Journal articles on the topic 'Permafrost – Thermal conductivity'
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1
Yang, Shuhua, Ren Li, Lin Zhao, Tonghua Wu, Xiaodong Wu, Yuxin Zhang, Jianzong Shi, and Yongping Qiao. "Evaluation of the Performance of CLM5.0 in Soil Hydrothermal Dynamics in Permafrost Regions on the Qinghai–Tibet Plateau." Remote Sensing 14, no. 24 (December 8, 2022): 6228. http://dx.doi.org/10.3390/rs14246228.
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Soil hydrothermal dynamics are a crucial parameter for understanding the internal physical conditions of the active layer in permafrost regions. It is very difficult to obtain data in permafrost regions, especially on the Qinghai–Tibet Plateau (QTP). Land surface modes (LSMs) provide an effective tool for soil hydrothermal dynamics. However, it is necessary to evaluate the simulation performance before using them. Here, we used two in situ sites along with the latest version of the Community Land Model (CLM5.0) to evaluate the simulated performance in the soil hydrothermal parameters of the model in permafrost regions on the QTP. Meanwhile, the effects of soil properties, thermal roughness length, and the freeze–thaw process on the simulation results were investigated. The results showed that CLM5.0 can capture the dynamic changes in soil hydrothermal changes well in permafrost regions on the QTP. Soil moisture and thermal conductivity were more sensitive to soil properties and the freeze–thaw process, while the thermal roughness length had a greater effect on soil temperature. Notably, although we improved the soil properties and thermal roughness length, there were still some errors, especially in the soil moisture and soil thermal conductivity. It may be caused by inappropriate hydrothermal parameterizations of the model, especially the soil thermal conductivity, hydraulic conductivity, unfrozen water scheme, and snow schemes. There is an urgent need for collaboration between experts in permafrost science, hydrological science, and modelers to develop the appropriate schemes for permafrost regions and enhance the LSMs.
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Pan, Xicai, Yanping Li, Qihao Yu, Xiaogang Shi, Daqing Yang, and Kurt Roth. "Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau." Cryosphere 10, no. 4 (July 25, 2016): 1591–603. http://dx.doi.org/10.5194/tc-10-1591-2016.
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Abstract. Seasonally variable thermal conductivity in active layers is one important factor that controls the thermal state of permafrost. The common assumption is that this conductivity is considerably lower in the thawed than in the frozen state, λt/λf < 1. Using a 9-year dataset from the Qinghai–Tibet Plateau (QTP) in conjunction with the GEOtop model, we demonstrate that the ratio λt/λf may approach or even exceed 1. This can happen in thick (> 1.5 m) active layers with strong seasonal total water content changes in the regions with summer-monsoon-dominated precipitation pattern. The conductivity ratio can be further increased by typical soil architectures that may lead to a dry interlayer. The unique pattern of soil hydraulic and thermal dynamics in the active layer can be one important contributor for the rapid permafrost warming at the study site. These findings suggest that, given the increase in air temperature and precipitation, soil hydraulic properties, particularly soil architecture in those thick active layers must be properly taken into account in permafrost models.
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Yi, S., J. Chen, Q. Wu, and Y. Ding. "Simulating the role of gravel on the dynamics of permafrost on the Qinghai-Tibetan Plateau." Cryosphere Discussions 7, no. 5 (September 24, 2013): 4703–40. http://dx.doi.org/10.5194/tcd-7-4703-2013.
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Abstract. Gravel (particle size ≥ 2 mm) is common in soil profiles of the Qinghai-Tibetan Plateau (QTP). It has different thermal and hydrological properties than other fine mineral soils (particle size < 2 mm), which may have significant impacts on the thermal and hydrological processes of soil. However, few models have considered gravel. In this study, we implemented the thermal and hydraulic properties of gravel into the Dynamic Organic Soil-Terrestrial Ecosystem Model to develop new schemes to simulate the dynamics of permafrost on the QTP. Results showed that: (1) the widely used Farouki thermal scheme always simulated higher thermal conductivity of frozen soils than unfrozen soils with the same soil water content; therefore it tends to overestimate permafrost thickness strongly; (2) there exists a soil moisture threshold, below which the new set of schemes with gravel simulated smaller thermal conductivity of frozen soils than unfrozen soils; (3) soil with gravel has higher hydraulic conductivity and poorer water retention capability; and simulations with gravel were usually drier than those without gravel; and (4) the new schemes simulated faster upward degradation than downward degradation; and the simulated permafrost thicknesses were sensitive to the fraction of gravel, the gravel size, the thickness of soil with gravel, and the subsurface drainage. To reduce the uncertainties in the projection of permafrost degradation on the QTP, more effort should be made to: (1) developing robust relationships between soil thermal and hydraulic properties and gravel characteristics based on laboratory work; and (2) compiling spatial datasets of the vertical distribution of gravel content based on measurements during drilling or the digging of soil pits.
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Barrere, Mathieu, Florent Domine, Bertrand Decharme, Samuel Morin, Vincent Vionnet, and Matthieu Lafaysse. "Evaluating the performance of coupled snow–soil models in SURFEXv8 to simulate the permafrost thermal regime at a high Arctic site." Geoscientific Model Development 10, no. 9 (September 21, 2017): 3461–79. http://dx.doi.org/10.5194/gmd-10-3461-2017.
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Abstract. Climate change projections still suffer from a limited representation of the permafrost–carbon feedback. Predicting the response of permafrost temperature to climate change requires accurate simulations of Arctic snow and soil properties. This study assesses the capacity of the coupled land surface and snow models ISBA-Crocus and ISBA-ES to simulate snow and soil properties at Bylot Island, a high Arctic site. Field measurements complemented with ERA-Interim reanalyses were used to drive the models and to evaluate simulation outputs. Snow height, density, temperature, thermal conductivity and thermal insulance are examined to determine the critical variables involved in the soil and snow thermal regime. Simulated soil properties are compared to measurements of thermal conductivity, temperature and water content. The simulated snow density profiles are unrealistic, which is most likely caused by the lack of representation in snow models of the upward water vapor fluxes generated by the strong temperature gradients within the snowpack. The resulting vertical profiles of thermal conductivity are inverted compared to observations, with high simulated values at the bottom of the snowpack. Still, ISBA-Crocus manages to successfully simulate the soil temperature in winter. Results are satisfactory in summer, but the temperature of the top soil could be better reproduced by adequately representing surface organic layers, i.e., mosses and litter, and in particular their water retention capacity. Transition periods (soil freezing and thawing) are the least well reproduced because the high basal snow thermal conductivity induces an excessively rapid heat transfer between the soil and the snow in simulations. Hence, global climate models should carefully consider Arctic snow thermal properties, and especially the thermal conductivity of the basal snow layer, to perform accurate predictions of the permafrost evolution under climate change.
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Westermann, S., T. V. Schuler, K. Gisnås, and B. Etzelmüller. "Transient thermal modeling of permafrost conditions in Southern Norway." Cryosphere Discussions 6, no. 6 (December 20, 2012): 5345–403. http://dx.doi.org/10.5194/tcd-6-5345-2012.
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Abstract. 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.
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Westermann, S., T. V. Schuler, K. Gisnås, and B. Etzelmüller. "Transient thermal modeling of permafrost conditions in Southern Norway." Cryosphere 7, no. 2 (April 25, 2013): 719–39. http://dx.doi.org/10.5194/tc-7-719-2013.
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Abstract. 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 snowpack. 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 km2 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 and 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 as an operational soil-temperature product for Norway are discussed.
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He, Ruixia, Ning Jia, Huijun Jin, Hongbo Wang, and Xinyu Li. "Experimental Study on Thermal Conductivity of Organic-Rich Soils under Thawed and Frozen States." Geofluids 2021 (September 23, 2021): 1–12. http://dx.doi.org/10.1155/2021/7566669.
