Thermalconductivity of soils in the active layer of Eastern Siberia
Landscape changes accompanied by changes in soil properties occur in Central Siberia as a result of forest fire, surface processes and human impact. A non-steady-state technique tested the thermal properties of Siberian soils. Thermalconductivity
Freezing ; Model ; Periglacial features ; Permafrost ; Soil properties ; Soil temperature ; Soil water ; Thermal regime
The effect of unfrozen water content on the thermal properties of the ground is discussed in the context of the TTOP model. Numerical simulations of the thermal regime for a range of fine-grained soils are used to determine the effect of variable
soil conductivity on the temperature at the top of permafrost. Results show that the temperature dependent conductivity function can be used with a temperature based on the surface freezing index to estimate an appropriate single value of the frozen
Apparent thermal diffusivity in soil: estimation from thermal records and suggestions for numerical modeling
The concept of apparent thermal diffusivity in soil is discussed and defined as consisting of an intrinsic and a pseudo part. A method that uses a numerical model of heat conduction and measured soil temperatures to estimate apparent thermal
Asian part of Russia ; Ground ice ; Ice ; Methodology ; Model ; Periglacial features ; Permafrost ; Porosity ; Sakha ; Thermalconductivity
of water in a fine-grained soil and a free space. It is shown that the calculated values of thermalconductivity for segregated ice are much higher than some previously published experimental values, probably due to some methodological shortcomings
Observation of thermal belt on an open slope by use of infrared thermography
An observation utilizing an infrared thermography was conducted on January 9, 2005, in the southern slope Mt. Houkyou and its accompanying slope holding a quarry where vegetation is scarce. The aim of this study is to deduce the effect of vegetation
on the thermal belt by comparing the cooling rate under differing land surface conditions; to measure the strength of the inversion layer created along the slope of Mt. Houkyou in order to quantify the role of the nocturnal drainage flow in maintaining
This paper shows the effect of thaw settlement on the thermal response of a small permafrost mound in Northern Québec to different scenarios of climate warming, with a finite-element, one-dimensional, heat conduction model. In addition
to the cryostratigraphy of the mound, the unfrozen water content, thermalconductivity and volumetric heat capacity of the marine sediments comprising the mound were integrated in the simulation. Thaw settlement, the direct results of ice melting in permafrost, brings
consisting of different natural material. For each plot, values of thermalconductivity were determined. The observations revealed a clear dependence of the sub-debris ice melt on the layer thickness, grain size, porosity and moisture content. For the sand
fraction the moisture content played a dominant role. These test fields were water saturated most of the time, resulting in an increased thermalconductivity. Highly porous volcanic material protected the ice much more effectively from melting than similar
layer thicknesses of the local mica schist. However, the analysis of thermal diffusivities demonstrated that the vertical moisture distribution of the debris cover must be taken into consideration, with the diffusivity values being significantly lower
The one dimensional heat conduction equation is applied to a non-uniform soil in which harmonic boundary conditions are specified. The analytic solutions are derived for practical use and satisfy a law that the thermal diffusivity is proportional
Night-frost modulation of near-surface soil-water ion concentration and thermal fields
the calculation of the apparent thermal diffusivity and relative ionic concentration yields estimates of the magnitude and direction of non-conductive processes.
