Cold Regions Science and Technology最新文献

{"title":"Spatiotemporal patterns and drivers of ground Freeze-Thaw dynamics across Northeastern China","authors":"Dongyu Yang ,&nbsp;Miao Li ,&nbsp;Zunyi Xie ,&nbsp;Xiaodong Wu ,&nbsp;Haoran Man ,&nbsp;Dianfan Guo ,&nbsp;Jianhua Ren ,&nbsp;Shuying Zang ,&nbsp;Luhe Wan","doi":"10.1016/j.coldregions.2025.104787","DOIUrl":"10.1016/j.coldregions.2025.104787","url":null,"abstract":"<div><div>Ground freeze-thaw dynamics critically affect carbon cycling and ecosystem stability in cold regions. In the frozen ground region of northeastern China (FGRN China), these dynamics are governed by synergistic biotic, climatic, physiographic, and anthropogenic drivers, making spatiotemporal characterization and causal attribution particularly challenging. We establish a ground freeze-thaw dynamic index (FTDI) based on the ground freezing index (GFI) and ground thawing index (GTI), to quantify ground freeze-thaw dynamics in FGRN China (1982–2020). Using geostatistics, geodetector, and structural equation model (SEM), we analyze spatiotemporal patterns, critical thresholds, and driving mechanisms. The results indicate that the area where FTDI &lt;0 (i.e., GFI &gt; GTI) is shrinking significantly at a rate of 0.45 × 10⁴ km²/a, with its gravity center shifting from the sporadic permafrost region (SPR) toward the discontinuous permafrost region (DPR) across the Da Xing'anling Mountains. This indicates that ground warming will be more pronounced in DPR within FGRN China. Furthermore, critical thresholds were detected only for precipitation changes (≈ −3.2 mm/a; beyond inhibiting thawing) and snow cover changes (≈ −0.19 %/a; beyond promoting thawing). SEM revealed a succession of dominant controlling factors and mechanistic transitions across the frozen ground degradation gradient. Precipitation changes primarily promoted thawing in DPR. In SPR, the inhibitory effect of soil water changes became prominent, while precipitation changes shifted from promotion to inhibition (suggesting a threshold). In the isolated patch permafrost region, thawing was regulated by the inhibitory effect of precipitation and the promoting effect of altitude. In the seasonal frozen ground region, the snow cover changes shifted from inhibition to promotion of thawing (suggesting a threshold). These findings reveal the environmental complexity governing ground freeze-thaw dynamics and provide insights into ecosystem stability and climate change projections in cold regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104787"},"PeriodicalIF":3.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vibration effects on the uniaxial compressive strength of compacted Antarctic snow","authors":"Enzhao Xiao ,&nbsp;Tong Han ,&nbsp;Qiming Zhang ,&nbsp;Zhenxuan Yin ,&nbsp;Hao Wang ,&nbsp;Biao Hu ,&nbsp;Xueyuan Tang ,&nbsp;Bo Sun ,&nbsp;Fan Zhang ,&nbsp;Yihe Wang","doi":"10.1016/j.coldregions.2025.104779","DOIUrl":"10.1016/j.coldregions.2025.104779","url":null,"abstract":"<div><div>Snow road and runway construction plays a vital role in developing logistical networks for Antarctic scientific expeditions. Previous studies based on unconfined compressive tests have demonstrated that the compressive strength of snow increases exponentially with density, establishing density as the dominant controlling factor. On the other hand, mechanical vibration applied to compacted snow layers has been demonstrated to significantly enhance snow hardness without markedly changing snow density. However, the strengthening effects of mechanical vibration on the uniaxial compressive strength of compacted Antarctic snow, and particularly the underlying mesoscale mechanisms remain poorly understood. The current paper addresses this gap through controlled experiments utilizing compacted Antarctic snow. Two groups of compacted snow samples were prepared: a control group using conventional layered compaction and an experimental group subjected to additional mechanical vibration after compaction. The results indicated that the experimental group achieved an average uniaxial compressive strength of 0.448 MPa, representing a 42.2 % increase compared to the control group (0.315 MPa). Mesoscale analysis revealed that mechanical