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DOI	10.5194/tc-8-1393-2014
	Importance of basal processes in simulations of a surging Svalbard outlet glacier
	Gladstone R.; Schäfer M.; Zwinger T.; Gong Y.; Strozzi T.; Mottram R.; Boberg F.; Moore J.C.
发表日期	2014
ISSN	19940416
卷号	8 期号:4
英文摘要	The outlet glacier of Basin 3 (B3) of Austfonna ice cap, Svalbard, is one of the fastest outlet glaciers in Svalbard, and shows dramatic changes since 1995. In addition to previously observed seasonal summer speed-up associated with the melt season, the winter speed of B3 has accelerated approximately fivefold since 1995. We use the Elmer/Ice full-Stokes model for ice dynamics to infer spatial distributions of basal drag for the winter seasons of 1995, 2008 and 2011. This "inverse" method is based on minimising discrepancy between modelled and observed surface velocities, using satellite remotely sensed velocity fields. We generate steady-state temperature distributions for 1995 and 2011. Frictional heating caused by basal sliding contributes significantly to basal temperatures of the B3 outlet glacier, with heat advection (a longer-timescale process than frictional heating) also being important in the steady state. We present a sensitivity experiment consisting of transient simulations under present-day forcing to demonstrate that using a temporally fixed basal drag field obtained through inversion can lead to thickness change errors of the order of 2 m yearg -1. Hence it is essential to incorporate the evolution of basal processes in future projections of the evolution of B3. Informed by a combination of our inverse method results and previous studies, we hypothesise a system of processes and feedbacks involving till deformation and basal hydrology to explain both the seasonal accelerations (short residence time pooling of meltwater at the ice-till interface) and the ongoing interannual speed-up (gradual penetration of water into the till, reducing till strength). © Author(s) 2014. CC Attribution 3.0 License.
语种	英语
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/120078
作者单位	Arctic Centre, University of Lapland, Rovaniemi, Finland; VAW, Eidgenossische Technische Hochschule Zürich, ETHZ, Switzerland; Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, TAS, Australia; CSC - IT Center for Science Ltd., Espoo, Finland; Gamma Remote Sensing and Consulting AG, Gümligen, Switzerland; Danish Meteorological Institute, Copenhagen, Denmark; Department of Earth Sciences, Uppsala University, Uppsala, Sweden; College of Global Change and Earth System Science, State Key Laboratory of Remote Sensing Science, Beijing Normal University, Beijing, China
推荐引用方式 GB/T 7714	Gladstone R.,Schäfer M.,Zwinger T.,et al. Importance of basal processes in simulations of a surging Svalbard outlet glacier[J],2014,8(4).
APA	Gladstone R..,Schäfer M..,Zwinger T..,Gong Y..,Strozzi T..,...&Moore J.C..(2014).Importance of basal processes in simulations of a surging Svalbard outlet glacier.Cryosphere,8(4).
MLA	Gladstone R.,et al."Importance of basal processes in simulations of a surging Svalbard outlet glacier".Cryosphere 8.4(2014).