Increased snow depth already observed, and that predicted for the future are of critical importance to many geophysical and biological processes as well as human activities. The future characteristics of sub-arctic landscapes where permafrost is particularly vulnerable will depend on complex interactions between snow cover, vegetation and permafrost. An experimental manipulation was, therefore, set up on a lowland peat plateau with permafrost, in northernmost Sweden, to simulate projected future increases in winter precipitation and to study their effects on permafrost and vegetation. After seven years of treatment, statistically significant differences between manipulated and control plots were found in mean winter ground temperatures, which were 1.5 degrees C higher in manipulated plots. During the winter, a difference in minimum temperatures of up to 9 degrees C higher could be found in individual manipulated plots compared with control plots. Active layer thicknesses increased at the manipulated plots by almost 20% compared with the control plots and a mean surface subsidence of 24 cm was recorded in the manipulated plots compared to 5 cm in the control plots. The graminoid Eriophorum vaginatum has expanded in the manipulated plots and the vegetation remained green longer in the season. (Less)

https://iopscience.iop.org/article/10.1088/1748-9326/8/3/035025/pdf

Rapid responses of permafrost and vegetation to experimentally increased snow cover in sub-arctic Sweden

Stable carbon isotopes from Torneträsk, northern Sweden provide a millennial length reconstruction of summer sunshine and its relationship to Arctic circulation

A research-based understanding of permafrost distribution at a sufficient spatial resolution is important to meet the demands of science, education and society. We present a new permafrost map for Norway, Sweden and Finland that provides a more detailed and updated description of permafrost distribution in this area than previously available. We implemented the CryoGRID1 model at 1km2 resolution, forced by a new operationally gridded data-set of daily air temperature and snow cover for Finland, Norway and Sweden. Hundred model realisations were run for each grid cell, based on statistical snow distributions, allowing for the representation of sub-grid variability of ground temperature. The new map indicates a total permafrost area (excluding palsas) of 23 400km2 in equilibrium with the average 1981-2010 climate, corresponding to 2.2 per cent of the total land area. About 56 per cent of the area is in Norway, 35 per cent in Sweden and 9 per cent in Finland. The model results are thoroughly evaluated, both quantitatively and qualitatively, as a collaboration project including permafrost experts in the three countries. Observed ground temperatures from 25 boreholes are within±2°C of the average modelled grid cell ground temperature, and all are within the range of the modelled ground temperature for the corresponding grid cell. Qualitative model evaluation by field investigators within the three countries shows that the map reproduces the observed lower altitudinal limits of mountain permafrost and the distribution of lowland permafrost. (Less)

/pdf/permafrost-map-for-norway-sweden-and-finland-292z9jy893.pdf

Permafrost Map for Norway, Sweden and Finland

Lilleoren, K.S. and Etzelmuller, B., 2011.Aregional inventory of rock glaciers and ice‐cored moraines in Norway. Geografiska Annaler: Series A, Physical Geography, 93, 175–191. DOI: 10.1111/j.1468‐...

/pdf/a-regional-inventory-of-rock-glaciers-and-ice-cored-moraines-3delpzy4qv.pdf

A regional inventory of rock glaciers and ice‐cored moraines in norway

CryoGRID 1.0 provides an equilibrium model of permafrost distribution in Norway at a spatial resolution of 1 km2. The approach was forced with gridded data on daily air temperature and snow cover. Ground thermal properties for different bedrock types and sediment covers were derived from surveys and geological maps to yield distributions of thermal conductivity, heat capacity and water content. The distribution of blockfields was derived from satellite images adapting a newly developed classification scheme. The model was evaluated using measured ground surface and ground temperatures, yielding a realistic description of the permafrost distribution in mainland Norway.

The model results show that permafrost underlies sites mainly with exposed bedrock or covered by coarse-grained sediments, such as blockfields and coarse tills. In northern Norway, palsa mires are abundant and organic material and vegetation strongly influence the ground thermal regime. Modelling suggests that permafrost in equilibrium with the 1981–2010 climate presently underlies between 6.1 per cent and 6.4 per cent of the total area of mainland Norway, an area significantly smaller than that modelled for the Little Ice Age climate (14%). CryoGRID 1.0 was subsequently forced using output from a regional climate model for the 2071–2100 period, which suggests that severe permafrost degradation will occur, leaving permafrost beneath an area of just 0.2 per cent of mainland Norway. Copyright © 2013 John Wiley & Sons, Ltd.

/pdf/cryogrid-1-0-permafrost-distribution-in-norway-estimated-by-182nciva6a.pdf

CryoGRID 1.0: Permafrost Distribution in Norway estimated by a Spatial Numerical Model

The mountain permafrost distribution in the Abisko region in northern Sweden has been assessed using a combination of empirical and statistical analysis. The empirical data was obtained using the b ...

Statistic-empirical modelling of mountain permafrost distribution in the Abisko region, sub-Arctic northern Sweden

Turf-banked lobes and terraces on the valley slopes and stone-banked or non-sorted lobes at summits show a distinct regional trend of decreasing size from west to east in the Abisko region, norther ...

Observations on Regional Variation in Solifluction Landform Morphology and Environment in the Abisko, northern Sweden

The occurrence of turf-banked solifluction landforms in the Abisko region was analysed using a grid-based approach and statistical modelling through logistic regression. Significant parameters in t ...

Spatial analysis of solifluction landforms and process rates in the Abisko Mountains, northern Sweden

Solifluction movement rates from 1952 to 2008 for the Abisko region, northern Sweden, have been compiled and analysed through correlation   tests and multiple regression. The temporal analysis is b ...

https://www.jstor.org/stable/info/25622655

56 years of solifluction measurements in the abisko mountains, northern sweden – analysis of temporal and spatial variations of slow soil surface movement

Seven sites within the mountain region of Abisko, northern Sweden, were selected for measurement of solifluction movement rates and correlation with the local environmental factors. Grids with size ...

Hanna Ridefelt

Papers

Statistic-empirical modelling of mountain permafrost distribution in the Abisko region, sub-Arctic northern Sweden

Observations on Regional Variation in Solifluction Landform Morphology and Environment in the Abisko, northern Sweden

Spatial analysis of solifluction landforms and process rates in the Abisko Mountains, northern Sweden

56 years of solifluction measurements in the abisko mountains, northern sweden – analysis of temporal and spatial variations of slow soil surface movement

Local variations of solifluction activity and environment in the Abisko Mountains, Northern Sweden