Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing
Unidad de excelencia María de Maeztu MdM-2015-0552 It is well known that glacial periods were punctuated by abrupt climate changes, with large impacts on air temperature, precipitation, and ocean circulation acrossa the globe. However, the long-held idea that freshwater forcing, caused by massive ic...
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ftuabarcelonapb:oai:ddd.uab.cat:187384 2023-05-15T17:36:25+02:00 Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing Brown, Nicolas Galbraith, Eric 2016 application/pdf https://ddd.uab.cat/record/187384 eng eng Climate of the past Vol. 12, issue 8 (Aug. 2016), p. 1663-1679 https://ddd.uab.cat/record/187384 urn:10.5194/cp-12-1663-2016 urn:oai:ddd.uab.cat:187384 urn:articleid:18149324v12n8p1663 urn:scopus_id:85016142205 urn:wos_id:000383792700001 urn:oai:egreta.uab.cat:publications/d95808c2-b359-47f9-b1f1-056dfda5bae9 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/4.0/ CC-BY Article 2016 ftuabarcelonapb 2023-02-06T21:13:37Z Unidad de excelencia María de Maeztu MdM-2015-0552 It is well known that glacial periods were punctuated by abrupt climate changes, with large impacts on air temperature, precipitation, and ocean circulation acrossa the globe. However, the long-held idea that freshwater forcing, caused by massive iceberg discharges, was the driving force behind these changes has been questioned in recent years. This throws into doubt the abundant literature on modelling abrupt climate change through "hosing" experiments, whereby the Atlantic Meridional Overturning Circulation (AMOC) is interrupted by an injection of freshwater to the North Atlantic: if some, or all, abrupt climate change was not driven by freshwater input, could its character have been very different than the typical hosed experiments? Here, we describe spontaneous, unhosed oscillations in AMOC strength that occur in a global coupled ocean-atmosphere model when integrated under a particular background climate state. We compare these unhosed oscillations to hosed oscillations under a range of background climate states in order to examine how the global imprint of AMOC variations depends on whether or not they result from external freshwater input. Our comparison includes surface air temperature, precipitation, dissolved oxygen concentrations in the intermediate-depth ocean, and marine export production. The results show that the background climate state has a significant impact on the character of the freshwater-forced AMOC interruptions in this model, with particularly marked variations in tropical precipitation and in the North Pacific circulation. Despite these differences, the first-order patterns of response to AMOC interruptions are quite consistent among all simulations, implying that the ocean-sea ice-atmosphere dynamics associated with an AMOC weakening dominate the global response, regardless of whether or not freshwater input is the cause. Nonetheless, freshwater addition leads to a more complete shutdown of the AMOC than occurs in the unhosed ... Article in Journal/Newspaper North Atlantic Sea ice Universitat Autònoma de Barcelona: Dipòsit Digital de Documents de la UAB Pacific Climate of the Past 12 8 1663 1679 |
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Open Polar |
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Universitat Autònoma de Barcelona: Dipòsit Digital de Documents de la UAB |
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ftuabarcelonapb |
language |
English |
description |
Unidad de excelencia María de Maeztu MdM-2015-0552 It is well known that glacial periods were punctuated by abrupt climate changes, with large impacts on air temperature, precipitation, and ocean circulation acrossa the globe. However, the long-held idea that freshwater forcing, caused by massive iceberg discharges, was the driving force behind these changes has been questioned in recent years. This throws into doubt the abundant literature on modelling abrupt climate change through "hosing" experiments, whereby the Atlantic Meridional Overturning Circulation (AMOC) is interrupted by an injection of freshwater to the North Atlantic: if some, or all, abrupt climate change was not driven by freshwater input, could its character have been very different than the typical hosed experiments? Here, we describe spontaneous, unhosed oscillations in AMOC strength that occur in a global coupled ocean-atmosphere model when integrated under a particular background climate state. We compare these unhosed oscillations to hosed oscillations under a range of background climate states in order to examine how the global imprint of AMOC variations depends on whether or not they result from external freshwater input. Our comparison includes surface air temperature, precipitation, dissolved oxygen concentrations in the intermediate-depth ocean, and marine export production. The results show that the background climate state has a significant impact on the character of the freshwater-forced AMOC interruptions in this model, with particularly marked variations in tropical precipitation and in the North Pacific circulation. Despite these differences, the first-order patterns of response to AMOC interruptions are quite consistent among all simulations, implying that the ocean-sea ice-atmosphere dynamics associated with an AMOC weakening dominate the global response, regardless of whether or not freshwater input is the cause. Nonetheless, freshwater addition leads to a more complete shutdown of the AMOC than occurs in the unhosed ... |
format |
Article in Journal/Newspaper |
author |
Brown, Nicolas Galbraith, Eric |
spellingShingle |
Brown, Nicolas Galbraith, Eric Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing |
author_facet |
Brown, Nicolas Galbraith, Eric |
author_sort |
Brown, Nicolas |
title |
Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing |
title_short |
Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing |
title_full |
Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing |
title_fullStr |
Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing |
title_full_unstemmed |
Hosed vs. unhosed : interruptions of the Atlantic Meridional overturning circulation in a global coupled model, with and without freshwater forcing |
title_sort |
hosed vs. unhosed : interruptions of the atlantic meridional overturning circulation in a global coupled model, with and without freshwater forcing |
publishDate |
2016 |
url |
https://ddd.uab.cat/record/187384 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic Sea ice |
genre_facet |
North Atlantic Sea ice |
op_relation |
Climate of the past Vol. 12, issue 8 (Aug. 2016), p. 1663-1679 https://ddd.uab.cat/record/187384 urn:10.5194/cp-12-1663-2016 urn:oai:ddd.uab.cat:187384 urn:articleid:18149324v12n8p1663 urn:scopus_id:85016142205 urn:wos_id:000383792700001 urn:oai:egreta.uab.cat:publications/d95808c2-b359-47f9-b1f1-056dfda5bae9 |
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/4.0/ |
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CC-BY |
container_title |
Climate of the Past |
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12 |
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8 |
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1663 |
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1679 |
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