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TitleSpatiotemporal impacts of wildfire and climate warming on permafrost across a subarctic region, Canada
AuthorZhang, Y; Wolfe, S A; Morse, P D; Olthof, I; Fraser, R H
SourceJournal of Geophysical Research, Earth Surface vol. 120, issue 11, 2015 p. 2338-2356, https://doi.org/10.1002/2015JF003679
Year2015
Alt SeriesEarth Sciences Sector, Contribution Series 20150203
PublisherAmerican geophysical Union
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
ProvinceNorthwest Territories
NTS85I; 85J; 85O; 85P
AreaYellowknife
Lat/Long WENS-116.0000 -111.0000 64.2500 62.2500
Subjectsgeophysics; surficial geology/geomorphology; environmental geology; glacial deposits; permafrost; freezing ground; ground ice; terrain sensitivity; peatlands; fires; climate; climatic fluctuations; climate, arctic; tundra
Illustrationslocation maps; photographs; satellite images; tables; histograms; plots
ProgramLand-based Infrastructure, Climate Change Geoscience
AbstractField observations show significant impacts of wildfires on active layer thickness and ground temperatures. However, the importance of fires to permafrost conditions at regional scales remains unclear, especially with climate warming. This study evaluated the regional impacts of fire on permafrost with climate change from 1942 to 2100 using a process-based model in a large subarctic region in the Northwest Territories, Canada. Climate warming is shown to be the dominant factor for permafrost reduction. The warming trend of climate reduces permafrost extent in this region from 67% at present to 2% by 2100. For burned areas, fire increases the reduction of permafrost extent by up to 9% on average, with up to 16% for forest, 10% for tundra and bogs, and 4% for fens. Fire accelerates permafrost disappearance by 5?years on average. The effects of fire on active layer thickness and permafrost extent are much larger in forest areas than in tundra, bogs, and fens. Since active layer is thicker after a fire and cannot recover in most of the areas, the fire effects on active layer are widespread. On average, fires thickens active layer by about 0.5?m. The fire effects on active layer increased significantly after 1990 due to climate warming.
Summary(Plain Language Summary, not published)
Site observations show significant impacts of wildfires on summer thaw depths and ground temperatures. However, the importance of fires to permafrost conditions at regional scales remains unclear, especially with climate warming. This study assessed regional impacts of fire and climate change during 1942-2100 using a process-based model for a large subarctic region in the Northwest Territories, Canada. Climate warming is shown to be the dominant factor for permafrost reduction. The warming trend of climate reduces permafrost extent in this region from 67% at present to 2% by 2100. For burned areas, fire increases the reduction of permafrost extent by up to 9% on average. The effects of fire on active-layer thickness and permafrost extent are much larger in forest areas than in tundra, bogs and fens. Since active layer is thicker after a fire and cannot recover in most of the areas, the fire effects on active layer are widespread.
GEOSCAN ID296905