nutrient transfer from the ocean to sea ice should be as consistent as possible with heat transfer, since all of these fluxes ...
    • The importance of turbulent ocean–sea ice nutrient exchanges for simulation of ice algal biomass and production with CICE6.1 and Icepack 1.2 

      Duarte, Pedro; Assmy, Philipp; Campbell, Karley; Sundfjord, Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-31)
      Different sea ice models apply unique approaches in the computation of nutrient diffusion between the ocean and the ice bottom, which are generally decoupled from the calculation of turbulent heat flux. A simple molecular diffusion formulation is often used. We argue that nutrient transfer from the ocean to sea ice should be as consistent as possible with heat transfer, since all of these fluxes ...
    • Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic 

      Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John; Olsen, Lasse; Kauko, Hanna M.; Bailey, Allison; Chierici, Melissa; Cohen, Lana; Doulgeris, Anthony Paul; Ehn, Jens K.; Fransson, Agneta; Gerland, Sebastian; Hop, Haakon; Hudson, Stephen R.; Hughes, Nick; Itkin, Polona; Johnsen, Geir; King, Jennifer A.; Koch, Boris P.; Koenig, Zoe; Kwasniewski, Slawomir; Laney, Samuel R.; Nikolaus, Marcel; Pavlov, Alexey K.; Polashenski, Christopher M.; Provost, Christine; Rösel, Anja; Sandbu, Marthe; Spreen, Gunnar; Smedsrud, Lars H.; Sundfjord, Arild; Taskjelle, Torbjørn; Tatarek, Agnieszka; Wiktor, Josef; Wagner, Penelope Mae; Wold, Anette; Steen, Harald; Granskog, Mats A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-19)
      The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating ...
    • Nutrients vs. turbulence, and the future of Arctic Ocean primary production 

      Randelhoff, Achim; Sundfjord, Arild; Fer, Ilker; Reigstad, Marit; Tremblay, Jean-Eric; Guthrie, John D. (Conference object; Konferansebidrag, 2016-11)
      This poster presents estimates of nitrate fluxes in the Arctic Ocean and speculates on the associated primary production in a future climate.
    • Overview of the MOSAiC expedition: Physical oceanography 

      Rabe, Benjamin; Baumann, Till Martin; Divine, Dmitry; Fer, Ilker; Gradinger, Rolf Rudolf; Granskog, Mats; Koenig, Zoe Charlotte; Muilwijk, Morven; Sundfjord, Arild; Heuze´, Céline; Regnery, Julia; Aksenov, Yevgeny; Allerholt, Jacob; Athanase, Marylou; Bai, Youcheng; Basque, Chris; Bauch, Dorothea; Chen, Dake; Cole, Sylvia T.; Craw, Lisa; Davies, Andrew; Damm, Ellen; Dethloff, Klaus; Doglioni, Francesca; Ebert, Falk; Fang, Ying-Chih; Fong, Allison A.; Graupner, Rainer; Haas, Christian; He, Hailun; He, Yan; Hoppmann, Mario; Janout, Markus; Kadko, David; Kanzow, Torsten; Karam, Salar; Kawaguchi, Yusuke; Kong, Bin; Krishfield, Richard A.; Krumpen, Thomas; Kuhlmey, David; Kuznetsov, Ivan; Lan, Musheng; Laukert, Georgi; Lei, Ruibo; Li, Lao; Torres-Valdés, Sinhué; Lin, Lina; Lin, Long; Liu, Hailong; Liu, Na; Loose, Brice; Ma, Xiaobing; McKay, Rosalie; Mallet, Maria; Mallet, Robbie D .C.; Maslowski, Wieslaw; Mertens, Christian; Mohrholz, Volker; Nicolaus, Marcel; O'Brien, Jeffrey K.; Perovich, Donald; Ren, Jian; Rex, Markus; Ribeiro, Natalia; Rinke, Annette; Sokolov, Vladimir; Sommerfeld, Anja; Spreen, Gunnar; Stanton, Timothy; Stephens, Mark; Su, Jie; Sukhikh, Natalia; Thomisch, Karolin; Tippenhauer, Sandra; Toole, John M.; Vredenborg, Myriel; Walter, Maren; Wang, Hangzhou; Wang, Lei; Wang, Yuntao; Wendisch, Manfred; Zhao, Jinping; Zhou, Meng; Zhu, Jialiang (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-07)
      Arctic Ocean properties and processes are highly relevant to the regional and global coupled climate system, yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography observations as part of the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC), a drift with the Arctic sea ice from October 2019 to September 2020. ...
    • Pelagic Ecosystem Characteristics Across the Atlantic Water Boundary Current from Rijpfjorden, Svalbard, to the Arctic Ocean during Summer (2010-2014) 

