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18 pages, 1210 KiB  
Article
Under-Resourced Learning Programs Imperil Active Stewardship of Alaska’s Marine Systems for Food Security
by John Fraser, Rosemary Aviste, Megan Harwell and Jin Liu
Sustainability 2025, 17(14), 6436; https://doi.org/10.3390/su17146436 - 14 Jul 2025
Viewed by 283
Abstract
The future of marine sustainability depends on public understanding and trust in the policy recommendations that emerge from scientific research. For common pool marine resource decisions made by the people who depend on these resources for their food, employment, and economic future, understanding [...] Read more.
The future of marine sustainability depends on public understanding and trust in the policy recommendations that emerge from scientific research. For common pool marine resource decisions made by the people who depend on these resources for their food, employment, and economic future, understanding the current status of these marine systems and change is essential to ensure these resources will persist into the future. As such, the informal learning infrastructure is essential to increasing marine science literacy in a changing world. This mixed-methods research study analyzed the distribution and accessibility of marine science education and research across Alaska’s five geographic regions. Using the PRISMA framework, we synthesized data from 198 institutions and analyzed peer-reviewed literature on marine ecosystems to identify geographic and thematic gaps in access to informal science learning and research focus. In parallel, we undertook geospatial analysis and resource availability to describe the distribution of resources, types of informal learning infrastructure present across the state, regional presence, and resources to support informal marine science learning opportunities. Findings from this multifactor research revealed a concentration of resources in urban hubs and a lack of consistent access to learning resources for rural and Indigenous communities. The configurative literature review of 9549 publications identified topical underrepresentation of the Bering Sea and Aleutian Islands, as well as a lack of research on seabirds across all regions. Considered together, these results recommend targeted investments in rural engagement with marine science programming, culturally grounded partnerships, and research diversification. This review concludes that disparities in learning resource support and government-funded priorities in marine wildlife research have created conditions that undermine the local people’s participation in the sustainability of sensitive resources and are likely exacerbating declines driven by rapid change in Arctic and sub-Arctic waters. Full article
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18 pages, 2243 KiB  
Article
Detection of a Novel Gull-like Clade of Newcastle Disease Virus and H3N8 Avian Influenza Virus in the Arctic Region of Russia (Taimyr Peninsula)
by Anastasiya Derko, Nikita Dubovitskiy, Alexander Prokudin, Junki Mine, Ryota Tsunekuni, Yuko Uchida, Takehiko Saito, Nikita Kasianov, Arina Loginova, Ivan Sobolev, Sachin Kumar, Alexander Shestopalov and Kirill Sharshov
Viruses 2025, 17(7), 955; https://doi.org/10.3390/v17070955 - 7 Jul 2025
Viewed by 439
Abstract
Wild waterbirds are circulating important RNA viruses, such as avian coronaviruses, avian astroviruses, avian influenza viruses, and avian paramyxoviruses. Waterbird migration routes cover vast territories both within and between continents. The breeding grounds of many species are in the Arctic, but research into [...] Read more.
Wild waterbirds are circulating important RNA viruses, such as avian coronaviruses, avian astroviruses, avian influenza viruses, and avian paramyxoviruses. Waterbird migration routes cover vast territories both within and between continents. The breeding grounds of many species are in the Arctic, but research into this region is rare. This study reports the first Newcastle disease virus (NDV) detection in Arctic Russia. As a result of a five-year study (from 2019 to 2023) of avian paramyxoviruses and avian influenza viruses in wild waterbirds of the Taimyr Peninsula, whole-genome sequences of NDV and H3N8 were obtained. The resulting influenza virus isolate was phylogenetically related to viruses that circulated between 2021 and 2023 in Eurasia, Siberia, and Asia. All NDV sequences were obtained from the Herring gull, and other gull sequences formed a separate gull-like clade in the sub-genotype I.1.2.1, Class II. This may indirectly indicate that different NDV variants adapt to more host species than is commonly believed. Further surveillance of other gull species may help to test the hypothesis of putative gull-specific NDV lineage and better understand their role in the evolution and global spread of NDV. Full article
(This article belongs to the Special Issue Evolution and Adaptation of Avian Viruses)
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26 pages, 11031 KiB  
Article
Energy and Sustainability Impacts of U.S. Buildings Under Future Climate Scenarios
by Mehdi Ghiai and Sepideh Niknia
Sustainability 2025, 17(13), 6179; https://doi.org/10.3390/su17136179 - 5 Jul 2025
Viewed by 389
Abstract
Projected changes in outdoor environmental conditions are expected to significantly alter building energy demand across the United States. Yet, policymakers and designers lack typology and climate-zone-specific guidance to support long-term planning. We simulated 10 U.S. Department of Energy (DOE) prototype buildings across all [...] Read more.
