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dc.contributor.authorWiedmann, Ingrid
dc.contributor.authorTremblay, Jean-Éric
dc.contributor.authorSundfjord, Arild
dc.contributor.authorReigstad, Marit
dc.date.accessioned2017-08-08T08:37:53Z
dc.date.available2017-08-08T08:37:53Z
dc.date.issued2017-08-02
dc.description.abstractIncreased 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 flux (into surface layers <65 m) and 2) the downward flux of particulate organic carbon (POC) to ≤200 m. In the Arctic-influenced, drift ice-covered northern Barents Sea, we found a low upward nitrate flux into the surface layers (<0.1 mmol nitrate m<sup>–2</sup> d<sup>–1</sup>) and a moderate downward POC flux (40–200 m: 150–250 mg POC m<sup>–2</sup> d<sup>–1</sup>) during the late phase of a peak bloom. A 1-D residence time calculation indicated that the nitrate concentration in the surface layers constantly declined. In the Atlantic-influenced, ice-free, and weakly stratified southern Barents Sea a high upward nitrate flux was found (into the surface layers ≤25 m: >5 mmol nitrate m<sup>–2</sup> d<sup>–1</sup>) during a post bloom situation which was associated with a high downward POC flux (40–120 m: 260–600 mg POC m<sup>–2</sup> d<sup>–1</sup>). We suggest that strong wind events during our field study induced vertical mixing processes and triggered upwards nitrate flux, while a combination of down-mixed phytoplankton and fast-sinking mesozooplankton fecal pellets enhanced the downward POC flux. The results of this study underscore the need to further investigate the role of strong, episodic wind events on the upward nitrate and downward POC fluxes in weakly stratified regions of the Arctic that may be ice-free in future.en_US
dc.descriptionA manuscript version of this article was part of Ingrid Wiedmann's doctoral thesis, which is available in Munin at <a href=http://hdl.handle.net/10037/8293>http://hdl.handle.net/10037/8293</a>en_US
dc.identifier.citationWiedmann I, Tremblay J, Sundfjord A, Reigstad M. Upward nitrate flux and downward particulate organic carbon flux under contrasting situations of stratification and turbulent mixing in an Arctic shelf sea. Elementa: Science of the Anthropocene. 2017;5(43)en_US
dc.identifier.cristinIDFRIDAID 1484287
dc.identifier.doihttps://doi.org/10.1525/elementa.235
dc.identifier.issn2325-1026
dc.identifier.urihttps://hdl.handle.net/10037/11282
dc.language.isoengen_US
dc.publisherUniversity of California Pressen_US
dc.relation.journalElementa: Science of the Anthropocene
dc.rights.accessRightsopenAccessen_US
dc.subjectnitrate fluxen_US
dc.subjectPOC exporten_US
dc.subjectsediment trapen_US
dc.subjectsedimentationen_US
dc.subjectwarming Arcticen_US
dc.subjectspace-for-time substitutionen_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497en_US
dc.subjectVDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497en_US
dc.titleUpward nitrate flux and downward particulate organic carbon flux under contrasting situations of stratification and turbulent mixing in an Arctic shelf seaen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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