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The surface energy balance at the Svalbard Archipelago has been simulated at high resolution with the Weather Research and Forecasting Model and compared with measurements of the individual energy fluxes from a tundra site near Ny-Ålesund (located north of Norway), as well as other near-surface measurements across the region. For surface air temperature, a good agreement between model and observations was found at all locations. High correlations were also found for daily averaged surface energy fluxes within the different seasons at the main site. The four radiation components showed correlations above 0.5 in all seasons (mostly above 0.9), whereas correlations between 0.3 and 0.8 were found for the sensible and latent heat fluxes. Underestimation of cloud cover and cloud optical thickness led to seasonal biases in incoming shortwave and longwave radiation of up to 30%. During summer, this was mainly a result of distinct days on which the model erroneously simulated cloud-free conditions, whereas the incoming radiation biases appeared to be more related to underestimation of cloud optical thickness during winter. The model overestimated both sensible and latent heat fluxes in most seasons. The model also initially overestimated the average Bowen ratio during summer by a factor of 6, but this bias was greatly reduced with two physically based model modifications that are related to frozen-ground hydrology. The seasonally averaged ground/snow heat flux was mostly in agreement with observations but showed too little short-time variability in the presence of thick snow. Overall, the model reproduced average temperatures well but overestimated diurnal cycles and showed considerable biases in the individual energy fluxes on seasonal and shorter time scales.

In this study three areas of different active, coarse-debris, slope processes are investigated in Northern and Eastern Iceland. Surface displacement of some glacier-derived rock glaciers and a debris-covered glacier in the Holar area, a moving debris accumulation close to Siglufjorður and a debris layer in Seyðisfjorður are measured. The displacement fields are obtained by cross-correlation matching of multi-temporal orthophotos. Orthophotos are generated using a Z/I-Imaging digital photogrammetric workstation and various series of air photos from 1964 to 1994. Cross-correlation matching is done with the CIAS software. The results are analyzed and used for rough surface age estimates. In addition, type and cause of movement are discussed. The velocity of the debris-covered glacier and the rock glaciers in the Holar area averages from 0.14 to 0.67 m a− 1. The debris accumulation at Almenningsnof close to Siglufjorður shows an average displacement of 0.19 m a− 1 with a maximum value of 0.84 m a− 1. The displacements at Almenningsnof agree well with displacements surveyed by GPS by the Icelandic road authorities. The measured velocities in Seyðisfjorður, although using air photos taken 30 years apart, turned out not to be significant, but the homogenous direction of the displacement vectors suggests that the debris is currently creeping. Based on the surface age results all the landforms in Holar are suggested to have developed during the late-Holocene cooling period, with ages from around 1500 and 3000 to around 5000 years for the different landforms. These surface age estimates coincide with data from moraine datings nearby and Holocene climatic development in the North Atlantic region.

Lake Hovsgol is located on the southern fringe of the continuous permafrost zone in northern Mongolia. This paper describes a GIS-based empirical permafrost model that is calibrated with ground temperature observations, and utilises a multi-criteria approach to derive zones of permafrost favourability based on terrain parameters and land cover information. The scores are derived either by logistic regression or from satellite image information. The model is validated by DC resistivity tomography measurements. The overall permafrost distribution in the study area is well-described and the method appears to be a valid approach for mapping permafrost at both local and regional scales in mountain areas with low data coverage. Copyright © 2006 John Wiley & Sons, Ltd.

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.

Earlier studies suggest that the altitudinal permafrost limit decreases from the west to the east in Southern Norway and that the lowermost altitudinal permafrost limit in Southern Scandinavia occurs in the eastern part of Southern Norway. Most investigations on mountain permafrost have been undertaken in Jotunheimen and Dovrefjell further west, and in order to validate this regional pattern, the distribution of permafrost has been mapped on the mountains Solen and Elgahogna in the Femunden region, Central-Eastern Norway. Empirical-statistical models based on BTS and logistic regression were developed for each mountain, and validated with DC resistivity measurements. Permafrost was found to be probable down to 1100–1300 m a.s.l., which validates the regional west–east gradient in the altitudinal permafrost limit. Elevation is the main controlling factor for permafrost distribution on both Solen and Elgahogna. In addition, potential solar radiation and the surface wetness pattern were significant in the So...