Projected changes in outdoor environmental conditions are expected to significantly alter building energy demand across the United States. Yet, policymakers and designers lack typology and climate-zone-specific guidance to support long-term planning. We simulated 10 U.S. Department of Energy (DOE) prototype buildings across all 16 ASHRAE climate zones with EnergyPlus. Future weather files generated in Meteonorm from a CMIP6 ensemble reflected two emissions pathways (RCP 4.5 and RCP 8.5) and two planning horizons (2050 and 2080), producing 800 simulations. Envelope parameters and schedules were held at DOE reference values to isolate the pure climate signal. Results show that cooling energy use intensity (EUI) in very hot-humid Zones 1A–2A climbs by 12% for full-service restaurants and 21% for medium offices by 2080 under RCP 8.5, while heating EUI in sub-arctic Zone 8 falls by 14–20%. Hospitals and large hotels change by < 6%, showing resilience linked to high internal gains. A simple linear-regression meta-model (R2 > 0.90) links baseline EUI to future percentage change, enabling rapid screening of vulnerable stock without further simulation. These high-resolution maps supply actionable targets for state code updates, retrofit prioritization, and long-term decarbonization planning to support climate adaptation and sustainable development. Full article
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18 pages, 1972 KiB  
Article
Learning from Arctic Microgrids: Cost and Resiliency Projections for Renewable Energy Expansion with Hydrogen and Battery Storage
by Paul Cheng McKinley, Michelle Wilber and Erin Whitney
Sustainability 2025, 17(13), 5996; https://doi.org/10.3390/su17135996 - 30 Jun 2025
Viewed by 368
Abstract
Electricity in rural Alaska is provided by more than 200 standalone microgrid systems powered predominantly by diesel generators. Incorporating renewable energy generation and storage to these systems can reduce their reliance on costly imported fuel and improve sustainability; however, uncertainty remains about optimal [...] Read more.
Electricity in rural Alaska is provided by more than 200 standalone microgrid systems powered predominantly by diesel generators. Incorporating renewable energy generation and storage to these systems can reduce their reliance on costly imported fuel and improve sustainability; however, uncertainty remains about optimal grid architectures to minimize cost, including how and when to incorporate long-duration energy storage. This study implements a novel, multi-pronged approach to assess the techno-economic feasibility of future energy pathways in the community of Kotzebue, which has already successfully deployed solar photovoltaics, wind turbines, and battery storage systems. Using real community load, resource, and generation data, we develop a series of comparison models using the HOMER Pro software tool to evaluate microgrid architectures to meet over 90% of the annual community electricity demand with renewable generation, considering both battery and hydrogen energy storage. We find that near-term planned capacity expansions in the community could enable over 50% renewable generation and reduce the total cost of energy. Additional build-outs to reach 75% renewable generation are shown to be competitive with current costs, but further capacity expansion is not currently economical. We additionally include a cost sensitivity analysis and a storage capacity sizing assessment that suggest hydrogen storage may be economically viable if battery costs increase, but large-scale seasonal storage via hydrogen is currently unlikely to be cost-effective nor practical for the region considered. While these findings are based on data and community priorities in Kotzebue, we expect this approach to be relevant to many communities in the Arctic and Sub-Arctic regions working to improve energy reliability, sustainability, and security. Full article
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23 pages, 5310 KiB  
Article
Ecoacoustic Baseline of a Successional Subarctic Ecosystem Post-Glaciation Amidst Climate Change in South-Central Alaska
by Timothy C. Mullet and Almo Farina
Diversity 2025, 17(7), 443; https://doi.org/10.3390/d17070443 - 23 Jun 2025
Viewed by 262
Abstract
As climate change alters subarctic ecosystems and human activities in Alaska, ecological baselines are critical for long-term conservation. We applied an ecoacoustic approach to characterize the ecological conditions of a rapidly deglaciating region in Kenai Fjords National Park, Alaska. Using automated recording units [...] Read more.
