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DOI	10.5194/tc-12-2667-2018
	Characteristics and fate of isolated permafrost patches in coastal Labrador, Canada
	Way R.G.; Lewkowicz A.G.; Zhang Y.
发表日期	2018
ISSN	19940416
卷号	12 期号:8
英文摘要	Bodies of peatland permafrost were examined at five sites along a 300km transect spanning the isolated patches permafrost zone in the coastal barrens of southeastern Labrador. Mean annual air temperatures ranged from +1°C in the south (latitude 51.4°N) to 1.1°C in the north (53.7°N) while mean ground temperatures at the top of the permafrost varied respectively from -0.7 to -2.3°C with shallow active layers (40-60cm) throughout. Small surface offsets due to wind scouring of snow from the crests of palsas and peat plateaux, and large thermal offsets due to thick peat are critical to permafrost, which is absent in wetland and forested and forest-tundra areas inland, notwithstanding average air temperatures much lower than near the coast. Most permafrost peatland bodies are less than 5m thick, with a maximum of 10m, with steep geothermal gradients. One-dimensional thermal modelling for two sites showed that they are in equilibrium with the current climate, but the permafrost mounds are generally relict and could not form today without the low snow depths that result from a heaved peat surface. Despite the warm permafrost, model predictions using downscaled global warming scenarios (RCP2.6, RCP4.5, and RCP8.5) indicate that perennially frozen ground will thaw from the base up and may persist at the southern site until the middle of the 21st century. At the northern site, permafrost is more resilient, persisting to the 2060s under RCP8.5, the 2090s under RCP4.5, or beyond the 21st century under RCP2.6. Despite evidence of peatland permafrost degradation in the study region, the local-scale modelling suggests that the southern boundary of permafrost may not move north as quickly as previously hypothesized. © Author(s) 2018.
学科领域	active layer; air temperature; coastal zone; frozen ground; geothermal gradient; global warming; peatland; permafrost; Canada; Labrador; Newfoundland and Labrador
语种	英语
scopus关键词	active layer; air temperature; coastal zone; frozen ground; geothermal gradient; global warming; peatland; permafrost; Canada; Labrador; Newfoundland and Labrador
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/119084
作者单位	Department of Geography and Planning, Queen's University, Kingston, K7L3N6, Canada; Labrador Institute, Memorial University of Newfoundland, Happy Valley-Goose Bay, A0P1E0, Canada; Department of Geography, Environment and Geomatics, University of Ottawa, Ottawa, K1N6N5, Canada; Canada Centre for Mapping and Earth Observation, Natural Resources Canada, Ottawa, K1A0E4, Canada
推荐引用方式 GB/T 7714	Way R.G.,Lewkowicz A.G.,Zhang Y.. Characteristics and fate of isolated permafrost patches in coastal Labrador, Canada[J],2018,12(8).
APA	Way R.G.,Lewkowicz A.G.,&Zhang Y..(2018).Characteristics and fate of isolated permafrost patches in coastal Labrador, Canada.Cryosphere,12(8).
MLA	Way R.G.,et al."Characteristics and fate of isolated permafrost patches in coastal Labrador, Canada".Cryosphere 12.8(2018).