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Thermal properties are important for featuring the water-heat transfer capacity of soil. They are also key to many processes in earth sciences, such as the land surface processes and ecological and geoenvironmental dynamics and their changes in permafrost regions. With loose and porous structures, the organic matter layer in soil strata substantially influences soil thermal conductivity. So far, thermal conductivity of mineral soils has been explored extensively and in depth, but there are only limited studies on that of organic soils. In this study, influences of soil temperature, soil moisture saturation (SMS), and soil organic matter (SOM) content on soil thermal conductivity were analyzed on the basis of laboratory experiments on the silt-organic soil mixtures of varied mixing ratios. Results show that soil thermal conductivity declines slowly with the lowering temperatures from 10 to 0°C; however, it increases and finally stabilizes when temperature further lowers from 0 to -10°C. It is important to note that thermal conductivity peaks in the temperature range of -2~0°C (silty and organic-poor soil) and -5~0°C (organic-rich soil), possibly due to phase changes of ice/water in warm permafrost. Under both thawed and frozen states, soil thermal conductivity is positively related with SMS. However, with rising SOM content, the growth rate of soil thermal conductivity with SMS slows gradually. Given the same SMS, soil thermal conductivity declines exponentially with increasing SOM content. Based on the experimental and theoretical analyses, a new empirical computational formula of soil thermal conductivity is established by taking into account of the SOM content, SMS, and soil temperature. The results may help better parameterize in simulating and predicting land surface processes and for optimizing frozen soil engineering designs and provide theoretical bases for exploring the dynamic mechanisms of environmental changes in cold regions under a changing climate.
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Cui, Fu-Qing, Zhi-Yun Liu, Jian-Bing Chen, Yuan-Hong Dong, Long Jin, and Hui Peng. "Experimental Test and Prediction Model of Soil Thermal Conductivity in Permafrost Regions." Applied Sciences 10, no. 7 (April 3, 2020): 2476. http://dx.doi.org/10.3390/app10072476.
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Soil thermal conductivity is a dominant parameter of an unsteady heat-transfer process, which further influences the stability and sustainability of engineering applications in permafrost regions. In this work, a laboratory test for massive specimens is performed to reveal the distribution characteristics and the parameter-influencing mechanisms of soil thermal conductivity along the Qinghai–Tibet Engineering Corridor (QTEC). Based on the measurement data of 638 unfrozen and 860 frozen soil specimens, binary fitting, radial basis function (RBF) neural network and ternary fitting (for frozen soils) prediction models of soil thermal conductivity have been developed and compared. The results demonstrate that, (1) particle size and intrinsic heat-conducting capacity of the soil skeleton have a significant influence on the soil thermal conductivity, and the typical specimens in the QTEC can be classified as three clusters according to their thermal conductivity probability distribution and water-holding capacity; (2) dry density as well as water content sometimes does not have a strong positive correlation with thermal conductivity of natural soil samples, especially for multiple soil types and complex compositions; (3) both the RBF neural network method and ternary fitting method have favorable prediction accuracy and a wide application range. The maximum determination coefficient (R2) and quantitative proportion of relative error within ±10% ( P ± 10 % ) of each prediction model reaches up to 0.82, 0.88, 81.4% and 74.5%, respectively. Furthermore, because the ternary fitting method can only be used for frozen soils, the RBF neural network method is considered the optimal approach among all three prediction methods. This study can contribute to the construction and maintenance of engineering applications in permafrost regions.
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Goodrich, L. E. "Field measurements of soil thermal conductivity." Canadian Geotechnical Journal 23, no. 1 (February 1, 1986): 51–59. http://dx.doi.org/10.1139/t86-006.
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Data representing the seasonal variation of thermal conductivity of the ground at depths within the seasonally active freezing/thawing zone are presented for a number of different soil conditions at four sites across Canada. An inexpensive probe apparatus suitable for routine field measurements is described.In all the cases examined, significant seasonal variations were confined to the first few decimetres. In addition to distinct seasonal differences associated with phase change, quite large changes occurred during the period when the soil was thawed in those cases where seasonal drying was possible. Below the seasonally active zone, thawed soil conductivities did not differ greatly among the three nonpermafrost sites in spite of soil composition ranging from marine clay to sandy silt. The data suggest that, even within a given soil layer, quite significant differences in thermal conductivity may be encountered in engineering structures such as embankments, presumably because of differences in drainage conditions. Key words: thermal conductivity, field measurements, phase relationships, drying, permafrost, clay, silt, peat.
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DOMINE, FLORENT, MARIA BELKE-BREA, DENIS SARRAZIN, LAURENT ARNAUD, MATHIEU BARRERE, and MATHILDE POIRIER. "Soil moisture, wind speed and depth hoar formation in the Arctic snowpack." Journal of Glaciology 64, no. 248 (November 28, 2018): 990–1002. http://dx.doi.org/10.1017/jog.2018.89.
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ABSTRACTBasal depth hoar that forms in Arctic snowpacks often has a low thermal conductivity, strongly contributing to the snowpack thermal insulance and impacting the permafrost thermal regime. At Ward Hunt Island (Canadian high Arctic, 83°05′N, 74°07′W) almost no depth hoar was observed in spring 2016 despite favorable thermal conditions. We hypothesize that depth hoar formation was impeded by the combination of two factors (1) strong winds in fall that formed hard dense wind slabs where water vapor transport was slow and (2) low soil moisture that led to rapid ground cooling with no zero-curtain period, which reduced soil temperature and the temperature gradient in the snowpack. Comparisons with detailed data from the subsequent winter at Ward Hunt and from Bylot Island (73°09′N, 80°00′W) and with data from Barrow and Alert indicate that both high wind speeds after snow onset and low soil moisture are necessary to prevent Arctic depth hoar formation. The role of convection to form depth hoar is discussed. A simple preliminary strategy to parameterize depth hoar thermal conductivity in snow schemes is proposed based on wind speed and soil moisture. Finally, warming-induced vegetation growth and soil moisture increase should reduce depth hoar thermal conductivity, potentially affecting permafrost temperature.
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Mühll, Daniel Vonder, and Wilfried Haeberli. "Thermal Characteristics of the Permafrost within an Active Rock Glacier (Murtèl/Corvatsch, Grisons, Swiss Alps)." Journal of Glaciology 36, no. 123 (1990): 151–58. http://dx.doi.org/10.1017/s0022143000009382.
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AbstractTemperatures from a bore hole through an active rock glacier in the eastern Swiss Alps are presented and thermal conditions within the slowly creeping permafrost are analyzed. Present mean annual temperature in the uppermost part of the permafrost is −3°C. Permafrost is 52 m thick and reaches heavily fissured bedrock. Thermal conductivity as determinedin situfrom seasonal temperature variations and measured in a cold laboratory using frozen samples is close to 2.5–3.0 W m−1°C−1. Vertical heat flow is anomalously high (around 150 mW m-2), probably due to heat advection from circulating ground water or air within the fissured bedrock zone. Beneath this zone, which could in fact represent a non-frozen intra-permafrost layer or “talik”, relic permafrost from past centuries may possibly exist as indicated by a corresponding heat-flow inversion. Given the current temperature condition at the surface of the rock glacier and the fact that the twentieth century is among the warmest in post-glacial time, permafrost conditions may be assumed to have existed during the whole of the Holocene and, hence, during the entire time of rock-glacier formation.
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Mühll, Daniel Vonder, and Wilfried Haeberli. "Thermal Characteristics of the Permafrost within an Active Rock Glacier (Murtèl/Corvatsch, Grisons, Swiss Alps)." Journal of Glaciology 36, no. 123 (1990): 151–58. http://dx.doi.org/10.3189/s0022143000009382.
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AbstractTemperatures from a bore hole through an active rock glacier in the eastern Swiss Alps are presented and thermal conditions within the slowly creeping permafrost are analyzed. Present mean annual temperature in the uppermost part of the permafrost is −3°C. Permafrost is 52 m thick and reaches heavily fissured bedrock. Thermal conductivity as determined in situ from seasonal temperature variations and measured in a cold laboratory using frozen samples is close to 2.5–3.0 W m−1 °C−1. Vertical heat flow is anomalously high (around 150 mW m-2), probably due to heat advection from circulating ground water or air within the fissured bedrock zone. Beneath this zone, which could in fact represent a non-frozen intra-permafrost layer or “talik”, relic permafrost from past centuries may possibly exist as indicated by a corresponding heat-flow inversion. Given the current temperature condition at the surface of the rock glacier and the fact that the twentieth century is among the warmest in post-glacial time, permafrost conditions may be assumed to have existed during the whole of the Holocene and, hence, during the entire time of rock-glacier formation.
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Levy, Joseph S., and Logan M. Schmidt. "Thermal properties of Antarctic soils: wetting controls subsurface thermal state." Antarctic Science 28, no. 5 (June 6, 2016): 361–70. http://dx.doi.org/10.1017/s0954102016000201.
