DOI: 10.5194/tc-14-905-2020
论文题名: Coupled modelling of subglacial hydrology and calving-front melting at Store Glacier, West Greenland
作者: Cook S.J. ; Christoffersen P. ; Todd J. ; Slater D. ; Chauché N.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 3 起始页码: 905
结束页码: 924
语种: 英语
英文关键词: discharge
; glacial hydrology
; iceberg calving
; melting
; meltwater
; numerical model
; subglacial environment
; three-dimensional modeling
; Arctic
; Greenland
; Store Glacier
英文摘要: We investigate the subglacial hydrology of Store Glacier in West Greenland, using the open-source, fullStokes model Elmer/Ice in a novel 3D application that includes a distributed water sheet, as well as discrete channelised drainage, and a 1D model to simulate submarine plumes at the calving front. At first, we produce a baseline winter scenario with no surface meltwater. We then investigate the hydrological system during summer, focussing specifically on 2012 and 2017, which provide examples of high and low surface-meltwater inputs, respectively. We show that the common assumption of zero winter freshwater flux is invalid, and we find channels over 1 m2 in area occurring up to 5 km inland in winter. We also find that the production of water from friction and geothermal heat is sufficiently high to drive year-round plume activity, with ice-front melting averaging 0.15 m d-1. When the model is forced with seasonally averaged surface melt from summer, we show a hydrological system with significant distributed sheet activity extending 65 and 45 km inland in 2012 and 2017, respectively; while channels with a cross-sectional area higher than 1 m2 form as far as 55 and 30 km inland. Using daily values for the surface melt as forcing, we find only a weak relationship between the input of surface meltwater and the intensity of plume melting at the calving front, whereas there is a strong correlation between surface-meltwater peaks and basal water pressures. The former shows that storage of water on multiple timescales within the subglacial drainage system plays an important role in modulating subglacial discharge. The latter shows that high melt inputs can drive high basal water pressures even when the channelised network grows larger. This has implications for the future velocity and mass loss of Store Glacier, and the consequent sea-level rise, in a warming world. © 2020 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164433
Appears in Collections: 气候变化与战略
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作者单位: Scott Polar Research Institute, University of Cambridge, Cambridge, United Kingdom; Department of Geography and Sustainable Development, University of St.Andrews, St.Andrews, United Kingdom; Scripps Institution of Oceanography, San Diego, United States; Access Arctic, Le Vieux Marigny 58160, Sauvigny-les-Bois, France
Recommended Citation:
Cook S.J.,Christoffersen P.,Todd J.,et al. Coupled modelling of subglacial hydrology and calving-front melting at Store Glacier, West Greenland[J]. Cryosphere,2020-01-01,14(3)