As climate change alters subarctic ecosystems and human activities in Alaska, ecological baselines are critical for long-term conservation. We applied an ecoacoustic approach to characterize the ecological conditions of a rapidly deglaciating region in Kenai Fjords National Park, Alaska. Using automated recording units deployed at increasing distances from a road, we collected over 120,000 one-minute audio samples during the tourist seasons of 2021 and 2022. Ecoacoustic indices—Sonic Heterogeneity Index (SHItf), Spectral Sonic Signature (SSS), Weighted Proportion of Occupied Frequencies (wPOF), and Normalized Difference Sonic Heterogeneity Index (NDSHI)—were used to measure spatio-temporal patterns of the sonoscape. Results revealed higher sonic heterogeneity near the road attributed to technophony (vehicles) and geophony (wind) that spanned across the frequency spectrum, masking mid-high frequency biophony. Seasonal phenology and diel variations reflected ecological and human rhythms, including biophony from the dawn chorus from May–June, technophony from vehicle-based tourism from July–September, and decreased sonic activity in the form of geophonic ambience in October. Low-frequency geophonies were prevalent throughout the sonoscape with more natural sounds at greater distances from the road. Our findings demonstrate the benefits of using ecoacoustic methods to assess ecosystem dynamics for establishing ecological baselines useful for future comparisons in rapidly changing environments. Full article
(This article belongs to the Special Issue Wildlife in Natural and Altered Environments)
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15 pages, 5545 KiB  
Article
Stable and Mobile (Water-Extractable) Forms of Organic Matter in High-Latitude Volcanic Soils Under Various Land Use Scenarios in Southeastern Iceland
by Aleksandra Kot, Urszula Norton, Grzegorz Kulczycki, Jón Guðmundsson, Agnieszka Medyńska-Juraszek, Chloe M. Mattilio, Szymon Jędrzejewski and Jarosław Waroszewski
Agriculture 2025, 15(12), 1255; https://doi.org/10.3390/agriculture15121255 - 10 Jun 2025
Viewed by 884
Abstract
High-latitude regions store substantial amounts of soil organic matter (SOM). Icelandic volcanic soils have exceptional capabilities for SOM accumulation, but recent changes in land use can significantly impact it. Water-extractable organic matter (WEOM) represents a labile SOM pool and serves as a reliable [...] Read more.
High-latitude regions store substantial amounts of soil organic matter (SOM). Icelandic volcanic soils have exceptional capabilities for SOM accumulation, but recent changes in land use can significantly impact it. Water-extractable organic matter (WEOM) represents a labile SOM pool and serves as a reliable index of SOM dynamics. We assessed the stable carbon (C), stable nitrogen (N), and WEOC (water-extractable organic carbon), as well as WETN (water-extractable total nitrogen), concentrations in soils under different land uses—semi-natural habitats (tundra and wetland) and human-managed areas (intensively and extensively grazed pasturelands and formerly and presently fertilized meadows)—in southeastern Iceland. The results suggest that human-managed sites contain more total C and N but less WEOM per unit of total C or N than semi-natural habitats, except for wetlands. Wetlands exhibited the highest WEOM content. Extensive pasturelands and fertilized meadows are becoming more common in local ecosystems, highlighting the direction of changes in Icelandic grasslands management. Full article
(This article belongs to the Section Ecosystem, Environment and Climate Change in Agriculture)
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22 pages, 32590 KiB  
Article
Can Ground-Penetrating Radar Detect Thermal Gradients in the Active Layer of Frozen Peatlands?