      Hop, Haakon; Assmy, Philipp; Wold, Anette; Sundfjord, Arild; Daase, Malin; Duarte, Pedro; Kwasniewski, Slawomir; Gluchowska, Marta; Wiktor, Józef Maria; Tatarek, Agnieszka; Wiktor, Józef Maria Jr.; Kristiansen, Svein; Fransson, Agneta Ingrid; Chierici, Melissa; Vihtakari, Mikko (Journal article; Peer reviewed, 2019-04-09)
      The northern coast of Svalbard contains high-arctic fjords, such as Rijpfjorden (80°N 22°30′E). This area has experienced higher sea and air temperatures and less sea ice in recent years, and models predict increasing temperatures in this region. Part of the West Spitsbergen Current (WSC), which transports relatively warm Atlantic water along the continental slope west of Svalbard, bypasses these ...
    • Potential drivers of sinking particle´s size spectra and vertical POC flux: Turbulence, phytoplankton and zooplankton 

      Wiedmann, Ingrid; Reigstad, Marit; Sundfjord, Arild; Basedow, Sünnje (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Sea ice thermohaline dynamics and biogeochemistry in the Arctic Ocean: Empirical and model results 

      Duarte, Pedro; Meyer, Amelie; Olsen, Lasse Mork; Kauko, Hanna Maria; Assmy, Philipp; Rösel, Anja; Itkin, Polona; Hudson, Stephen R.; Granskog, Mats A.; Gerland, Sebastian; Sundfjord, Arild; Steen, Harald; Hop, Haakon; Cohen, Lana; Peterson, Algot Kristoffer; Jeffery, Nicole; Elliott, Scott M.; Hunke, Elizabeth Clare; Turner, Adrian K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-11)
      Large changes in the sea ice regime of the Arctic Ocean have occurred over the last decades justifying the development of models to forecast sea ice physics and biogeochemistry. The main goal of this study is to evaluate the performance of the Los Alamos Sea Ice Model (CICE) to simulate physical and biogeochemical properties at time scales of a few weeks and to use the model to analyze ice algal ...
    • Seasonal variability and fluxes of nitrate in the surface waters over the Arctic shelf slope 

      Randelhoff, Achim; Sundfjord, Arild; Reigstad, Marit (Conference object; Konferansebidrag, 2015-03)
      Understanding the present state and possible future scenarios of Arctic Ocean primary productivity has been hampered by the scarcity of year-round nutrient measurements. Here, the first year-long moored timeseries of near-surface nitrate concentrations in the Eastern Arctic, together with hydrography, currents and chlorophyll-a fluorescence, is reported from ...
    • Seasonal variation in transport of zooplankton into the Arctic Basin through the Atlantic gateway, Fram Strait 

      Basedow, Sünnje Linnéa; Sundfjord, Arild; von Appen, Wilken-Jon; Halvorsen, Elisabeth; Kwasniewski, Slawomir; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-04)
      The largest contribution of oceanic heat to the Arctic Ocean is the warm Atlantic Water (AW) inflow through the deep Fram Strait. The AW current also carries Atlantic plankton into the Arctic Basin and this inflow of zooplankton biomass through the Atlantic-Arctic gateway far exceeds the inflow through the shallow Pacific-Arctic gateway. However, because this transport has not yet been adequately ...
    • Seasonality of the Physical and Biogeochemical Hydrography in the Inflow to the Arctic Ocean Through Fram Strait 

