DOI: 10.5194/tc-14-3917-2020
论文题名: Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model
作者: Schannwell C. ; Drews R. ; Ehlers T.A. ; Eisen O. ; Mayer C. ; Malinen M. ; Smith E.C. ; Eisermann H.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 11 起始页码: 3917
结束页码: 3934
语种: 英语
英文关键词: geometry
; grounding line
; ice sheet
; orbital forcing
; parameterization
; quantitative analysis
; uncertainty analysis
英文摘要: Simulations of ice sheet evolution over glacial cycles require integration of observational constraints using ensemble studies with fast ice sheet models. These include physical parameterisations with uncertainties, for example, relating to grounding-line migration. More complete ice dynamic models are slow and have thus far only be applied for 1000 years, leaving many model parameters unconstrained. Here we apply a 3D thermomechanically coupled full-Stokes ice sheet model to the Ekström Ice Shelf embayment, East Antarctica, over a full glacial cycle (40 000 years). We test the model response to differing ocean bed properties that provide an envelope of potential ocean substrates seawards of today's grounding line. The end-member scenarios include a hard, high-friction ocean bed and a soft, low-friction ocean bed. We find that predicted ice volumes differ by 50% under almost equal forcing. Grounding-line positions differ by up to 49 km, show significant hysteresis, and migrate non-steadily in both scenarios with long quiescent phases disrupted by leaps of rapid migration. The simulations quantify the evolution of two different ice sheet geometries (namely thick and slow vs. thin and fast), triggered by the variable grounding-line migration over the differing ocean beds. Our study extends the timescales of 3D full-Stokes by an order of magnitude compared to previous studies with the help of parallelisation. The extended time frame for full-Stokes models is a first step towards better understanding other processes such as erosion and sediment redistribution in the ice shelf cavity impacting the entire catchment geometry. © 2020 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164579
Appears in Collections: 气候变化与战略
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作者单位: Department of Geosciences, University of Tübingen, Tübingen, Germany; Department of Glaciology, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Department of Geosciences, University of Bremen, Bremen, Germany; Bavarian Academy of Sciences and Humanities, Munich, Germany; CSC-IT Center for Science Ltd., Espoo, Finland; Max Planck Institute for Meteorology, Hamburg, Germany; School of Earth and Environment, University of Leeds, Leeds, United Kingdom
Recommended Citation:
Schannwell C.,Drews R.,Ehlers T.A.,et al. Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model[J]. Cryosphere,2020-01-01,14(11)