by Pavel Ryazantsev
Remote Sens. 2025, 17(11), 1805; https://doi.org/10.3390/rs17111805 - 22 May 2025
Viewed by 435
Abstract
The degradation of subarctic peatland ecosystems under climate change impacts surrounding landscapes, carbon balance, and biogeochemical cycles. To assess these ecosystems’ responses to climate change, it is essential to consider not only the active-layer thickness but also its thermo-hydraulic conditions. Ground-penetrating radar is [...] Read more.
The degradation of subarctic peatland ecosystems under climate change impacts surrounding landscapes, carbon balance, and biogeochemical cycles. To assess these ecosystems’ responses to climate change, it is essential to consider not only the active-layer thickness but also its thermo-hydraulic conditions. Ground-penetrating radar is one of the leading methods for studying the active layer, and this paper proposes systematically investigating its potential to determine the thermal properties of the active layer. Collected experimental data confirm temperature hysteresis in peat linked to changes in water and ice content, which GPR may detect. Using palsa mires of the Kola Peninsula (NW Russia) as a case study, we analyze relationships between peat parameters in the active layer and search for thermal gradient responses in GPR signal attributes. The results reveal that frequency-dependent GPR attributes can delineate thermal intervals of ±1 °C through disperse waveguides. However, further verification is needed to clarify the conditions under which GPR can reliably detect temperature variations in peat, considering factors such as moisture content and peat structure. In conclusion, our study discusses the potential of GPR for remotely monitoring freeze–thaw processes and moisture distribution in frozen peatlands and its role as a valuable tool for studying peat thermal properties in terms of permafrost stability prediction. Full article
(This article belongs to the Special Issue Remote Sensing of the Cryosphere (Second Edition))
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19 pages, 6962 KiB  
Article
Topographic Wetness Index as a Factor of the Toxic Metals’ Accumulation by the Alkaline Sorption Barrier and the Choice of Revegetation Strategy in the Subarctic
by Marina Slukovskaya, Yury Dvornikov, Tatiana Ivanova, Ekaterina Kopeina, Anna Petrova, Anna Shirokaya, Andrey Novikov, Liubov’ Ivanova and Irina Kremenetskaya
Soil Syst. 2025, 9(2), 52; https://doi.org/10.3390/soilsystems9020052 - 16 May 2025
Viewed by 468
Abstract
Creation of alkaline bulk layers from mining waste is economically viable way to prevent the migration of toxic metals down the soil profile and revegetate heavy polluted soils over large areas. We have conducted perennial experiments on the revegetation of industrial barren located [...] Read more.
Creation of alkaline bulk layers from mining waste is economically viable way to prevent the migration of toxic metals down the soil profile and revegetate heavy polluted soils over large areas. We have conducted perennial experiments on the revegetation of industrial barren located near the operating nonferrous smelter in humid subarctic climate. A vermiculite–lizardite material from closed phlogopite mining, containing 10% layered silicates, was used to create the alkaline sorption barrier on the sites with high level of Cu/Ni pollution and wide range of topographic wetness index (TWI). We have revealed the strong effect of TWI on metal accumulation by mineral material with the highest effectiveness for the most wet sites. At the same time, the stable Ca and Mg content over seasons revealed the prolonged material effect for the maintenance of alkalinity and macronutrient supply. Further, we demonstrate the potential of Festuca rubra, Festuca ovina, Achillea millefolium, Deschampsia cespitosa, Dactylis glomerata, Rumex acetosella, Silene suecica, and for the revegetation of mineral material in dry locations. We demonstrated the effectiveness of alkaline geochemical barrier for the accumulation of toxic metals and successful plant growth in a wide range of topographic units. Full article
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29 pages, 4243 KiB  
Article
Sustainable Heating Analysis and Energy Model Development of a Community Building in Kuujjuaq, Nunavik
by Alice Cavalerie, Jasmin Raymond, Louis Gosselin, Jean Rouleau and Ali Hakkaki-Fard
Thermo 2025, 5(2), 14; https://doi.org/10.3390/thermo5020014 - 29 Apr 2025
Viewed by 805
Abstract
Energy transition is a challenge for remote northern communities mainly relying on diesel for electricity generation and space heating. Solar-assisted ground-coupled heat pump (SAGCHP) systems represent an alternative that was investigated in this study for the Kuujjuaq Forum, a multi-activity facility in Nunavik, [...] Read more.