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AbstractMineral soils in the McMurdo Dry Valleys (MDV), Antarctica, are commonly considered to be dry, and therefore to be good insulators with low thermal diffusivity values (~0.2 mm2s-1). However, field measurements of soil moisture profiles with depth, coupled with observations of rapid ground ice melt, suggest that the thermal characteristics of MDV soils, and thus their resistance to thaw, may be spatially variable and strongly controlled by soil moisture content. The thermal conductivity, heat capacity and thermal diffusivity of 17 MDV soils were measured over a range of soil moisture conditions from dry to saturated. We found that thermal diffusivity varied by a factor of eight for these soils, despite the fact that they consist of members of only two soil groups. The thermal diffusivity of the soils increased in all cases with increasing soil moisture content, suggesting that permafrost and ground ice thaw in mineral soils may generate a positive thawing feedback in which wet soils conduct additional heat to depth, enhancing rates of permafrost thaw and thermokarst formation.
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Isaksen, Ketil, Daniel Vonder Mühll, Hansueli Gubler, Thomas Kohl, and Johan Ludvig Sollid. "Ground surface-temperature reconstruction based on data from a deep borehole in permafrost at Janssonhaugen, Svalbard." Annals of Glaciology 31 (2000): 287–94. http://dx.doi.org/10.3189/172756400781820291.
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AbstractAnalyses of the geothermal gradient in permafrost areas constitute a key signal of the ground-surface temperature history. Permafrost temperatures in selected areas are particularly well suited to reconstructing past surface-temperature changes, mainly because there is no thermal disturbance due to circulating groundwater. One year of temperature data from an instrumented 102 m deep borehole in permafrost on Janssonhaugen, Svalbard, is presented. Ground thermal properties are calculated. The average value for the thermal conductivity is 1.85 ±0.05 W m–1 K–1 , and the average value for the thermal diffusivity is 1.1m2 s–1, which gives a phase speed for the annual wave of 5.65 × KT2 m d–1. The depth of zero annual amplitude is 18 m The permafrost thickness is estimated as approximately 220 m. Analysis of the temperatures reveals an increasing temperature gradient with depth. Using a heat-conduction inversion model, a palaeoclimatic reconstruction is presented, showing a warming of the surface temperature over the last 60–80 years. The temperature profile represents a regional signal on Svalbard, which shows an inflection associated with near-surface warming of 1.5 ± 0.5°C in the 20th century.
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Gavril'ev, R. I. "Thermal conductivity of permafrost soils in relation to natural moisture content." Journal of Engineering Physics 56, no. 6 (June 1989): 701–6. http://dx.doi.org/10.1007/bf00870445.
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Cheng, Youkun, Zhenwu Shi, and Fajin Zu. "Temperature Field Distribution and Thermal Stability of Roadbed in Permafrost Regions." International Journal of Heat and Technology 39, no. 1 (February 28, 2021): 241–50. http://dx.doi.org/10.18280/ijht.390127.
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Many highways and railways in western China are built on permafrost roadbed. Frost heave and thaw settlement might cause diseases to frozen soil roadbed, such as deformation and cracking. For long-term operation, frozen soil roadbed should be kept stable and durable. Therefore, this paper analyzes the distribution law of temperature field of roadbed in permafrost regions, under the effect of thermal stability. Based on the thermodynamic properties of permafrost, the authors analyzed the influence of engineering geological factors, roadbed structural factors, and natural environmental factors on the thermal stability of frozen soil roadbed. Next, the antifreeze mechanism of frozen soil roadbed was described, together with the calculation methods for the relevant parameters. Afterwards, the temperature field of the roadbed with low thermal conductivity insulation material was analyzed by two methods, namely, steady-state thermal analysis and transient thermal analysis, and the solving process of roadbed temperature field was explained in details. The proposed analysis method and solving algorithm were proved valid through experiments. The research results provide a reference for the reasonable design of frozen soil roadbed.
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Galkin, Aleksandr, and V. Yu Pankov. "Thermal protection of roads in the permafrost zone." Journal of Applied Engineering Science 20, no. 2 (2022): 395–99. http://dx.doi.org/10.5937/jaes0-34379.
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The problem of choosing a method of construction of thermal protection layer of the road pavement in permafrost zone was solved. Simple engineering formulas to justify the choice of the specific type of thermal insulation structure were obtained. It was determined that a structure composed of two layers (separate layers insulant and of sand) is always more efficient than a thermal insulation mixture (combined insulant and sand) applied in one layer for the purposes of maximizing thermal resistance. At the same time, a quantitative assessment demonstrated that in many practical cases, the difference in thermal resistance of the two kinds of structures is slight and is within the margins of permissible precision of engineering calculations. For this reason, it is expedient to also consider the technological demands of application of one or the other type of thermal insulation layer in addition to the thermal resistance considerations. Formulas to find the area of rational use of thermal insulation mixtures instead of merely sand bedding were devised. It was determined that the thickness of bedding in one or the other case is significantly dependent on the ratio of thermal conductivity coefficients of sand and the insulant. In addition, the change in relative thickness of the layer can have both negative and positive values.
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Subin, Zachary M., Charles D. Koven, William J. Riley, Margaret S. Torn, David M. Lawrence, and Sean C. Swenson. "Effects of Soil Moisture on the Responses of Soil Temperatures to Climate Change in Cold Regions*." Journal of Climate 26, no. 10 (May 8, 2013): 3139–58. http://dx.doi.org/10.1175/jcli-d-12-00305.1.
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Abstract At high latitudes, changes in soil moisture could alter soil temperatures independently of air temperature changes by interacting with the snow thermal rectifier. The authors investigated this mechanism with model experiments in the Community Land Model 4 (CLM4) with prescribed atmospheric forcing and vegetation state. Under equilibrium historical conditions, increasing CO2 concentrations experienced by plants from 285 to 857 ppm caused local increases in soil water-filled pore space of 0.1–0.2 in some regions throughout the globe. In permafrost regions that experienced this moistening, vertical- and annual- mean soil temperatures increased by up to 3°C (0.27°C averaged over all permafrost areas). A similar pattern of moistening and consequent warming occurred in simulations with prescribed June–September (JJAS) rainfall increases of 25% over historical values, a level of increase commensurate with projected future rainfall increases. There was a strong sensitivity of the moistening responses to the baseline hydrological state. Experiments with perturbed physics confirmed that the simulated warming in permafrost soils was caused by increases in the soil latent heat of fusion per unit volume and in the soil thermal conductivity due to the increased moisture. In transient Representative Concentration Pathway 8.5 (RCP8.5) scenario experiments, soil warming due to increased CO2 or JJAS rainfall was smaller in magnitude and spatial extent than in the equilibrium experiments. Active-layer deepening associated with soil moisture changes occurred over less than 8% of the current permafrost area because increased heat of fusion and soil thermal conductivity had compensating effects on active-layer depth. Ongoing modeling challenges make these results tentative.
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Chuvilin, Evgeny, Gennadiy Tipenko, Boris Bukhanov, Vladimir Istomin, and Dimitri Pissarenko. "Simulating Thermal Interaction of Gas Production Wells with Relict Gas Hydrate-Bearing Permafrost." Geosciences 12, no. 3 (March 2, 2022): 115. http://dx.doi.org/10.3390/geosciences12030115.
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The thermal interaction of a gas production well with ice-rich permafrost that bears relict gas hydrates is simulated in Ansys Fluent using the enthalpy formulation of the Stefan problem. The model admits phase changes of pore ice and hydrate (ice melting and gas hydrate dissociation) upon permafrost thawing. The solution is derived from the energy conservation within the modeling domain by solving a quasilinear thermal conductivity equation. The calculations are determined for a well completion with three casing strings and the heat insulation of a gas lifting pipe down to a depth of 55 m. The thermal parameters of permafrost are selected according to laboratory and field measurements from the Bovanenkovo gas-condensate field in the Yamal Peninsula. The modeling results refer to the Bovanenkovo field area and include the size of the thawing zone around wells, with regard to free methane release as a result of gas hydrate dissociation in degrading permafrost. The radius of thawing around a gas well with noninsulated lifting pipes operating for 30 years may reach 10 m or more, while in the case of insulated lifting pipes, no thawing is expected. As predicted by the modeling for the Bovanenkovo field, methane emission upon the dissociation of gas hydrates caused by permafrost thawing around producing gas wells may reach 400,000–500,000 m3 over 30 years.
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Hrbáček, Filip, Daniel Nývlt, Kamil Láska, Michaela Kňažková, Barbora Kampová, Zbyněk Engel, Marc Oliva, and Carsten W. Mueller. "Permafrost and active layer research on James Ross Island: An overview." Czech Polar Reports 9, no. 1 (January 1, 2019): 20–36. http://dx.doi.org/10.5817/cpr2019-1-3.
