Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic
Antarctic Intermediate Water (AAIW) plays important roles in the global climate system and the global ocean nutrient and carbon cycles. However, it is unclear how AAIW responds to global climate changes. In particular, neodymium isotopic composition (εNd) reconstructions from different locations fro...
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ftdatacite:10.7892/boris.106910 2023-05-15T13:34:39+02:00 Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic Joos, Fortunat Rempfer, Johannes Zhang, Jiaxu Liu, Zhengyu Gu, Sifan Oppo, Delia W. 2017 application/pdf https://dx.doi.org/10.7892/boris.106910 https://boris.unibe.ch/106910/ en eng American Geophysical Union info:eu-repo/semantics/openAccess 530 Physics 550 Earth sciences & geology Text article-journal ScholarlyArticle 2017 ftdatacite https://doi.org/10.7892/boris.106910 2021-11-05T12:55:41Z Antarctic Intermediate Water (AAIW) plays important roles in the global climate system and the global ocean nutrient and carbon cycles. However, it is unclear how AAIW responds to global climate changes. In particular, neodymium isotopic composition (εNd) reconstructions from different locations from the tropical Atlantic have led to a debate on the relationship between northward penetration of AAIW into the tropical Atlantic and the Atlantic meridional overturning circulation (AMOC) variability during the last deglaciation. We resolve this controversy by studying the transient oceanic evolution during the last deglaciation using a neodymium-enabled ocean model. Our results suggest a coherent response of AAIW and AMOC: when AMOC weakens, the northward penetration and transport of AAIW decrease while its depth and thickness increase. Our study highlights that as part of the return flow of the North Atlantic Deep Water,the northward penetration of AAIW in the Atlantic is determined predominately by AMOC intensity. Moreover, the inconsistency among different tropical Atlantic εNd reconstructions is reconciled by considering their corresponding core locations and depths, which were in fluenced by different water masses in the past. The very radiogenic water from the bottom of the Gulf of Mexico and the Caribbean Sea, which was previously overlooked in the interpretations of deglacial εNd variability, can be transported to shallow layers during active AMOC and modulates εNd in the tropical Atlantic. Changes in the AAIW core depth must also be considered. Thus, interpretation of εNd reconstructions from the tropical Atlantic is more complicated than suggested in previous studies. Text Antarc* Antarctic North Atlantic Deep Water North Atlantic DataCite Metadata Store (German National Library of Science and Technology) Antarctic |
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English |
topic |
530 Physics 550 Earth sciences & geology |
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530 Physics 550 Earth sciences & geology Joos, Fortunat Rempfer, Johannes Zhang, Jiaxu Liu, Zhengyu Gu, Sifan Oppo, Delia W. Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic |
topic_facet |
530 Physics 550 Earth sciences & geology |
description |
Antarctic Intermediate Water (AAIW) plays important roles in the global climate system and the global ocean nutrient and carbon cycles. However, it is unclear how AAIW responds to global climate changes. In particular, neodymium isotopic composition (εNd) reconstructions from different locations from the tropical Atlantic have led to a debate on the relationship between northward penetration of AAIW into the tropical Atlantic and the Atlantic meridional overturning circulation (AMOC) variability during the last deglaciation. We resolve this controversy by studying the transient oceanic evolution during the last deglaciation using a neodymium-enabled ocean model. Our results suggest a coherent response of AAIW and AMOC: when AMOC weakens, the northward penetration and transport of AAIW decrease while its depth and thickness increase. Our study highlights that as part of the return flow of the North Atlantic Deep Water,the northward penetration of AAIW in the Atlantic is determined predominately by AMOC intensity. Moreover, the inconsistency among different tropical Atlantic εNd reconstructions is reconciled by considering their corresponding core locations and depths, which were in fluenced by different water masses in the past. The very radiogenic water from the bottom of the Gulf of Mexico and the Caribbean Sea, which was previously overlooked in the interpretations of deglacial εNd variability, can be transported to shallow layers during active AMOC and modulates εNd in the tropical Atlantic. Changes in the AAIW core depth must also be considered. Thus, interpretation of εNd reconstructions from the tropical Atlantic is more complicated than suggested in previous studies. |
format |
Text |
author |
Joos, Fortunat Rempfer, Johannes Zhang, Jiaxu Liu, Zhengyu Gu, Sifan Oppo, Delia W. |
author_facet |
Joos, Fortunat Rempfer, Johannes Zhang, Jiaxu Liu, Zhengyu Gu, Sifan Oppo, Delia W. |
author_sort |
Joos, Fortunat |
title |
Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic |
title_short |
Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic |
title_full |
Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic |
title_fullStr |
Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic |
title_full_unstemmed |
Coherent Response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation During the Last Deglaciation: Reconciling Contrasting Neodymium Isotope Reconstructions From the Tropical Atlantic |
title_sort |
coherent response of antarctic intermediate water and atlantic meridional overturning circulation during the last deglaciation: reconciling contrasting neodymium isotope reconstructions from the tropical atlantic |
publisher |
American Geophysical Union |
publishDate |
2017 |
url |
https://dx.doi.org/10.7892/boris.106910 https://boris.unibe.ch/106910/ |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.7892/boris.106910 |
_version_ |
1766055054204207104 |