Now showing items 1-4 of 4

    • Arctic Observations Identify Phytoplankton Community Composition as Driver of Carbon Flux Attenuation 

      Wiedmann, Ingrid; Ceballos-Romero, E.; Villa-Alfageme, M.; Renner, Angelika; Dybwad, Christine; van der Jagt, Helga; Svensen, Camilla; Assmy, Philipp; Wiktor, Josef; Tatarek, Agnieszka; Różańska‐Pluta, M.; Iversen, Morten H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-24)
      The attenuation coefficient <i>b</i> is one of the most common ways to describe how strong the carbon flux is attenuated throughout the water column. Therefore, <i>b</i> is an essential input variable in many carbon flux and climate models. Marsay et al. (2015, <a href=https://doi.org/10.1073/pnas.1415311112>https://doi.org/10.1073/pnas.1415311112</a>) proposed that the median surface water temperature ...
    • 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 ...
    • Early spring subglacial discharge plumes fuel under-ice primary production at a Svalbard tidewater glacier 

      Vonnahme, Tobias; Persson, Emma; Dietrich, Ulrike; Hejdukova, Eva; Dybwad, Christine; Elster, Josef; Chierici, Melissa; Gradinger, Rolf (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-27)
      Subglacial upwelling of nutrient-rich bottom water is known to sustain elevated summer primary production in tidewater-glacier-influenced fjord systems. However, the importance of subglacial upwelling during the early spring season has not been considered yet. We hypothesized that subglacial discharge under sea ice is present in early spring and that its flux is sufficient to increase phytoplankton ...