气候变化领域集成服务门户(CCPortal): Seasonal evolution of the effective thermal conductivity of the snow and the soil in high Arctic herb tundra at Bylot Island, Canada

CCPortal

DOI	10.5194/tc-10-2573-2016
	Seasonal evolution of the effective thermal conductivity of the snow and the soil in high Arctic herb tundra at Bylot Island, Canada
	Domine F.; Barrere M.; Sarrazin D.
发表日期	2016
ISSN	19940416
卷号	10 期号:6
英文摘要	The values of the snow and soil thermal conductivity, ksnow and ksoil, strongly impact the thermal regime of the ground in the Arctic, but very few data are available to test model predictions for these variables. We have monitored ksnow and ksoil using heated needle probes at Bylot Island in the Canadian High Arctic (73°-N, 80°-W) between July 2013 and July 2015. Few ksnow data were obtained during the 2013-2014 winter, because little snow was present. During the 2014-2015 winter ksnow monitoring at 2, 12 and 22-cm heights and field observations show that a depth hoar layer with ksnow around 0.02-W-m-1-K-1 rapidly formed. At 12 and 22-cm, wind slabs with ksnow around 0.2 to 0.3-W-m-1-K-1 formed. The monitoring of ksoil at 10-cm depth shows that in thawed soil ksoil was around 0.7-W-m-1-K-1, while in frozen soil it was around 1.9-W-m-1-K-1. The transition between both values took place within a few days, with faster thawing than freezing and a hysteresis effect evidenced in the thermal conductivity-liquid water content relationship. The fast transitions suggest that the use of a bimodal distribution of ksoil for modelling may be an interesting option that deserves further testing. Simulations of ksnow using the snow physics model Crocus were performed. Contrary to observations, Crocus predicts high ksnow values at the base of the snowpack (0.12-0.27-W-m-1-K-1) and low ones in its upper parts (0.02-0.12-W-m-1-K-1). We diagnose that this is because Crocus does not describe the large upward water vapour fluxes caused by the temperature gradient in the snow and soil. These fluxes produce mass transfer between the soil and lower snow layers to the upper snow layers and the atmosphere. Finally, we discuss the importance of the structure and properties of the Arctic snowpack on subnivean life, as species such as lemmings live under the snow most of the year and must travel in the lower snow layer in search of food. © Author(s) 2016.
学科领域	bimodal association; flux measurement; freeze-thaw cycle; herb; hysteresis; mass transfer; seasonal variation; snowpack; soil property; spatiotemporal analysis; temperature gradient; thermal conductivity; thermal regime; tundra; water content; water vapor; Bylot Island; Canada; Canadian Arctic; Nunavut; Crocus
语种	英语
scopus关键词	bimodal association; flux measurement; freeze-thaw cycle; herb; hysteresis; mass transfer; seasonal variation; snowpack; soil property; spatiotemporal analysis; temperature gradient; thermal conductivity; thermal regime; tundra; water content; water vapor; Bylot Island; Canada; Canadian Arctic; Nunavut; Crocus
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/119555
作者单位	Takuvik Joint International Laboratory, Université Laval (Canada), 1045 Avenue de la Médecine, Québec City, QC, Canada; CNRS-INSU, France; Department of Chemistry, Université Laval, Québec City, QC, Canada; Centre d'Études Nordiques, Université Laval, Québec City, QC, Canada; Department of Geography, Université Laval, Québec City, QC, Canada; Météo-France - CNRS, CNRM UMR 3589, CEN, Grenoble, France; LGGE, CNRS-UJF, Grenoble, France
推荐引用方式 GB/T 7714	Domine F.,Barrere M.,Sarrazin D.. Seasonal evolution of the effective thermal conductivity of the snow and the soil in high Arctic herb tundra at Bylot Island, Canada[J],2016,10(6).
APA	Domine F.,Barrere M.,&Sarrazin D..(2016).Seasonal evolution of the effective thermal conductivity of the snow and the soil in high Arctic herb tundra at Bylot Island, Canada.Cryosphere,10(6).
MLA	Domine F.,et al."Seasonal evolution of the effective thermal conductivity of the snow and the soil in high Arctic herb tundra at Bylot Island, Canada".Cryosphere 10.6(2016).