/pdf/permafrost-and-climate-in-europe-monitoring-and-modelling-1ihtzbpajq.pdf

Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses

This paper provides a review of permafrost modelling advances, primarily since the 2003 permafrost conference in Zurich, Switzerland, with an emphasis on spatial permafrost models, in both arctic and high mountain environments. Models are categorised according to temporal, thermal and spatial criteria, and their approach to defining the relationship between climate, site surface conditions and permafrost status. The most significant recent advances include the expanding application of permafrost thermal models within spatial models, application of transient numerical thermal models within spatial models and incorporation of permafrost directly within global circulation model (GCM) land surface schemes. Future challenges for permafrost modelling will include establishing the appropriate level of integration required for accurate simulation of permafrost-climate interaction within GCMs, the integration of environmental change such as treeline migration into permafrost response to climate change projections, and para- meterising the effects of sub-grid scale variability in surface processes and properties on small-scale (large area) spatial models. Copyright # 2008 John Wiley & Sons, Ltd.

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Recent Advances in Permafrost Modelling

. Measurements of environmental variables are often used to validate and calibrate physically-based models. Depending on their application, the models are used at different scales, ranging from few meters to tens of kilometers. Environmental variables can vary strongly within the grid cells of these models. Validating a model with a single measurement is therefore delicate and susceptible to induce bias in further model applications. To address the question of uncertainty associated with scale in permafrost models, we present data of 390 spatially-distributed ground surface temperature measurements recorded in terrain of high topographic variability in the Swiss Alps. We illustrate a way to program, deploy and refind a large number of measurement devices efficiently, and present a strategy to reduce data loss reported in earlier studies. Data after the first year of deployment is presented. The measurements represent the variability of ground surface temperatures at two different scales ranging from few meters to some kilometers. On the coarser scale, the dependence of mean annual ground surface temperature on elevation, slope, aspect and ground cover type is modelled with a multiple linear regression model. Sampled mean annual ground surface temperatures vary from −4 °C to 5 °C within an area of approximately 16 km2 subject to elevational differences of approximately 1000 m. The measurements also indicate that mean annual ground surface temperatures vary up to 6 °C (i.e., from −2 °C to 4 °C) even within an elevational band of 300 m. Furthermore, fine-scale variations can be high (up to 2.5 °C) at distances of less than 14 m in homogeneous terrain. The effect of this high variability of an environmental variable on model validation and applications in alpine regions is discussed.

/pdf/scale-dependent-measurement-and-analysis-of-ground-surface-4ou7p68af3.pdf

Scale-dependent measurement and analysis of ground surface temperature variability in alpine terrain

This paper provides a review of research and techniques that focus on the seasonally thawed portion of the Earth above permafrost terrain known as the active layer. The paper examines various diffe...

The active layer: A conceptual review of monitoring, modelling techniques and changes in a warming climate:

[1] The Hovsgol mountain region (49°–52°N, 98°–102°E) of northern Mongolia contains widespread mountain permafrost and comprises the southern fringe of the Siberian continuous permafrost zone. In this paper, we report our initial monitoring of permafrost by means of measuring ground temperatures and active layer thickness in boreholes and some cryogenic processes under the influence of climate warming and human activities in the region. The average rate of increase in mean annual permafrost temperatures is from 0.2°C to 0.4°C per decade. Permafrost has been degrading more intensively during the last 15 years (since 1990s) than during the previous 15–20 years (1970s and 1980s). Recent degradation of permafrost under climate warming in the Hovsgol mountain region is generally more intensive than in the Hentei and Hangai Mountain regions. Moreover, livestock grazing in some local areas accelerates degradation of permafrost due to loss of vegetation cover. Year-round temperature recordings by data loggers placed beneath different vegetation covers showed marked differences in active layer thickness and ground temperature.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2006JF000543

Permafrost monitoring in the Hovsgol mountain region, Mongolia

Near-surface temperature variations in different topographic settings were obtained from miniature temperature data-loggers at 17 locations over a 2-year period in the Lake Hovsgol area in northern Mongolia. These measurements were used to analyse the influence of vegetation, solar radiation, surface wetness and snow cover on the ground thermal regime. An empirical modelling approach was applied in order to estimate the spatial distribution of ground surface temperatures, the presence of permafrost and the depth of the active layer. Our study shows that spatial interpolation of ground surface temperature parameters, mainly known from previous research in the Arctic, can be feasible in the arid mountain environments of Central Asia. Copyright © 2006 John Wiley & Sons, Ltd.

S. Anarmaa

Papers

Spatial distribution of ground surface temperatures and active layer depths in the Hövsgöl area, northern Mongolia