Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2
The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the Northern Hemisphere climate system. Significant interest went into the question of how excessive freshwater input through melting of continental ice can affect its overturning vigor and, hence, heat supply, to high...
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fttriple:oai:gotriple.eu:10670/1.hi59ha 2023-05-15T16:41:16+02:00 Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 Gutjahr, Marcus Lippold, Joerg https://doi.org/10.1029/2011PA002114 https://archimer.ifremer.fr/doc/00227/33837/32443.pdf https://archimer.ifremer.fr/doc/00227/33837/ en eng Amer Geophysical Union doi:10.1029/2011PA002114 10670/1.hi59ha https://archimer.ifremer.fr/doc/00227/33837/32443.pdf https://archimer.ifremer.fr/doc/00227/33837/ other Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2011-06 , Vol. 26 , N. 2 , P. PA2101 geo envir Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ fttriple https://doi.org/10.1029/2011PA002114 2023-01-22T17:57:43Z The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the Northern Hemisphere climate system. Significant interest went into the question of how excessive freshwater input through melting of continental ice can affect its overturning vigor and, hence, heat supply, to higher northern latitudes. Such forcing can be tested by investigating its behavior during extreme iceberg discharge events into the open North Atlantic during the last glacial period, the so-called Heinrich events (HE). Here we present neodymium (Nd) isotope compositions of past seawater, a sensitive chemical water mass tag, extracted from sediments of Ocean Drilling Program Site 1063 in the western North Atlantic (Bermuda Rise), covering the period surrounding HE 2, the Last Glacial Maximum, and the early deglaciation. These data are compared with a record of the kinematic circulation tracer (Pa-231/Th-230)(xs) extracted from the same sediment core. Both tracers indicate significant circulation changes preceding intense ice rafting during HE 2 by almost 2 kyr. Moreover, the Nd isotope record suggests the presence of deeply ventilating North Atlantic Deep Water early during Marine Isotope Stage 2 until it was replaced by Southern Source Water at similar to 27 ka. The early switch to high (Pa/Th)(xs) and radiogenic epsilon Nd in relation to intensified ice rafting during HE 2 suggests that ice rafting into the open North Atlantic during major HE 2 was preceded by an early change of the AMOC. This opens the possibility that variations in AMOC contributed to or even triggered the ice sheet instability rather than merely responding to it. Text Ice Sheet North Atlantic Deep Water North Atlantic Unknown Paleoceanography 26 2 n/a n/a |
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geo envir Gutjahr, Marcus Lippold, Joerg Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 |
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geo envir |
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The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the Northern Hemisphere climate system. Significant interest went into the question of how excessive freshwater input through melting of continental ice can affect its overturning vigor and, hence, heat supply, to higher northern latitudes. Such forcing can be tested by investigating its behavior during extreme iceberg discharge events into the open North Atlantic during the last glacial period, the so-called Heinrich events (HE). Here we present neodymium (Nd) isotope compositions of past seawater, a sensitive chemical water mass tag, extracted from sediments of Ocean Drilling Program Site 1063 in the western North Atlantic (Bermuda Rise), covering the period surrounding HE 2, the Last Glacial Maximum, and the early deglaciation. These data are compared with a record of the kinematic circulation tracer (Pa-231/Th-230)(xs) extracted from the same sediment core. Both tracers indicate significant circulation changes preceding intense ice rafting during HE 2 by almost 2 kyr. Moreover, the Nd isotope record suggests the presence of deeply ventilating North Atlantic Deep Water early during Marine Isotope Stage 2 until it was replaced by Southern Source Water at similar to 27 ka. The early switch to high (Pa/Th)(xs) and radiogenic epsilon Nd in relation to intensified ice rafting during HE 2 suggests that ice rafting into the open North Atlantic during major HE 2 was preceded by an early change of the AMOC. This opens the possibility that variations in AMOC contributed to or even triggered the ice sheet instability rather than merely responding to it. |
format |
Text |
author |
Gutjahr, Marcus Lippold, Joerg |
author_facet |
Gutjahr, Marcus Lippold, Joerg |
author_sort |
Gutjahr, Marcus |
title |
Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 |
title_short |
Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 |
title_full |
Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 |
title_fullStr |
Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 |
title_full_unstemmed |
Early arrival of Southern Source Water in the deep North Atlantic prior to Heinrich event 2 |
title_sort |
early arrival of southern source water in the deep north atlantic prior to heinrich event 2 |
publisher |
Amer Geophysical Union |
url |
https://doi.org/10.1029/2011PA002114 https://archimer.ifremer.fr/doc/00227/33837/32443.pdf https://archimer.ifremer.fr/doc/00227/33837/ |
genre |
Ice Sheet North Atlantic Deep Water North Atlantic |
genre_facet |
Ice Sheet North Atlantic Deep Water North Atlantic |
op_source |
Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2011-06 , Vol. 26 , N. 2 , P. PA2101 |
op_relation |
doi:10.1029/2011PA002114 10670/1.hi59ha https://archimer.ifremer.fr/doc/00227/33837/32443.pdf https://archimer.ifremer.fr/doc/00227/33837/ |
op_rights |
other |
op_doi |
https://doi.org/10.1029/2011PA002114 |
container_title |
Paleoceanography |
container_volume |
26 |
container_issue |
2 |
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1766031704636522496 |