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This study summarizes the current state of the active layer and permafrost research on James Ross Island. The analysis of climate parameters covers the reference period 2011–2017. The mean annual air temperature at the AWS-JGM site was -6.9°C (ranged from -3.9°C to -8.2°C). The mean annual ground temperature at the depth of 5 cm was -5.5°C (ranged from -3.3°C to -6.7°C) and it also reached -5.6°C (ranged from -4.0 to -6.8°C) at the depth of 50 cm. The mean daily ground temperature at the depth of 5 cm correlated moderately up to strongly with the air temperature depending on the season of the year. Analysis of the snow effect on the ground thermal regime confirmed a low insulating effect of snow cover when snow thickness reached up to 50 cm. A thicker snow accumulation, reaching at least 70 cm, can develop around the hyaloclastite breccia boulders where a well pronounced insulation effect on the near-surface ground thermal regime was observed. The effect of lithology on the ground physical properties and the active layer thickness was also investigated. Laboratory analysis of ground thermal properties showed variation in thermal conductivity (0.3 to 0.9 W m-1 K-1). The thickest active layer (89 cm) was observed on the Berry Hill slopes site, where the lowest thawing degree days index (321 to 382°C·day) and the highest value of thermal conductivity (0.9 W m-1 K-1) was observed. The clearest influence of lithological conditions on active layer thickness was observed on the CALM-S grid. The site comprises a sandy Holocene marine terrace and muddy sand of the Whisky Bay Formation. Surveying using a manual probe, ground penetrating radar, and an electromagnetic conductivity meter clearly showed the effect of the lithological boundary on local variability of the active layer thickness.
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Han, Qiang, Zhiguo Wang, and Rui Qin. "Thermal Conductivity Model Analysis of Unsaturated Ice-Containing Soil." Geofluids 2022 (July 12, 2022): 1–15. http://dx.doi.org/10.1155/2022/3717705.
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In cold locales, the thermal conductivity of soil porous media varies according to their composition and the phase state of the substance contained within the pore space. During the winter, water and other media in the soil pore space freeze-thaw, resulting in their phase state, composition, distribution, and significant thermal conductivity changes. There are some shortcomings in the current research regarding the thermal conductivity change pattern of unsaturated ice-containing soils. In this paper, the representative elementary volume (REV) selection method is given for unsaturated ice-containing soil with porosity as a representative state variable. Under the condition of freeze-thaw, two thermal conductivity REV analysis models for unsaturated ice-containing soil are established: a simplified volume-weighted average REV model and a fine volume-weighted average REV model; accordingly, a macroscopic thermal conductivity analysis model is given. The computational analysis is carried out with an actual unsaturated ice-containing soil example. The influence of the application of frozen soil in China is examined for its effect on the variation law of the thermal conductivity of porous medium. The variation characteristics of thermal conductivity of permafrost soil with related parameters (porosity, water ratio, moisture percentage, ice content, and tortuosity) are discussed. The model built in this paper provides novel concepts and methods for analyzing the thermal conductivity characteristics of unsaturated soil, as well as enhancing and advancing the analysis.
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Brooks, Heather, Guy Doré, and Sharon L. Smith. "Permafrost geotechnical index property variation and its effect on thermal conductivity calculations." Cold Regions Science and Technology 148 (April 2018): 63–76. http://dx.doi.org/10.1016/j.coldregions.2018.01.004.
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Lebret, P., A. Dupas, M. Clet, J. P. Coutard, J. P. Lautridou, S. Courbouleix, M. Garcin, M. Levy, and B. Van Vliet-Lanoë. "Modelling of permafrost thickness during the late glacial stage in France: preliminary results." Canadian Journal of Earth Sciences 31, no. 6 (June 1, 1994): 959–68. http://dx.doi.org/10.1139/e94-085.
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Research on permafrost in France has concentrated on field evidence of fossil permafrost and the mapping of its possible distribution. Few attempts have been made to estimate permafrost thickness. Studies devoted to this subject in North America and Siberia have shown that permafrost may be very thick (several hundred metres), may be rapidly laid down (in < 2000 years in northwest Canada) and causes complex water flow patterns between the base of the permafrost and the soil surface. Using the "Gelsol" code developed by the Laboratoire central des ponts et chaussées (Central Laboratory of the French Department of Public Works) for geotechnical purposes, this paper presents the first results of modeling permafrost development at depth. These preliminary tests show the influence of parameters such as mean annual ground temperature, heat flow, thermal conductivity related to lithology, and water content of the rocks involved on permafrost depth during the last glacial cycle (Weichselian). The results from simple cases indicate that the permafrost was from ten of metres to over 300 m thick. Although these are only calculated values, they are much higher than the few figures found in the literature, and must betaken into consideration when searching for fossilized traces of deep permafrost.
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Fillion, Marie-Hélène, Jean Côté, and Jean-Marie Konrad. "Thermal radiation and conduction properties of materials ranging from sand to rock-fill." Canadian Geotechnical Journal 48, no. 4 (April 2011): 532–42. http://dx.doi.org/10.1139/t10-093.
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This paper presents an experimental study on thermal radiation and the thermal conductivity of rock-fill materials using a 1 m × 1 m × 1 m heat transfer cell. Testing temperatures are applied by temperature-controlled fluid circulation at the top and bottom of the sample. Heat flux and temperature profiles are measured to establish the effective thermal conductivity λe, which includes contributions from both conduction and radiation heat transfer mechanisms. The materials studied had an equivalent particle size (d10) ranging from 90 to 100 mm and porosity (n) ranging from 0.37 to 0.41. The experimental results showed that thermal radiation greatly affects the effective thermal conductivity of materials with λe values ranging from 0.71 to 1.02 W·m−1·K−1, compared with a typical value of 0.36 W·m−1·K−1 for conduction alone. As expected, the effective thermal conductivity increased with particle size. An effective thermal conductivity model has been proposed, and predictions have been successfully compared with the experimental results. Radiation heat transfer becomes significant for d10 higher than 10 mm and predominant at values higher than 90 mm. The results of the study also suggest that the cooling potential of convection embankments used to preserve permafrost conditions may not be as efficient as expected because of ignored radiation effects.
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Cui, Fu-Qing, Wei Zhang, Zhi-Yun Liu, Wei Wang, Jian-bing Chen, Long Jin, and Hui Peng. "Assessment for Thermal Conductivity of Frozen Soil Based on Nonlinear Regression and Support Vector Regression Methods." Advances in Civil Engineering 2020 (August 28, 2020): 1–12. http://dx.doi.org/10.1155/2020/8898126.
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The comprehensive understanding of the variation law of soil thermal conductivity is the prerequisite of design and construction of engineering applications in permafrost regions. Compared with the unfrozen soil, the specimen preparation and experimental procedures of frozen soil thermal conductivity testing are more complex and challengeable. In this work, considering for essentially multiphase and porous structural characteristic information reflection of unfrozen soil thermal conductivity, prediction models of frozen soil thermal conductivity using nonlinear regression and Support Vector Regression (SVR) methods have been developed. Thermal conductivity of multiple types of soil samples which are sampled from the Qinghai-Tibet Engineering Corridor (QTEC) are tested by the transient plane source (TPS) method. Correlations of thermal conductivity between unfrozen and frozen soil has been analyzed and recognized. Based on the measurement data of unfrozen soil thermal conductivity, the prediction models of frozen soil thermal conductivity for 7 typical soils in the QTEC are proposed. To further facilitate engineering applications, the prediction models of two soil categories (coarse and fine-grained soil) have also been proposed. The results demonstrate that, compared with nonideal prediction accuracy of using water content and dry density as the fitting parameter, the ternary fitting model has a higher thermal conductivity prediction accuracy for 7 types of frozen soils (more than 98% of the soil specimens’ relative error are within 20%). The SVR model can further improve the frozen soil thermal conductivity prediction accuracy and more than 98% of the soil specimens’ relative error are within 15%. For coarse and fine-grained soil categories, the above two models still have reliable prediction accuracy and determine coefficient (R2) ranges from 0.8 to 0.91, which validates the applicability for small sample soils. This study provides feasible prediction models for frozen soil thermal conductivity and guidelines of the thermal design and freeze-thaw damage prevention for engineering structures in cold regions.
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Sheng, Yingjie, Tianlai Yu, Yuxuan Wu, and Xingyu Wang. "Study on the Effect of Insulation Materials on the Temperature Field of Piles in Ice-Rich Areas." Applied Sciences 12, no. 23 (November 29, 2022): 12235. http://dx.doi.org/10.3390/app122312235.
