DOI: 10.5194/tc-9-1265-2015
Scopus记录号: 2-s2.0-84934950368
论文题名: Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra
作者: Domine F ; , Barrere M ; , Sarrazin D ; , Morin S ; , Arnaud L
刊名: Cryosphere
ISSN: 19940416
出版年: 2015
卷: 9, 期: 3 起始页码: 1265
结束页码: 1276
语种: 英语
英文关键词: algorithm
; arctic environment
; automation
; hoar frost
; metamorphism
; shrub
; snowpack
; thermal conductivity
; tundra
; Canada
; Quebec [Canada]
; Umiujaq
; Betula nana
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75281
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Takuvik Joint International Laboratory, Université Laval (Canada), CNRS-INSU (France), Pavillon Alexandre Vachon, 1045 avenue de La Médecine, Québec, QC, 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, France
Recommended Citation:
Domine F,, Barrere M,, Sarrazin D,et al. Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra[J]. Cryosphere,2015-01-01,9(3)