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Influence of snow on near-surface ground temperatures in upland and alluvial environments of the outer Mackenzie Delta, Northwest Territories

P. D. Morse, C. R. Burn and S. V. Kokelj
Influence of snow on near-surface ground temperatures in upland and alluvial environments of the outer Mackenzie Delta, Northwest Territories (in Fundamental and applied research on permafrost in Canada--Recherche fondamentale et appliquee sur le pergelisol au Canada, C. R. Burn (editor) and M. Allard (editor))
Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre (August 2012) 49 (8): 895-913

Abstract

Relations between snow cover, active-layer thickness, and near-surface ground temperatures were determined in 2005-2009 for a diverse range of alluvial and upland settings in the outer Mackenzie Delta. Here, the snow cover developed primarily by wind redistribution, with its spatial variation controlled by topography in uplands and vegetation height in alluvial lowlands. Snow cover was the primary influence on freeze-back duration and the mean annual temperature at the top of permafrost (TTOP), with the difference in median TTOP between alluvial (-3.7 degrees C) and upland (-6.1 degrees C) settings related to the greater snow depth and soil moisture in the alluvial plain. The active layer was generally deeper in the wet alluvial lowlands, where the average duration of active-layer freeze back (101 days) was nearly double the time taken in the well-drained uplands (55 days). The surface offset (Delta T (sub S) ; up to 11 degrees C) dominated the difference between annual mean air temperature (AMAT) and TTOP (Delta T). In alluvial terrain, Delta T (sub S) varied with snow depth, but in the uplands, Delta T (sub S) was more consistent from site to site. The small thermal offset (<2 degrees C) was slightly greater in alluvial terrain than in the uplands. The overall range in Delta T (2-10 degrees C) led to a range during the study of 7.2 degrees C in TTOP at the sites. The range in AMAT was 1.3 degrees C but up to 1.7 degrees C in TTOP at any one site. Permafrost was well established throughout the area except adjacent to channels where TTOP was close to 0 degrees C.


ISSN: 0008-4077
EISSN: 1480-3313
Coden: CJESAP
Serial Title: Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre
Serial Volume: 49
Serial Issue: 8
Title: Influence of snow on near-surface ground temperatures in upland and alluvial environments of the outer Mackenzie Delta, Northwest Territories
Title: Fundamental and applied research on permafrost in Canada--Recherche fondamentale et appliquee sur le pergelisol au Canada
Author(s): Morse, P. D.Burn, C. R.Kokelj, S. V.
Author(s): Burn, C. R.editor
Author(s): Allard, M.editor
Affiliation: Carleton University, Department of Geography and Environmental Studies, Ottawa, ON, Canada
Affiliation: Carleton University, Department of Geography and Environmental Studies, Ottawa, ON, Canada
Pages: 895-913
Published: 201208
Text Language: English
Summary Language: French
Publisher: National Research Council of Canada, Ottawa, ON, Canada
References: 44
Accession Number: 2012-094278
Categories: Environmental geology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: Accessed on August 23, 2012
Illustration Description: illus. incl. 5 tables, sketch maps
Source Medium: WWW
N69°00'00" - N69°30'00", W135°40'00" - W134°49'60"
Secondary Affiliation: Universite Laval, CAN, CanadaAboriginal Affairs and Northern Development Canada, CAN, Canada
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute.
Update Code: 201249
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