Antarctic icebergs reorganize ocean circulation during Pleistocene glacials
The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1...
Published in: | Nature |
---|---|
Main Authors: | , , , , , , , , , , , , , , , , , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Nature Publishing Group
2021
|
Subjects: | |
Online Access: | http://hdl.handle.net/10261/258181 https://doi.org/10.1038/s41586-020-03094-7 https://doi.org/10.13039/501100000780 https://doi.org/10.13039/501100001656 https://doi.org/10.13039/501100004837 https://doi.org/10.13039/501100000270 |
id |
ftcsic:oai:digital.csic.es:10261/258181 |
---|---|
record_format |
openpolar |
spelling |
ftcsic:oai:digital.csic.es:10261/258181 2024-02-11T09:58:51+01:00 Antarctic icebergs reorganize ocean circulation during Pleistocene glacials Starr, Aidan Hall, Ian R. Barker, Stephen Rackow, Thomas Zhang, Xu Hemming, Sidney R. Van Der Lubber, H. J. L. Knorr, Gregor Berke, Melissa A. Bigg, Grant R. Cartagena Sierra, Alejandra Jiménez Espejo, Francisco J. Gong, Xun Gruetzner, Jens Lathika, Nambiyathodi LeVay, Leah J. Robinson, Rebecca S. Ziegler, Martin Ministerio de Ciencia e Innovación (España) Natural Environment Research Council (UK) National Key Research and Development Program (China) Helmholtz Association European Commission 2021-01-13 http://hdl.handle.net/10261/258181 https://doi.org/10.1038/s41586-020-03094-7 https://doi.org/10.13039/501100000780 https://doi.org/10.13039/501100001656 https://doi.org/10.13039/501100004837 https://doi.org/10.13039/501100000270 unknown Nature Publishing Group #PLACEHOLDER_PARENT_METADATA_VALUE# info:eu-repo/grantAgreement/MICINN///CTM2017-89711-C2-1-P Publisher's version http://dx.doi.org/10.1038/s41586-020-03094-7 Sí doi:10.1038/s41586-020-03094-7 issn: 1476-4687 Nature 589: 236- 241 (2021) http://hdl.handle.net/10261/258181 http://dx.doi.org/10.13039/501100000780 http://dx.doi.org/10.13039/501100001656 http://dx.doi.org/10.13039/501100004837 http://dx.doi.org/10.13039/501100000270 open Atlantic Ocean Pleistocene Global climate Iceberg Oceanic circulation artículo http://purl.org/coar/resource_type/c_6501 2021 ftcsic https://doi.org/10.1038/s41586-020-03094-710.13039/50110000078010.13039/50110000165610.13039/50110000483710.13039/501100000270 2024-01-16T11:17:34Z The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1.5 million years the AMOC had markedly different features from today; in the Atlantic basin, deep waters of Southern Ocean origin increased in volume while above them the core of the North Atlantic Deep Water (NADW) shoaled. An absence of evidence on the origin of this phenomenon means that the sequence of events leading to global glacial conditions remains unclear. Here we present multi-proxy evidence showing that northward shifts in Antarctic iceberg melt in the Indian–Atlantic Southern Ocean (0–50° E) systematically preceded deep-water mass reorganizations by one to two thousand years during Pleistocene-era glaciations. With the aid of iceberg-trajectory model experiments, we demonstrate that such a shift in iceberg trajectories during glacial periods can result in a considerable redistribution of freshwater in the Southern Ocean. We suggest that this, in concert with increased sea-ice cover, enabled positive buoyancy anomalies to ‘escape’ into the upper limb of the AMOC, providing a teleconnection between surface Southern Ocean conditions and the formation of NADW. The magnitude and pacing of this mechanism evolved substantially across the mid-Pleistocene transition, and the coeval increase in magnitude of the ‘southern escape’ and deep circulation perturbations implicate this mechanism as a key feedback in the transition to the ‘100-kyr world’, in which glacial–interglacial cycles occur at roughly 100,000-year periods. Acknowledgements This research used samples and/or data provided by the International Ocean Discovery Program (IODP). Funding for this research was provided by The Natural Environmental Research Council GW4+ Doctoral Training Partnership (A.S.) and NERC grant NE/P000037/1 (I.R.H.). A.S. ... Article in Journal/Newspaper Antarc* Antarctic Iceberg* NADW North Atlantic Deep Water North Atlantic Sea ice Southern Ocean Digital.CSIC (Spanish National Research Council) Antarctic Indian Southern Ocean Nature 589 7841 236 241 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
topic |
Atlantic Ocean Pleistocene Global climate Iceberg Oceanic circulation |
spellingShingle |
Atlantic Ocean Pleistocene Global climate Iceberg Oceanic circulation Starr, Aidan Hall, Ian R. Barker, Stephen Rackow, Thomas Zhang, Xu Hemming, Sidney R. Van Der Lubber, H. J. L. Knorr, Gregor Berke, Melissa A. Bigg, Grant R. Cartagena Sierra, Alejandra Jiménez Espejo, Francisco J. Gong, Xun Gruetzner, Jens Lathika, Nambiyathodi LeVay, Leah J. Robinson, Rebecca S. Ziegler, Martin Antarctic icebergs reorganize ocean circulation during Pleistocene glacials |