This review paper aims at discussing aspects and concepts of the significance of the spatial and temporal distribution of permafrost on glacial and gravitational processes in southern Norway. The study first reviews the distribution of mountain permafrost in southern Norway in comparison with high-relief alpine areas like the Alps, and then discusses the influence of permafrost on gravitational and glacial–geomorphological processes. The basis for the paper is a regional-scale distribution model of mountain permafrost in southern Norway, which is analysed in relation to topographic variations within the same area. The model allows a crude extrapolation to past and future permafrost distribution, which is discussed in relation to geomorphic processes.

Based on velocity measurements of surface and subsurface creep, sediment flux due to solifluction and ploughing boulder activity were estimated in a mid-alpine site in southern Norway (Finse, UTM185198). The results indicate geomorphic work performed by solifluction of approximately 9 MJkm -2 a -1 and imply that sediment flux rates by solifluction under favourable conditions may be comparable to or exceed those of rapid mass movement obtained in more alpine environments.

European mountain permafrost is generally only a few degrees below zero Celsius, and may therefore be highly sensitive to climate change. Permafrost degradation may lead to thaw settlement and reduction in the stability of mountain slopes. Engineering projects within the high mountain zone require careful investigations of potential permafrost-related hazards. This paper summarizes a staged approach to such investigations. Phase 1 involves walkover site survey supported by a desk study to define potential permafrost hazard zones. Data from permafrost distribution maps, topographic and geological maps are integrated, preferably using GIS methodology. If permafrost is possible and is judged to pose a significant threat to the development, phase 2 investigations are recommended whereby field thermal measurements, drilling of exploratory boreholes, and geophysical surveys are undertaken to clarify permafrost characteristics. The resulting data set should form an important component in subsequent engineering design. On a larger scale, a similar approach should be adopted as part of land-use planning within the mountain permafrost zone. Copyright © 2001 John Wiley & Sons, Ltd. RESUME Generalement, le pergelisol europeen de montagne est seulement quelques degres en dessous du zero Celsius et est, de ce fait, tres sensible aux changements climatiques. La degradation du pergelisol peut entrainer des affaissements du sol au degel et une reduction de la stabilite des pentes de montagne. Des projets d'ingenierie dans la haute montagne exigent donc des recherches soigneuses concernant les risques potentiels lies a l'existence du pergelisol. Le present article resume une approche en differentes etapes d'une telle recherche. La phase 1 consiste en un examen attentif du terrain, travail suivi par une etude en laboratoire afin de definir les zones potentielles ou existerait un pergelisol dangereux. Des donnees provenant de cartes de la distribution du pergelisol ainsi que de cartes topographiques et geologiques doivent etre integrees en utilisant si possible un systeme d'information geographique. Si un pergelisol est possible et parait constituer une menace, une deuxieme phase de recherches est recommandee. Elle comprendra des mesures de temperature sur le terrain, la realisation de forages d'exploration et des leves geophysiques pour definir les caracteristiques du pergelisol. Les donnees recueillies constitueront une partie importante du projet d'ingenierie. A une echelle plus grande, une approche semblable devrait etre adoptee dans toute etude visant a modifier l'affectation de terrains dans la zone du pergelisol de montagne. Copyright © 2001 John Wiley & Sons, Ltd.