Association ; Forest ; Impact ; Poland ; Thermal regime
A research on the influence of forest associations on the diversification of thermal and humidity conditions of the forest interior was conducted from 2007 to 2008 in six measurement points in the Borecka Forest. The empirical data allowed observing
that in autumn the selected forest associations experience diverse thermal conditions. These differences result mainly from the amount of foliage on the tree tops. - (BJ)
Impacts of grassland vegetation cover on the active-layer thermal regime, Northeast Qinghai-Tibet Plateau, China
China ; Climatic change ; Grassland ; Impact ; Mountain ; Periglacial features ; Permafrost ; Plant cover ; Plateau ; Qinghai ; Thermal regime ; Tibet
vegetation covers exhibited greater annual variability in soil temperatures, and may be more sensitive to changes in air temperature. Low vegetation covers are also linked to higher thermal diffusivity and thermalconductivity in the soils. The maintenance
The study was conducted in the watershed of the Zuomaokong River in an alpine meadow over a three-year period. A high vegetation cover (93%) delayed thawing and freezing at a given depth relative to sites with lower covers (65%, 30% and 5%). Low
Albedo ; Debris cover ; Glacial ablation ; Glacial features ; Glacier ; Glacier mass balance ; Himalaya ; Model ; Nepal ; Seasonal variability ; Thermalconductivity
be possible in coarse surface layers; 3) phase changes associated with seasonal change have a marked effect on the effective thermal diffusivity of the debris. Effective thermalconductivity determined from vertical temperature profiles in the debris
The AA. report measurements of vertical temperature profiles in debris on the Ngozumpa glacier in the Khumbu Himal region,Nepal, that show : 1) conductive processes dominate during the ablation season in matrix-supported diamict; 2) ventilation may
Active layer thermal regime at three rock glaciers in Greenland
Active layer ; Freezing ; Greenland ; Meltwater ; Periglacial features ; Permafrost ; Rock glacier ; Roughness ; Snow cover ; Thermal regime
par conduction et par d'autres voies, et du rôle des rugosités différentes de la surface dans les différents degrés de ventilation de la couche active.
Thermal characterisation of active layer across a soil moisture gradient in the McMurdo Dry Valleys, Antarctica
Here, the AA. present results of a study to characterise soil thermal properties along a soil moisture gradient adjacent to Lake Fryxell in Taylor Valley, Antarctica. The goals were to characterise the thermal characteristics of these relatively wet
gradient of wet to dry soils adjacent to Lake Fryxell from January 2006 to January 2007. They used a numerical model to estimate apparent thermal diffusivity (ATD) and simulate observed temperature time series. Estimated bulk ATD values were consistently
greater in locations of enhanced soil moisture, so lakeside soils were more likely to conducte energy into the subsurface. Increased soil moisture across the landscape would likely increase ATD, allowing for greater heat exchange between the atmosphere
Model ; Mountain ; Norway ; Periglacial features ; Permafrost ; Radiation ; Snow ; Soil temperature ; Spatial distribution ; Thermal regime
The TTOP-model uses seasonal n-factors (nt and nf) and air temperature to model the mean annual ground-surface temperature (MAGST), and a ratio of thawed to frozen thermalconductivity to model the average TTOP. This study presents 28 and 36 values
Active layer ; Alaska ; Arctic Region ; Model ; Periglacial features ; Permafrost ; Simulation ; Snow cover ; Soil temperature ; Thermal regime
This study addresses the impact of variations in the timing and duration of seasonal snow cover on the thermal regime of the active layer and permafrost in the Alaskan Arctic through numerical modelling. Meteorological data from 1995 to 1998
at Barrow, Alaska, were used as baseline inputs. The active layer thickness in 1998 and the ground temperatures at depths of 0.0, 0.5, 1.0, and 2.0 m during September 1997 through August 1998 were simulated. A series of simulation cases was conducted
This paper presents the results of 3 ground-penetrating radar (GPR) surveys conducted, in 2002, over the course of a summer ablation season at a polythermal glacier, Stagnation Glacier, Bylot Island, in the Canadian Arctic. The AA. compare
Changes in the dynamics and thermal regime of the permafrost and active layer of The High Arctic coastal area in north-west Spitsbergen, Svalbard
Active layer ; Arctic Region ; Climatic change ; Cold area ; Permafrost ; Polar region ; Spitsbergen ; Svalbard ; Temperature ; Thermal regime ; Time series
The study was conducted on the Kaffiøyra Plain (Svalbard) at several fixed sites, which represent places typical of the region : a sandy beach, a tundra plain and a moraine ridge. Analysis includes both the ground thawing depth and its near-surface
thermal structure. The results show that in recent years, at 2 measurement points (on the beach and on the moraine) a significantly deeper thawing was observed. Generally, in the years 2008–2012 the mean thickness of the active layer in the Kaffiøyra
(solar) radiation. A Fourier decomposition of the temperature measurements provided an estimate of the in situ thermalconductivity of the rock and was used to calculate the conductive term. The shortwave radiation term was determined on the basis
The study site is a steep gneiss slope known as Rochers de Valabres (Alpes-Maritimes, France). Attention was focused on 2 major contributors to the heat balance; the heat flux entering the rock mass through conduction and the incoming shortwave