气候变化领域集成服务门户(CCPortal): Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra

CCPortal

DOI	10.5194/tc-9-1265-2015
	Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra
	Domine F.; Barrere M.; Sarrazin D.; Morin S.; Arnaud L.
发表日期	2015
ISSN	19940416
卷号	9 期号:3
英文摘要	The effective thermal conductivity of snow, keff, is a critical variable which determines the temperature gradient in the snowpack and heat exchanges between the ground and the atmosphere through the snow. Its accurate knowledge is therefore required to simulate snow metamorphism, the ground thermal regime, permafrost stability, nutrient recycling and vegetation growth. Yet, few data are available on the seasonal evolution of snow thermal conductivity in the Arctic. We have deployed heated needle probes on low-Arctic shrub tundra near Umiujaq, Quebec, (N56°34′; W76°29′) and monitored automatically the evolution of keff for two consecutive winters, 2012-2013 and 2013-2014, at four heights in the snowpack. Shrubs are 20 cm high dwarf birch. Here, we develop an algorithm for the automatic determination of keff from the heating curves and obtain 404 keff values. We evaluate possible errors and biases associated with the use of the heated needles. The time evolution of keff is very different for both winters. This is explained by comparing the meteorological conditions in both winters, which induced different conditions for snow metamorphism. In particular, important melting events in the second year increased snow hardness, impeding subsequent densification and increase in thermal conductivity. We conclude that shrubs have very important impacts on snow physical evolution: (1) shrubs absorb light and facilitate snow melt under intense radiation; (2) the dense twig network of dwarf birch prevent snow compaction, and therefore keff increase; (3) the low density depth hoar that forms within shrubs collapsed in late winter, leaving a void that was not filled by snow. © Author(s) 2015.
学科领域	algorithm; arctic environment; automation; hoar frost; metamorphism; shrub; snowpack; thermal conductivity; tundra; Canada; Quebec [Canada]; Umiujaq; Betula nana
语种	英语
scopus关键词	algorithm; arctic environment; automation; hoar frost; metamorphism; shrub; snowpack; thermal conductivity; tundra; Canada; Quebec [Canada]; Umiujaq; Betula nana
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/119880
作者单位	Takuvik Joint International Laboratory, Université Laval (Canada), CNRS-INSU (France), Pavillon Alexandre Vachon, 1045 avenue de La Médecine, Québec, QC G1V 0A6, Canada; Department of Chemistry, Université Laval, Québec, QC, Canada; Centre for Northern Studies, Université Laval, Québec, QC, Canada; Department of Geography, Université Laval, Québec, QC, Canada; Météo-France - CNRS, CNRM-GAME UMR 3589, CEN, Grenoble, France; LGGE, Université Grenoble Alpes, CNRS - UMR5183, Grenoble, 38041, France
推荐引用方式 GB/T 7714	Domine F.,Barrere M.,Sarrazin D.,et al. Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra[J],2015,9(3).
APA	Domine F.,Barrere M.,Sarrazin D.,Morin S.,&Arnaud L..(2015).Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra.Cryosphere,9(3).
MLA	Domine F.,et al."Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra".Cryosphere 9.3(2015).