In recent years successful attempts have been made to develop and improve spatial modelling of mountain permafrost distribution. Work package 4 of the PACE project (Permafrost and Climate in Europe) sought to provide the essential basis not only of present-day modelling capability, but also of future enhancements in modelling methodology. This paper briefly outlines the currently available typology of models, which involve various levels of sophistication at different spatio-temporal scales. Appropriate models may be applied to a range of environmental issues in cold mountain areas, including engineering applications, climate-change scenarios, large-scale mapping, studies of surface processes or environmental concerns. Special emphasis is given here to aspects of energy exchange at the surface and within the active layer. Such energy fluxes remain poorly understood but play an essential role in process-oriented research and sensitivity studies with respect to complex interactions and feedbacks within the system. In contrast to relatively flat permafrost areas in polar and subpolar lowlands, circulation of water and air can cause important lateral fluxes of matter and energy within coarse blocks on steep slopes and result in highly variable and sometimes extreme thermal offsets between the ground surface and the permafrost table. Measuring and numerically modelling such fluxes together with coupling time-dependent surface and subsurface ground thermal conditions in characteristic materials (bedrock, ice-rich debris, fine-grained deposits) constitute the main challenge for research in the near future. Copyright  2001 John Wiley & Sons, Ltd. R ´

Alpine permafrost and frost-related geomorphological processes are sensitive to climatic change. Thus, there is an increasing demand for permafrost maps in high-alpine environments. The objective of this paper is to present the application of terrain analysis and classification based on digital elevation models (DEMs) together with remotely sensed data (e.g. Landsat TM) in mapping of permafrost and slope activity as a supplement to existing methods. The study reviews principles and recent developments in this field, and presents three different approaches in the form of case studies from mountain areas of southern Norway. Copyright © 2001 John Wiley & Sons, Ltd. RESUME Le pergelisol alpin et les processus geomorphologiques dus au gel sont sensibles aux changements de climat. II y a, en consequence, une demande accrue de cartes du pergelisol dans les environnements de hautes altitudes. L'objectif de cet article est de presenter comment l'analyse du terrain et une classification du sol basee sur des modeles d'altitude, combinees avec l'utilisation de donnees de teledetection (Landsat TM), peuvent servir a cartographier le pergelisol et l'activite geomorphologique sur les versants, et constituer un supplement aux methodes deja existantes. L'etude passe en revue les principes et les developpements recents dans ce domaine et presente trois differentes approches dans des etudes de cas de regions montagneuses de Norvege meridionale. Copyright © 2001 John Wiley & Sons, Ltd.

Direct solar radiation integrated over one year is a function of latitude and time of year, and topographic slope , aspect and shadowing control the local distribution. Recently, several spatial models have been developed which estimate the radiation balance based on digital elevation models, taking into account aspect, slope and shadowing effects. For the periglacial realm, these models are integrated both in models estimating possible occurrence of mountain permafrost and in studies of active layer dynamics. In this article our aim is to assess and discuss sensitivity and validations of the radiation balance model SRAD, in comparison with two other topographic-based radiation models. The study site and field data are from Finse, Southern Norway.

This paper reviews the principles related to the mapping and modelling of the occurrence and distribution of mountain permafrost. It gives a state-of-the art report about this topic and defines future research needs.

Two small high-Arctic glaciers (Longyearbreen and Larsbreen) on Svalbard (78°N 15°E) were studied with respect to glaciological and hydrological characteristics. Fieldwork during the melting season of 1993 and 1994 was coupled with digital map analysis based on high-resolution digital elevation models (DEM) to reveal the dynamics and temperature regime of small glaciers in a high-Arctic environment, and its relationship to the material transport and sedimentation of these glaciers. The study showed Longyearbreen and Larsbreen to be low activity glaciers, cold-based with temperate patches, and thus having a low potential of basal erosion. The transport of ions and suspended solids in the glacial meltwater implies storage of material in and around the glacier which comes into contact with the meltwater. The study suggests that small Arctic glaciers couple the slope system with the fluvial system and therefore build a highly effective denudation system. Small polythermal glaciers are therefore important in u...

