气候变化领域集成服务门户(CCPortal): The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland

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DOI	10.5194/tc-8-1801-2014
	The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland
	Keegan K.; Albert M.R.; Baker I.
发表日期	2014
ISSN	19940416
卷号	8 期号:5
英文摘要	Typically, gas transport through firn is modeled in the context of an idealized firn column. However, in natural firn, imperfections are present, which can alter transport dynamics and therefore reduce the accuracy of reconstructed climate records. For example, ice layers have been found in several firn cores collected in the polar regions. Here, we examined the effects of two ice layers found in a NEEM, Greenland firn core on gas transport through the firn. These ice layers were found to have permeability values of 3.0 and 4.0 × 10-10m2, and are therefore not impermeable layers. However, the shallower ice layer was found to be significantly less permeable than the surrounding firn, and can therefore retard gas transport. Large closed bubbles were found in the deeper ice layer, which will have an altered gas composition than that expected because they were closed near the surface after the water phase was present. The bubbles in this layer represent 12% of the expected closed porosity of this firn layer after the firn-ice transition depth is reached, and will therefore bias the future ice core gas record. The permeability and thickness of the ice layers at the North Greenland Eemian Ice Drilling (NEEM) site suggest that they do not disrupt the firn-air concentration profiles and that they do not need to be accounted for in gas transport models at NEEM. © Author(s) 2014. CC Attribution 3.0 License.
学科领域	cryosphere; Eemian; firn; gas transport; ice core; ice sheet; permeability; porosity; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	cryosphere; Eemian; firn; gas transport; ice core; ice sheet; permeability; porosity; 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/120049
作者单位	Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
推荐引用方式 GB/T 7714	Keegan K.,Albert M.R.,Baker I.. The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland[J],2014,8(5).
APA	Keegan K.,Albert M.R.,&Baker I..(2014).The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland.Cryosphere,8(5).
MLA	Keegan K.,et al."The impact of ice layers on gas transport through firn at the North Greenland Eemian Ice Drilling (NEEM) site, Greenland".Cryosphere 8.5(2014).