Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project
International audience Reconstructions of sea surface temperature (SST) from relatively stable periods in the past, such as the Last Glacial Maximum (LGM), represent one of the best means to constrain climate sensitivity and provide targets to evaluate coupled atmosphere-ocean general circulation mo...
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ftceafr:oai:HAL:hal-04113684v1 2024-04-28T08:29:08+00:00 Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project Waelbroeck, Claire Paul, A. Kucera, M. Rosell-Melé, A. Weinelt, M. Schneider, R. Mix, A. Project Members, Margo Laboratoire des Sciences du Climat et de l'Environnement (LSCE) Commissariat à l'énergie atomique et aux énergies alternatives (CEA) Vienna (Austria), Austria 2009-04-19 https://hal.science/hal-04113684 en eng HAL CCSD hal-04113684 https://hal.science/hal-04113684 BIBCODE: 2009EGUGA.11.8142W EGU General Assembly 2009 https://hal.science/hal-04113684 EGU General Assembly 2009, Apr 2009, Vienna (Austria), Austria. pp.8142 [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/conferenceObject Conference papers 2009 ftceafr 2024-04-11T00:29:40Z International audience Reconstructions of sea surface temperature (SST) from relatively stable periods in the past, such as the Last Glacial Maximum (LGM), represent one of the best means to constrain climate sensitivity and provide targets to evaluate coupled atmosphere-ocean general circulation models. The first quantitative global reconstruction of SST at the LGM was developed by the CLIMAP (Climate: Long-Range Investigation, Mapping and Prediction) project. Since then, there has not been any concerted effort to synthesize existing paleodata at the global scale, although several shortcomings of CLIMAP pioneering work have become apparent.We present a LGM global synthesis of SST reconstructions undertaken by the MARGO (Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface) project. The objective has been to compile and analyse available estimates of LGM SSTs based on all prevalent microfossil-based (i.e., transfer functions based on planktonic foraminifera, diatoms, dinoflagellate cysts and radiolarians abundances) and geochemical (i.e., alkenones and planktonic foraminifera Mg/Ca) paleothermometers. The MARGO project approach is to argue that no current proxy method is objectively better than another to provide an accurate picture of past SST, and that consequently the multiproxy approach yields the least biased representation of past reality. As originally suggested by CLIMAP, the strongest annual mean cooling (up to -10Ë C) occurred in the mid-latitude North Atlantic and extended into the western Mediterranean (-6Ë C). However, in contrast to CLIMAP, MARGO data indicate that the cooling was more pronounced in the eastern than in the western basin. The magnitude and position of a steep temperature gradient between 60 and 45Ë N are supported by four different proxies. In contrast with the CLIMAP reconstruction, all proxies also agree on ice-free conditions in the Nordic Seas during glacial summer. However, large discrepancies with respect to glacial temperatures recorded by different ... Conference Object Nordic Seas North Atlantic Planktonic foraminifera HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) |
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Open Polar |
collection |
HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) |
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ftceafr |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
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[SDU]Sciences of the Universe [physics] Waelbroeck, Claire Paul, A. Kucera, M. Rosell-Melé, A. Weinelt, M. Schneider, R. Mix, A. Project Members, Margo Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Reconstructions of sea surface temperature (SST) from relatively stable periods in the past, such as the Last Glacial Maximum (LGM), represent one of the best means to constrain climate sensitivity and provide targets to evaluate coupled atmosphere-ocean general circulation models. The first quantitative global reconstruction of SST at the LGM was developed by the CLIMAP (Climate: Long-Range Investigation, Mapping and Prediction) project. Since then, there has not been any concerted effort to synthesize existing paleodata at the global scale, although several shortcomings of CLIMAP pioneering work have become apparent.We present a LGM global synthesis of SST reconstructions undertaken by the MARGO (Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface) project. The objective has been to compile and analyse available estimates of LGM SSTs based on all prevalent microfossil-based (i.e., transfer functions based on planktonic foraminifera, diatoms, dinoflagellate cysts and radiolarians abundances) and geochemical (i.e., alkenones and planktonic foraminifera Mg/Ca) paleothermometers. The MARGO project approach is to argue that no current proxy method is objectively better than another to provide an accurate picture of past SST, and that consequently the multiproxy approach yields the least biased representation of past reality. As originally suggested by CLIMAP, the strongest annual mean cooling (up to -10Ë C) occurred in the mid-latitude North Atlantic and extended into the western Mediterranean (-6Ë C). However, in contrast to CLIMAP, MARGO data indicate that the cooling was more pronounced in the eastern than in the western basin. The magnitude and position of a steep temperature gradient between 60 and 45Ë N are supported by four different proxies. In contrast with the CLIMAP reconstruction, all proxies also agree on ice-free conditions in the Nordic Seas during glacial summer. However, large discrepancies with respect to glacial temperatures recorded by different ... |
author2 |
Laboratoire des Sciences du Climat et de l'Environnement (LSCE) Commissariat à l'énergie atomique et aux énergies alternatives (CEA) |
format |
Conference Object |
author |
Waelbroeck, Claire Paul, A. Kucera, M. Rosell-Melé, A. Weinelt, M. Schneider, R. Mix, A. Project Members, Margo |
author_facet |
Waelbroeck, Claire Paul, A. Kucera, M. Rosell-Melé, A. Weinelt, M. Schneider, R. Mix, A. Project Members, Margo |
author_sort |
Waelbroeck, Claire |
title |
Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project |
title_short |
Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project |
title_full |
Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project |
title_fullStr |
Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project |
title_full_unstemmed |
Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum: report of the MARGO Project |
title_sort |
constraints on the magnitude and patterns of ocean cooling at the last glacial maximum: report of the margo project |
publisher |
HAL CCSD |
publishDate |
2009 |
url |
https://hal.science/hal-04113684 |
op_coverage |
Vienna (Austria), Austria |
genre |
Nordic Seas North Atlantic Planktonic foraminifera |
genre_facet |
Nordic Seas North Atlantic Planktonic foraminifera |
op_source |
EGU General Assembly 2009 https://hal.science/hal-04113684 EGU General Assembly 2009, Apr 2009, Vienna (Austria), Austria. pp.8142 |
op_relation |
hal-04113684 https://hal.science/hal-04113684 BIBCODE: 2009EGUGA.11.8142W |
_version_ |
1797587476604256256 |