vibration increased the minimum cut density index (MCDI) from 0.425 g/cm³ to 0.505 g/cm³ and raised the directional connectivity index (DCI) from 0.575 to 0.587, while reducing the mean values and standard deviations of structure and pore thicknesses. It is speculated that compaction creates random large pores and microcracks within particles. Vibration-induced oscillatory stresses propagate these microcracks, fragmenting particles near pores. These fragments then fill pore spaces, yielding more uniform pore distribution while maintaining constant overall density. These findings provide theoretical guidance for optimizing the construction of snow infrastructures in polar and cold regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104779"},"PeriodicalIF":3.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the impacts of climate warming and engineering activities on the thermal regime of permafrost in the Kunlun Mountains, Qinghai-Tibet Railway","authors":"Zhanju Lin,&nbsp;Xuhui Wang,&nbsp;Xuyang Wu,&nbsp;Wenjiao Li,&nbsp;Peng Zhang,&nbsp;Nuocheng Li,&nbsp;Xingwen Fan","doi":"10.1016/j.coldregions.2025.104777","DOIUrl":"10.1016/j.coldregions.2025.104777","url":null,"abstract":"<div><div>The thermal stability of permafrost, a foundation for engineering infrastructure in cold regions, is increasingly threatened by the dual stressors of climate change and anthropogenic disturbance. This study investigates the dynamics of the crushed rock revetted embankment at the Kunlun Mountain Section of the Qinghai-Tibet Railway, systematically investigating the coupled impacts of climate warming and engineering activities on permafrost thermal stability using borehole temperature monitoring data (2008–2024) and climatic parameter analysis. Results show that under climate-driven effects, the study area experienced an air temperature increase of 0.2 °C per decade over the 2015–2024. Concurrently, the mean annual air thawing degree-days (TDD) rose by 13.8 °C·d/a, leading to active-layer thickening at a rate of 3.8 cm·a⁻¹at natural ground sites. From 2008 to 2024, the active layer had thickened by 0.7–0.8 m. At the embankment toe (BH 5), the active-layer thickening rate (3.3 cm·a⁻¹) was 25 % lower than that at the natural ground borehole (3.8 cm·a⁻¹); correspondingly, the underlying permafrost temperature increase rate at the toe (0.3 °C per decade) was lower than that at the natural borehole (0.5–0.6 °C per decade). Permafrost warming rates decreased with depth. Shallow layers (above −2 m) were significantly influenced by climate, with warming rates of 0.3–0.6 °C per decade. In contrast, deep layers (below −10 m) showed warming rates converging with the background atmospheric temperature trend (0.2 °C per decade). Thermal regime disturbance was most pronounced at horizontal distances of 3.0–5.0 m from the embankment. Nevertheless, the crushed-rock revetment maintained a permafrost table 0.6 m shallower than that of natural ground, confirming its “thermal diode” effect (facilitating convective cooling in winter), which partially offset climate warming impacts. This study provides critical empirical data and validates the cooling mechanism of crushed-rock revetment, which is essential for predicting the long-term thermal stability and informing adaptive maintenance strategies for railway infrastructure in warming permafrost regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104777"},"PeriodicalIF":3.8,"publicationDate":"2025-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled effects of subzero temperature and impact loading on the dynamic mechanical properties and fracture mechanism of dolomite","authors":"Xiong Yin ,&nbsp;Qifeng Guo ,&nbsp;Zimu Shi ,&nbsp;Jingxuan Yan ,&nbsp;Yunhong Guo ,&nbsp;Fei Li","doi":"10.1016/j.coldregions.2025.104774","DOIUrl":"10.1016/j.coldregions.2025.104774","url":null,"abstract":"<div><div>To investigate the dynamic mechanical response and fracture mechanisms of frozen saturated dolomite under impact loading, dynamic compression tests were performed using a split Hopkinson pressure bar (SHPB) system over a temperature range from −40 °C to 25 °C and impact pressures ranging from 0.26 MPa to 0.50 MPa. A relationship model describing the correlation between