Blar i forfatter "Peeken, Ilka"

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    • Ballasting by cryogenic gypsum enhances carbon export in a Phaeocystis under-ice bloom 

      Wollenburg, JE; Katlein, C; Nehrke, Gernot; Nöthig, E.-M; Matthiessen, J; Wolf-Gladrow, Dieter A.; Nikolopoulos, A.; Gazquez-Sanchez, F; Rossmann, L; Assmy, Philipp; Babin, Marcel; Bruyant, F; Beaulieu, Michaël; Dybwad, Christine; Peeken, Ilka (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-16)
      Mineral ballasting enhances carbon export from the surface to the deep ocean; however, little is known about the role of this process in the ice-covered Arctic Ocean. Here, we propose gypsum ballasting as a new mechanism that likely facilitated enhanced vertical carbon export from an under-ice phytoplankton bloom dominated by the haptophyte Phaeocystis. In the spring 2015 abundant gypsum crystals ...

    • Carbon export in the seasonal sea ice zone north of Svalbard from winter to late summer 

      Dybwad, Christine; Assmy, Philipp; Olsen, Lasse Mork; Peeken, Ilka; Nikolopoulos, Anna; Krumpen, Thomas; Randelhoff, Achim; Tatarek, Agnieszka; Wiktor, Józef M.; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-21)
      Phytoplankton blooms in the Arctic Ocean's seasonal sea ice zone are expected to start earlier and occur further north with retreating and thinning sea ice cover. The current study is the first compilation of phytoplankton bloom development and fate in the seasonally variable sea ice zone north of Svalbard from winter to late summer, using short-term sediment trap deployments. Clear seasonal patterns ...

    • Changes in Sea-Ice Protist Diversity With Declining Sea Ice in the Arctic Ocean From the 1980s to 2010s 

      Hop, Haakon; Vihtakari, Mikko; Bluhm, Bodil; Assmy, Philipp; Poulin, Michel; Gradinger, Rolf; Peeken, Ilka; von Quillfeldt, Cecilie; Olsen, Lasse Mork; Zhitina, Ludmila; Melnikov, Igor A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-06)
      The large declines in Arctic sea-ice age and extent over the last decades could have altered the diversity of sea-ice associated unicellular eukaryotes (referred to as sea-ice protists). A time series from the Russian ice-drift stations from the 1980s to the 2010s revealed changes in community composition and diversity of sea-ice protists from the Central Arctic Ocean. However, these observations ...

    • The future of Arctic sea-ice biogeochemistry and ice-associated ecosystems 

      Lannuzel, Delphine; Tedesco, Letizia; Leeuwe, Maria van; Campbell, Karley; Flores, Hauke; Delille, Bruno; Miller, Lisa; Stefels, Jacqueline; Assmy, Philipp; Bowman, Jeff; Brown, Kristina; Castellani, Giulia; Chierici, Melissa; Crabeck, Odile; Damm, Ellen; Else, Brent; Fransson, Agneta; Fripiat, Francois; Geilfus, Nicolas-Xavier; Jacques, Caroline; Jones, Elizabeth; Kaartokallio, Hermanni; kotovitch, marie; Meiners, Klaus M.; Moreau, Sebastien; Nomura, Daiki; Peeken, Ilka; Rintala, Janne-Markus; Steiner, Nadja; Tison, Jean-Louis; Vancoppenolle, Martin; Linden, Fanny Van der; Vichi, Marcello; Wongpan, Pat (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-27)
      The Arctic sea-ice-scape is rapidly transforming. Increasing light penetration will initiate earlier seasonal primary production. This earlier growing season may be accompanied by an increase in ice algae and phytoplankton biomass, augmenting the emission of dimethylsulfide and capture of carbon dioxide. Secondary production may also increase on the shelves, although the loss of sea ice exacerbates ...

    • Macrofauna and meiofauna food-web structure from Arctic fjords to deep Arctic Ocean during spring: A stable isotope approach 

      Oleszczuk, Barbara; Silberberger, Marc Jürgen; Grzelak, Katarzyna; Winogradow, Aleksandra; Dybwad, Christine Schumann; Peeken, Ilka; Wiedmann, Ingrid; Kędra, Monika (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-13)
      The knowledge on benthic trophic relations is particularly important for understanding the functioning of still pristine and less studied Arctic Ocean ecosystems. This study examines the benthic food-web structure in the European sector of the Arctic Ocean and assesses if and how it differs along depth gradients in the marginal seaice zone during spring. Samples of the sediment organic matter were ...

    • A red tide in the pack ice of the Arctic Ocean 

      Olsen, Lasse Mork; Duarte, Pedro; Peralta-Ferriz, Cecilia; Kauko, Hanna Maria; Johansson, Malin; Peeken, Ilka; Różańska-Pluta, Magdalena; Tatarek, Agnieszka; Wiktor, Jozef; Fernández-Méndez, Mar; Wagner, Penelope Mae; Pavlov, Alexey K.; Hop, Haakon; Assmy, Phillipp (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-02)
      In the Arctic Ocean ice algae constitute a key ecosystem component and the ice algal spring bloom a critical event in the annual production cycle. The bulk of ice algal biomass is usually found in the bottom few cm of the sea ice and dominated by pennate diatoms attached to the ice matrix. Here we report a red tide of the phototrophic ciliate <i>Mesodinium rubrum</i> located at the ice-water interface ...

    • Sea-ice associated carbon flux in Arctic spring 

      Ehrlich, Julia; Bluhm, Bodil; Peeken, Ilka; Massicotte, P.; Schaafsma, Fokje L.; Castellani, Guilia; Brandt, Angelika; Flores, Hauke (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-13)
      The Svalbard region faces drastic environmental changes, including sea-ice loss and “Atlantification” of Arctic waters, caused primarily by climate warming. These changes result in shifts in the sea-ice-associated (sympagic) community structure, with consequences for the sympagic food web and carbon cycling. To evaluate the role of sympagic biota as a source, sink, and transmitter of carbon, we ...

    • The seeding of ice algal blooms in Arctic pack ice: The multiyear ice seed repository hypothesis 

      Olsen, Lasse Mork; Laney, Samuel R.; Duarte, Pedro; Kauko, Hanna M.; Fernández-Méndez, Mar; Mundy, Christopher John; Rösel, Anja; Meyer, Amelie; Itkin, Polona; Cohen, Lana; Peeken, Ilka; Tatarek, Agnieszka; Róźańska-Pluta, Magdalena; Wiktor, Josef; Taskjelle, Torbjørn; Pavlov, Alexey; Hudson, Stephen R.; Granskog, Mats A.; Hop, Haakon; Assmy, Philipp (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-03)
      During the Norwegian young sea ICE expedition (N-ICE2015) from January to June 2015 the pack ice in the Arctic Ocean north of Svalbard was studied during four drifts between 83° and 80°N. This pack ice consisted of a mix of second year, fi rst year, and young ice. The physical properties and ice algal community composition was investigated in the three different ice types during the ...

    • Sympagic fauna in and under Arctic pack ice in the annual sea ice system of the new Arctic Frontiers in Marine Science 

      Ehrlich, Julia; Schaafsma, Fokje L.; Bluhm, Bodil; Peeken, Ilka; Castellani, Guilia; Brandt, Angelika; Flores, Hauke (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-19)
      A strong decline and thinning of the Arctic sea-ice cover over the past five decades has been documented. The former multiyear sea-ice system has largely changed to an annual system and with it the dynamics of sea-ice transport across the Arctic Ocean. Less sea ice is reaching the Fram Strait and more ice and ice-transported material is released in the northern Laptev Sea and the central Arctic ...