Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean
Two coupled climate models, differing primarily in horizontal resolution and treatment of mesoscale eddies, were used to assess the impact of perturbations in wind stress and Antarctic ice sheet (AIS) melting on the Southern Ocean meridional overturning circulation (SO MOC), which plays an important...
Published in: | Journal of Geophysical Research: Oceans |
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Online Access: | http://www.osti.gov/servlets/purl/1961758 https://www.osti.gov/biblio/1961758 https://doi.org/10.1029/2022jc019105 |
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ftosti:oai:osti.gov:1961758 2023-07-30T03:57:16+02:00 Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean Tesdal, Jan‐Erik MacGilchrist, Graeme A. Beadling, Rebecca L. Griffies, Stephen M. Krasting, John P. Durack, Paul J. 2023-07-10 application/pdf http://www.osti.gov/servlets/purl/1961758 https://www.osti.gov/biblio/1961758 https://doi.org/10.1029/2022jc019105 unknown http://www.osti.gov/servlets/purl/1961758 https://www.osti.gov/biblio/1961758 https://doi.org/10.1029/2022jc019105 doi:10.1029/2022jc019105 54 ENVIRONMENTAL SCIENCES 2023 ftosti https://doi.org/10.1029/2022jc019105 2023-07-11T10:25:19Z Two coupled climate models, differing primarily in horizontal resolution and treatment of mesoscale eddies, were used to assess the impact of perturbations in wind stress and Antarctic ice sheet (AIS) melting on the Southern Ocean meridional overturning circulation (SO MOC), which plays an important role in global climate regulation. The largest impact is found in the SO MOC lower limb, associated with the formation of Antarctic Bottom Water (AABW), which in both models is enhanced by wind and weakened by AIS meltwater perturbations. Even though both models under the AIS melting perturbation show similar AABW transport reductions of 4–5 Sv (50%–60%), the volume deflation of AABW south of 30°S is four times greater in the higher resolution simulation (-20 vs. -5 Sv). Water mass transformation (WMT) analysis reveals that surface-forced dense water formation on the Antarctic shelf is absent in the higher resolution and reduced by half in the lower resolution model in response to the increased AIS melting. However, the decline of the AABW volume (and its inter-model difference) far exceeds the surface-forced WMT changes alone, which indicates that the divergent model responses arise from interactions between changes in surface forcing and interior mixing processes. This model divergence demonstrates an important source of uncertainty in climate modeling, and indicates that accurate shelf processes together with scenarios accounting for AIS melting are necessary for robust projections of the deep ocean's response to anthropogenic forcing. Other/Unknown Material Antarc* Antarctic Ice Sheet Southern Ocean SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic Southern Ocean The Antarctic Journal of Geophysical Research: Oceans 128 3 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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ftosti |
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54 ENVIRONMENTAL SCIENCES |
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54 ENVIRONMENTAL SCIENCES Tesdal, Jan‐Erik MacGilchrist, Graeme A. Beadling, Rebecca L. Griffies, Stephen M. Krasting, John P. Durack, Paul J. Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
Two coupled climate models, differing primarily in horizontal resolution and treatment of mesoscale eddies, were used to assess the impact of perturbations in wind stress and Antarctic ice sheet (AIS) melting on the Southern Ocean meridional overturning circulation (SO MOC), which plays an important role in global climate regulation. The largest impact is found in the SO MOC lower limb, associated with the formation of Antarctic Bottom Water (AABW), which in both models is enhanced by wind and weakened by AIS meltwater perturbations. Even though both models under the AIS melting perturbation show similar AABW transport reductions of 4–5 Sv (50%–60%), the volume deflation of AABW south of 30°S is four times greater in the higher resolution simulation (-20 vs. -5 Sv). Water mass transformation (WMT) analysis reveals that surface-forced dense water formation on the Antarctic shelf is absent in the higher resolution and reduced by half in the lower resolution model in response to the increased AIS melting. However, the decline of the AABW volume (and its inter-model difference) far exceeds the surface-forced WMT changes alone, which indicates that the divergent model responses arise from interactions between changes in surface forcing and interior mixing processes. This model divergence demonstrates an important source of uncertainty in climate modeling, and indicates that accurate shelf processes together with scenarios accounting for AIS melting are necessary for robust projections of the deep ocean's response to anthropogenic forcing. |
author |
Tesdal, Jan‐Erik MacGilchrist, Graeme A. Beadling, Rebecca L. Griffies, Stephen M. Krasting, John P. Durack, Paul J. |
author_facet |
Tesdal, Jan‐Erik MacGilchrist, Graeme A. Beadling, Rebecca L. Griffies, Stephen M. Krasting, John P. Durack, Paul J. |
author_sort |
Tesdal, Jan‐Erik |
title |
Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean |
title_short |
Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean |
title_full |
Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean |
title_fullStr |
Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean |
title_full_unstemmed |
Revisiting Interior Water Mass Responses to Surface Forcing Changes and the Subsequent Effects on Overturning in the Southern Ocean |
title_sort |
revisiting interior water mass responses to surface forcing changes and the subsequent effects on overturning in the southern ocean |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1961758 https://www.osti.gov/biblio/1961758 https://doi.org/10.1029/2022jc019105 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Southern Ocean |
genre_facet |
Antarc* Antarctic Ice Sheet Southern Ocean |
op_relation |
http://www.osti.gov/servlets/purl/1961758 https://www.osti.gov/biblio/1961758 https://doi.org/10.1029/2022jc019105 doi:10.1029/2022jc019105 |
op_doi |
https://doi.org/10.1029/2022jc019105 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
128 |
container_issue |
3 |
_version_ |
1772816577658355712 |