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Multi-site observations of near-surface soil temperature in northwestern Canada: implications for high-resolution permafrost mapping
Yu
Zhang, Canada Centre for Mapping and Earth Observation, yu.zhang@canada.ca
Permafrost temperature observations are sparse, which limits our understanding and mapping permafrost at landscape scale. From August 2016 to August 2017, we measured near-surface (5 cm depth) soil temperatures (Tnss) at 107 sites around Inuvik and Tuktoyaktuk in northwestern Canada. They are in northern boreal area and low-arctic tundra, respectively. The data show strong site variations and allow us to quantify the statistics about their relations with ecotopes. The site variation of Tnss mainly occurs in snow-cover period, indicating the importance of snow. Ecotopes are effective for stratifying Tnss in snow-cover period and annual mean Tnss, but not for Tnss in thawing months. Ecotopes are useful to stratify organic layer thickness and active-layer thickness (ALT) in low-arctic tundra, but not in northern boreal area. The site variation of ALT within each area does not correlate with thawing season Tnss but is determined by the edaphic factor. There is a significant and positive correlation between ALT and Tnss in snow-cover period in both areas. The soil near the highway is warmer due to snow accumulation near the embankment and changes of land cover during highway construction. These results are useful for understanding and mapping permafrost at landscape scale and for assessing the impacts of highway on permafrost. Associated Project(s): Poster Location ID: 72 Session Assigned: Permafrost and Hydrology
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