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Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean
(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. ...
Upward nitrate flux and downward particulate organic carbon flux under contrasting situations of stratification and turbulent mixing in an Arctic shelf sea
(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 ...
Seasonality of vertical flux and sinking particle characteristics in an ice-free high arctic fjord—Different from subarctic fjords?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-23)
The arctic Adventfjorden (78°N, 15°E, Svalbard) used to be seasonally ice-covered but has mostly been ice-free
since 2007. We used this ice-free arctic fjord as a model area to investigate (1) how the vertical
fl
ux of biomass
(chlorophyll
a
and particulate organic carbon, POC) follows the seasonality of suspended material, (2) how sink-
ing particle characteristics change seasonally and ...
Arctic Ocean outflow shelves in the changing Arctic: A review and perspectives
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-28)
Over the past decade or so, international research efforts, many of which were part of the International Polar Year, have accrued our understanding of the Arctic outflow shelves. The Arctic outflow shelves, namely the East Greenland Shelf (EGS) and the Canadian Arctic Archipelago (CAA), serve as conduits through which Arctic sea ice and waters and their properties are exported to the North Atlantic. ...
Effects of mortality changes on biomass and production in Calanus spp. populations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011-04-28)
Calanus species are the main link between primary producers and higher trophic-level organisms in the Barents Sea. The natural mortality rate is an essential parameter for determining the standing stock of Calanus, but it is also one of the most uncertain parameters in present knowledge. The level of human activity, and the associated risk of pollution, is increasing in the Barents Sea, and knowledge ...
Spring bloom dynamics in Kongsfjorden, Svalbard: nutrients, phytoplankton, protozoans and primary production
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
The marine ecosystem in Kongsfjorden (79 N), a glacial fjord in Svalbard, is to a large extent well known with regard to hydrography, mesozooplankton and higher trophic levels. Research on primary production and lower trophic levels is still scare and especially investigations from winter and spring periods. The spring bloom dynamics in Kongsfjordenwere investigated in 2002. The development in ...
Episodic Arctic CO2 Limitation in the West Svalbard Shelf
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-06)
The European Sector of the Arctic Ocean is characterized by low CO<sub>2</sub> concentrations in seawater during spring and summer, largely due to strong biological uptake driven by extensive plankton blooms in spring. The spring plankton bloom is eventually terminated by nutrient depletion and grazing. However, low CO<sub>2</sub> concentrations in seawater and low atmospheric resupply of CO<sub>2</sub> ...
Seasonal dynamics of meroplankton in a high-latitude fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-09)
Knowledge on the seasonal timing and composition of pelagic larvae of many benthic invertebrates, referred to as meroplankton, is limited for high-latitude fjords and coastal areas. We investigated the seasonal dynamics of meroplankton in the sub-Arctic Porsangerfjord (70°N), Norway, by examining their seasonal changes in relation to temperature, chlorophyll a and salinity. Samples were collected ...
Continuous daylight in the high-Arctic summer supports high plankton respiration rates compared to those supported in the dark
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-28)
Plankton respiration rate is a major component of global CO2 production and is forecasted to increase rapidly in the Arctic with warming. Yet, existing assessments in the Arctic evaluated plankton respiration in the dark. Evidence that plankton respiration may be stimulated in the light is particularly relevant for the high Arctic where plankton communities experience continuous daylight in spring ...
Spatial patterns of spring meroplankton along environmental gradients in a sub-Arctic fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)
The spatial patterns in abundance and composition of benthic invertebrate larvae
(meroplankton), the correlation between these patterns and environmental variables (temperature,
salinity and chl a) and the relative abundance of meroplankton in the mesozooplankton community
were investigated in the sub-Arctic Porsangerfjord, Norway (70° N). Zooplankton samples
and CTD-profiles were collected at ...