English
norskBlar i forfatter "Dybwad, Christine"
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Arctic Observations Identify Phytoplankton Community Composition as Driver of Carbon Flux Attenuation
(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
(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
(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
(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 ... -
Fate of production in the Arctic seasonal ice zone. An investigation of suspended biomass, vertical export and the impact of grazers during the onset of the spring bloom north of Svalbard
(Master thesis; Mastergradsoppgave, 2016-05-15)In the Arctic Ocean, biological productivity is largely determined by sea ice, making the seasonal sea ice zone (SSIZ) its most productive region. The current study is a combined investigation of the suspended biomass, vertical export of organic material, and potential retention processes by zooplankton, during a crucial period of bloom development in the Eurasian SSIZ north of Svalbard, where few ... -
Vertical Carbon Export in a Changing Arctic Seasonal Ice Zone: Composition and seasonality in the area north of Svalbard and in an Arctic glacial fjord
(Doctoral thesis; Doktorgradsavhandling, 2023-12-11)The ocean’s biological carbon pump (BCP) is a vital part of the global carbon cycle as it produces, transforms, and transfers organic carbon from the surface ocean to the deep. To model the oceans capacity to store carbon today and in the future, we need to understand these processes well. In the Eurasian Arctic, the marine ecosystems who control most of the BCP face a rapid decline in sea ice cover, ...
