DOI: 10.1002/2017JF004522
Scopus记录号: 2-s2.0-85046681571
论文题名: Dynamic Hydraulic Conductivity Reconciles Mismatch Between Modeled and Observed Winter Subglacial Water Pressure
作者: Downs J.Z. ; Johnson J.V. ; Harper J.T. ; Meierbachtol T. ; Werder M.A.
刊名: Journal of Geophysical Research: Earth Surface
ISSN: 21699003
出版年: 2018
卷: 123, 期: 4 起始页码: 818
结束页码: 836
语种: 英语
英文关键词: conductivity
; hydrology
; modeling
; pressure
; subglacial
; water
Scopus关键词: drainage network
; glacial hydrology
; hydraulic conductivity
; hydrological modeling
; ice sheet
; meltwater
; pressure field
; winter
; Arctic
; Greenland
英文摘要: The link between subglacial hydrology and basal sliding has prompted work on basal hydrology models with water pressure and drainage capacity as prognostic variables. We find that the Glacier Drainage System model, which belongs to a commonly used family of subglacial hydrology models that include both channelized and distributed drainage components, underpredicts winter water pressure when compared to borehole observations from western Greenland given a wide range of plausible parameter values and inputs. This problem, though previously noted by other modelers, has not been addressed. Possible causes for the discrepancy including idealized model inputs or unconstrained parameters are investigated through a series of modeling experiments on both synthetic and realistic ice sheet geometries. Numerical experiments reveal that englacial storage and hydraulic conductivity in the distributed system are the primary controls on winter water pressure in Glacier Drainage System model. Observations of temperate layer thickness and englacial water content from western Greenland imply an upper bound on englacial storage, suggesting that a reduction in hydraulic conductivity is the most plausible cause of high winter water pressure. We conclude that hydraulic conductivity acts as a proxy for the subgrid-scale connectivity of the linked cavity system and should therefore change seasonally in correspondence with melt water availability. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114197
Appears in Collections: 气候减缓与适应
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作者单位: Department of Mathematics, University of Montana, Missoula, MT, United States; Department of Computer Science, University of Montana, Missoula, MT, United States; Department of Geosciences, University of Montana, Missoula, MT, United States; Laboratory of Hydraulics, Hydrology and Glaciology (VAW), Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
Recommended Citation:
Downs J.Z.,Johnson J.V.,Harper J.T.,et al. Dynamic Hydraulic Conductivity Reconciles Mismatch Between Modeled and Observed Winter Subglacial Water Pressure[J]. Journal of Geophysical Research: Earth Surface,2018-01-01,123(4)