Glacial North Atlantic: Sea-surface conditions reconstructed by GLAMAP 2000
Type | Article | ||||||||
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Date | 2003-08 | ||||||||
Language | English | ||||||||
Author(s) | Pflaumann U1, Sarnthein M1, Chapman M2, D'Abreu L3, Funnell B2, Huels M4, Kiefer T1, Maslin M5, Schulz H6, Swallow J7, Van Kreveld S1, Vautravers M3, Vogelsang E1, Weinelt M1 | ||||||||
Affiliation(s) | 1 : Univ Kiel, Inst Geowissensch, D-24098 Kiel, Germany. 2 : Univ E Anglia, Sch Environm Sci, Norwich NR4 7TJ, Norfolk, England. 3 : Univ Cambridge, Dept Earth Sci, Cambridge CB2 3EQ, England. 4 : Univ Kiel, Leibniz Lab, D-24098 Kiel, Germany. 5 : UCL, Dept Geog, London WC1H 0AP, England. 6 : Univ Tubingen, Geol Palaontol Inst, Tubingen, Germany. 7 : Nat Hist Museum, Dept Paleontol, London SW7 5BD, England. |
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Source | Paleoceanography (0883-8305) (Amer Geophysical Union), 2003-08 , Vol. 18 , N. 3 , P. 10.1-10.21 | ||||||||
DOI | 10.1029/2002PA000774 | ||||||||
WOS© Times Cited | 162 | ||||||||
Keyword(s) | Last Glacial Maximum, Atlantic sea-surface temperatures, seasonality, sea ice cover, glacial cooling near equator, glacial upwelling intensity | ||||||||
Abstract | The response of the tropical ocean to global climate change and the extent of sea ice in the glacial nordic seas belong to the great controversies in paleoclimatology. Our new reconstruction of peak glacial sea surface temperatures (SSTs) in the Atlantic is based on census counts of planktic foraminifera, using the Maximum Similarity Technique Version 28 (SIMMAX-28) modern analog technique with 947 modern analog samples and 119 well-dated sediment cores. Our study compares two slightly different scenarios of the Last Glacial Maximum (LGM), the Environmental Processes of the Ice Age: Land, Oceans, Glaciers (EPILOG), and Glacial Atlantic Ocean Mapping (GLAMAP 2000) time slices. The comparison shows that the maximum LGM cooling in the Southern Hemisphere slightly preceeded that in the north. In both time slices sea ice was restricted to the north western margin of the nordic seas during glacial northern summer, while the central and eastern parts were ice-free. During northern glacial winter, sea ice advanced to the south of Iceland and Faeroe. In the central northern North Atlantic an anticyclonic gyre formed between 45degrees and 60degreesN, with a cool water mass centered west of Ireland, where glacial cooling reached a maximum of >12degreesC. In the subtropical ocean gyres the new reconstruction supports the glacial-to-interglacial stability of SST as shown by CLIMAP Project Members (CLIMAP) [1981]. The zonal belt of minimum SST seasonality between 2degrees and 6degreesN suggests that the LGM caloric equator occupied the same latitude as today. In contrast to the CLIMAP reconstruction, the glacial cooling of the tropical east Atlantic upwelling belt reached up to 6degrees-8degreesC during Northern Hemisphere summer. Differences between these SIMMAX-based and published U37(k)- and Mg/Ca-based equatorial SST records are ascribed to strong SST seasonalities and SST signals that were produced by different planktic species groups during different seasons. | ||||||||
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