Energy transition is a challenge for remote northern communities mainly relying on diesel for electricity generation and space heating. Solar-assisted ground-coupled heat pump (SAGCHP) systems represent an alternative that was investigated in this study for the Kuujjuaq Forum, a multi-activity facility in Nunavik, Canada. The energy requirements of community buildings facing a subarctic climate are poorly known. Based on energy bills, technical documents, and site visits, this study provided an opportunity to better document the energy consumption of such building, especially considering the recent solar photovoltaic (PV) system installed on part of the roof. A comprehensive model was developed to analyze the building’s heating demand and simulate the performance of a ground-source heat pump (GSHP) coupled with PV panels. The air preheating load, accounting for 268,200 kWh and 47% of the total heating demand, was identified as an interesting and realistic load that could be met by SAGCHP. The GSHP system would require a total length of at least 8000 m, with boreholes at depths between 170 and 200 m to meet this demand. Additional PV panels covering the entire roof could supply 30% of the heat pump’s annual energy demand on average, with seasonal variations from 22% in winter to 53% in spring. Economic and environmental analysis suggest potential annual savings of CAD 164,960 and 176.7 tCO2eq emissions reduction, including benefits from exporting solar energy surplus to the local grid. This study provides valuable insights on non-residential building energy consumption in subarctic conditions and demonstrates the technical viability of SAGCHP systems for large-scale applications in remote communities. Full article
(This article belongs to the Special Issue Innovative Technologies to Optimize Building Energy Performance)
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23 pages, 5520 KiB  
Article
Multivariate Insight into Soil Organic Matter Dynamics in Subarctic Abandoned Farmland by the Chronosequence Approach
by Timur Nizamutdinov, Sizhong Yang, Xiaodong Wu, Vladislav Gurzhiy and Evgeny Abakumov
Agronomy 2025, 15(4), 893; https://doi.org/10.3390/agronomy15040893 - 3 Apr 2025
Viewed by 556
Abstract
Agricultural land abandonment is a widespread phenomenon found in many regions of the world. There are many studies on post-agricultural changes in temperate, arid, semi-arid regions, etc., but studies of such soils in boreal or Arctic conditions are rare. Our study aims to [...] Read more.
