Cessation of deep convection in the open Southern Ocean under anthropogenic climate change
International audience n 1974, newly available satellite observations unveiled the presence of a giant ice-free area, or polynya, within the Antarctic ice pack of the Weddell Sea, which persisted during the two following winters(1). Subsequent research showed that deep convective overturning had ope...
Published in: | Nature Climate Change |
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Online Access: | https://hal.science/hal-02437670 https://hal.science/hal-02437670/document https://hal.science/hal-02437670/file/Manuscript.pdf https://doi.org/10.1038/nclimate2132 |
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ftunivnantes:oai:HAL:hal-02437670v1 2023-05-15T13:39:32+02:00 Cessation of deep convection in the open Southern Ocean under anthropogenic climate change de Lavergne, Casimir Palter, Jaime Galbraith, Eric, Bernardello, Raffaele Marinov, Irina Department of Atmospheric and Oceanic Sciences Montréal McGill University = Université McGill Montréal, Canada Department of Earth and Planetary Sciences Montréal (EPS) Department of Earth and Environmental Science Philadelphia University of Pennsylvania 2014-04 https://hal.science/hal-02437670 https://hal.science/hal-02437670/document https://hal.science/hal-02437670/file/Manuscript.pdf https://doi.org/10.1038/nclimate2132 en eng HAL CCSD Nature Publishing Group info:eu-repo/semantics/altIdentifier/doi/10.1038/nclimate2132 hal-02437670 https://hal.science/hal-02437670 https://hal.science/hal-02437670/document https://hal.science/hal-02437670/file/Manuscript.pdf doi:10.1038/nclimate2132 WOS: 000333669600021 info:eu-repo/semantics/OpenAccess ISSN: 1758-678X EISSN: 1758-6798 Nature Climate Change https://hal.science/hal-02437670 Nature Climate Change, 2014, 4 (4), pp.278-282. ⟨10.1038/nclimate2132⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2014 ftunivnantes https://doi.org/10.1038/nclimate2132 2023-02-22T02:52:54Z International audience n 1974, newly available satellite observations unveiled the presence of a giant ice-free area, or polynya, within the Antarctic ice pack of the Weddell Sea, which persisted during the two following winters(1). Subsequent research showed that deep convective overturning had opened a conduit between the surface and the abyssal ocean, and had maintained the polynya through the massive release of heat from the deep sea(2,3). Although the polynya has aroused continued interest(1-9), the presence of a fresh surface layer has prevented the recurrence of deep convection there since 1976(8), and it is now largely viewed as a naturally rare event(10). Here, we present a new analysis of historical observations and model simulations that suggest deep convection in the Weddell Sea was more active in the past, and has been weakened by anthropogenic forcing. The observations show that surface freshening of the southern polar ocean since the 1950s has considerably enhanced the salinity stratification. Meanwhile, among the present generation of global climate models, deep convection is common in the Southern Ocean under pre-industrial conditions, but weakens and ceases under a climate change scenario owing to surface freshening. A decline of open-ocean convection would reduce the production rate of Antarctic Bottom Waters, with important implications for ocean heat and carbon storage, and may have played a role in recent Antarctic climate change. Article in Journal/Newspaper Antarc* Antarctic ice pack Southern Ocean Weddell Sea Université de Nantes: HAL-UNIV-NANTES Antarctic Southern Ocean The Antarctic Weddell Weddell Sea Nature Climate Change 4 4 278 282 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere de Lavergne, Casimir Palter, Jaime Galbraith, Eric, Bernardello, Raffaele Marinov, Irina Cessation of deep convection in the open Southern Ocean under anthropogenic climate change |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience n 1974, newly available satellite observations unveiled the presence of a giant ice-free area, or polynya, within the Antarctic ice pack of the Weddell Sea, which persisted during the two following winters(1). Subsequent research showed that deep convective overturning had opened a conduit between the surface and the abyssal ocean, and had maintained the polynya through the massive release of heat from the deep sea(2,3). Although the polynya has aroused continued interest(1-9), the presence of a fresh surface layer has prevented the recurrence of deep convection there since 1976(8), and it is now largely viewed as a naturally rare event(10). Here, we present a new analysis of historical observations and model simulations that suggest deep convection in the Weddell Sea was more active in the past, and has been weakened by anthropogenic forcing. The observations show that surface freshening of the southern polar ocean since the 1950s has considerably enhanced the salinity stratification. Meanwhile, among the present generation of global climate models, deep convection is common in the Southern Ocean under pre-industrial conditions, but weakens and ceases under a climate change scenario owing to surface freshening. A decline of open-ocean convection would reduce the production rate of Antarctic Bottom Waters, with important implications for ocean heat and carbon storage, and may have played a role in recent Antarctic climate change. |
author2 |
Department of Atmospheric and Oceanic Sciences Montréal McGill University = Université McGill Montréal, Canada Department of Earth and Planetary Sciences Montréal (EPS) Department of Earth and Environmental Science Philadelphia University of Pennsylvania |
format |
Article in Journal/Newspaper |
author |
de Lavergne, Casimir Palter, Jaime Galbraith, Eric, Bernardello, Raffaele Marinov, Irina |
author_facet |
de Lavergne, Casimir Palter, Jaime Galbraith, Eric, Bernardello, Raffaele Marinov, Irina |
author_sort |
de Lavergne, Casimir |
title |
Cessation of deep convection in the open Southern Ocean under anthropogenic climate change |
title_short |
Cessation of deep convection in the open Southern Ocean under anthropogenic climate change |
title_full |
Cessation of deep convection in the open Southern Ocean under anthropogenic climate change |
title_fullStr |
Cessation of deep convection in the open Southern Ocean under anthropogenic climate change |
title_full_unstemmed |
Cessation of deep convection in the open Southern Ocean under anthropogenic climate change |
title_sort |
cessation of deep convection in the open southern ocean under anthropogenic climate change |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://hal.science/hal-02437670 https://hal.science/hal-02437670/document https://hal.science/hal-02437670/file/Manuscript.pdf https://doi.org/10.1038/nclimate2132 |
geographic |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic ice pack Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic ice pack Southern Ocean Weddell Sea |
op_source |
ISSN: 1758-678X EISSN: 1758-6798 Nature Climate Change https://hal.science/hal-02437670 Nature Climate Change, 2014, 4 (4), pp.278-282. ⟨10.1038/nclimate2132⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1038/nclimate2132 hal-02437670 https://hal.science/hal-02437670 https://hal.science/hal-02437670/document https://hal.science/hal-02437670/file/Manuscript.pdf doi:10.1038/nclimate2132 WOS: 000333669600021 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1038/nclimate2132 |
container_title |
Nature Climate Change |
container_volume |
4 |
container_issue |
4 |
container_start_page |
278 |
op_container_end_page |
282 |
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1766120059142406144 |