Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas
Dansgaard-Oeschger (D-O) cycles are the most dramatic, frequent, and wide-reaching abrupt climate changes in the geologic record. On Greenland, D-O cycles are characterized by an abrupt warming of 105 degrees C from a cold stadial to a warm interstadial phase, followed by gradual cooling before a ra...
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fttriple:oai:gotriple.eu:10670/1.4xih8z 2023-05-15T16:13:02+02:00 Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas Dokken, Trond M. Nisancioglu, Kerim H. Li, Camille Battisti, David S. Kissel, Catherine https://doi.org/10.1002/palo.20042 https://archimer.ifremer.fr/doc/00264/37490/35779.pdf https://archimer.ifremer.fr/doc/00264/37490/ en eng Amer Geophysical Union doi:10.1002/palo.20042 10670/1.4xih8z https://archimer.ifremer.fr/doc/00264/37490/35779.pdf https://archimer.ifremer.fr/doc/00264/37490/ lic_creative-commons other Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2013-09 , Vol. 28 , N. 3 , P. 491-502 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ fttriple https://doi.org/10.1002/palo.20042 2023-01-22T17:55:37Z Dansgaard-Oeschger (D-O) cycles are the most dramatic, frequent, and wide-reaching abrupt climate changes in the geologic record. On Greenland, D-O cycles are characterized by an abrupt warming of 105 degrees C from a cold stadial to a warm interstadial phase, followed by gradual cooling before a rapid return to stadial conditions. The mechanisms responsible for these millennial cycles are not fully understood but are widely thought to involve abrupt changes in Atlantic Meridional Overturning Circulation due to freshwater perturbations. Here we present a new, high-resolution multiproxy marine sediment core monitoring changes in the warm Atlantic inflow to the Nordic seas as well as in local sea ice cover and influx of ice-rafted debris. In contrast to previous studies, the freshwater input is found to be coincident with warm interstadials on Greenland and has a Fennoscandian rather than Laurentide source. Furthermore, the data suggest a different thermohaline structure for the Nordic seas during cold stadials in which relatively warm Atlantic water circulates beneath a fresh surface layer and the presence of sea ice is inferred from benthic oxygen isotopes. This implies a delicate balance between the warm subsurface Atlantic water and fresh surface layer, with the possibility of abrupt changes in sea ice cover, and suggests a novel mechanism for the abrupt D-O events observed in Greenland ice cores. Text Fennoscandian Greenland Greenland ice cores Nordic Seas Sea ice Unknown Greenland Paleoceanography 28 3 491 502 |
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envir geo Dokken, Trond M. Nisancioglu, Kerim H. Li, Camille Battisti, David S. Kissel, Catherine Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas |
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envir geo |
description |
Dansgaard-Oeschger (D-O) cycles are the most dramatic, frequent, and wide-reaching abrupt climate changes in the geologic record. On Greenland, D-O cycles are characterized by an abrupt warming of 105 degrees C from a cold stadial to a warm interstadial phase, followed by gradual cooling before a rapid return to stadial conditions. The mechanisms responsible for these millennial cycles are not fully understood but are widely thought to involve abrupt changes in Atlantic Meridional Overturning Circulation due to freshwater perturbations. Here we present a new, high-resolution multiproxy marine sediment core monitoring changes in the warm Atlantic inflow to the Nordic seas as well as in local sea ice cover and influx of ice-rafted debris. In contrast to previous studies, the freshwater input is found to be coincident with warm interstadials on Greenland and has a Fennoscandian rather than Laurentide source. Furthermore, the data suggest a different thermohaline structure for the Nordic seas during cold stadials in which relatively warm Atlantic water circulates beneath a fresh surface layer and the presence of sea ice is inferred from benthic oxygen isotopes. This implies a delicate balance between the warm subsurface Atlantic water and fresh surface layer, with the possibility of abrupt changes in sea ice cover, and suggests a novel mechanism for the abrupt D-O events observed in Greenland ice cores. |
format |
Text |
author |
Dokken, Trond M. Nisancioglu, Kerim H. Li, Camille Battisti, David S. Kissel, Catherine |
author_facet |
Dokken, Trond M. Nisancioglu, Kerim H. Li, Camille Battisti, David S. Kissel, Catherine |
author_sort |
Dokken, Trond M. |
title |
Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas |
title_short |
Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas |
title_full |
Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas |
title_fullStr |
Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas |
title_full_unstemmed |
Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas |
title_sort |
dansgaard-oeschger cycles: interactions between ocean and sea ice intrinsic to the nordic seas |
publisher |
Amer Geophysical Union |
url |
https://doi.org/10.1002/palo.20042 https://archimer.ifremer.fr/doc/00264/37490/35779.pdf https://archimer.ifremer.fr/doc/00264/37490/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Fennoscandian Greenland Greenland ice cores Nordic Seas Sea ice |
genre_facet |
Fennoscandian Greenland Greenland ice cores Nordic Seas Sea ice |
op_source |
Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2013-09 , Vol. 28 , N. 3 , P. 491-502 |
op_relation |
doi:10.1002/palo.20042 10670/1.4xih8z https://archimer.ifremer.fr/doc/00264/37490/35779.pdf https://archimer.ifremer.fr/doc/00264/37490/ |
op_rights |
lic_creative-commons other |
op_doi |
https://doi.org/10.1002/palo.20042 |
container_title |
Paleoceanography |
container_volume |
28 |
container_issue |
3 |
container_start_page |
491 |
op_container_end_page |
502 |
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1765998632831549440 |