|
|
|
|
|
| Duplessy, Jc; Labeyrie, L; Juilletleclerc, A; Maitre, F; Duprat, J; Sarnthein, M. |
| We have developed a new method to reconstruct surface water salinity of the North Atlantic Ocean, based on a comparison between transfer function estimates of sea surface temperature and the oxygen isotope ratio of two common planktonic foraminiferal species, N. pachyderma (left coiling) and G. bulloides. We first used core-top analyses to demonstrate that, under modern conditions, the paleotemperatures determined from the isotopic composition of foraminiferal shells are linearly linked to the summer sea surface temperature only within a certain temperature range, characteristic of each species, which is termed the "optimum temperature range". We then used this information to derive an estimate of the isotopic composition and salinity of the North Atlantic... |
| Tipo: Text |
Palavras-chave: PALEO-OCEANOGRAPHY; PALEOCLIMATOLOGY; ISOTOPES; SALINITY; ATLANTIC OCEAN. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00101/21261/18872.pdf |
| |
|
|
| Pflaumann, U; Sarnthein, M; Chapman, M; D'Abreu, L; Funnell, B; Huels, M; Kiefer, T; Maslin, M; Schulz, H; Swallow, J; Van Kreveld, S; Vautravers, M; Vogelsang, E; Weinelt, M. |
| 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... |
| Tipo: Text |
Palavras-chave: Last Glacial Maximum; Atlantic sea-surface temperatures; Seasonality; Sea ice cover; Glacial cooling near equator; Glacial upwelling intensity. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00225/33668/32070.pdf |
| |
|
|
| Weinelt, M; Vogelsang, E; Kucera, M; Pflaumann, U; Sarnthein, M; Voelker, A; Erlenkeuser, H; Malmgren, Ba. |
| Short-term changes in sea surface conditions controlling the thermohaline circulation in the northern North Atlantic are expected to be especially efficient in perturbing global climate stability. Here we assess past variability of sea surface temperature (SST) in the northeast Atlantic and Norwegian Sea during Marine Isotope Stage (MIS) 2 and, in particular, during the Last Glacial Maximum (LGM). Five high-resolution SST records were established on a meridional transect (53 degreesN - 72 degreesN) to trace centennial-scale oscillations in SST and sea-ice cover. We used three independent computational techniques ( SIMMAX modern analogue technique, Artificial Neural Networks ( ANN), and Revised Analog Method ( RAM)) to reconstruct SST from planktonic... |
| Tipo: Text |
|
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00225/33667/32066.pdf |
| |
|
|
|
