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| Titel |
Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr |
| VerfasserIn |
C. V. Dylmer, J. Giraudeau, F. Eynaud, K. Husum, A. Vernal |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 4 ; Nr. 9, no. 4 (2013-07-16), S.1505-1518 |
| Datensatznummer |
250018089
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| Publikation (Nr.) |
 copernicus.org/cp-9-1505-2013.pdf |
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| Zusammenfassung |
Three marine sediment cores distributed along the Norwegian (MD95-2011),
Barents Sea (JM09-KA11-GC), and Svalbard (HH11-134-BC) continental margins
have been investigated in order to reconstruct changes in the poleward flow
of Atlantic waters (AW) and in the nature of upper surface water masses
within the eastern Nordic Seas over the last 3000 yr. These reconstructions
are based on a limited set of coccolith proxies: the abundance ratio between
Emiliania huxleyi and Coccolithus pelagicus, an
index of Atlantic vs. Polar/Arctic surface water masses; and
Gephyrocapsa muellerae, a drifted coccolith species from the
temperate North Atlantic, whose abundance changes are related to variations
in the strength of the North Atlantic Current.
The entire investigated area, from 66 to 77° N, was affected by an
overall increase in AW flow from 3000 cal yr BP (before present) to the present. The
long-term modulation of westerlies' strength and location, which are
essentially driven by the dominant mode of the North Atlantic Oscillation
(NAO), is thought to explain the observed dynamics of poleward AW flow. The
same mechanism also reconciles the recorded opposite zonal shifts in the
location of the Arctic front between the area off western Norway and the
western Barents Sea–eastern Fram Strait region.
The Little Ice Age (LIA) was governed by deteriorating conditions, with
Arctic/Polar waters dominating in the surface off western Svalbard and
western Barents Sea, possibly associated with both severe sea ice conditions
and a strongly reduced AW strength. A sudden short pulse of resumed high WSC
(West Spitsbergen Current) flow interrupted this cold spell in eastern Fram Strait from 330 to
410 cal yr BP. Our dataset not only confirms the high amplitude warming of
surface waters at the turn of the 19th century off western Svalbard, it also
shows that such a warming was primarily induced by an excess flow of AW which
stands as unprecedented over the last 3000 yr. |
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