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| Titel |
Teleconnections between North Pacfic and North Atlantic climate variations during the last deglaciation from laminated sediments |
| VerfasserIn |
Julia Gottschalk, Michael Schulz, Ute Merkel, Lars Max, Ralf Tiedemann |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046894
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| Zusammenfassung |
| Past oceanographic and climatic changes in the North Pacific and its remote interplay with
the North Atlantic are only poorly constrained mainly due to the limited number of sediment
records and the poor preservation of carbonate-bearing sediments. Sediment core
SO201-2-114-KL from the western Bering Sea (167-E, 59.23-N, 1394 m WD) features
laminated sediment units representing the Bølling-Allerød (BA) and the Preboreal (PB),
which is a common feature in the North Pacific and the Bering Sea. They are considered to
reflect changes in bottom ventilation and/or surface productivity. The cause of the
wide-spread occurrence of laminated sediments in the North Pacific still remains
elusive. Alkenone-based reconstructed sea surface temperatures in conjunction with
ultra high-resolution XRF scanning of sediment core SO201-2-114-KL reveal that
laminated sediments manifest a North Pacific warming in concert with the North
Atlantic. This is associated with a retreat of sea ice and the increase of sea surface
productivity in the western Bering Sea during the BA and PB that induces the laminae
formation. The geochemical variability of laminations points to interannual and decadal
fluctuations of the sea surface temperature and consequently the sea ice extent,
which might be paced by the Pacific Decadal Oscillation and the El Niño-Southern
Oscillation. Freshwater hosing experiments with the comprehensive climate model
CCSM3 simulating the BA and the Heinrich Stadial 1 point as well to the inter-basin
dependence between the North Atlantic and North Pacific. The remote and synchronous
response of the North Pacific to climate anomalies in the North Atlantic emanates from
changes in atmospheric circulation. This emphases the primarily atmospheric origin of
the laminae formation and their internal geochemical variability. Furthermore, an
inverse pattern of overturning in both ocean basins is evident, which supports the
inferred prevalence of low ventilation rates during the time of laminae formation.
It confirms the operation of a Pacific–Atlantic seesaw in overturning circulation. |
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