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| Titel |
Palynology of the late Holocene in Disko Bugt, West Greenland: evidence for
centennial variability in sea-surface conditions. |
| VerfasserIn |
Estelle Allan, Anne de Vernal, Matthias Moros, Marie-Michèle Ouellet-Bernier |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250121846
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| Publikation (Nr.) |
 EGU/EGU2016-708.pdf |
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| Zusammenfassung |
| The palynological analyses of a sediment core collected in Disko Bay (core 343310; 68˚
38,861’N, 53˚ 49,493’W) provide a dinocyst record of the last 1500 years with 5-30 year
time resolution and thus permit reconstruction of changes in surface water, including sea-ice
cover, temperature and salinity. Dinocyst assemblages are characterized by high taxonomic
diversity (18 taxa) with dominance of Islandinium minutum, Pentapharsodinium dalei,
Brigantedinium spp. and Islandinium? cezare and by very high concentrations (>105
cysts.cm−3) leading to calculate fluxes of the order of (>104 cysts.cm−2.years−1). The
modern analogue technique (MAT) was applied to dinocyst assemblages to quantitatively
reconstruct paleo-sea-surface conditions. The seasonal sea ice cover shows large
amplitude variations from 2 to 8 months.yr−1(sea ice coverage >50%), with maxima at
1050-1300 AD, 1400-1500 AD, 1550-1600 AD and 1770-1800 AD, which reflect
episodic cooling during the last millennium. In the overall record, sea ice cover and
salinity variation are correlated with increase sea ice extent corresponding with
decrease salinity and vice versa, which suggests strong linkages between the regional
freshwater/meltwater budget and winter sea ice. Relationship between sea ice cover
and the North Atlantic Oscillation (NAO) is also possible. The increased sea ice
being associated with dominant NAO+ mode can be linked with change of the
regional properties of the West Greenland Current, the marked by lower influence of
warm and saline Atlantic waters relative to an increase influence of the polar and
low salinity in Arctic waters from East Greenland Current under NAO+ situation. |
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