Cristin-resultat-ID: 1243150
Sist endret: 25. januar 2016 14:39
NVI-rapporteringsår: 2015
Resultat
Vitenskapelig artikkel
2015

Holocene multidecadal- to millennial-scale variations in Iceland-Scotland overflow and their relationship to climate

Bidragsytere:
  • Tor Lien Mjell
  • Ulysses S Ninnemann
  • Tor Eldevik og
  • Helga Flesche Kleiven

Tidsskrift

Paleoceanography
ISSN 0883-8305
e-ISSN 1944-9186
NVI-nivå 0

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2015
Trykket: 2015
Volum: 30
Hefte: 5
Sider: 558 - 569

Importkilder

Scopus-ID: 2-s2.0-84935890632

Klassifisering

Vitenskapsdisipliner

Meteorologi

Beskrivelse Beskrivelse

Tittel

Holocene multidecadal- to millennial-scale variations in Iceland-Scotland overflow and their relationship to climate

Sammendrag

The Nordic Seas overflows are an important part of the Atlantic thermohaline circulation. While there is growing evidence that the overflow of dense water changed on orbital time scales during the Holocene, less is known about the variability on shorter time scales beyond the instrumental record. Here we reconstruct the relative changes in flow strength of Iceland-Scotland Overflow Water (ISOW), the eastern branch of the overflows, on multidecadal-millennial time scales. The reconstruction is based on mean sortable silt (inline image) from a sediment core on the Gardar Drift (60°19′N, 23°58′W, 2081 m). Our inline image record reveals that the main variance in ISOW vigor occurred on millennial time scales (1–2 kyr) with particularly prominent fluctuations after 8 kyr. Superimposed on the millennial variability, there were multidecadal-centennial flow speed fluctuations during the early Holocene (10–9 kyr) and one prominent minimum at 0.9 kyr. We find a broad agreement between reconstructed ISOW and regional North Atlantic climate, where a strong (weak) ISOW is generally associated with warm (cold) climate. We further identify the possible contribution of anomalous heat and freshwater forcing, respectively, related to reconstructed overflow variability. We infer that ocean poleward heat transport can explain the relationship between regional climate and ISOW during the middle to late Holocene, whereas freshwater input provides a possible explanation for the reduced overflow during early Holocene (8–10 kyr).

Bidragsytere

Tor Lien Mjell

  • Tilknyttet:
    Forfatter
    ved Institutt for geovitenskap ved Universitetet i Bergen
  • Tilknyttet:
    Forfatter
    ved NORCE Klima ved NORCE Norwegian Research Centre AS

Ulysses Silas Ninnemann

Bidragsyterens navn vises på dette resultatet som Ulysses S Ninnemann
  • Tilknyttet:
    Forfatter
    ved Institutt for geovitenskap ved Universitetet i Bergen

Tor Eldevik

  • Tilknyttet:
    Forfatter
    ved Geofysisk institutt ved Universitetet i Bergen
Aktiv cristin-person

Helga Flesche Kleiven

  • Tilknyttet:
    Forfatter
    ved Institutt for geovitenskap ved Universitetet i Bergen
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