the fractal characteristics and energy dissipation of frozen saturated dolomite was established. Scanning electron microscopy (SEM) was employed to examine the post-impact microstructure of the samples, thus revealing the dynamic fracture mechanisms of dolomite under combined subzero temperature and impact loading conditions. The results indicate that the dynamic mechanical behavior of dolomite exhibits distinct temperature and strain-rate effects. As the temperature decreases and the strain rate increases, both the dynamic compressive strength and elastic modulus of the samples increase correspondingly. Variations in freezing temperature and strain rate alter the energy dissipation mechanisms of the samples, which in turn influence the fragment-size distribution characteristics. As the temperature decreases, the energy dissipation density of frozen saturated dolomite exhibits a clear quadratic relationship with the fractal dimension. In contrast, as the strain rate increases, these two parameters demonstrate a significant logarithmic relationship. In addition, the freezing temperature exerts a marked influence on the microscopic fracture characteristics of saturated dolomite. At room temperature, both brittle and localized ductile fractures are observed on the microfracture surfaces of the saturated samples, thereby indicating composite fracture characteristics. However, as the temperature decreases to subzero temperatures, the microfracture mode transforms into a typical brittle fracture, and the brittleness becomes increasingly evident with further temperature reduction. These findings provide valuable theoretical guidance for the design and optimization of blasting parameters in open-pit mines located in cold alpine regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104774"},"PeriodicalIF":3.8,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature-dependent shear behavior of glacial till-ice composite: Experimental insights from the southeastern Tibetan Plateau","authors":"Zhenxing Liu ,&nbsp;Jiao Wang ,&nbsp;Peng Cui ,&nbsp;Yao Jiang ,&nbsp;Tao Wei ,&nbsp;Jingxuan Cao","doi":"10.1016/j.coldregions.2025.104776","DOIUrl":"10.1016/j.coldregions.2025.104776","url":null,"abstract":"<div><div>The Tibetan Plateau, often referred to as the “Third Pole,” exhibits heightened sensitivity and vulnerability to global climate change. It has been documented that the progressive retreat of high-altitude glaciers in this region, a phenomenon attributed to global warming, has led to the accumulation of extensive loose and unvegetated glacial till with buried ice (glacial till-ice composite). These unconsolidated deposits frequently serve as primary source materials for glacier-related hazards, including landslides and debris flows. Especially, the Parlung Tsangpo drainage basin in the southeastern portion of the Tibetan Plateau contains many glaciers with associated unconsolidated till. While significant efforts have been directed toward assessing the potential risks of glacier hazards in this area, the mechanical properties of glacial till-ice composite in response to climate warming remain poorly understood. To address this gap, a series of shear tests on glacial till-ice composite were conducted using a high-precision, temperature-controlled triaxial coupling test system, aiming to elucidate the shear deformation characteristics of glacial till-ice composite under varying temperatures and ice content levels. The findings reveal that the internal friction angle and cohesion of glacial till-ice composite undergo stage-wise changes with temperature, with the most pronounced reduction in strength observed within the −3 to −5 °C range. Furthermore, within this temperature interval, the cohesion of glacial till-ice composite demonstrates an exponential increase with rising ice content. In contrast to conventional frozen soils, glacial till-ice composites exhibit strength degradation over a narrower temperature range, characterized by accelerated strength attenuation and more significant strength loss during the deterioration process. To quantify these effects, Boltzmann and exponential attenuation functions were introduced to describe the influence of temperature and ice content on the shear strength of glacial till-ice composite. Based on the experimental results, a critical shear strength line for glacial till-ice composite was established as a function of temperature and ice content, and a strength degradation model incorporating these variables was developed. This model offers theoretical backing for disaster prevention and risk assessment of glacier debris flows.