Agricultural land abandonment is a widespread phenomenon found in many regions of the world. There are many studies on post-agricultural changes in temperate, arid, semi-arid regions, etc., but studies of such soils in boreal or Arctic conditions are rare. Our study aims to fill the gaps in research on the processes of post-agricultural soil transformation, with a focus on the harsh climatic conditions of the Arctic and Subarctic regions. Parameters of soil organic matter (SOM) are largely reflected in the quality of soil, and this study investigates the dynamics of SOM properties in Subarctic agricultural soils in process of post-agrogenic transformation and long-term fertilization. Using a chronosequence approach (0–25 years of abandonment) and a reference site with over 90 years of fertilization, we performed elemental (CHN-O) analysis, solid-state 13C NMR spectroscopy of SOM, PXRD of soil and parent material, and multivariate statistical analysis to identify the connections between SOM composition and other soil properties. The results revealed transient increases in soil organic carbon (SOC) during early abandonment (5–10 years; 3.75–4.03%), followed by significant declines after 25 years (2.15–2.27%), driven by mineralization in quartz-dominated soils lacking reactive minerals for organo-mineral stabilization. The reference site (the Yamal Agricultural Station) maintained stable SOC (3.58–3.83%) through long-term organic inputs, compensating for poor mineralogical protection. 13C NMR spectroscopy highlighted shifts from labile alkyl-C (40.88% in active fields) to oxidized O-alkyl-C (21.6% in late abandonment) and lignin-derived aryl-C (15.88% at middle abandonment), reflecting microbial processing and humification. Freeze–thaw cycles and quartz dominance mineralogy exacerbated SOM vulnerability, while fertilization sustained alkyl-C (39.61%) and balanced C:N (19–20) ratios. Principal Component Analysis linked SOC loss to declining nutrient retention and showed SOM to be reliant on physical occlusion and biochemical recalcitrance, both vulnerable to Subarctic freeze–thaw cycles that disrupt aggregates. These findings underscore the fragility of SOM in Subarctic agroecosystems, emphasizing the necessity of organic amendments to counteract limitations of poor mineralogical composition and climatic stress. Full article
(This article belongs to the Special Issue Soil Organic Matter and Tillage)
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41 pages, 17061 KiB  
Article
Multiple Ecological Niche Modeling Reveals Niche Conservatism and Divergence in East Asian Yew (Taxus)
by Chuncheng Wang, Minqiu Wang, Shanshan Zhu, Xingtong Wu, Shaolong Yang, Yadan Yan and Yafeng Wen
Plants 2025, 14(7), 1094; https://doi.org/10.3390/plants14071094 - 1 Apr 2025
Cited by 1 | Viewed by 586
Abstract
Understanding ecological niche evolution patterns is crucial for elucidating biogeographic history and guiding biodiversity conservation. Taxus is a Tertiary relict gymnosperm with 11 lineages mainly distributed across East Asia, spanning from tropical to subarctic regions. However, the spatiotemporal dynamics of its ecological niche [...] Read more.
Understanding ecological niche evolution patterns is crucial for elucidating biogeographic history and guiding biodiversity conservation. Taxus is a Tertiary relict gymnosperm with 11 lineages mainly distributed across East Asia, spanning from tropical to subarctic regions. However, the spatiotemporal dynamics of its ecological niche evolution and the roles of ecological and geographical factors in lineage diversification, remain unclear. Using occurrence records, environmental data, and reconstructed phylogenies, we employed ensemble ecological niche models (eENMs), environmental principle components analysis (PCA-env), and phyloclimatic modeling to analyze niche similarity and evolution among 11 Taxus lineages. Based on reconstructed Bayesian trees and geographical distribution characteristics, we classified the eleven lineages into four clades: Northern (T. cuspidata), Central (T. chinensis, T. qinlingensis, and the Emei type), Western (T. wallichiana, T. florinii, and T. contorta), and Southern (T. calcicola, T. phytonii, T. mairei, and the Huangshan type). Orogenic activities and climate changes in the Tibetan Plateau since the Late Miocene likely facilitated the local adaptation of ancestral populations in Central China, the Hengduan Mountains, and the Yunnan–Guizhou Plateau, driving their expansion and diversification towards the west and south. Key environmental variables, including extreme temperature, temperature and precipitation variability, light, and altitude, were identified as major drivers of current niche divergence. Both niche conservatism and divergence were observed, with early conservatism followed by recent divergence. The Southern clade exhibits high heat and moisture tolerance, suggesting an adaptive shift, while the Central and Western clades retain ancestral drought and cold tolerance, displaying significant phylogenetic niche conservatism (PNC). We recommend prioritizing the conservation of T. qinlingensis, which exhibits the highest PNC level, particularly in the Qinling, Daba, and Taihang Mountains, which are highly degraded and vulnerable to future climate fluctuations. Full article
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20 pages, 6877 KiB  
Article
Analyses of Variation Trends of Winter Cold Snaps in Subarctic and Arctic Alaska
by Xiaofeng Chang, Zhaohui Yang, Yimeng Zhu, Kaiwen Zhang and Changlei Dai
Sustainability 2025, 17(6), 2438; https://doi.org/10.3390/su17062438 - 11 Mar 2025
Viewed by 645
Abstract
Arctic Alaska is warming at twice the rate of the rest of the nation, severely impacting infrastructure built on permafrost. As winters warm, the effectiveness of thermosyphons used to stabilize foundations diminishes, increasing the risk of infrastructure failure. Because thermosyphons operate with the [...] Read more.
