Cristin-resultat-ID: 2054063
Sist endret: 29. september 2022, 12:41
NVI-rapporteringsår: 2022
Resultat
Vitenskapelig artikkel
2022

Nitrogen Isotope Evidence for Changing Arctic Ocean Ventilation Regimes During the Cenozoic

Bidragsytere:
  • Jochen Manfred Knies

Tidsskrift

Geophysical Research Letters
ISSN 0094-8276
e-ISSN 1944-8007
NVI-nivå 2

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2022
Publisert online: 2022
Trykket: 2022
Volum: 49
Hefte: 17
Artikkelnummer: e2022GL099
Open Access

Importkilder

Scopus-ID: 2-s2.0-85138007062

Beskrivelse Beskrivelse

Tittel

Nitrogen Isotope Evidence for Changing Arctic Ocean Ventilation Regimes During the Cenozoic

Sammendrag

In this work, I report on the coupling of dinitrogen (N2) fixation and denitrification in oxygen-deficient waters of the Arctic Ocean during the Paleogene. This coupling fertilized marine phytoplankton growth and favored organic carbon burial. Reduced vertical mixing due to salinity stratification in a tectonically closed oceanic basin created conditions favorable for N2-fixation by phytoplankton harboring diazotrophic bacterial symbionts. A positive shift of 5‰ in the δ15N record indicates a change in the main source of biologically available nitrogen due to rapidly changing nutrient availability. I interpret this shift as a switch to Atlantic-sourced nitrate as the main nitrogen source owing to the opening of the Arctic-Atlantic gateway to the northern North Atlantic. While the timing of the opening is still disputed among the available Arctic records, I use evidence from the northern North Atlantic to argue that the Arctic Ocean has been fully ventilated since the early Neogene

Bidragsytere

Jochen Manfred Knies

  • Tilknyttet:
    Forfatter
    ved Norges geologiske undersøkelse
  • Tilknyttet:
    Forfatter
    ved Centre for Arctic Gas Hydrate, Environment and Climate ved UiT Norges arktiske universitet
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