气候变化领域集成服务门户(CCPortal): Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet

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DOI	10.5194/tc-11-247-2017
	Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet
	Bernales J.; Rogozhina I.; Greve R.; Thomas M.
发表日期	2017
ISSN	19940416
卷号	11 期号:1
英文摘要	The shallow ice approximation (SIA) is commonly used in ice-sheet models to simplify the force balance equations within the ice. However, the SIA cannot adequately reproduce the dynamics of the fast flowing ice streams usually found at the margins of ice sheets. To overcome this limitation, recent studies have introduced heuristic hybrid combinations of the SIA and the shelfy stream approximation. Here, we implement four different hybrid schemes into a model of the Antarctic Ice Sheet in order to compare their performance under present-day conditions. For each scheme, the model is calibrated using an iterative technique to infer the spatial variability in basal sliding parameters. Model results are validated against topographic and velocity data. Our analysis shows that the iterative technique compensates for the differences between the schemes, producing similar ice-sheet configurations through quantitatively different results of the sliding coefficient calibration. Despite this we observe a robust agreement in the reconstructed patterns of basal sliding parameters. We exchange the calibrated sliding parameter distributions between the schemes to demonstrate that the results of the model calibration cannot be straightforwardly transferred to models based on different approximations of ice dynamics. However, easily adaptable calibration techniques for the potential distribution of basal sliding coefficients can be implemented into ice models to overcome such incompatibility, as shown in this study. © Author(s) 2017.
学科领域	calibration; comparative study; heuristics; ice sheet; model; numerical method; performance assessment; spatial variation; Antarctic Ice Sheet; Antarctica
语种	英语
scopus关键词	calibration; comparative study; heuristics; ice sheet; model; numerical method; performance assessment; spatial variation; Antarctic Ice Sheet; Antarctica
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119472
作者单位	GFZ German Research Centre for Geosciences, Section 1.3: Earth System Modelling, Potsdam, Germany; Institute of Meteorology, Free University Berlin, Berlin, Germany; MARUM Centre for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
推荐引用方式 GB/T 7714	Bernales J.,Rogozhina I.,Greve R.,et al. Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet[J],2017,11(1).
APA	Bernales J.,Rogozhina I.,Greve R.,&Thomas M..(2017).Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet.Cryosphere,11(1).
MLA	Bernales J.,et al."Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet".Cryosphere 11.1(2017).