Holocene variations of sea-surface conditions in the southeastern Barents Sea, reconstructed from dinoflagellate cyst assemblages

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Abstract

Palynomorphs were analysed in two sediment cores from the southeastern Barents Sea representing the past 8.3 and 4.4 kyr. High dinocyst contents and species diversity enabled the application of the best analogue method to quantitatively reconstruct sea-surface salinities, temperatures and ice cover using 677 modern reference sites from the North Atlantic and Arctic seas, including new data from the Barents Sea reported here. At the southern core site, where waters are affected by the Atlantic inflow, sea-surface conditions were relatively warm and stable between ca. 8000 and 5000 calendar yr BP. In contrast, the past 5 kyr had periods with cooler temperatures and extended ice cover, fluctuating mostly at 1–1.5 kyr frequencies at both sites. Most pronounced coolings occurred around 8.1, 5, 3.5–3.2 and 2.5 ka. The northern site additionally shows younger cooling events, tentatively dated to 1.4, 0.3 and 0.1 ka. Identified variations in sea-surface conditions indicate changes in Atlantic water inputs to the Barents Sea. Our results generally correlate to palaeoclimatic reconstructions from northwestern Eurasia, exemplified by palynological records from Karelia. This correlation suggests that sea-surface variations in the Barents Sea reflect large-scale changes in atmospheric and oceanic interactions between the North Atlantic and the Arctic. Copyright © 2001 John Wiley & Sons, Ltd.

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