气候变化领域集成服务门户(CCPortal): Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska

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DOI	10.5194/tc-13-2657-2019
	Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska
	Recinos B.; Maussion F.; Rothenpieler T.; Marzeion B.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	2657
结束页码	2672
卷号	13 期号:10
英文摘要	Frontal ablation is a major component of the mass budget of calving glaciers, strongly affecting their dynamics. Most global-scale ice volume estimates to date still suffer from considerable uncertainties related to (i) the implemented frontal ablation parameterization or (ii) not accounting for frontal ablation at all in the glacier model. To improve estimates of the ice thickness distribution of glaciers, it is thus important to identify and test low-cost and robust parameterizations of this process. By implementing such parameterization into the ice thickness estimation module of the Open Global Glacier Model (OGGM v1.1.2), we conduct a first assessment of the impact of accounting for frontal ablation on the estimate of ice stored in glaciers in Alaska. We find that inversion methods based on mass conservation systematically underestimate the mass turnover and, therefore, the thickness of tidewater glaciers when neglecting frontal ablation. This underestimation can amount to up to 19% on a regional scale and up to 30% for individual glaciers. The effect is independent of the size of the glacier. Additionally, we perform different sensitivity experiments to study the influence of (i) a constant of proportionality (k) used in the frontal ablation parameterization, (ii) Glen's temperature-dependent creep parameter (A) and (iii) a sliding velocity parameter (fs) on the regional dynamics of Alaska tidewater glaciers. OGGM is able to reproduce previous regional frontal ablation estimates, applying a number of combinations of values for k, Glen's A and fs. Our sensitivity studies also show that differences in thickness between accounting for and not accounting for frontal ablation occur mainly at the lower parts of the glacier, both above and below sea level. This indicates that not accounting for frontal ablation will have an impact on the estimate of the glaciers' potential contribution to sea-level rise. Introducing frontal ablation increases the volume estimate of Alaska marine-terminating glaciers from 9.18±0.62 to 10.61±0.75mm s.l.e, of which 1.52±0.31mm s.l.e (0.59±0.08mm s.l.e when ignoring frontal ablation) are found to be below sea level. © Author(s) 2019.
学科领域	glacier; ice thickness; marine environment; sea ice; sea level change; tidewater glacier
语种	英语
scopus关键词	glacier; ice thickness; marine environment; sea ice; sea level change; tidewater glacier
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/118826
作者单位	Institute of Geography, Climate Lab, University of Bremen, Bremen, Germany; MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Department of Atmospheric and Cryospheric Sciences, Universität Innsbruck, Innsbruck, Austria
推荐引用方式 GB/T 7714	Recinos B.,Maussion F.,Rothenpieler T.,et al. Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska[J],2019,13(10).
APA	Recinos B.,Maussion F.,Rothenpieler T.,&Marzeion B..(2019).Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska.The Cryosphere,13(10).
MLA	Recinos B.,et al."Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska".The Cryosphere 13.10(2019).