Arctic Alaska is warming at twice the rate of the rest of the nation, severely impacting infrastructure built on permafrost. As winters warm, the effectiveness of thermosyphons used to stabilize foundations diminishes, increasing the risk of infrastructure failure. Because thermosyphons operate with the highest efficiency during winter cold snaps, studying the variation trends and patterns of winter cold snaps in Alaska is particularly important. To address this issue, this study analyzes the historical temperature data of four selected locations in Subarctic and Arctic Alaska, including Bethel, Fairbanks, Nome, and Utqiagvik. The winter cold snap is defined as a period when the average daily temperature drops below a specific site’s mean winter air temperature. The frequency, duration, and intensity of the winter cold snaps are computed to reveal their trends. The results indicate that the mean annual air temperature (MAAT) shows a warming trend, accompanied by sudden warming after 1975 for all study sites. The long-term average monthly air temperature also indicates that the most significant warming occurs in the winter months from December to March. While the frequencies of winter cold snaps remain relatively unchanged, the mean intensity and duration of cold snaps show a declining trend. Most importantly, the most intense cold snap during which the thermosyphons are the most effective is becoming much milder over time for all study sites. This study focuses specifically on the impact of changes in winter cold spells on thermosyphon effectiveness while acknowledging the complexity of other influencing factors, such as temperature differences, design features, coolant properties, and additional climatic parameters (e.g., wind speed, precipitation, and humidity). The data for this study were obtained from the NOAA NCEI website. The findings of this study can serve as a valuable reference for the retrofit or design of foundations and for decision making in selecting appropriate foundation stabilizing measures to ensure the long-term stability and resilience of infrastructure in permafrost regions. Moreover, the insights gained from this research on freeze–thaw dynamics, which are also relevant to black soils, align with the journal’s focus on sustainable soil utilization and infrastructure resilience. Full article
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33 pages, 6353 KiB  
Article
Improved Method for the Retrieval of Extinction Coefficient Profile by Regularization Techniques
by Richard Matthias Herrmann, Christoph Ritter, Christine Böckmann and Sandra Graßl
Remote Sens. 2025, 17(5), 841; https://doi.org/10.3390/rs17050841 - 27 Feb 2025
Viewed by 636
Abstract
In this work, we revise the retrieval of extinction coefficient profiles from Raman Lidar. This is an ill-posed problem, and we show that methods like Levenberg–Marquardt or Tikhonov–Phillips can be applied. We test these methods for a synthetic Lidar profile (known solution) with [...] Read more.
