气候变化领域集成服务门户(CCPortal): The past, present, and future viscous heat dissipation available for Greenland subglacial conduit formation

CCPortal

DOI	10.5194/tc-11-303-2017
	The past, present, and future viscous heat dissipation available for Greenland subglacial conduit formation
	Mankoff K.D.; Tulaczyk S.M.
发表日期	2017
ISSN	19940416
卷号	11 期号:1
英文摘要	Basal hydrology of the Greenland Ice Sheet (GIS) influences its dynamics and mass balance through basal lubrication and ice-bed decoupling or efficient water removal and ice-bed coupling. Variations in subglacial water pressure through the seasonal evolution of the subglacial hydrological system help control ice velocity. Near the ice sheet margin, large basal conduits are melted by the viscous heat dissipation (VHD) from surface runoff routed to the bed. These conduits may lead to efficient drainage systems that lower subglacial water pressure, increase basal effective stress, and reduce ice velocity. In this study we quantify the energy available for VHD historically at present and under future climate scenarios. At present, 345km3 of annual runoff delivers 66GW to the base of the ice sheet per year. These values are already ~50% more than the historical 1960-1999 value of 46GW. By 2100 under IPCC AR5 RCP8.5 (RCP4.5) scenarios, 1278 (524)km3 of runoff may deliver 310 (110)GW to the ice sheet base. Hence, the ice sheet may experience a 5-to-7-fold increase in VHD in the near future which will enhance opening of subglacial conduits near the margin and will warm basal ice in the interior. The other significant basal heat source is geothermal heat flux (GHF), which has an estimated value of 36 GW within the present-day VHD area. With increasing surface meltwater penetration to the bed the basal heat budget in the active basal hydrology zone of the GIS will be increasingly dominated by VHD and relatively less sensitive to GHF, which may result in spatial changes in the ice flow field and in its seasonal variability. © Author(s) 2017.
学科领域	basal ice; flow field; geothermal power; GIS; heat budget; heat flux; heat source; ice field; ice flow; ice sheet; Intergovernmental Panel on Climate Change; meltwater; runoff; seasonal variation; subglacial environment; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	basal ice; flow field; geothermal power; GIS; heat budget; heat flux; heat source; ice field; ice flow; ice sheet; Intergovernmental Panel on Climate Change; meltwater; runoff; seasonal variation; subglacial environment; Arctic; Greenland; Greenland Ice Sheet
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/119451
作者单位	Department of Geosciences, Pennsylvania State University, University Park, PA 16802, United States; Earth and Planetary Sciences Department, University of California Santa Cruz, Santa Cruz, CA 95064, United States
推荐引用方式 GB/T 7714	Mankoff K.D.,Tulaczyk S.M.. The past, present, and future viscous heat dissipation available for Greenland subglacial conduit formation[J],2017,11(1).
APA	Mankoff K.D.,&Tulaczyk S.M..(2017).The past, present, and future viscous heat dissipation available for Greenland subglacial conduit formation.Cryosphere,11(1).
MLA	Mankoff K.D.,et al."The past, present, and future viscous heat dissipation available for Greenland subglacial conduit formation".Cryosphere 11.1(2017).