This paper presents map analysis of digital elevation models for glaciological applications. The approach has been to combine spatial information describing the geometry of the glaciers with physical models of glaciological processes and to adjust empirical parameters to give a best fit with field observations. This applies to description of the basal shear stress and the resulting flow due to deformation of the ice. The outputs display spatial distributions, which can be adjusted to field observations through flexible routines of averaging the geographical information. Further, this approach is applied to description of the potential driving water along the bed, defined by the basal topography of the glacier and a model assuming that the basal water pressure is related to the thickness of the ice. The results produce predictions of the location of subglacial waterways and their drainage basins, which can be adjusted to field observations by choice of an empirical parameter, giving the basal water pressur...

Finsterwalderbreen (77°26’ N, 15° 15’ E) is a 35 km2 polythermal, surge-type glacier in southern Spitsbergen, Svalbard. Extensive field investigations have been carried out on the glacier, including mapping of bed topography by radio-echo soundings, mass-balance measurements and hydrological and meteorological registrations. In this paper we have used surface and bed topography and observations of summer ablation to estimate total runoff and subglacial drainage pattern by means of spatial map analysis in standard geographic information system software. The location and relative importance of the water-channel outlets from the glacier were estimated, as well as the change in drainage pattern over the period 1970–90. The results could be compared to direct observations of drainage pattern and discharge recordings. The analyses indicate that the location of the subglacial channels is dominated by the surface topography and thus that the channels are partly pressurized.

(2007). Sediment budgets and rates of sediment transfer across cold environments in europe: introduction and background to the european science foundation network ‘sedimentary source‐to‐sink fluxes in cold environments’(sediflux) Geografiska Annaler: Series A, Physical Geography: Vol. 89, No. 1, pp. 1-3.

Rock glacier structure, velocity and morphology were studied on the island of Prins Karls Forland, western Svalbard (78°50′N, 10°30′E). On the north-western part of the island, lobate rock glaciers build a 10 km long continuous transition between rockwall and strandflat area. In this area, a high-resolution digital elevation model (DEM) was constructed, and surface velocity measurements and DC resistivity soundings were carried out on selected rock glaciers. The conceptual model of Haeberli and Vonder Muhll is discussed for high arctic areas, where the permafrost base is beneath the base of the rock glaciers. © 1998 John Wiley & Sons, Ltd. La structure, la vitesse et la morphologie des glaciers rocheux ont ete etudiees sur l'ile Prins Karls Forland, dans le Svalbard occidental (78°50′N, 10°30′E). Dans la partie nord-ouest de l'ile, des glaciers rocheux lobes constituent une transition continue de 10 km de longueur entre la falaise rocheuse et la plate-forme marine. Dans cette zone, un modele de relief digital a haute resolution a ete etabli, et des mesures de vitesse de surface ainsi que des sondages par resistivite ont ete realises sur certains glaciers rocheux. Le modele conceptuel de Haeberli et Vonder Muhl (1996) est discute dans son application a des regions du haut Arctique ou la base du pergelisol se trouve sous la base du glacier rocheux. © 1998 John Wiley & Sons, Ltd.

The Norwegian traffic network is impacted by about 2000 landslides, avalanches, and debris flows each year that incur high economic losses. Despite the urgent need to mitigate future losses, efforts to locate potential debris flow source areas have been rare at the regional scale. We tackle this research gap by exploring a minimal set of possible topographic predictors of debris flow initiation that we input to a Weights-of-Evidence (WofE) model for mapping the regional susceptibility to debris flows in western Norway. We use an inventory of 429 debris flows that were recorded between 1979 and 2008, and use the terrain variables of slope, total curvature, and contributing area (flow accumulation) to compute the posterior probabilities of local debris flow occurrence. The novelty of our approach is that we quantify the uncertainties in the WofE approach arising from different predictor classification schemes and data input, while estimating model accuracy and predictive performance from independent test data. Our results show that a percentile-based classification scheme excels over a manual classification of the predictor variables because differing abundances in manually defined bins reduce the reliability of the conditional independence tests, a key, and often neglected, prerequisite for the WofE method. The conditional dependence between total curvature and flow accumulation precludes their joint use in the model. Slope gradient has the highest true positive rate (88%), although the fraction of area classified as susceptible is very large (37%). The predictive performance, i.e. the reduction of false positives, is improved when combined with either total curvature or flow accumulation. Bootstrapping shows that the combination of slope and flow accumulation provides more reliable predictions than the combination of slope and total curvature, and helps refining the use of slope–area plots for identifying morphometric fingerprints of debris flow source areas, an approach used outside the field of landslide susceptibility assessments.

