气候变化领域集成服务门户(CCPortal): Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system

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DOI	10.5194/tc-9-1649-2015
	Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system
	Rosier S.H.R.; Gudmundsson G.H.; Green J.A.M.
发表日期	2015
ISSN	19940416
卷号	9 期号:4
英文摘要	Observations show that the flow of Rutford Ice Stream (RIS) is strongly modulated by the ocean tides, with the strongest tidal response at the 14.77-day tidal period (Msf). This is striking because this period is absent in the tidal forcing. A number of mechanisms have been proposed to account for this effect, yet previous modelling studies have struggled to match the observed large amplitude and decay length scale. We use a nonlinear 3-D viscoelastic full-Stokes model of ice-stream flow to investigate this open issue. We find that the long period Msf modulation of ice-stream velocity observed in data cannot be reproduced quantitatively without including a coupling between basal sliding and tidally induced subglacial water pressure variations, transmitted through a highly conductive drainage system at low effective pressure. Furthermore, the basal sliding law requires a water pressure exponent that is strongly nonlinear with q Combining double low line 10 and a nonlinear basal shear exponent of m Combining double low line 3. Coupled model results show that sub-ice shelf tides result in a ∼12 % increase in mean horizontal velocity of the adjoining ice stream. Observations of tidally induced variations in flow of ice streams provide stronger constraints on basal sliding processes than provided by any other set of measurements. © Author(s) 2015.
学科领域	amplitude; data set; glacial hydrology; hydrological modeling; low pressure; nonlinearity; numerical model; pressure effect; temporal variation; three-dimensional modeling; tidal cycle; Antarctica
语种	英语
scopus关键词	amplitude; data set; glacial hydrology; hydrological modeling; low pressure; nonlinearity; numerical model; pressure effect; temporal variation; three-dimensional modeling; tidal cycle; 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/119833
作者单位	School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB, United Kingdom; British Antarctic Survey, High Cross, Madingley Rd., Cambridge, CB3 0ET, United Kingdom
推荐引用方式 GB/T 7714	Rosier S.H.R.,Gudmundsson G.H.,Green J.A.M.. Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system[J],2015,9(4).
APA	Rosier S.H.R.,Gudmundsson G.H.,&Green J.A.M..(2015).Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system.Cryosphere,9(4).
MLA	Rosier S.H.R.,et al."Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system".Cryosphere 9.4(2015).