Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years
Antarctic Intermediate Water is an essential limb of the Atlantic meridional overturning circulation that redistributes heat and nutrients within the Atlantic Ocean. Existing reconstructions have yielded conflicting results on the history of Antarctic Intermediate Water penetration into the Atlantic...
Published in: | Paleoceanography |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
AGU
2016
|
Subjects: | |
Online Access: | http://eprints.esc.cam.ac.uk/3928/ http://eprints.esc.cam.ac.uk/3928/1/palo20370.pdf https://doi.org/10.1002/2016PA002975 |
id |
ftucambridgeesc:oai:eprints.esc.cam.ac.uk:3928 |
---|---|
record_format |
openpolar |
spelling |
ftucambridgeesc:oai:eprints.esc.cam.ac.uk:3928 2023-05-15T13:55:44+02:00 Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years Howe, Jacob N. W. Piotrowski, Alexander M. Oppo, Delia W. Huang, Kuo-Fang Mulitza, Stefan Chiessi, Cristiano M. Blusztajn, Jurek 2016 text http://eprints.esc.cam.ac.uk/3928/ http://eprints.esc.cam.ac.uk/3928/1/palo20370.pdf https://doi.org/10.1002/2016PA002975 en eng AGU http://eprints.esc.cam.ac.uk/3928/1/palo20370.pdf Howe, Jacob N. W. and Piotrowski, Alexander M. and Oppo, Delia W. and Huang, Kuo-Fang and Mulitza, Stefan and Chiessi, Cristiano M. and Blusztajn, Jurek (2016) Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years. Paleoceanography, 31 (10). pp. 1302-1314. ISSN 1944-9186 %7C 0883-8305 DOI https://doi.org/10.1002/2016PA002975 <https://doi.org/10.1002/2016PA002975> 01 - Climate Change and Earth-Ocean Atmosphere Systems Article PeerReviewed 2016 ftucambridgeesc https://doi.org/10.1002/2016PA002975 2020-08-27T18:09:49Z Antarctic Intermediate Water is an essential limb of the Atlantic meridional overturning circulation that redistributes heat and nutrients within the Atlantic Ocean. Existing reconstructions have yielded conflicting results on the history of Antarctic Intermediate Water penetration into the Atlantic across the most recent glacial termination. In this study we present leachate, foraminiferal, and detrital neodymium isotope data from three intermediate-depth cores collected from the southern Brazil margin in the South Atlantic covering the past 25 kyr. These results reveal that strong chemical leaching following decarbonation does not extract past seawater neodymium composition in this location. The new foraminiferal records reveal no changes in seawater Nd isotopes during abrupt Northern Hemisphere cold events at these sites. We therefore conclude that there is no evidence for greater incursion of Antarctic Intermediate Water into the South Atlantic during either the Younger Dryas or Heinrich Stadial 1. We do, however, observe more radiogenic Nd isotope values in the intermediate-depth South Atlantic during the mid-Holocene. This radiogenic excursion coincides with evidence for a southward shift in the Southern Hemisphere westerlies that may have resulted in a greater entrainment of radiogenic Pacific-sourced water during intermediate water production in the Atlantic sector of the Southern Ocean. Our intermediate-depth records show similar values to a deglacial foraminiferal Nd isotope record from the deep South Atlantic during the Younger Dryas but are clearly distinct during the Last Glacial Maximum and Heinrich Stadial 1, demonstrating that the South Atlantic remained chemically stratified during Heinrich Stadial 1. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Cambridge, Department of Earth Sciences: ESC Publications Antarctic Pacific Southern Ocean Paleoceanography 31 10 1302 1314 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
spellingShingle |
01 - Climate Change and Earth-Ocean Atmosphere Systems Howe, Jacob N. W. Piotrowski, Alexander M. Oppo, Delia W. Huang, Kuo-Fang Mulitza, Stefan Chiessi, Cristiano M. Blusztajn, Jurek Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years |
topic_facet |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
description |
Antarctic Intermediate Water is an essential limb of the Atlantic meridional overturning circulation that redistributes heat and nutrients within the Atlantic Ocean. Existing reconstructions have yielded conflicting results on the history of Antarctic Intermediate Water penetration into the Atlantic across the most recent glacial termination. In this study we present leachate, foraminiferal, and detrital neodymium isotope data from three intermediate-depth cores collected from the southern Brazil margin in the South Atlantic covering the past 25 kyr. These results reveal that strong chemical leaching following decarbonation does not extract past seawater neodymium composition in this location. The new foraminiferal records reveal no changes in seawater Nd isotopes during abrupt Northern Hemisphere cold events at these sites. We therefore conclude that there is no evidence for greater incursion of Antarctic Intermediate Water into the South Atlantic during either the Younger Dryas or Heinrich Stadial 1. We do, however, observe more radiogenic Nd isotope values in the intermediate-depth South Atlantic during the mid-Holocene. This radiogenic excursion coincides with evidence for a southward shift in the Southern Hemisphere westerlies that may have resulted in a greater entrainment of radiogenic Pacific-sourced water during intermediate water production in the Atlantic sector of the Southern Ocean. Our intermediate-depth records show similar values to a deglacial foraminiferal Nd isotope record from the deep South Atlantic during the Younger Dryas but are clearly distinct during the Last Glacial Maximum and Heinrich Stadial 1, demonstrating that the South Atlantic remained chemically stratified during Heinrich Stadial 1. |
format |
Article in Journal/Newspaper |
author |
Howe, Jacob N. W. Piotrowski, Alexander M. Oppo, Delia W. Huang, Kuo-Fang Mulitza, Stefan Chiessi, Cristiano M. Blusztajn, Jurek |
author_facet |
Howe, Jacob N. W. Piotrowski, Alexander M. Oppo, Delia W. Huang, Kuo-Fang Mulitza, Stefan Chiessi, Cristiano M. Blusztajn, Jurek |
author_sort |
Howe, Jacob N. W. |
title |
Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years |
title_short |
Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years |
title_full |
Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years |
title_fullStr |
Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years |
title_full_unstemmed |
Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years |
title_sort |
antarctic intermediate water circulation in the south atlantic over the past 25,000 years |
publisher |
AGU |
publishDate |
2016 |
url |
http://eprints.esc.cam.ac.uk/3928/ http://eprints.esc.cam.ac.uk/3928/1/palo20370.pdf https://doi.org/10.1002/2016PA002975 |
geographic |
Antarctic Pacific Southern Ocean |
geographic_facet |
Antarctic Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
http://eprints.esc.cam.ac.uk/3928/1/palo20370.pdf Howe, Jacob N. W. and Piotrowski, Alexander M. and Oppo, Delia W. and Huang, Kuo-Fang and Mulitza, Stefan and Chiessi, Cristiano M. and Blusztajn, Jurek (2016) Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years. Paleoceanography, 31 (10). pp. 1302-1314. ISSN 1944-9186 %7C 0883-8305 DOI https://doi.org/10.1002/2016PA002975 <https://doi.org/10.1002/2016PA002975> |
op_doi |
https://doi.org/10.1002/2016PA002975 |
container_title |
Paleoceanography |
container_volume |
31 |
container_issue |
10 |
container_start_page |
1302 |
op_container_end_page |
1314 |
_version_ |
1766262575965667328 |