This paper presents an approach to long-term glacier monitoring. Mathematical surface descriptors, such as altitude, slope and curvature (surface form) are used to classify and quantify glacier surface developments. The analysis is based on photogrammetically derived grid-based digital elevation models over a period of decades. This paper outlines the concept and applies it to five valley glaciers in Spitsbergen, Svalbard, which differ with respect to size, thermal regime and dynamics. The results reflect differences between the glaciers investigated which are attributable to glacier dynamics, in particular concerning the glacier’s possible surge behaviour during a period with retreat and mass losses.

The landscape is a complex surface influenced by a variety of factors (e.g. vegetation, soil, geology, land use and human impacts) in addition to topography. The realization of the importance of the topography in determining a range of physical processes, however (Moore et al. 1991, Pennock et al. 1987), has increased interest in focusing on the topographical factor alone. This is central to this paper, where a landscape classification is carried out only by regarding the topographical aspect of the landscape.

The formation of ice-cored moraines and push moraines is discussed in the light of glacier thermal regime and glacier dynamics. Data from two Svalbard valley glaciers, Erikbreen and Usherbreen are presented. On Erikbreen, fossil forms were investigated, while on Usherbreen a surge ending in 1985 caused the formation of new push-moraine ridges. The push moraines are considered as a soil-mechanical problem. In a theoretical discussion the stress transmitted by the glaciers to the proglacial sediments is estimated. On Usherbreen, the compressive flow results in deformation both in old front ridges and in undisturbed frozen sediment layers in the front sandur. Thus, folding, thrust faulting and overriding all occur. Deformation of proglacial sediments seems to be highly dependent on the mechanical properties of the sediments. The sediments are strongly influenced by permafrost conditions. The unfrozen water content in the sediments governs the deformability, which in turn is partly determined by pore-water salinity. The distribution of push moraines in Svalbard is therefore restricted to areas below the Holocene marine limit, and they occur most frequently in areas of sedimentary bedrock. This study concludes that push moraines and ice-cored moraines require permafrost conditions. Push-moraine ridges are not formed in direct contact with the glacier, so they are geomorphologically not moraines, but deformed permafrost sediments. A model for glacier debris sedimentation and deformation is outlined for Svalbard glaciers ending on land.

Thermal modeling is a powerful tool to infer the temperature regime of the ground in permafrost areas. We present a transient permafrost model, CryoGrid 2, that calculates ground temperatures according to conductive heat transfer in the soil and in the snow pack. CryoGrid 2 is forced by operational air temperature and snow depth products for potential permafrost areas in Southern Norway for the period 1958 to 2009 at 1 km spatial resolution. In total, an area of about 80 000 km2 is covered. The model results are validated against borehole temperatures, permafrost probability maps from "Bottom Temperature of Snow" measurements and inventories of landforms indicative of permafrost occurrence. The validation demonstrates that CryoGrid 2 can reproduce the observed lower permafrost limit to within 100 m at all validation sites, while the agreement between simulated and measured borehole temperatures is within 1 K for most sites. The number of grid cells with simulated permafrost does not change significantly between the 1960s the 1990s. In the 2000s, a significant reduction of about 40% of the area with average 2 m ground temperatures below 0 °C is found which mostly corresponds to degrading permafrost with still negative temperatures in deeper ground layers. The thermal conductivity of the snow is the largest source of uncertainty in CryoGrid 2 strongly affecting the simulated permafrost area. Finally, the prospects of employing CryoGrid 2 for an operational soil temperature product for Norway are discussed.