      Randelhoff, Achim; Reigstad, Marit; Chierici, Melissa; Sundfjord, Arild; Ivanov, Vladimir; Cape, Matthias; Vernet, Maria; Tremblay, Jean-Éric; Bratbak, Gunnar; Kristiansen, Svein (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-29)
      Eastern Fram Strait and the shelf slope region north of Svalbard is dominated by the advection of warm, salty and nutrient-rich Atlantic Water (AW). This oceanic heat contributes to keeping the area relatively free of ice. The last years have seen a dramatic decrease in regional sea ice extent, which is expected to drive large increases in pelagic primary production and thereby changes in marine ...
    • Still Arctic? — The changing Barents Sea 

      Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa; Hop, Haakon; Renaud, Paul Eric; Smedsrud, Lars Henrik; Stige, Leif Christian; Årthun, Marius; Berge, Jørgen; Bluhm, Bodil Annikki Ulla Barbro; Borgå, Katrine; Bratbak, Gunnar; Divine, Dmitry V; Eldevik, Tor; Eriksen, Elena; Fer, Ilker; Fransson, Agneta; Gradinger, Rolf Rudolf; Granskog, Mats A.; Haug, Tore; Husum, Katrine; Johnsen, Geir; Jonassen, Marius Opsanger; Jørgensen, Lis Lindal; Kristiansen, Svein; Larsen, Aud; Lien, Vidar Surén; Lind, Sigrid; Lindstrøm, Ulf Ove; Mauritzen, Cecilie; Melsom, Arne; Mernild, Sebastian H.; Müller, Malte; Nilsen, Frank; Primicerio, Raul; Søreide, Janne; van der Meeren, Gro Ingleid; Wassmann, Paul (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-13)
      The Barents Sea is one of the Polar regions where current climate and ecosystem change is most pronounced. Here we review the current state of knowledge of the physical, chemical and biological systems in the Barents Sea. Physical conditions in this area are characterized by large seasonal contrasts between partial sea-ice cover in winter and spring versus predominantly open water in summer and ...
    • Upward nitrate flux and downward particulate organic carbon flux under contrasting situations of stratification and turbulent mixing in an Arctic shelf sea 

      Wiedmann, Ingrid; Tremblay, Jean-Éric; Sundfjord, Arild; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-02)
      Increased sea ice melt alters vertical surface-mixing processes in Arctic seas. More melt water strengthens the stratification, but an absent ice cover also exposes the uppermost part of the water column to wind-induced mixing processes. We conducted a field study in the Barents Sea, an Arctic shelf sea, to examine the effects of stratification and vertical mixing processes on 1) the upward nitrate ...
    • Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean 

      Randelhoff, Achim; Fer, Ilker; Sundfjord, Arild; Tremblay, Jean-Éric; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-31)
      <p>This study compiles colocated oceanic observations of high-resolution vertical profiles of nitrate concentration and turbulent microstructure around the Svalbard shelf slope, covering both the permanently ice-free Fram Strait and the pack ice north of Svalbard. The authors present an overview over the seasonal evolution of the distribution of nitrate and its relation to upper ocean stratification. ...
    • Winter storms accelerate the demise of sea ice in the Atlantic sector of the Arctic Ocean 

      Graham, Robert M.; Itkin, Polona; Meyer, Amelie; Sundfjord, Arild; Spreen, Gunnar; Smedsrud, Lars H.; Liston, Glen E.; Cheng, Bin; Cohen, Lana; Divine, Dmitry; Fer, Ilker; Fransson, Agneta; Gerland, Sebastian; Haapala, Jari; Hudson, Stephen R.; Johansson, Malin; King, Jennifer A.; Merkouriadi, Ioanna; Peterson, Algot Kristoffer; Provost, Christine; Randelhoff, Achim; Rinke, Annette; Rösel, Anja; Sennechael, Nathalie; Walden, Von P.; Duarte, Pedro; Assmy, Philipp; Steen, Harald; Granskog, Mats A. (Journal article; Peer reviewed, 2019-06-25)
      A large retreat of sea-ice in the ‘stormy’ Atlantic Sector of the Arctic Ocean has become evident through a series of record minima for the winter maximum sea-ice extent since 2015. Results from the Norwegian young sea ICE (N-ICE2015) expedition, a five-month-long (Jan-Jun) drifting ice station in first and second year pack-ice north of Svalbard, showcase how sea-ice in this region is frequently ...