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Concrete piles in ice-rich areas exist in negative-temperature environments, which seriously affect the concrete’s strength. In order to maintain the quality of concrete piles in these areas, the temperature during the concrete strength formation period needs to be controlled. In this paper, the temperature field of the pile body of a test pile with double sheaths filled with polyurethane insulation and one without polyurethane insulation were measured. The temperature disturbance law of the pile base with/without insulation was obtained and comprehensively analyzed. The temperature of the pile body was shown to increase with the thickness of the insulation layer. Analysis of the thermal and physical properties of the insulation materials showed a linear relationship between pile temperature and thermal conductivity, in which a lower thermal conductivity resulted in a higher pile temperature. The effect of applying insulation around the pile perimeter in the ice-rich permafrost region on the concrete strength of the pile foundation was verified. The test pile with insulated double sheaths showed better strength at all ages than the test pile without insulation. The use of insulation maintained the temperature of pile foundations in ice-rich areas and ensured that the pile foundations were in better condition, thus improving the concrete strength at all ages. Adopting a double-sheathing configuration with polyurethane as an insulating layer can improve the concrete strength of the pile. This method is applicable to the ice-rich permafrost area in the Daxinganling Mountains and also has reference value for middle and low-latitude wetland permafrost areas.
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Willeit, M., and A. Ganopolski. "Coupled Northern Hemisphere permafrost-ice sheet evolution over the last glacial cycle." Climate of the Past Discussions 11, no. 1 (February 27, 2015): 555–601. http://dx.doi.org/10.5194/cpd-11-555-2015.
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Abstract. Permafrost influences a number of processes which are relevant for local and global climate. For example, it is well known that permafrost plays an important role in global carbon and methane cycles. Less is known about the interaction between permafrost and ice sheets. In this study a permafrost module is included in the Earth system model CLIMBER-2 and the coupled Northern Hemisphere (NH) permafrost-ice sheet evolution over the last glacial cycle is explored. The model performs generally well at reproducing present-day permafrost extent and thickness. Modelled permafrost thickness is sensitive to the values of ground porosity, thermal conductivity and geothermal heat flux. Permafrost extent at the last glacial maximum (LGM) agrees well with reconstructions and previous modelling estimates. Present-day permafrost thickness is far from equilibrium over deep permafrost regions. Over Central Siberia and the Arctic Archipelago permafrost is presently up to 200–500 m thicker than it would be at equilibrium. In these areas, present-day permafrost depth strongly depends on the past climate history and simulations indicate that deep permafrost has a memory of surface temperature variations going back to at least 800 kya. Over the last glacial cycle permafrost has a relatively modest impact on simulated NH ice sheet volume except at LGM, when including permafrost increases ice volume by about 15 m sea level equivalent. This is explained by a delayed melting of the ice base from below by the geothermal heat flux when the ice sheet sits on a porous sediment layer and permafrost has to be melted first. Permafrost affects ice sheet dynamics only when ice extends over areas covered by thick sediments, which is the case at LGM.
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Ekici, A., S. Chadburn, N. Chaudhary, L. H. Hajdu, A. Marmy, S. Peng, J. Boike, et al. "Site-level model intercomparison of high latitude and high altitude soil thermal dynamics in tundra and barren landscapes." Cryosphere Discussions 8, no. 5 (September 18, 2014): 4959–5013. http://dx.doi.org/10.5194/tcd-8-4959-2014.
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Abstract. Modelling soil thermal dynamics at high latitudes and altitudes requires representations of specific physical processes such as snow insulation, soil freezing/thawing, as well as subsurface conditions like soil water/ice content and soil texture type. We have compared six different land models (JSBACH, ORCHIDEE, JULES, COUP, HYBRID8, LPJ-GUESS) at four different sites with distinct cold region landscape types (i.e. Schilthorn-Alpine, Bayelva-high Arctic, Samoylov-wet polygonal tundra, Nuuk-non permafrost Arctic) to quantify the importance of physical processes in capturing observed temperature dynamics in soils. This work shows how a range of models can represent distinct soil temperature regimes in permafrost and non-permafrost soils. Snow insulation is of major importance for estimating topsoil conditions and must be combined with accurate subsoil temperature dynamics to correctly estimate active layer thicknesses. Analyses show that land models need more realistic surface processes (such as detailed snow dynamics and moss cover with changing thickness/wetness) as well as better representations of subsoil thermal dynamics (i.e. soil heat transfer mechanism and correct parameterization of heat conductivity/capacities).
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Chuvilin, Evgeny, and Boris Bukhanov. "Thermal Conductivity of Frozen Sediments Containing Self-Preserved Pore Gas Hydrates at Atmospheric Pressure: An Experimental Study." Geosciences 9, no. 2 (January 29, 2019): 65. http://dx.doi.org/10.3390/geosciences9020065.
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The paper presents the results of an experimental thermal conductivity study of frozen artificial and natural gas hydrate-bearing sediments at atmospheric pressure (0.1 MPa). Samples of hydrate-saturated sediments are highly stable and suitable for the determination of their physical properties, including thermal conductivity, due to the self-preservation of pore methane hydrate at negative temperatures. It is suggested to measure the thermal conductivity of frozen sediments containing self-preserved pore hydrates by a KD-2 needle probe which causes very little thermal impact on the samples. As shown by the special measurements of reference materials with known thermal conductivities, the values measured with the KD-2 probe are up to 20% underestimated and require the respective correction. Frozen hydrate-bearing sediments differ markedly in thermal conductivity from reference frozen samples of the same composition but free from pore hydrate. The difference depends on the physical properties of the sediments and on changes in their texture and structure associated with the self-preservation effect. Namely, it increases proportionally to the volumetric hydrate content, hydrate saturation, and the percentage of water converted to hydrate. Thermal conductivity is anisotropic in core samples of naturally frozen sediments that enclose visible ice-hydrate lenses and varies with the direction of measurements with respect to the lenses. Thermal conductivity measurements with the suggested method provide a reliable tool for detection of stable and relict gas hydrates in permafrost.
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Willeit, M., and A. Ganopolski. "Coupled Northern Hemisphere permafrost–ice-sheet evolution over the last glacial cycle." Climate of the Past 11, no. 9 (September 18, 2015): 1165–80. http://dx.doi.org/10.5194/cp-11-1165-2015.
Full textAbstract:
Abstract. Permafrost influences a number of processes which are relevant for local and global climate. For example, it is well known that permafrost plays an important role in global carbon and methane cycles. Less is known about the interaction between permafrost and ice sheets. In this study a permafrost module is included in the Earth system model CLIMBER-2, and the coupled Northern Hemisphere (NH) permafrost–ice-sheet evolution over the last glacial cycle is explored. The model performs generally well at reproducing present-day permafrost extent and thickness. Modeled permafrost thickness is sensitive to the values of ground porosity, thermal conductivity and geothermal heat flux. Permafrost extent at the Last Glacial Maximum (LGM) agrees well with reconstructions and previous modeling estimates. Present-day permafrost thickness is far from equilibrium over deep permafrost regions. Over central Siberia and the Arctic Archipelago permafrost is presently up to 200–500 m thicker than it would be at equilibrium. In these areas, present-day permafrost depth strongly depends on the past climate history and simulations indicate that deep permafrost has a memory of surface temperature variations going back to at least 800 ka. Over the last glacial cycle permafrost has a relatively modest impact on simulated NH ice sheet volume except at LGM, when including permafrost increases ice volume by about 15 m sea level equivalent in our model. This is explained by a delayed melting of the ice base from below by the geothermal heat flux when the ice sheet sits on a porous sediment layer and permafrost has to be melted first. Permafrost affects ice sheet dynamics only when ice extends over areas covered by thick sediments, which is the case at LGM.
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Domine, Florent, Mathieu Barrere, and Samuel Morin. "The growth of shrubs on high Arctic tundra at Bylot Island: impact on snow physical properties and permafrost thermal regime." Biogeosciences 13, no. 23 (December 12, 2016): 6471–86. http://dx.doi.org/10.5194/bg-13-6471-2016.
