Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet
We present projections of West Antarctic surface mass balance (SMB) and surface melt to 2080–2100 under the RCP8.5 scenario and based on a regional model at 10 km resolution. Our projections are built by adding a CMIP5 (Coupled Model Intercomparison Project Phase 5) multi-model-mean seasonal climate...
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ftdoajarticles:oai:doaj.org/article:330226c0275c41f1b318ae21d7da82ca 2023-05-15T13:43:40+02:00 Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet M. Donat-Magnin N. C. Jourdain C. Kittel C. Agosta C. Amory H. Gallée G. Krinner M. Chekki 2021-02-01T00:00:00Z https://doi.org/10.5194/tc-15-571-2021 https://doaj.org/article/330226c0275c41f1b318ae21d7da82ca EN eng Copernicus Publications https://tc.copernicus.org/articles/15/571/2021/tc-15-571-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-571-2021 1994-0416 1994-0424 https://doaj.org/article/330226c0275c41f1b318ae21d7da82ca The Cryosphere, Vol 15, Pp 571-593 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-571-2021 2022-12-31T04:04:49Z We present projections of West Antarctic surface mass balance (SMB) and surface melt to 2080–2100 under the RCP8.5 scenario and based on a regional model at 10 km resolution. Our projections are built by adding a CMIP5 (Coupled Model Intercomparison Project Phase 5) multi-model-mean seasonal climate-change anomaly to the present-day model boundary conditions. Using an anomaly has the advantage to reduce CMIP5 model biases, and a perfect-model test reveals that our approach captures most characteristics of future changes despite a 16 %–17 % underestimation of projected SMB and melt rates. SMB over the grounded ice sheet in the sector between Getz and Abbot increases from 336 Gt yr −1 in 1989–2009 to 455 Gt yr −1 in 2080–2100, which would reduce the global sea level changing rate by 0.33 mm yr −1 . Snowfall indeed increases by 7.4 % ∘ C −1 to 8.9 % ∘ C −1 of near-surface warming due to increasing saturation water vapour pressure in warmer conditions, reduced sea-ice concentrations, and more marine air intrusion. Ice-shelf surface melt rates increase by an order of magnitude in the 21st century mostly due to higher downward radiation from increased humidity and to reduced albedo in the presence of melting. There is a net production of surface liquid water over eastern ice shelves (Abbot, Cosgrove, and Pine Island) but not over western ice shelves (Thwaites, Crosson, Dotson, and Getz). This is explained by the evolution of the melt-to-snowfall ratio: below a threshold of 0.60 to 0.85 in our simulations, firn air is not entirely depleted by melt water, while entire depletion and net production of surface liquid water occur for higher ratios. This suggests that western ice shelves might remain unaffected by hydrofracturing for more than a century under RCP8.5, while eastern ice shelves have a high potential for hydrofracturing before the end of this century. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Sea ice The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic West Antarctic Ice Sheet Getz ENVELOPE(-145.217,-145.217,-76.550,-76.550) The Cryosphere 15 2 571 593 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. Donat-Magnin N. C. Jourdain C. Kittel C. Agosta C. Amory H. Gallée G. Krinner M. Chekki Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
We present projections of West Antarctic surface mass balance (SMB) and surface melt to 2080–2100 under the RCP8.5 scenario and based on a regional model at 10 km resolution. Our projections are built by adding a CMIP5 (Coupled Model Intercomparison Project Phase 5) multi-model-mean seasonal climate-change anomaly to the present-day model boundary conditions. Using an anomaly has the advantage to reduce CMIP5 model biases, and a perfect-model test reveals that our approach captures most characteristics of future changes despite a 16 %–17 % underestimation of projected SMB and melt rates. SMB over the grounded ice sheet in the sector between Getz and Abbot increases from 336 Gt yr −1 in 1989–2009 to 455 Gt yr −1 in 2080–2100, which would reduce the global sea level changing rate by 0.33 mm yr −1 . Snowfall indeed increases by 7.4 % ∘ C −1 to 8.9 % ∘ C −1 of near-surface warming due to increasing saturation water vapour pressure in warmer conditions, reduced sea-ice concentrations, and more marine air intrusion. Ice-shelf surface melt rates increase by an order of magnitude in the 21st century mostly due to higher downward radiation from increased humidity and to reduced albedo in the presence of melting. There is a net production of surface liquid water over eastern ice shelves (Abbot, Cosgrove, and Pine Island) but not over western ice shelves (Thwaites, Crosson, Dotson, and Getz). This is explained by the evolution of the melt-to-snowfall ratio: below a threshold of 0.60 to 0.85 in our simulations, firn air is not entirely depleted by melt water, while entire depletion and net production of surface liquid water occur for higher ratios. This suggests that western ice shelves might remain unaffected by hydrofracturing for more than a century under RCP8.5, while eastern ice shelves have a high potential for hydrofracturing before the end of this century. |
format |
Article in Journal/Newspaper |
author |
M. Donat-Magnin N. C. Jourdain C. Kittel C. Agosta C. Amory H. Gallée G. Krinner M. Chekki |
author_facet |
M. Donat-Magnin N. C. Jourdain C. Kittel C. Agosta C. Amory H. Gallée G. Krinner M. Chekki |
author_sort |
M. Donat-Magnin |
title |
Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet |
title_short |
Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet |
title_full |
Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet |
title_fullStr |
Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet |
title_full_unstemmed |
Future surface mass balance and surface melt in the Amundsen sector of the West Antarctic Ice Sheet |
title_sort |
future surface mass balance and surface melt in the amundsen sector of the west antarctic ice sheet |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-571-2021 https://doaj.org/article/330226c0275c41f1b318ae21d7da82ca |
long_lat |
ENVELOPE(-145.217,-145.217,-76.550,-76.550) |
geographic |
Antarctic West Antarctic Ice Sheet Getz |
geographic_facet |
Antarctic West Antarctic Ice Sheet Getz |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Sea ice The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Sea ice The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 571-593 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/571/2021/tc-15-571-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-571-2021 1994-0416 1994-0424 https://doaj.org/article/330226c0275c41f1b318ae21d7da82ca |
op_doi |
https://doi.org/10.5194/tc-15-571-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
2 |
container_start_page |
571 |
op_container_end_page |
593 |
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1766191630685044736 |