topic_facet |
Atlantic Ocean Pleistocene Global climate Iceberg Oceanic circulation |
description |
The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1.5 million years the AMOC had markedly different features from today; in the Atlantic basin, deep waters of Southern Ocean origin increased in volume while above them the core of the North Atlantic Deep Water (NADW) shoaled. An absence of evidence on the origin of this phenomenon means that the sequence of events leading to global glacial conditions remains unclear. Here we present multi-proxy evidence showing that northward shifts in Antarctic iceberg melt in the Indian–Atlantic Southern Ocean (0–50° E) systematically preceded deep-water mass reorganizations by one to two thousand years during Pleistocene-era glaciations. With the aid of iceberg-trajectory model experiments, we demonstrate that such a shift in iceberg trajectories during glacial periods can result in a considerable redistribution of freshwater in the Southern Ocean. We suggest that this, in concert with increased sea-ice cover, enabled positive buoyancy anomalies to ‘escape’ into the upper limb of the AMOC, providing a teleconnection between surface Southern Ocean conditions and the formation of NADW. The magnitude and pacing of this mechanism evolved substantially across the mid-Pleistocene transition, and the coeval increase in magnitude of the ‘southern escape’ and deep circulation perturbations implicate this mechanism as a key feedback in the transition to the ‘100-kyr world’, in which glacial–interglacial cycles occur at roughly 100,000-year periods. Acknowledgements This research used samples and/or data provided by the International Ocean Discovery Program (IODP). Funding for this research was provided by The Natural Environmental Research Council GW4+ Doctoral Training Partnership (A.S.) and NERC grant NE/P000037/1 (I.R.H.). A.S. ... |
author2 |
Ministerio de Ciencia e Innovación (España) Natural Environment Research Council (UK) National Key Research and Development Program (China) Helmholtz Association European Commission |
format |
Article in Journal/Newspaper |
author |
Starr, Aidan Hall, Ian R. Barker, Stephen Rackow, Thomas Zhang, Xu Hemming, Sidney R. Van Der Lubber, H. J. L. Knorr, Gregor Berke, Melissa A. Bigg, Grant R. Cartagena Sierra, Alejandra Jiménez Espejo, Francisco J. Gong, Xun Gruetzner, Jens Lathika, Nambiyathodi LeVay, Leah J. Robinson, Rebecca S. Ziegler, Martin |
author_facet |
Starr, Aidan Hall, Ian R. Barker, Stephen Rackow, Thomas Zhang, Xu Hemming, Sidney R. Van Der Lubber, H. J. L. Knorr, Gregor Berke, Melissa A. Bigg, Grant R. Cartagena Sierra, Alejandra Jiménez Espejo, Francisco J. Gong, Xun Gruetzner, Jens Lathika, Nambiyathodi LeVay, Leah J. Robinson, Rebecca S. Ziegler, Martin |
author_sort |
Starr, Aidan |
title |
Antarctic icebergs reorganize ocean circulation during Pleistocene glacials |
title_short |
Antarctic icebergs reorganize ocean circulation during Pleistocene glacials |
title_full |
Antarctic icebergs reorganize ocean circulation during Pleistocene glacials |
title_fullStr |
Antarctic icebergs reorganize ocean circulation during Pleistocene glacials |
title_full_unstemmed |
Antarctic icebergs reorganize ocean circulation during Pleistocene glacials |
title_sort |
antarctic icebergs reorganize ocean circulation during pleistocene glacials |
publisher |
Nature Publishing Group |
publishDate |
2021 |
url |
http://hdl.handle.net/10261/258181 https://doi.org/10.1038/s41586-020-03094-7 https://doi.org/10.13039/501100000780 https://doi.org/10.13039/501100001656 https://doi.org/10.13039/501100004837 https://doi.org/10.13039/501100000270 |
geographic |
Antarctic Indian Southern Ocean |
geographic_facet |
Antarctic Indian Southern Ocean |
genre |
Antarc* Antarctic Iceberg* NADW North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Iceberg* NADW North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
op_relation |
#PLACEHOLDER_PARENT_METADATA_VALUE# info:eu-repo/grantAgreement/MICINN///CTM2017-89711-C2-1-P Publisher's version http://dx.doi.org/10.1038/s41586-020-03094-7 Sí doi:10.1038/s41586-020-03094-7 issn: 1476-4687 Nature 589: 236- 241 (2021) http://hdl.handle.net/10261/258181 http://dx.doi.org/10.13039/501100000780 http://dx.doi.org/10.13039/501100001656 http://dx.doi.org/10.13039/501100004837 http://dx.doi.org/10.13039/501100000270 |
op_rights |
open |
op_doi |
https://doi.org/10.1038/s41586-020-03094-710.13039/50110000078010.13039/50110000165610.13039/50110000483710.13039/501100000270 |
container_title |
Nature |
container_volume |
589 |
container_issue |
7841 |
container_start_page |
236 |
op_container_end_page |
241 |
_version_ |
1790594634054893568 |