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Abstract. With climate warming, shrubs have been observed to grow on Arctic tundra. Their presence is known to increase snow height and is expected to increase the thermal insulating effect of the snowpack. An important consequence would be the warming of the ground, which will accelerate permafrost thaw, providing an important positive feedback to warming. At Bylot Island (73° N, 80° W) in the Canadian high Arctic where bushes of willows (Salix richardsonii Hook) are growing, we have observed the snow stratigraphy and measured the vertical profiles of snow density, thermal conductivity and specific surface area (SSA) in over 20 sites of high Arctic tundra and in willow bushes 20 to 40 cm high. We find that shrubs increase snow height, but only up to their own height. In shrubs, snow density, thermal conductivity and SSA are all significantly lower than on herb tundra. In shrubs, depth hoar which has a low thermal conductivity was observed to grow up to shrub height, while on herb tundra, depth hoar only developed to 5 to 10 cm high. The thermal resistance of the snowpack was in general higher in shrubs than on herb tundra. More signs of melting were observed in shrubs, presumably because stems absorb radiation and provide hotspots that initiate melting. When melting was extensive, thermal conductivity was increased and thermal resistance was reduced, counteracting the observed effect of shrubs in the absence of melting. Simulations of the effect of shrubs on snow properties and on the ground thermal regime were made with the Crocus snow physics model and the ISBA (Interactions between Soil–Biosphere–Atmosphere) land surface scheme, driven by in situ and reanalysis meteorological data. These simulations did not take into account the summer impact of shrubs. They predict that the ground at 5 cm depth at Bylot Island during the 2014–2015 winter would be up to 13 °C warmer in the presence of shrubs. Such warming may however be mitigated by summer effects.
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Yi, Shuhua, Yujie He, Xinlei Guo, Jianjun Chen, Qingbai Wu, Yu Qin, and Yongjian Ding. "The physical properties of coarse-fragment soils and their effects on permafrost dynamics: a case study on the central Qinghai–Tibetan Plateau." Cryosphere 12, no. 9 (September 27, 2018): 3067–83. http://dx.doi.org/10.5194/tc-12-3067-2018.
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Abstract. Soils on the Qinghai–Tibetan Plateau (QTP) have distinct physical properties from agricultural soils due to weak weathering and strong erosion. These properties might affect permafrost dynamics. However, few studies have investigated both quantitatively. In this study, we selected a permafrost site on the central region of the QTP and excavated soil samples down to 200 cm. We measured soil porosity, thermal conductivity, saturated hydraulic conductivity, and matric potential in the laboratory. Finally, we ran a simulation model replacing default sand or loam parameters with different combinations of these measured parameters. Our results showed that the mass of coarse fragments in the soil samples (diameter >2 mm) was ∼55 % on average, soil porosity was less than 0.3 m3 m−3, saturated hydraulic conductivity ranged from 0.004 to 0.03 mm s−1, and saturated matric potential ranged from −14 to −604 mm. When default sand or loam parameters in the model were substituted with these measured values, the errors of soil temperature, soil liquid water content, active layer depth, and permafrost lower boundary depth were reduced (e.g., the root mean square errors of active layer depths simulated using measured parameters versus the default sand or loam parameters were about 0.28, 1.06, and 1.83 m). Among the measured parameters, porosity played a dominant role in reducing model errors and was typically much smaller than for soil textures used in land surface models. We also demonstrated that soil water dynamic processes should be considered, rather than using static properties under frozen and unfrozen soil states as in most permafrost models. We conclude that it is necessary to consider the distinct physical properties of coarse-fragment soils and water dynamics when simulating permafrost dynamics of the QTP. Thus it is important to develop methods for systematic measurement of physical properties of coarse-fragment soils and to develop a related spatial data set for porosity.
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Zhang, Yun Feng, Kai Han, Ben Liang Xu, and Zheng Rong Chang. "Experimental Study on the Temperature Evenness of Heat Pipe Using Magnetic Nano-Fluids as the Working Medium in Permafrost Regions." Advanced Materials Research 614-615 (December 2012): 327–30. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.327.
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The simulation experiment system of permafrost regions with low temperature environment and the temperature evenness test system of heat pipe were established and researched experimentally. The temperature evenness of heat pipe using magnetic nano-fluids as the working medium and the traditional heat pipe were comparative analysised at the simulation environment of permafrost regions with low temperature. The experiment results show that the heat pipe using magnetic nano-fluids as the working medium has better thermal conductivity, less heat transfer temperature difference, and the more heat transfer ability, more widely applicable temperature range, more applicable to the life and the higher working efficiency. The results provide a new idea to develop higher efficiency heat pipe having the better temperature evenness.
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Gray, James T., and Roger J. E. Brown. "Permafrost presence and distribution in the Chic-Chocs Mountains, Gaspésie, Québec." Géographie physique et Quaternaire 33, no. 3-4 (January 25, 2011): 299–316. http://dx.doi.org/10.7202/1000366ar.
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Ground temperature studies, begun in 1977, revealed the presence of permafrost at the summit of Mont Jacques-Cartier (1270 m), in Gaspésie. Temperature profile data to a depth of 30 m in a drill hole indicates an active layer slightly thicker than 5.75 m, overlying a permafrost body extending beyond the base of the hole. Downward extrapolation of the profile, based on heat flow data and thermal conductivity measurements show that this permafrost body is from 45-60 m thick. That the permafrost is contemporary is indicated by the proximity of the permafrost table to the surface, by the low mean annual air temperature for the site (-3°C to -5°C), and by the lack of a thick insulative blanket of snow in the winter. A mean annual ground surface temperature of -1°C to -1.5°C is estimated for the site. The Mont Jacques-Cartier data enabled a regional lower limit of 1,000 — 1,100 m to be established for extensive permafrost in the Chic-Chocs Mountains in treeless exposed situations. A limited amount of ground temperature data from Mont Logan and Mont Albert tends to confirm the validity of this regional limit, which was then used, in association with our knowledge of the vegetation cover, to map the distribution of extensive permafrost bodies for the entire eastern Chic-Chocs Mountains. Although not observed in this study, permafrost may exist below this regional limit, in either coarse debris accumulations, or in organic terrains at high altitudes subject to sufficiently thick accumulations of peat
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Loginova, M. E., F. A. Agzamov, and D. R. Sultanov. "PENETRATION OF HEAT INTO PERMAFROST DURING SEALING WELLS WITH DIFFERENT THERMAL CONDUCTIVITY CEMENTING MATERIALS." Petroleum Engineering 15, no. 4 (December 2017): 24. http://dx.doi.org/10.17122/ngdelo-2017-4-24-31.
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Sannikov, G. S. "NATURAL FACTORS OF SMALL THERMOKARST LAKES DYNAMICS INSIDE THE BOVANENKOVO GAS FIELD." Oil and Gas Studies, no. 3 (June 30, 2015): 122–26. http://dx.doi.org/10.31660/0445-0108-2015-3-122-126.
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This paper is dedicated to studying the causes of small thermokarst lakes number change in the territory of the Bovanenkovo gas field (Western Yamal) happened for the last 30 years. The relations between small thermokarst lakes dynamics and some natural environment factors were identified. These factors include a geomorphological level, microrelief, thermal conductivity of the upper five meters of the the permafrost stratum section. A mechanism of small thermokarst lakes emerging and disappearing was proposed.
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Marchand, Nicolas, Alain Royer, Gerhard Krinner, Alexandre Roy, Alexandre Langlois, and Céline Vargel. "Snow-Covered Soil Temperature Retrieval in Canadian Arctic Permafrost Areas, Using a Land Surface Scheme Informed with Satellite Remote Sensing Data." Remote Sensing 10, no. 11 (October 29, 2018): 1703. http://dx.doi.org/10.3390/rs10111703.
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High-latitude areas are very sensitive to global warming, which has significant impacts on soil temperatures and associated processes governing permafrost evolution. This study aims to improve first-layer soil temperature retrievals during winter. This key surface state variable is strongly affected by snow’s geophysical properties and their associated uncertainties (e.g., thermal conductivity) in land surface climate models. We used infrared MODIS land-surface temperatures (LST) and Advanced Microwave Scanning Radiometer for EOS (AMSR-E) brightness temperatures (Tb) at 10.7 and 18.7 GHz to constrain the Canadian Land Surface Scheme (CLASS), driven by meteorological reanalysis data and coupled with a simple radiative transfer model. The Tb polarization ratio (horizontal/vertical) at 10.7 GHz was selected to improve snowpack density, which is linked to the thermal conductivity representation in the model. Referencing meteorological station soil temperature measurements, we validated the approach at four different sites in the North American tundra over a period of up to 8 years. Results show that the proposed method improves simulations of the soil temperature under snow (Tg) by 64% when using remote sensing (RS) data to constrain the model, compared to model outputs without satellite data information. The root mean square error (RMSE) between measured and simulated Tg under the snow ranges from 1.8 to 3.5 K when using RS data. Improved temporal monitoring of the soil thermal state, along with changes in snow properties, will improve our understanding of the various processes governing soil biological, hydrological, and permafrost evolution.
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Melnikov, V. P., K. S. Ivanov, A. A. Melnikova, and Z. B. Dashinimaev. "Granular Thermal Insulation Material for Transport Construction in the Arctic Zones." Ecology and Industry of Russia 25, no. 5 (May 12, 2021): 32–38. http://dx.doi.org/10.18412/1816-0395-2021-5-32-38.
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In the studies, the extrusion method of synthesis of foam-glass ceramic was used, which contributed to the intensification of the silicate formation process and a decrease in the consumption of the alkaline component by 1.8 times. It was found that samples of granulated foam-glass ceramic with a fraction of 5–20 mm have the required compressive strength and effective thermal conductivity, which allow their use in the construction of transport infrastructure in permafrost conditions. Considering the colossal length of the Arctic zone of Russia, the perspective of the proposed approach is the possibility of creating mobile complexes for the production of heat-insulating material near the construction of highways.
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Galushkin, Yurii. "Numerical simulation of permafrost evolution as a part of sedimentary basin modeling: permafrost in the Pliocene–Holocene climate history of the Urengoy field in the West Siberian basin." Canadian Journal of Earth Sciences 34, no. 7 (July 1, 1997): 935–48. http://dx.doi.org/10.1139/e17-078.
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Present-day temperature profile may be used as an important constraint for reconstruction of the thermal regime in sedimentary basin modeling. This type of profile is significantly non-steady state, especially for basins located at high and middle latitudes. However, estimations of past thermal regimes are indefinite and often limited by knowledge of past glaciations and by the simple two-layer model usually employed. In this paper, permafrost modeling was carried out as a continuation of basin modeling of the sedimentary section of Urengoy field of the West Siberian basin (66°N, 77°E). Consideration of surface temperatures beginning with the Triassic, a refined initial temperature distribution, permafrost modeling for the past 3.4 Ma, and use of a real lithological cross section distinguish this approach from previous studies. Depth and time variations in thermophysical parameters of rocks (heat conductivity, heat capacity, unfrozen water content, salt content, and porosity) had a considerable influence on the results of modeling. The time 3.4 Ma, when air temperatures in the area became lower than 0 °C, has been considered as the initial time for permafrost modeling. According to the model, initial temperatures deviated 10–15 °C from their present-day values due to climate variations during the last 3.4 Ma. Deviations in the value of heat flow can exceed 100%. There were about five glacial periods in the Late Pliocene and nearly the same number in the Pleistocene in the area. The estimated thickness of permafrost did not exceed 650 m and the depth of the lower boundary of methane hydrate stability did not exceed 900 m (from the ground surface). Today, the predicted depths of permafrost [Formula: see text] and of hydrate stability (from 250 to 700 m) are in reasonable agreement with the observed values for the Urengoy area.
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Ponomarev, Evgenii, Tatiana Ponomareva, Oxana Masyagina, Evgeny Shvetsov, Oleg Ponomarev, Konstantin Krasnoshchekov, and Alexander Dergunov. "Post-Fire Effect Modeling for the Permafrost Zone in Central Siberia on the Basis of Remote Sensing Data." Proceedings 18, no. 1 (June 4, 2019): 6. http://dx.doi.org/10.3390/ecrs-3-06202.
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The increasing trend of larch forests burning in the permafrost zone (60–65° N, 95–105° E) is observed in Siberia. Up to 10–15% of entire larch forests were damaged by wildfire during the last two decades. Current research analysed the reflectance and thermal anomalies of the post-pyrogenic sites under the conditions of permafrost. Studies are based on a long-term Terra and Aqua/MODIS (Moderate Resolution Imaging Spectroradiometer) survey for 2006–2018. We used IR thermal range data of 10.780–11.280 microns (MOD11A1 product) and we evaluated the Normalized Difference Vegetation Index (NDVI) from MOD09GQ product as well. The averaged temperature and NDVI dynamics were investigated in total for 50 post-fire plots under different stages of succession (1, 2, 5 and 10 years after burning) in comparison with non-disturbed vegetation cover sites under the same conditions. We recorded higher temperatures (20–47% higher than average background value) and lower NDVI values (9–63% lower than non-disturbed vegetation cover) persisting for the first 10 years after the fire. Under conditions of natural restoration, thermal anomalies of the ground cover remained significant for more than 15 years, which was reflected in long-term satellite data and confirmed by ground-based measurements. To estimate the impact of thermal anomalies on soil temperature and thawed layer depth we used the Stefan’s solution for the thermal conductivity equation. According to the results of numerical simulation, depth of the seasonal thawed layer could increase more than 20% in comparison with the average statistical norm under the conditions of excessive heating of the underlying layers. This is a significant factor in the stability of Siberian permafrost ecosystems requiring long-term monitoring.
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Zhang, Jun-wei, Yi-chong Zhang, Lei Li, Bing-feng Liu, and Zhi-rong Mei. "A Closed-Form Solution for the Analysis of Antifreeze Disease Fortification Length in a Permafrost Tunnel." Advances in Civil Engineering 2020 (February 18, 2020): 1–20. http://dx.doi.org/10.1155/2020/7367954.
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Frost damage in permafrost tunnels is very common, and this can have a negative influence on traffic. The most serious frost damage typically occurs at a certain length from the tunnel opening. Thus the antifreeze measures of the lining structure in this area need to be strengthened. In this study, the antifreeze disease fortification length for permafrost tunnels is determined from heat transfer and mathematical physics equations by the theoretical analysis method. The temperature distribution characteristics of the lining along the tunnel axis under the influence of the tunnel depth, the tunnel radius, the wind velocity at the tunnel opening, and the thermal conductivity of the insulation layer are analysed. The results show that the longitudinal temperature characteristics in the tunnel axis are influenced by many factors. The proposed antifreeze disease length of the permafrost tunnel was found to be approximately 31 times of the tunnel diameter, which agrees with the results of the numerical simulation. It verifies the rationality of the theoretical calculation. This value, 31 times of the tunnel diameter, can be used as a reference for the design of the tunnel antifreeze disease fortification length.
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Kamnev, Yaroslav K., Mikhail Yu Filimonov, Aleksandr N. Shein, and Nataliia A. Vaganova. "Automated Monitoring The Temperature Under Buildings With Pile Foundations In Salekhard (Preliminary Results)." GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY 14, no. 4 (October 12, 2021): 75–82. http://dx.doi.org/10.24057/2071-9388-2021-021.
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In the paper, we consider a method of ground temperature monitoring using the thermometric boreholes and computer modeling the residential buildings with the pile foundation in the city of Salekhard; note that it is located in the permafrost zone. Construction of the residential buildings and industrial structures in the permafrost zone and their operation is carried out according to the principle of preserving the frozen state of foundations. For ground temperature monitoring, thermometric boreholes are used. In a given time period, the measured temperatures are transferred to a server for further processing. Information about the temperature is an important factor for the safety of the buildings and it can be used to evaluate the piles bearing capacity. It allows to propose options for the soil thermal stabilization or to eliminate the detected technogenic heat sources. An approach of mathematical modeling to reconstruct the temperature fields in the pile foundation base of a building is discussed taking into account the data of temperature monitoring. 24 boreholes were equipped with more than 400 in-borehole thermal sensors for testing the method under the residential building I. The preliminary modeling is carried out for December and January 2020 for the contact thermal conductivity model with phase transition with the upper part of the geological section typical for Salekhard (the sandy soils). The modeling describes the freezing processes during the months in detail. The thermal monitoring allows to say that the ground in the base of the Residential building I is stable. But there are detected heat transfers near the borehole T1 at the depth of 12–14 m. The combination of monitoring and computer modeling makes it possible to assess the safety of the operation of the residential buildings in cities located in the permafrost zones.
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Merzlikin, V. G., G. I. Bolkina, and L. N. Ignatova. "Effective and Ecological Technologies of Application of Structured Materials for Roadbed in the Permafrost Regions." Solid State Phenomena 284 (October 2018): 950–55. http://dx.doi.org/10.4028/www.scientific.net/ssp.284.950.
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The work is devoted to effective and ecological technologies for the application of functional structured materials for roads, railways, airfields on permafrost with forced cooling of the sub-soil foundation. The physical and mathematical simulation of the thermal state of frozen ground with single and double-layer coatings was performed. The temperature profiles of a model combine roadbed on the longstanding permafrost have been calculated at winter conditions of the Northern Hemisphere. This roadbed include an upper surface coating with low thermal conductivity and high emissivity in the long-wavelength IR range at convective-radiative heat exchange. The second high-conductive subsurface coating is laid on the underlying sub-soil and ensures its cooling as the “heat pump”. The efficiency of the proposed technology of roadbed construction based on the use of non-toxic waste of numerous industrial productions. The carried out research will be in demand for the specialists of transport support, engineering glaciology, in the field of climatology, oceanology, construction, environmental measures, and also in the presentation of financial and economic forecasts of the prospects for the development of polar and subpolar regions, the Arctic and the Antarctic, and high-mountain.