Glacial and glaciohydrologic processes that control the glaciofluvial sediment delivery from Erikbreen, a polythermal glacier on the north coast of Spitsbergen (79°40'N, 12°30'E), were studied during the summer seasons of 1990,1991 and 1992. Erikbreen differs from most glaciers of similar size in Svalbard, by the high flow velocity and a heavily crevassed surface. Water tracing experiments were conducted to study the geometry and stability of subglacial conduits, and the influence of the drainage system on subglacial sediment withdrawal. The withdrawal of sediments was monitored in the proglacial stream. High concentrations of suspended sediments were found. The type of drainage system and the presence of unconsolidated sediments at the glacier bed exerts the main control on the glaciofluvial sediment delivery. Annual delivery of suspended sediments varies by a magnitude, runoff being the controlling variable.

The results from new global positioning system (GPS) surveys in 1998 and 2000 show, that errors exist in the results from terrestrial surveys in 1996. The published displacement values of Berthling et al. (1998) are too large. This note corrects these displacement values. Copyright © 2003 John Wiley & Sons, Ltd.

Debris flows, triggered by extreme precipitation events and rapid snow melt, cause considerable damage to the Norwegian infrastructure every year. To define intensity-duration (ID) thresholds for debris flow initiation critical water supply conditions arising from intensive rainfall or snow melt were assessed on the basis of daily hydro-meteorological information for 502 documented debris flow events. Two threshold types were computed: one based on absolute ID relationships and one using ID relationships normalized by the local precipitation day normal (PDN). For each threshold type, minimum, medium and maximum threshold values were defined by fitting power law curves along the 10th, 50th and 90th percentiles of the data population. Depending on the duration of the event, the absolute threshold intensities needed for debris flow initiation vary between 15 and 107 mm day−1. Since the PDN changes locally, the normalized thresholds show spatial variations. Depending on location, duration and threshold level, the normalized threshold intensities vary between 6 and 250 mm day−1. The thresholds obtained were used for a frequency analysis of over-threshold events giving an estimation of the exceedance probability and thus potential for debris flow events in different parts of Norway. The absolute thresholds are most often exceeded along the west coast, while the normalized thresholds are most frequently exceeded on the west-facing slopes of the Norwegian mountain ranges. The minimum thresholds derived in this study are in the range of other thresholds obtained for regions with a climate comparable to Norway. Statistics reveal that the normalized threshold is more reliable than the absolute threshold as the former shows no spatial clustering of debris flows related to water supply events captured by the threshold.

A heat flow model was used to simulate both past and future ground temperatures of mountain permafrost in Southern Norway. A reconstructed air temperature series back to 1860 was used to evaluate the permafrost evolution since the end of the Little Ice Age in the region. The impact of a changing climate on discontinuous mountain permafrost until 2100 is predicted by using downscaled temperatures from an ensemble of downscaled climate models for the A1B scenario. From 13 borehole locations two consecutive years of ground temperature, air temperature and snow cover data are available for model calibration and validation. The boreholes are located at different elevations and in substrates having different thermal properties. With an increase of air temperature of ~+1.5 °C over 1860–2010 and an additional warming of +2.8 °C towards 2100 in air temperature, we simulate the evolution of ground temperatures for the borehole locations. According to model results, the active-layer thickness has increased since 1860 by about 0.5–5 m and >10 m for the sites Juvvass and Tron, respectively. The simulations also suggest that at an elevation of about 1900 m a.s.l. permafrost will degrade until the end of this century with a likelihood of 55–75% given the chosen A1B scenario.

