Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth
Despite its importance for climate and the carbon cycle, the deep ocean circulation during the Last Glacial Maximum (LGM) remains poorly understood. Whereas most studies suggest a shallower Atlantic Meridional Overturning Circulation (AMOC) than at present day, there is disagreement about its transp...
Published in: | Quaternary Science Reviews |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Pergamon-Elsevier Science Ltd
|
Subjects: | |
Online Access: | http://hdl.handle.net/11336/153462 |
id |
ftconicet:oai:ri.conicet.gov.ar:11336/153462 |
---|---|
record_format |
openpolar |
spelling |
ftconicet:oai:ri.conicet.gov.ar:11336/153462 2023-10-09T21:56:03+02:00 Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth Muglia, Juan Schmittner, Andreas application/pdf http://hdl.handle.net/11336/153462 eng eng Pergamon-Elsevier Science Ltd info:eu-repo/semantics/altIdentifier/url/https://linkinghub.elsevier.com/retrieve/pii/S0277379121000512 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.quascirev.2021.106844 http://hdl.handle.net/11336/153462 Muglia, Juan; Schmittner, Andreas; Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth; Pergamon-Elsevier Science Ltd; Quaternary Science Reviews; 257; 4-2021; 1-14 0277-3791 CONICET Digital CONICET info:eu-repo/semantics/restrictedAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ CIRCULATION GLOBAL LAST GLACIAL MAXIMUM PALEOCLIMATE MODELING https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion ftconicet https://doi.org/10.1016/j.quascirev.2021.106844 2023-09-24T20:25:18Z Despite its importance for climate and the carbon cycle, the deep ocean circulation during the Last Glacial Maximum (LGM) remains poorly understood. Whereas most studies suggest a shallower Atlantic Meridional Overturning Circulation (AMOC) than at present day, there is disagreement about its transport rate, with estimates ranging from stronger to weaker than today. Older deep ocean radiocarbon ages have been suggested to imply a more sluggish circulation. Here we use a global isotope-enabled ocean-climate model to systematically explore the different effects of AMOC depth and strength on carbon isotope (13C and radiocarbon) distributions and constraints provided by sediment data. We find that existing data constrain the AMOC depth well, favoring simulations with a shallower-than-present LGM AMOC reaching 2000−2500 m of depth. However, they provide weaker constraints on AMOC strength. Comparisons with two high vertical resolution LGM δ13C profiles suggest LGM AMOC strength between 11 and 18 Sv, but more data are needed to refine this estimate. Contrary to past conjectures, we find radiocarbon age to be only weakly related with deep water transport rates, but strongly dependent on Southern Ocean surface reservoir ages, which are highly correlated with AMOC depth. In addition, upon changes of deep transport rates and/or water mass geometry, variations in modeled δ13C and radiocarbon age are highly correlated, suggesting that they do not act as independent traces for physical ocean processes. Fil: Muglia, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Schmittner, Andreas. State University of Oregon. College of Earth, Ocean and Atmospheric Sciences; Estados Unidos Article in Journal/Newspaper Southern Ocean CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) Andreas ENVELOPE(-60.729,-60.729,-64.008,-64.008) Argentina Southern Ocean Quaternary Science Reviews 257 106844 |
institution |
Open Polar |
collection |
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) |
op_collection_id |
ftconicet |
language |
English |
topic |
CIRCULATION GLOBAL LAST GLACIAL MAXIMUM PALEOCLIMATE MODELING https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
spellingShingle |
CIRCULATION GLOBAL LAST GLACIAL MAXIMUM PALEOCLIMATE MODELING https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 Muglia, Juan Schmittner, Andreas Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth |
topic_facet |
CIRCULATION GLOBAL LAST GLACIAL MAXIMUM PALEOCLIMATE MODELING https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
description |
Despite its importance for climate and the carbon cycle, the deep ocean circulation during the Last Glacial Maximum (LGM) remains poorly understood. Whereas most studies suggest a shallower Atlantic Meridional Overturning Circulation (AMOC) than at present day, there is disagreement about its transport rate, with estimates ranging from stronger to weaker than today. Older deep ocean radiocarbon ages have been suggested to imply a more sluggish circulation. Here we use a global isotope-enabled ocean-climate model to systematically explore the different effects of AMOC depth and strength on carbon isotope (13C and radiocarbon) distributions and constraints provided by sediment data. We find that existing data constrain the AMOC depth well, favoring simulations with a shallower-than-present LGM AMOC reaching 2000−2500 m of depth. However, they provide weaker constraints on AMOC strength. Comparisons with two high vertical resolution LGM δ13C profiles suggest LGM AMOC strength between 11 and 18 Sv, but more data are needed to refine this estimate. Contrary to past conjectures, we find radiocarbon age to be only weakly related with deep water transport rates, but strongly dependent on Southern Ocean surface reservoir ages, which are highly correlated with AMOC depth. In addition, upon changes of deep transport rates and/or water mass geometry, variations in modeled δ13C and radiocarbon age are highly correlated, suggesting that they do not act as independent traces for physical ocean processes. Fil: Muglia, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Schmittner, Andreas. State University of Oregon. College of Earth, Ocean and Atmospheric Sciences; Estados Unidos |
format |
Article in Journal/Newspaper |
author |
Muglia, Juan Schmittner, Andreas |
author_facet |
Muglia, Juan Schmittner, Andreas |
author_sort |
Muglia, Juan |
title |
Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth |
title_short |
Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth |
title_full |
Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth |
title_fullStr |
Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth |
title_full_unstemmed |
Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth |
title_sort |
carbon isotope constraints on glacial atlantic meridional overturning: strength vs depth |
publisher |
Pergamon-Elsevier Science Ltd |
url |
http://hdl.handle.net/11336/153462 |
long_lat |
ENVELOPE(-60.729,-60.729,-64.008,-64.008) |
geographic |
Andreas Argentina Southern Ocean |
geographic_facet |
Andreas Argentina Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
info:eu-repo/semantics/altIdentifier/url/https://linkinghub.elsevier.com/retrieve/pii/S0277379121000512 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.quascirev.2021.106844 http://hdl.handle.net/11336/153462 Muglia, Juan; Schmittner, Andreas; Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth; Pergamon-Elsevier Science Ltd; Quaternary Science Reviews; 257; 4-2021; 1-14 0277-3791 CONICET Digital CONICET |
op_rights |
info:eu-repo/semantics/restrictedAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
op_doi |
https://doi.org/10.1016/j.quascirev.2021.106844 |
container_title |
Quaternary Science Reviews |
container_volume |
257 |
container_start_page |
106844 |
_version_ |
1779320453728305152 |