Role of CO2 and Southern Ocean winds in glacial abrupt climate change
The study of Greenland ice cores revealed two decades ago the abrupt character of glacial millennial-scale climate variability. Several triggering mechanisms have been proposed and confronted against growing proxy-data evidence. Although the implication of North Atlantic deep water (NADW) formation...
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ftunivcmadrid:oai:www.ucm.es:24179 2023-05-15T16:28:22+02:00 Role of CO2 and Southern Ocean winds in glacial abrupt climate change Banderas Carreño, Rubén Álvarez Solas, Jorge Montoya, M. 2012-06-01 application/pdf https://eprints.ucm.es/id/eprint/24179/ https://eprints.ucm.es/id/eprint/24179/1/alvarezsolas01libre.pdf https://doi.org/10.5194/cp-8-1011-2012 en eng Copernicus Gesellschaft MBH https://eprints.ucm.es/id/eprint/24179/1/alvarezsolas01libre.pdf cc_by info:eu-repo/semantics/openAccess CC-BY Astrofísica Física atmosférica Astronomía info:eu-repo/semantics/article PeerReviewed 2012 ftunivcmadrid https://doi.org/10.5194/cp-8-1011-2012 2022-05-12T19:55:58Z The study of Greenland ice cores revealed two decades ago the abrupt character of glacial millennial-scale climate variability. Several triggering mechanisms have been proposed and confronted against growing proxy-data evidence. Although the implication of North Atlantic deep water (NADW) formation reorganisations in glacial abrupt climate change seems robust nowadays, the final cause of these reorganisations remains unclear. Here, the role of CO2 and Southern Ocean winds is investigated using a coupled model of intermediate complexity in an experimental setup designed such that the climate system resides close to a threshold found in previous studies. An initial abrupt surface air temperature (SAT) increase over the North Atlantic by 4 K in less than a decade, followed by a more gradual warming greater than 10 K on centennial timescales, is simulated in response to increasing atmospheric CO2 levels and/or enhancing southern westerlies. The simulated peak warming shows a similar pattern and amplitude over Greenland as registered in ice core records of Dansgaard-Oeschger (D/O) events. This is accompanied by a strong Atlantic meridional overturning circulation (AMOC) intensification. The AMOC strengthening is found to be caused by a northward shift of NADW formation sites into the Nordic Seas as a result of a northward retreat of the sea-ice front in response to higher temperatures. This leads to enhanced heat loss to the atmosphere as well as reduced freshwater fluxes via reduced sea-ice import into the region. In this way, a new mechanism that is consistent with proxy data is identified by which abrupt climate change can be promoted. Article in Journal/Newspaper Greenland Greenland ice cores ice core NADW Nordic Seas North Atlantic Deep Water North Atlantic Sea ice Southern Ocean Universidad Complutense de Madrid (UCM): E-Prints Complutense Greenland Southern Ocean Climate of the Past 8 3 1011 1021 |
institution |
Open Polar |
collection |
Universidad Complutense de Madrid (UCM): E-Prints Complutense |
op_collection_id |
ftunivcmadrid |
language |
English |
topic |
Astrofísica Física atmosférica Astronomía |
spellingShingle |
Astrofísica Física atmosférica Astronomía Banderas Carreño, Rubén Álvarez Solas, Jorge Montoya, M. Role of CO2 and Southern Ocean winds in glacial abrupt climate change |
topic_facet |
Astrofísica Física atmosférica Astronomía |
description |
The study of Greenland ice cores revealed two decades ago the abrupt character of glacial millennial-scale climate variability. Several triggering mechanisms have been proposed and confronted against growing proxy-data evidence. Although the implication of North Atlantic deep water (NADW) formation reorganisations in glacial abrupt climate change seems robust nowadays, the final cause of these reorganisations remains unclear. Here, the role of CO2 and Southern Ocean winds is investigated using a coupled model of intermediate complexity in an experimental setup designed such that the climate system resides close to a threshold found in previous studies. An initial abrupt surface air temperature (SAT) increase over the North Atlantic by 4 K in less than a decade, followed by a more gradual warming greater than 10 K on centennial timescales, is simulated in response to increasing atmospheric CO2 levels and/or enhancing southern westerlies. The simulated peak warming shows a similar pattern and amplitude over Greenland as registered in ice core records of Dansgaard-Oeschger (D/O) events. This is accompanied by a strong Atlantic meridional overturning circulation (AMOC) intensification. The AMOC strengthening is found to be caused by a northward shift of NADW formation sites into the Nordic Seas as a result of a northward retreat of the sea-ice front in response to higher temperatures. This leads to enhanced heat loss to the atmosphere as well as reduced freshwater fluxes via reduced sea-ice import into the region. In this way, a new mechanism that is consistent with proxy data is identified by which abrupt climate change can be promoted. |
format |
Article in Journal/Newspaper |
author |
Banderas Carreño, Rubén Álvarez Solas, Jorge Montoya, M. |
author_facet |
Banderas Carreño, Rubén Álvarez Solas, Jorge Montoya, M. |
author_sort |
Banderas Carreño, Rubén |
title |
Role of CO2 and Southern Ocean winds in glacial abrupt climate change |
title_short |
Role of CO2 and Southern Ocean winds in glacial abrupt climate change |
title_full |
Role of CO2 and Southern Ocean winds in glacial abrupt climate change |
title_fullStr |
Role of CO2 and Southern Ocean winds in glacial abrupt climate change |
title_full_unstemmed |
Role of CO2 and Southern Ocean winds in glacial abrupt climate change |
title_sort |
role of co2 and southern ocean winds in glacial abrupt climate change |
publisher |
Copernicus Gesellschaft MBH |
publishDate |
2012 |
url |
https://eprints.ucm.es/id/eprint/24179/ https://eprints.ucm.es/id/eprint/24179/1/alvarezsolas01libre.pdf https://doi.org/10.5194/cp-8-1011-2012 |
geographic |
Greenland Southern Ocean |
geographic_facet |
Greenland Southern Ocean |
genre |
Greenland Greenland ice cores ice core NADW Nordic Seas North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
genre_facet |
Greenland Greenland ice cores ice core NADW Nordic Seas North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
op_relation |
https://eprints.ucm.es/id/eprint/24179/1/alvarezsolas01libre.pdf |
op_rights |
cc_by info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/cp-8-1011-2012 |
container_title |
Climate of the Past |
container_volume |
8 |
container_issue |
3 |
container_start_page |
1011 |
op_container_end_page |
1021 |
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1766018017125203968 |