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104776"},"PeriodicalIF":3.8,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable utilization of steel slags as road abrasives for ice melting application","authors":"Saken Sandybay ,&nbsp;Islam Orynbassarov ,&nbsp;Chang-Seon Shon ,&nbsp;Dichuan Zhang ,&nbsp;Jong Ryeol Kim ,&nbsp;Chul-Woo Chung","doi":"10.1016/j.coldregions.2025.104773","DOIUrl":"10.1016/j.coldregions.2025.104773","url":null,"abstract":"<div><div>Abrasives are essential for surface treatment in cold climates, where snow and ice pose significant challenges to transportation infrastructure and road safety. This study addresses the growing need for effective, sustainable winter road maintenance (WRM) methods by exploring basic oxygen furnace slag (BOFS) as an alternative abrasive for ice-melting applications. Fresh and stockpiled (aged) BOFSs were first evaluated for their physical and mechanical properties, including abrasive angularity, absorption capacity, and thermal capacity, to assess their potential for improved surface treatment for ice melting. Then, BOFS was combined with deicing salts, such as sodium chloride (NaCl) and calcium chloride (CaCl₂) to form a blended ice-melting agent for winter maintenance. A series of laboratory tests was conducted to evaluate ice-melting performance using a petri dish and polishing ice-melting tests, as well as to examine surface temperature and clogging effects after abrasive application under controlled conditions. The experimental results show that both BOFS demonstrated good ice-melting efficiency and had higher heat and water absorption capacities than natural abrasives. For instance, slag-based abrasives show approximately 30–40 % higher ice-melting efficiency than river sand and exhibit a 2–3 °C higher temperature rise under sunlight exposure. The findings of this study highlight the potential of BOFS not only as a viable abrasive material but also as a way to reduce environmental impacts associated with traditional practices that use natural sand. This research lays the groundwork for adopting slag as a sustainable alternative to conventional WRM abrasives, balancing performance, cost, and environmental considerations.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"242 ","pages":"Article 104773"},"PeriodicalIF":3.8,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the influence of train-induced wind on the temperature field of high-speed railway tunnel in cold region in different temperature modes","authors":"Weiping Xu ,&nbsp;JinHang Qin ,&nbsp;KeGuo Sun ,&nbsp;Yong Wei ,&nbsp;Bing Jiang ,&nbsp;Chao Liu ,&nbsp;Yangyang Li ,&nbsp;Leilei Peng","doi":"10.1016/j.coldregions.2025.104775","DOIUrl":"10.1016/j.coldregions.2025.104775","url":null,"abstract":"<div><div>As railway networks rapidly expand and high-speed trains operate at greater velocities, tunnel temperature profiles are increasingly affected by train-induced winds. Based on the tunnel characteristic temperature (<em>T</em>_<em>C</em>) and external temperature of the tunnel (<em>T</em>_<em>E</em>), four basic tunnel internal-external temperature modes are determined: T-NN(<em>T</em>_<em>C</em> and <em>T</em>_<em>E</em> are both negative), T-PP(<em>T</em>_<em>C</em> and <em>T</em>_<em>E</em> are both positive), T-NP(<em>T</em>_<em>C</em> is negative, <em>T</em>_<em>E</em> is positive) and T-PN(<em>T</em>_<em>C</em> is positive, <em>T</em>_<em>E</em> is negative), and further subdivided into T-NN1(<em>T</em>_<em>C</em> and <em>T</em>_<em>E</em> are both negative, <em>T</em>_<em>C</em>&gt;<em>T</em>_<em>E</em>), T-NN2(<em>T</em>_<em>C</em> and <em>T</em>_<em>E</em> are both negative, <em>T</em>_<em>C</em>&lt;<em>T</em>_<em>E</em>), T-PP1(<em>T</em>_<em>C</em> and <em>T</em>_<em>E</em> are both positive, <em>T</em>_<em>C</em>&gt;<em>T</em>_<em>E</em>), T-PP2(<em>T</em>_<em>C</em> and <em>T</em>_<em>E</em> are both positive, <em>T</em>_<em>C</em>&lt;<em>T</em>_<em>E</em>), T-NP and T-PN. Then numerical analyses based on FLUENT are conducted to analyze the effects of train-induced winds on tunnel air temperature distribution across different temperature modes. Finally, the effect of train speeds and blocking rates on tunnel internal air temperature distribution is systematically analyzed. The results show that, according to measured data, temperature modes are ranked as T-NN1 (87.01 %) &gt; T-NN2 (7.28 %) &gt; T-PN (4.47 %) &gt; T-PP1 (0.64 %) &gt; T-PP2 (0.51 %) &gt; T-NP (0.09 %) in terms of the probability of occurrence. Furthermore, Train-induced winds produce a double thermal effect. In T-NP, T-PP2 and T-NN2 modes, the train-induced wind increases the air temperature of the entrance section and improves tunnel's cold resistance, but it weakens cold resistance in T-PN, T-NN1, and T-PP1 modes. Therefore, when selecting locations for tunnel openings in high-speed railroads, it is recommended to prioritize areas with high solar radiation intensity in order to increase the percentage of T-PP2, T-NP and T-NN2 modes. Moreover, in T-NN and T-PN modes, increased train speeds and higher blocking ratios proportionally extend sub-zero temperature zones, complicating frost prevention. Conversely, T-PP and T-NP modes demonstrate an inverse relationship, which is not conducive to frost protection.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104775"},"PeriodicalIF":3.8,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study of test methods for the acoustic properties of snow","authors":"Xiaomin Chang ,&nbsp;Xuanhao Chen ,&nbsp;Ming Xue ,&nbsp;Guangyu Zuo ,&nbsp;Yinke Dou","doi":"10.1016/j.coldregions.2025.104772","DOIUrl":"10.1016/j.coldregions.2025.104772","url":null,"abstract":"<div><div>Acoustic attenuation is a key property of snow and plays a significant role in avalanche early warning. However, due to the dynamic changes in snow properties under natural environmental conditions, the automated monitoring of snow acoustic attenuation remains highly challenging. In this study, an acoustic testing system was designed using the transmission method to conduct acoustic measurements on natural snow samples and obtain information on the variations in snow acoustic properties under different conditions. Experimental results indicate that under an ambient temperature of −10 °C, the attenuation coefficient of snow layers increases with rising acoustic wave frequency across different snow densities. Additionally, as snow density increases, the attenuation coefficient increases while the boundary sound absorption coefficient decreases. Within the temperature range of −10 °C to 5 °C, the attenuation coefficient shows an increasing trend with rising temperature. In the range of −10 °C to −2.5 °C, the boundary sound absorption coefficient remains relatively stable, while from −2.5 °C to 5 °C, it shows a decreasing trend with increasing temperature. Within a snow water content range of 0–20 %, the attenuation coefficient increases with higher water content, whereas the boundary sound absorption coefficient decreases. Based on the experimental data, predictive models for the attenuation coefficient were developed with respect to ambient temperature and water content. The models demonstrated good predictive performance, with coefficients of determination (R²), root mean square errors (RMSE), biases (BIAS), and Nash-Sutcliffe efficiencies (NASH) of 0.918, 0.061, 0.002, and 0.982 for temperature-based models, and 0.946, 0.026, −0.001, and 0.991 for water content-based models, respectively. These results suggest that the models offer high predictive accuracy and provide a foundation for the automated observation of snow acoustic attenuation characteristics.