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Wang, Wenli, Annette Rinke, John C. Moore, Duoying Ji, Xuefeng Cui, Shushi Peng, David M. Lawrence, et al. "Evaluation of air–soil temperature relationships simulated by land surface models during winter across the permafrost region." Cryosphere 10, no. 4 (August 11, 2016): 1721–37. http://dx.doi.org/10.5194/tc-10-1721-2016.
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Abstract. A realistic simulation of snow cover and its thermal properties are important for accurate modelling of permafrost. We analyse simulated relationships between air and near-surface (20 cm) soil temperatures in the Northern Hemisphere permafrost region during winter, with a particular focus on snow insulation effects in nine land surface models, and compare them with observations from 268 Russian stations. There are large cross-model differences in the simulated differences between near-surface soil and air temperatures (ΔT; 3 to 14 °C), in the sensitivity of soil-to-air temperature (0.13 to 0.96 °C °C−1), and in the relationship between ΔT and snow depth. The observed relationship between ΔT and snow depth can be used as a metric to evaluate the effects of each model's representation of snow insulation, hence guide improvements to the model's conceptual structure and process parameterisations. Models with better performance apply multilayer snow schemes and consider complex snow processes. Some models show poor performance in representing snow insulation due to underestimation of snow depth and/or overestimation of snow conductivity. Generally, models identified as most acceptable with respect to snow insulation simulate reasonable areas of near-surface permafrost (13.19 to 15.77 million km2). However, there is not a simple relationship between the sophistication of the snow insulation in the acceptable models and the simulated area of Northern Hemisphere near-surface permafrost, because several other factors, such as soil depth used in the models, the treatment of soil organic matter content, hydrology and vegetation cover, also affect the simulated permafrost distribution.
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Yang, Shuhua, Ren Li, Tonghua Wu, Xiaodong Wu, Lin Zhao, Guojie Hu, Xiaofan Zhu, et al. "Evaluation of soil thermal conductivity schemes incorporated into CLM5.0 in permafrost regions on the Tibetan Plateau." Geoderma 401 (November 2021): 115330. http://dx.doi.org/10.1016/j.geoderma.2021.115330.
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Ming, Feng, Dong Qing Li, and Kun Zhang. "Theoretical Study on Thaw Settlement of Saturated Frozen Soil." Applied Mechanics and Materials 204-208 (October 2012): 155–62. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.155.
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The consolidation of frozen soil is a coupled action of temperature and deformation. Using moving boundary method and taking the void ratio as a variable, the large strain thaw consolidation mathematical model is built according to Gibson’s large strain consolidation theory and thermal conductivity equation with consideration of phase change. In order to verify the model, a simple example is simulated by FEM software. The result shows that the consolidation range and consolidation rate are decided by the temperature boundary; the change of void and deformation are influenced by pore pressure dissipation and the thaw process in permafrost are delayed by consolidation process.
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Inzhutov, Ivan, Victor Zhadanov, Maxim Semenov, Sergei Amelchugov, Alexey Klimov, Peter Melnikov, and Nadezhda Klinduh. "A comparative analysis of foundation design solutions on permafrost soils." E3S Web of Conferences 110 (2019): 01019. http://dx.doi.org/10.1051/e3sconf/201911001019.
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The article analyzes design solutions of foundations on permafrost soils, their advantages and disadvantages. Innovative design solutions that increase the energy efficiency of buildings are proposed. Examples of innovative foundations of platform type are given. Spatial ventilated foundations are less sensitive to soil deformation. The construction of such a foundation can be made of various materials such as reinforced concrete, metal and timber. A spatial foundation platform based on timber is proposed as one of the innovative examples, which is a promising constructive solution of foundations for construction in the Arctic regions. Wood has a small coefficient of thermal conductivity, which significantly increases the energy efficiency of the structure as a whole. Due to prefabrication of timber structures, the speed of construction is increased. Platforms can have solutions in the form of: system of cross beams, structural plates, plate-rod structure, as well as in the form of shells and folds. Regardless of the design solution, the spatial foundation platform is prefabricated.
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Zsoter, Ervin, Gabriele Arduini, Christel Prudhomme, Elisabeth Stephens, and Hannah Cloke. "Hydrological Impact of the New ECMWF Multi-Layer Snow Scheme." Atmosphere 13, no. 5 (May 2, 2022): 727. http://dx.doi.org/10.3390/atmos13050727.
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The representation of snow is a crucial aspect of land-surface modelling, as it has a strong influence on energy and water balances. Snow schemes with multiple layers have been shown to better describe the snowpack evolution and bring improvements to soil freezing and some hydrological processes. In this paper, the wider hydrological impact of the multi-layer snow scheme, implemented in the ECLand model, was analyzed globally on hundreds of catchments. ERA5-forced reanalysis simulations of ECLand were coupled to CaMa-Flood, as the hydrodynamic model to produce river discharge. Different sensitivity experiments were conducted to evaluate the impact of the ECLand snow and soil freezing scheme changes on the terrestrial hydrological processes, with particular focus on permafrost. It was found that the default multi-layer snow scheme can generally improve the river discharge simulation, with the exception of permafrost catchments, where snowmelt-driven floods are largely underestimated, due to the lack of surface runoff. It was also found that appropriate changes in the snow vertical discretization, destructive metamorphism, snow-soil thermal conductivity and soil freeze temperature could lead to large river discharge improvements in permafrost by adjusting the evolution of soil temperature, infiltration and the partitioning between surface and subsurface runoff.
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Yoon, Seok, Dinh-Viet Le, and Gyu-Hyun Go. "Artificial Neural Network-Based Model for Prediction of Frost Heave Behavior of Silty Soil Specimen." Applied Sciences 11, no. 22 (November 16, 2021): 10834. http://dx.doi.org/10.3390/app112210834.
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Frost heave action is a major issue in permafrost regions that can give rise to various geotechnical engineering problems. To analyze and predict this phenomenon at a specimen scale, this study conducted a fully coupled thermal-hydro-mechanical analysis and evaluated the frost heave behavior of frozen soil considering geotechnical parameters. Furthermore, a parametric study was performed to quantitatively analyze the effects of major geotechnical properties on frost heave behavior. According to the results of the parametric study, the amount of heave tended to decrease as the particle thermal conductivity increased, whereas the frost heave ratio tended to increase as the initial hydraulic conductivity increased. After evaluating the sensitivity of each parameter to frost heave behavior through statistical analyses, an artificial neural network model was developed to practically predict frost heave behavior. According to the verification results of the neural network model, the trained network model demonstrated a reliable accuracy (R2 = 0.893) in predicting frost heave ratio, even when the model used test datasets that were not part of the training datasets.
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Domine, F., M. Barrere, D. Sarrazin, S. Morin, and L. Arnaud. "Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra." Cryosphere 9, no. 3 (June 22, 2015): 1265–76. http://dx.doi.org/10.5194/tc-9-1265-2015.
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Abstract. The effective thermal conductivity of snow, keff, is a critical variable which determines the temperature gradient in the snowpack and heat exchanges between the ground and the atmosphere through the snow. Its accurate knowledge is therefore required to simulate snow metamorphism, the ground thermal regime, permafrost stability, nutrient recycling and vegetation growth. Yet, few data are available on the seasonal evolution of snow thermal conductivity in the Arctic. We have deployed heated needle probes on low-Arctic shrub tundra near Umiujaq, Quebec, (N56°34'; W76°29') and monitored automatically the evolution of keff for two consecutive winters, 2012–2013 and 2013–2014, at four heights in the snowpack. Shrubs are 20 cm high dwarf birch. Here, we develop an algorithm for the automatic determination of keff from the heating curves and obtain 404 keff values. We evaluate possible errors and biases associated with the use of the heated needles. The time evolution of keff is very different for both winters. This is explained by comparing the meteorological conditions in both winters, which induced different conditions for snow metamorphism. In particular, important melting events in the second year increased snow hardness, impeding subsequent densification and increase in thermal conductivity. We conclude that shrubs have very important impacts on snow physical evolution: (1) shrubs absorb light and facilitate snow melt under intense radiation; (2) the dense twig network of dwarf birch prevent snow compaction, and therefore keff increase; (3) the low density depth hoar that forms within shrubs collapsed in late winter, leaving a void that was not filled by snow.