In this work, we revise the retrieval of extinction coefficient profiles from Raman Lidar. This is an ill-posed problem, and we show that methods like Levenberg–Marquardt or Tikhonov–Phillips can be applied. We test these methods for a synthetic Lidar profile (known solution) with different noise realizations. Further, we apply these methods to three different cases of data from the Arctic: under daylight (Arctic Haze), under daylight with a high and vertically extended aerosol layer, and at nighttime with high extinction. We show that our methods work and allow a trustful derivation of extinction up to clearly higher altitudes (at about half a signal-to-noise ratio) compared with the traditional, non-regularized Ansmann solution. However, these new methods are not trivial and require a choice of parameters, which depend on the noise of the data. As the Lidar signal quality quickly decreases with range, a separation of the profile into several sub-intervals seems beneficial. Full article
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19 pages, 4354 KiB  
Article
Post-Agricultural Shifts in Soils of Subarctic Environment on the Example of Plaggic Podzols Chronosequence
by Timur Nizamutdinov, Sizhong Yang and Evgeny Abakumov
Agronomy 2025, 15(3), 584; https://doi.org/10.3390/agronomy15030584 - 26 Feb 2025
Cited by 3 | Viewed by 649
Abstract
This study investigates the post-agricultural transformation of Plaggic Podzols in a Subarctic environment, focusing on the Yamal region, Western Siberia. Agricultural practices historically altered the natural Histic Entic Podzols, leading to their conversion into anthropogenic soils with enhanced organic matter and nutrient profiles. [...] Read more.
This study investigates the post-agricultural transformation of Plaggic Podzols in a Subarctic environment, focusing on the Yamal region, Western Siberia. Agricultural practices historically altered the natural Histic Entic Podzols, leading to their conversion into anthropogenic soils with enhanced organic matter and nutrient profiles. Using a chronosequence approach, soil profiles were analyzed across active and abandoned agricultural fields to assess changes in soil properties over 25 years of abandonment. Results revealed a significant decline in SOC (2.73 → 2.21%, r2 = 0.28) and clay (5.26 → 12.45%, r2 = 0.84), which is reflected in the values of SOC/clay and SOC/(silt + clay) ratios. Nevertheless, the values of the ratios are still above the thresholds, indicating that the “health” of the soils is satisfactory. We detected a decrease in Nt (0.17 → 0.12%, r2 = 0.79) and consequently an increase in the C:N ratio (18.6 → 22.1), indirectly indicating a decrease in SOM quality. Nutrient losses (NPK) with increasing abandonment periods were pronounced, with their concentrations indicative of soil quality degradation. Trace metal concentrations remained below pollution thresholds, reflecting minimal ecological risk according to Igeo, RI, and PLI indexes. The results highlight the necessity for further research on organo-mineral interactions and SOM quality assessment. The findings provide insights into the challenges of soil restoration in Polar regions, emphasizing the role of climate, land-use history, and management practices in shaping soil health and fertility. Full article
(This article belongs to the Special Issue The Impact of Land Use Change on Soil Quality Evolution)
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16 pages, 1597 KiB  
Article
Culturable Plastisphere from the 75° N Subarctic Transect as a Potential Vector of Pathogens and Antibiotic-Resistant Bacteria
by Gabriella Caruso, Maria Papale, Alessandro Ciro Rappazzo and Maurizio Azzaro
J. Mar. Sci. Eng. 2025, 13(3), 448; https://doi.org/10.3390/jmse13030448 - 26 Feb 2025
Cited by 1 | Viewed by 652
Abstract
Plastic pollution is a global emerging concern, but in the Arctic Ocean, the role of the plastisphere as a potential carrier of pathogens and antibiotic-resistant bacteria is unknown yet. An initial assessment of the spread of these target bacteria through their colonization of [...] Read more.
Plastic pollution is a global emerging concern, but in the Arctic Ocean, the role of the plastisphere as a potential carrier of pathogens and antibiotic-resistant bacteria is unknown yet. An initial assessment of the spread of these target bacteria through their colonization of plastic particles, attributed to the micro-sized fraction (less than 5 mm, named microplastics, MPs), was carried out across the 75° N transect (Greenland Sea). To fill the knowledge gaps regarding the bacterial community associated withmicroplastics (MPs)—belonging to the so-called “plastisphere”—and the potential risks related to their spread, our study focused on the abundance and taxonomic composition of the plastisphere, including potential pathogenic and antibiotic-resistant bacteria, using a culture-dependent approach. MPs particles were collected through a Manta net, and decimal dilutions were cultured on Marine agar plates to estimate the abundance of culturable heterotrophic bacteria. For the search of target pathogenic bacterial species (Escherichia coli, