Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation
Different proxies for sea surface temperature (SST) often exhibit divergent trends for deglacial warming in tropical regions, hampering our understanding of the phase relationship between tropical SSTs and continental ice volume at glacial terminations. To reconcile divergent SST trends, we report r...
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Language: | English |
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Amer Geophysical Union
2013
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Online Access: | https://archimer.ifremer.fr/doc/00291/40174/39037.pdf https://archimer.ifremer.fr/doc/00291/40174/39038.pdf https://archimer.ifremer.fr/doc/00291/40174/39039.pdf https://archimer.ifremer.fr/doc/00291/40174/39040.pdf https://archimer.ifremer.fr/doc/00291/40174/39041.txt https://doi.org/10.1002/palo.20053 https://archimer.ifremer.fr/doc/00291/40174/ |
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ftarchimer:oai:archimer.ifremer.fr:40174 2023-05-15T13:50:50+02:00 Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation Wang, Yiming V. Leduc, Guillaume Regenberg, Marcus Andersen, Nils Larsen, Thomas Blanz, Thomas Schneider, Ralph R. 2013-12 application/pdf https://archimer.ifremer.fr/doc/00291/40174/39037.pdf https://archimer.ifremer.fr/doc/00291/40174/39038.pdf https://archimer.ifremer.fr/doc/00291/40174/39039.pdf https://archimer.ifremer.fr/doc/00291/40174/39040.pdf https://archimer.ifremer.fr/doc/00291/40174/39041.txt https://doi.org/10.1002/palo.20053 https://archimer.ifremer.fr/doc/00291/40174/ eng eng Amer Geophysical Union https://archimer.ifremer.fr/doc/00291/40174/39037.pdf https://archimer.ifremer.fr/doc/00291/40174/39038.pdf https://archimer.ifremer.fr/doc/00291/40174/39039.pdf https://archimer.ifremer.fr/doc/00291/40174/39040.pdf https://archimer.ifremer.fr/doc/00291/40174/39041.txt doi:10.1002/palo.20053 https://archimer.ifremer.fr/doc/00291/40174/ 2013. American Geophysical Union. All Rights Reserved. info:eu-repo/semantics/openAccess restricted use Paleoceanography (0883-8305) (Amer Geophysical Union), 2013-12 , Vol. 28 , N. 4 , P. 619-632 Sea surface temperature Tropical Indian Ocean Last Deglacial text Publication info:eu-repo/semantics/article 2013 ftarchimer https://doi.org/10.1002/palo.20053 2021-09-23T20:26:50Z Different proxies for sea surface temperature (SST) often exhibit divergent trends for deglacial warming in tropical regions, hampering our understanding of the phase relationship between tropical SSTs and continental ice volume at glacial terminations. To reconcile divergent SST trends, we report reconstructions of two commonly used paleothermometers (the foraminifera G. ruber Mg/Ca and the alkenone unsaturation index) from a marine sediment core collected in the southwestern tropical Indian Ocean encompassing the last 37,000 years. Our results show that SSTs derived from the alkenone unsaturation index (U-37(K)) are consistently warmer than those derived from Mg/Ca by similar to 2-3 degrees C except for the Heinrich Event 1. In addition, the initial timing for the deglacial warming of alkenone SST started at similar to 15.6 ka, which lags behind that of Mg/Ca temperatures by 2.5 kyr. We argue that the discrepancy between the two SST proxies reflects seasonal differences between summer and winter rather than postdepositional processes or sedimentary biases. The U-37(K) SST record clearly mimics the deglacial SST trend recorded in the North Atlantic region for the earlier part of the termination, indicating that the early deglacial warming trend attributed to local summer temperatures was likely mediated by changes in the Atlantic Meridional Overturning Circulation at the onset of the deglaciation. In contrast, the glacial to interglacial SST pattern recorded by G. ruber Mg/Ca probably reflects cold season SSTs. This indicates that the cold season SSTs was likely mediated by climate changes in the southern hemisphere, as it closely tracks the Antarctic timing of deglaciation. Therefore, our study reveals that the tropical southwestern Indian Ocean seasonal SST was closely linked to climate changes occurring in both hemispheres. The austral summer and winter recorded by each proxy is further supported with seasonal SST trends modeled by Atmosphere-ocean General Circulation Models for our core site. Our interpretation that the alkenone and Mg/Ca SSTs are seasonally biased may also explain similar proxy mismatches observed in other tropical regions at the onset of the last termination. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic Austral Indian The Antarctic Paleoceanography 28 4 619 632 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Sea surface temperature Tropical Indian Ocean Last Deglacial |
spellingShingle |
Sea surface temperature Tropical Indian Ocean Last Deglacial Wang, Yiming V. Leduc, Guillaume Regenberg, Marcus Andersen, Nils Larsen, Thomas Blanz, Thomas Schneider, Ralph R. Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation |
topic_facet |
Sea surface temperature Tropical Indian Ocean Last Deglacial |
description |
Different proxies for sea surface temperature (SST) often exhibit divergent trends for deglacial warming in tropical regions, hampering our understanding of the phase relationship between tropical SSTs and continental ice volume at glacial terminations. To reconcile divergent SST trends, we report reconstructions of two commonly used paleothermometers (the foraminifera G. ruber Mg/Ca and the alkenone unsaturation index) from a marine sediment core collected in the southwestern tropical Indian Ocean encompassing the last 37,000 years. Our results show that SSTs derived from the alkenone unsaturation index (U-37(K)) are consistently warmer than those derived from Mg/Ca by similar to 2-3 degrees C except for the Heinrich Event 1. In addition, the initial timing for the deglacial warming of alkenone SST started at similar to 15.6 ka, which lags behind that of Mg/Ca temperatures by 2.5 kyr. We argue that the discrepancy between the two SST proxies reflects seasonal differences between summer and winter rather than postdepositional processes or sedimentary biases. The U-37(K) SST record clearly mimics the deglacial SST trend recorded in the North Atlantic region for the earlier part of the termination, indicating that the early deglacial warming trend attributed to local summer temperatures was likely mediated by changes in the Atlantic Meridional Overturning Circulation at the onset of the deglaciation. In contrast, the glacial to interglacial SST pattern recorded by G. ruber Mg/Ca probably reflects cold season SSTs. This indicates that the cold season SSTs was likely mediated by climate changes in the southern hemisphere, as it closely tracks the Antarctic timing of deglaciation. Therefore, our study reveals that the tropical southwestern Indian Ocean seasonal SST was closely linked to climate changes occurring in both hemispheres. The austral summer and winter recorded by each proxy is further supported with seasonal SST trends modeled by Atmosphere-ocean General Circulation Models for our core site. Our interpretation that the alkenone and Mg/Ca SSTs are seasonally biased may also explain similar proxy mismatches observed in other tropical regions at the onset of the last termination. |
format |
Article in Journal/Newspaper |
author |
Wang, Yiming V. Leduc, Guillaume Regenberg, Marcus Andersen, Nils Larsen, Thomas Blanz, Thomas Schneider, Ralph R. |
author_facet |
Wang, Yiming V. Leduc, Guillaume Regenberg, Marcus Andersen, Nils Larsen, Thomas Blanz, Thomas Schneider, Ralph R. |
author_sort |
Wang, Yiming V. |
title |
Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation |
title_short |
Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation |
title_full |
Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation |
title_fullStr |
Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation |
title_full_unstemmed |
Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation |
title_sort |
northern and southern hemisphere controls on seasonal sea surface temperatures in the indian ocean during the last deglaciation |
publisher |
Amer Geophysical Union |
publishDate |
2013 |
url |
https://archimer.ifremer.fr/doc/00291/40174/39037.pdf https://archimer.ifremer.fr/doc/00291/40174/39038.pdf https://archimer.ifremer.fr/doc/00291/40174/39039.pdf https://archimer.ifremer.fr/doc/00291/40174/39040.pdf https://archimer.ifremer.fr/doc/00291/40174/39041.txt https://doi.org/10.1002/palo.20053 https://archimer.ifremer.fr/doc/00291/40174/ |
geographic |
Antarctic Austral Indian The Antarctic |
geographic_facet |
Antarctic Austral Indian The Antarctic |
genre |
Antarc* Antarctic North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic |
op_source |
Paleoceanography (0883-8305) (Amer Geophysical Union), 2013-12 , Vol. 28 , N. 4 , P. 619-632 |
op_relation |
https://archimer.ifremer.fr/doc/00291/40174/39037.pdf https://archimer.ifremer.fr/doc/00291/40174/39038.pdf https://archimer.ifremer.fr/doc/00291/40174/39039.pdf https://archimer.ifremer.fr/doc/00291/40174/39040.pdf https://archimer.ifremer.fr/doc/00291/40174/39041.txt doi:10.1002/palo.20053 https://archimer.ifremer.fr/doc/00291/40174/ |
op_rights |
2013. American Geophysical Union. All Rights Reserved. info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1002/palo.20053 |
container_title |
Paleoceanography |
container_volume |
28 |
container_issue |
4 |
container_start_page |
619 |
op_container_end_page |
632 |
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1766254145071742976 |