Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II
At the southern tip of Africa, the Agulhas Current reflects back into the Indian Ocean causing so-called "Agulhas rings" to spin off and release relatively warm and saline water into the South Atlantic Ocean. Previous reconstructions of the dynamics of the Agulhas Current, based on paleo-s...
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ftuabarcelonapb:oai:ddd.uab.cat:132784 2023-05-15T18:00:45+02:00 Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II Kasper, S. Van der Meer, M. T. J. Mets, A. Zahn, Rainer Sinninghe Damsté, J. S. Schouten, Stefan 2014 application/pdf https://ddd.uab.cat/record/132784 eng eng Climate of the past Vol. 10, issue 1 (February 2014), p. 251-260 https://ddd.uab.cat/record/132784 urn:10.5194/cp-10-251-2014 urn:oai:ddd.uab.cat:132784 urn:articleid:18149324v10n1p251 urn:scopus_id:84893632503 urn:wos_id:000333837600017 urn:altmetric_id:2099774 urn:oai:egreta.uab.cat:publications/c66c7f5e-20f1-42f9-995d-bc336ee71abd open access Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. https://creativecommons.org/licenses/by/3.0/ CC-BY Article 2014 ftuabarcelonapb 2023-02-06T21:03:29Z At the southern tip of Africa, the Agulhas Current reflects back into the Indian Ocean causing so-called "Agulhas rings" to spin off and release relatively warm and saline water into the South Atlantic Ocean. Previous reconstructions of the dynamics of the Agulhas Current, based on paleo-sea surface temperature and sea surface salinity proxies, inferred that Agulhas leakage from the Indian Ocean to the South Atlantic was reduced during glacial stages as a consequence of shifted wind fields and a northwards migration of the subtropical front. Subsequently, this might have led to a buildup of warm saline water in the southern Indian Ocean. To investigate this latter hypothesis, we reconstructed sea surface salinity changes using alkenone δD, and paleo-sea surface temperature using TEX H¦86 and U K¦37, from two sediment cores (MD02-2594, MD96-2080) located in the Agulhas leakage area during Termination I and II. Both U K¦37 and TEX H¦86 temperature reconstructions indicate an abrupt warming during the glacial terminations, while a shift to more negative δDalkenone values of approximately 14‰ during glacial Termination I and II is also observed. Approximately half of the isotopic shift can be attributed to the change in global ice volume, while the residual isotopic shift is attributed to changes in salinity, suggesting relatively high salinities at the core sites during glacials, with subsequent freshening during glacial terminations. Approximate estimations suggest that δDalkenone represents a salinity change of ca. 1.7-1.9 during Termination I and Termination II. These estimations are in good agreement with the proposed changes in salinity derived from previously reported combined planktonic Foraminifera δ¹⁸ O values and Mg/Ca-based temperature reconstructions. Our results confirm that the δD of alkenones is a potentially suitable tool to reconstruct salinity changes independent of planktonic Foraminifera δ¹⁸ O. Article in Journal/Newspaper Planktonic foraminifera South Atlantic Ocean Universitat Autònoma de Barcelona: Dipòsit Digital de Documents de la UAB Indian Climate of the Past 10 1 251 260 |
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Open Polar |
collection |
Universitat Autònoma de Barcelona: Dipòsit Digital de Documents de la UAB |
op_collection_id |
ftuabarcelonapb |
language |
English |
description |
At the southern tip of Africa, the Agulhas Current reflects back into the Indian Ocean causing so-called "Agulhas rings" to spin off and release relatively warm and saline water into the South Atlantic Ocean. Previous reconstructions of the dynamics of the Agulhas Current, based on paleo-sea surface temperature and sea surface salinity proxies, inferred that Agulhas leakage from the Indian Ocean to the South Atlantic was reduced during glacial stages as a consequence of shifted wind fields and a northwards migration of the subtropical front. Subsequently, this might have led to a buildup of warm saline water in the southern Indian Ocean. To investigate this latter hypothesis, we reconstructed sea surface salinity changes using alkenone δD, and paleo-sea surface temperature using TEX H¦86 and U K¦37, from two sediment cores (MD02-2594, MD96-2080) located in the Agulhas leakage area during Termination I and II. Both U K¦37 and TEX H¦86 temperature reconstructions indicate an abrupt warming during the glacial terminations, while a shift to more negative δDalkenone values of approximately 14‰ during glacial Termination I and II is also observed. Approximately half of the isotopic shift can be attributed to the change in global ice volume, while the residual isotopic shift is attributed to changes in salinity, suggesting relatively high salinities at the core sites during glacials, with subsequent freshening during glacial terminations. Approximate estimations suggest that δDalkenone represents a salinity change of ca. 1.7-1.9 during Termination I and Termination II. These estimations are in good agreement with the proposed changes in salinity derived from previously reported combined planktonic Foraminifera δ¹⁸ O values and Mg/Ca-based temperature reconstructions. Our results confirm that the δD of alkenones is a potentially suitable tool to reconstruct salinity changes independent of planktonic Foraminifera δ¹⁸ O. |
format |
Article in Journal/Newspaper |
author |
Kasper, S. Van der Meer, M. T. J. Mets, A. Zahn, Rainer Sinninghe Damsté, J. S. Schouten, Stefan |
spellingShingle |
Kasper, S. Van der Meer, M. T. J. Mets, A. Zahn, Rainer Sinninghe Damsté, J. S. Schouten, Stefan Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II |
author_facet |
Kasper, S. Van der Meer, M. T. J. Mets, A. Zahn, Rainer Sinninghe Damsté, J. S. Schouten, Stefan |
author_sort |
Kasper, S. |
title |
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II |
title_short |
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II |
title_full |
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II |
title_fullStr |
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II |
title_full_unstemmed |
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II |
title_sort |
salinity changes in the agulhas leakage area recorded by stable hydrogen isotopes of c37 alkenones during termination i and ii |
publishDate |
2014 |
url |
https://ddd.uab.cat/record/132784 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Planktonic foraminifera South Atlantic Ocean |
genre_facet |
Planktonic foraminifera South Atlantic Ocean |
op_relation |
Climate of the past Vol. 10, issue 1 (February 2014), p. 251-260 https://ddd.uab.cat/record/132784 urn:10.5194/cp-10-251-2014 urn:oai:ddd.uab.cat:132784 urn:articleid:18149324v10n1p251 urn:scopus_id:84893632503 urn:wos_id:000333837600017 urn:altmetric_id:2099774 urn:oai:egreta.uab.cat:publications/c66c7f5e-20f1-42f9-995d-bc336ee71abd |
op_rights |
open access Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. https://creativecommons.org/licenses/by/3.0/ |
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CC-BY |
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Climate of the Past |
container_volume |
10 |
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251 |
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260 |
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1766169959579254784 |