DOI: 10.5194/tc-15-1215-2021
论文题名: Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet
作者: Kittel C. ; Amory C. ; Agosta C. ; Jourdain N.C. ; Hofer S. ; Delhasse A. ; Doutreloup S. ; Huot P.-V. ; Lang C. ; Fichefet T. ; Fettweis X.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 3 起始页码: 1215
结束页码: 1236
语种: 英语
英文摘要: 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 Modele Atmospherique Regional (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 sealevel-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 C2.5 °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 (C7.5 °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. © 2021 Copernicus GmbH. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164726
Appears in Collections: 气候变化与战略
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作者单位: Laboratory of Climatology, Department of Geography, SPHERES Research Unit, University of Liège, Liège,, Belgium; Institut des Geósciences de l'Environnement (IGE), Univ. Grenoble Alpes, CNRS, IRD, G-INP, Grenoble, France; Laboratoire des Sciences du Climat et de l'Environnement, LSCE-IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France; Department of Geosciences, University of Oslo, Oslo, Norway; Earth and Climate, Earth and Life Institute, Catholic University of Louvain, Louvain-la-Neuve, Belgium; National Centre for Atmospheric Science, University of Reading, Reading, United Kingdom
Recommended Citation:
Kittel C.,Amory C.,Agosta C.,et al. Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet[J]. Cryosphere,2021-01-01,15(3)