Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet
The future surface mass balance (SMB) will influence the ice dynamics and the contribution of the Antarctic ice sheet (AIS) to the sea level rise. Most of recent Antarctic SMB projections were based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5). However, new CMIP6 results h...
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2021
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00055833 2023-05-15T13:37:34+02:00 Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet Kittel, Christoph Amory, Charles Agosta, Cécile Jourdain, Nicolas C. Hofer, Stefan Delhasse, Alison Doutreloup, Sébastien Huot, Pierre-Vincent Lang, Charlotte Fichefet, Thierry Fettweis, Xavier 2021-03 electronic https://doi.org/10.5194/tc-15-1215-2021 https://noa.gwlb.de/receive/cop_mods_00055833 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00055484/tc-15-1215-2021.pdf https://tc.copernicus.org/articles/15/1215/2021/tc-15-1215-2021.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-15-1215-2021 https://noa.gwlb.de/receive/cop_mods_00055833 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00055484/tc-15-1215-2021.pdf https://tc.copernicus.org/articles/15/1215/2021/tc-15-1215-2021.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2021 ftnonlinearchiv https://doi.org/10.5194/tc-15-1215-2021 2022-02-08T22:34:20Z The future surface mass balance (SMB) will influence the ice dynamics and the contribution of the Antarctic ice sheet (AIS) to the sea level rise. Most of recent Antarctic SMB projections were based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5). However, new CMIP6 results have revealed a +1.3 ∘C higher mean Antarctic near-surface temperature than in CMIP5 at the end of the 21st century, enabling estimations of future SMB in warmer climates. Here, we investigate the AIS sensitivity to different warmings with an ensemble of four simulations performed with the polar regional climate model Modèle Atmosphérique Régional (MAR) forced by two CMIP5 and two CMIP6 models over 1981–2100. Statistical extrapolation enables us to expand our results to the whole CMIP5 and CMIP6 ensembles. Our results highlight a contrasting effect on the future grounded ice sheet and the ice shelves. The SMB over grounded ice is projected to increase as a response to stronger snowfall, only partly offset by enhanced meltwater run-off. This leads to a cumulated sea-level-rise mitigation (i.e. an increase in surface mass) of the grounded Antarctic surface by 5.1 ± 1.9 cm sea level equivalent (SLE) in CMIP5-RCP8.5 (Relative Concentration Pathway 8.5) and 6.3 ± 2.0 cm SLE in CMIP6-ssp585 (Shared Socioeconomic Pathways 585). Additionally, the CMIP6 low-emission ssp126 and intermediate-emission ssp245 scenarios project a stabilized surface mass gain, resulting in a lower mitigation to sea level rise than in ssp585. Over the ice shelves, the strong run-off increase associated with higher temperature is projected to decrease the SMB (more strongly in CMIP6-ssp585 compared to CMIP5-RCP8.5). Ice shelves are however predicted to have a close-to-present-equilibrium stable SMB under CMIP6 ssp126 and ssp245 scenarios. Future uncertainties are mainly due to the sensitivity to anthropogenic forcing and the timing of the projected warming. While ice shelves should remain at a close-to-equilibrium stable SMB under the Paris Agreement, MAR projects strong SMB decrease for an Antarctic near-surface warming above +2.5 ∘C compared to 1981–2010 mean temperature, limiting the warming range before potential irreversible damages on the ice shelves. Finally, our results reveal the existence of a potential threshold (+7.5 ∘C) that leads to a lower grounded-SMB increase. This however has to be confirmed in following studies using more extreme or longer future scenarios. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelves The Cryosphere Niedersächsisches Online-Archiv NOA Antarctic The Antarctic The Cryosphere 15 3 1215 1236 |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Kittel, Christoph Amory, Charles Agosta, Cécile Jourdain, Nicolas C. Hofer, Stefan Delhasse, Alison Doutreloup, Sébastien Huot, Pierre-Vincent Lang, Charlotte Fichefet, Thierry Fettweis, Xavier Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet |
topic_facet |
article Verlagsveröffentlichung |
description |
The future surface mass balance (SMB) will influence the ice dynamics and the contribution of the Antarctic ice sheet (AIS) to the sea level rise. Most of recent Antarctic SMB projections were based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5). However, new CMIP6 results have revealed a +1.3 ∘C higher mean Antarctic near-surface temperature than in CMIP5 at the end of the 21st century, enabling estimations of future SMB in warmer climates. Here, we investigate the AIS sensitivity to different warmings with an ensemble of four simulations performed with the polar regional climate model Modèle Atmosphérique Régional (MAR) forced by two CMIP5 and two CMIP6 models over 1981–2100. Statistical extrapolation enables us to expand our results to the whole CMIP5 and CMIP6 ensembles. Our results highlight a contrasting effect on the future grounded ice sheet and the ice shelves. The SMB over grounded ice is projected to increase as a response to stronger snowfall, only partly offset by enhanced meltwater run-off. This leads to a cumulated sea-level-rise mitigation (i.e. an increase in surface mass) of the grounded Antarctic surface by 5.1 ± 1.9 cm sea level equivalent (SLE) in CMIP5-RCP8.5 (Relative Concentration Pathway 8.5) and 6.3 ± 2.0 cm SLE in CMIP6-ssp585 (Shared Socioeconomic Pathways 585). Additionally, the CMIP6 low-emission ssp126 and intermediate-emission ssp245 scenarios project a stabilized surface mass gain, resulting in a lower mitigation to sea level rise than in ssp585. Over the ice shelves, the strong run-off increase associated with higher temperature is projected to decrease the SMB (more strongly in CMIP6-ssp585 compared to CMIP5-RCP8.5). Ice shelves are however predicted to have a close-to-present-equilibrium stable SMB under CMIP6 ssp126 and ssp245 scenarios. Future uncertainties are mainly due to the sensitivity to anthropogenic forcing and the timing of the projected warming. While ice shelves should remain at a close-to-equilibrium stable SMB under the Paris Agreement, MAR projects strong SMB decrease for an Antarctic near-surface warming above +2.5 ∘C compared to 1981–2010 mean temperature, limiting the warming range before potential irreversible damages on the ice shelves. Finally, our results reveal the existence of a potential threshold (+7.5 ∘C) that leads to a lower grounded-SMB increase. This however has to be confirmed in following studies using more extreme or longer future scenarios. |
format |
Article in Journal/Newspaper |
author |
Kittel, Christoph Amory, Charles Agosta, Cécile Jourdain, Nicolas C. Hofer, Stefan Delhasse, Alison Doutreloup, Sébastien Huot, Pierre-Vincent Lang, Charlotte Fichefet, Thierry Fettweis, Xavier |
author_facet |
Kittel, Christoph Amory, Charles Agosta, Cécile Jourdain, Nicolas C. Hofer, Stefan Delhasse, Alison Doutreloup, Sébastien Huot, Pierre-Vincent Lang, Charlotte Fichefet, Thierry Fettweis, Xavier |
author_sort |
Kittel, Christoph |
title |
Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet |
title_short |
Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet |
title_full |
Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet |
title_fullStr |
Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet |
title_full_unstemmed |
Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet |
title_sort |
diverging future surface mass balance between the antarctic ice shelves and grounded ice sheet |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-1215-2021 https://noa.gwlb.de/receive/cop_mods_00055833 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00055484/tc-15-1215-2021.pdf https://tc.copernicus.org/articles/15/1215/2021/tc-15-1215-2021.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelves The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-15-1215-2021 https://noa.gwlb.de/receive/cop_mods_00055833 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00055484/tc-15-1215-2021.pdf https://tc.copernicus.org/articles/15/1215/2021/tc-15-1215-2021.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-15-1215-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
3 |
container_start_page |
1215 |
op_container_end_page |
1236 |
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1766094128519577600 |