The polythcrmal valley glacier Erikbreen (79°40?N 12°30?E), northern Spitsbergen, was investigated in 1970 and 1990 using digital photogrammetry and digital elevation model (DEM) techniques. The bottom topography was derived from radio-echo soundings. Based on the DEM, mass balance and changes of surface slope, crevasse and flow pattern were evaluated, and internal ice deformation velocities were calculated. Calculations of the total mass balance show that Erikbreen has not been in equilibrium for the last 20 years. The average surface lowering was 0.38 m/a and the volume had decreased by 5% to 6% from 1970 to 1990 or on the average by 3.5 × 10?1 water. The glacier surface subsided over the whole glacier area except in minor areas with northfacing slopes in the accumulation area. The surface slope and the crevasse pattern, however, did not change significantly during the 20-year-period, except in areas below 100 ma.s.l.

The thermal regime of the valley glacier, Erikbreen, northern Spitsbergen (79°40?N, 12°30?E) was studied using radio-echo sounding and temperature measurements from eight boreholes ranging from 13.5 to 24 m. Radar images indicate a glacier with a two-layered thermal structure. A surface layer of cold ice, 20 to 60 m thick along the centre flow line, extends from an altitude above equilibrium line to the glacier front. This layer represents 20 to 35% of the glacier thickness, except at the floating front, where the cold layer is about 50%. The ice beneath the cold surface layer is interpreted to be temperate. Cold-based areas exist near the glacier margin and in some locations in the accumulation area; the ice is interpreted to be entirely temperate in central parts of the accumulation area at high altitude. Freezing of temperate ice at the base of the cold surface layer is probably the main mechanism of cold ice formation in the frontal parts of Erikbreen. Calculated heat fluxes based on the borehole measurements show that a steady state cold layer 25 to 30 m thick is likely, assuming a surface melting of 1.7 m/y and a maximum water content of 3%. In the frontal parts the calculated mean annual upward heat flux at 10 to 15 m depth is roughly 0.6 W/m2.

[1] This study contains the first quantitative description of mountain permafrost in Iceland, obtained through analysis of four ground temperature time series from recently established shallow boreholes at high altitude (∼900 m above sea level) in central and eastern Iceland. Permafrost is present at three of the four boreholes, where temperatures range from −2° to 0°C. During the data-logging period, 2004–2006, the thickness of the active layer at the individual sites varied between less than 2 m and more than 5 m, mainly owing to differences in near-surface ice content. The ground temperature profiles are nonlinear, with near-surface temperature perturbations considered to be related to a recent warming of the ground surface. At the one nonpermafrost site the insulating influence of winter snow cover is more pronounced. A one-dimensional heat-conduction model was calibrated using ground temperature measurements and driven by surface temperature time series. The model results reproduce the measured ground temperature pattern well. This simplified model, simulating the results of possible future climate scenarios, indicates that permafrost degradation will occur at these sites within decades, depending on climate scenarios chosen and subsurface ice content.

[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.

(2002). Editorial: Professor Johan Ludvig Sollid. Norsk Geografisk Tidsskrift - Norwegian Journal of Geography: Vol. 56, Special issue dedicated to the 70th anniversary of Professor Johan Ludvig Sollid (eds. Bernd Etzelmuller & Jon Ove Hagen), pp. 49-50.

Professor Johan Ludvig Sollid at the Department of Physical Geography, University of Oslo, and Dr Geir-Harald Strand at the Norwegian Institute of Land Inventory (Norsk institutt for jordog skogkartlegging - NIJOS), in collaboration with the editor of the Norwegian Journal of Geography Tormod Klemsdal, took the initiative in September 1993 to launch a special issue of the Journal with the scope ‘Applications in Geographical Information Technology (GIT)’. Dr Bernd Etzelmuller, Department of Physical Geography, University of Oslo, and Dr Kjell Kjenstad, Sysdeco GIs A/S, Kongsberg, were chosen as editors for the special issue.