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"243 ","pages":"Article 104772"},"PeriodicalIF":3.8,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of borehole stability in Antarctic drilling considering time-varying temperature effect","authors":"Yi Wei ,&nbsp;Yongsheng Liu ,&nbsp;Haoran Xu ,&nbsp;Zijun Dou ,&nbsp;Gansheng Yang","doi":"10.1016/j.coldregions.2025.104763","DOIUrl":"10.1016/j.coldregions.2025.104763","url":null,"abstract":"<div><div>In Antarctic air drilling, borehole stability critically depends on heat transfer between ice walls and airflow, the ice sheet temperature gradient, and air's non-isothermal flow. Effective mitigation of thermally induced borehole collapse/closure risks in Antarctic air drilling necessitates understanding the aero-thermo-mechanical (ATM) coupling effect in Antarctic air drilling systems. This paper presents a coupled ATM model, which incorporates a Helmholtz energy thermodynamic model for air and the equation of state for H₂O Ice Ih revised by IAPWS (the International Association for the Properties of Water and Steam), characterizing real thermodynamic behavior and properties of air and ice. And three failure indices are modified to account for temperature sensitivity and compared with the Derradji-Aouat failure index. They are used to quantify high-strain-rate brittle failure risks from the perspective of tension, shear, and phase transition. Ice deformation under low strain rates is governed by the Maxwell model. Numerical solutions derived from U.S. RAM-2 drilling parameters via finite element methods reveal key findings: As airflow transitions from the drill hose into the annulus through a “transition zone,” it exhibits abrupt property changes. The ATM coupling effect creates localized regions along the ice wall with steep temperature gradients (ΔT ≈ 20 K) and stress fluctuations (Δσ ≈ 0.01 MPa). Extreme transitions in these regions increase closure or collapse risks, primarily due to tensile failure. Lowering the temperature of the injected air can effectively reduce tensile failure risks. This paper proposes an operational control process to achieve this.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"242 ","pages":"Article 104763"},"PeriodicalIF":3.8,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decadal variations in the northern boundary of permafrost in the Xidatan region of the Qinghai-Xizang Plateau: Insights from InSAR and field monitoring","authors":"Ju Xin ,&nbsp;Luo Jing ,&nbsp;Niu Fujun ,&nbsp;Yu Fan ,&nbsp;Ding Zekun ,&nbsp;Yin Guoan ,&nbsp;Lin Zhanju ,&nbsp;Gao Zeyong","doi":"10.1016/j.coldregions.2025.104771","DOIUrl":"10.1016/j.coldregions.2025.104771","url":null,"abstract":"<div><div>Permafrost proximate to the boundary is extremely vulnerable to climate change. The Xidatan region, located at the northern boundary of permafrost on the Qinghai-Xizang Plateau (QXP), has been experiencing accelerated degradation, which introduces considerable uncertainties to future land use, water resource management, and infrastructure maintenance on the QXP. In this study, we obtained surface temporal deformation for the Xidatan region from 2017 to 2025 using Sentinel-1 data. We investigated permafrost deformation characteristics in the Xidatan region using long-term deformation rates from five profiles and ground temperature monitoring data. Ground temperature monitoring data from the Xidatan region indicate that over the past decade, mean annual ground temperature warming rates at depths of 6 m (WR₋₆) and 15 m (WR₋₁₅) were 0.012 °C/a and 0.015 °C/a, respectively. This indicates a significant warming process in the permafrost layer. InSAR analysis reveals a pronounced long-term subsidence trend in the Xidatan region, with substantial spatial differences in surface deformation. Subsidence is particularly evident in higher-elevation areas, while lower-elevation areas exhibit slight surface uplift. Analysis of surface deformation characteristics and borehole validation indicate that the lowest elevation of permafrost occurrence in the Xidatan region was approximately 4406 m by 2025. Compared to previous research, the permafrost limit has risen by a maximum of 37 m from 2012 to 2025. Permafrost degradation in the Xidatan region is primarily attributed to climate warming and increased anthropogenic disturbances. Should air temperatures continue rising, the northern boundary of permafrost distribution on the QXP will continue to ascend to higher elevations.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"242 ","pages":"Article 104771"},"PeriodicalIF":3.8,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}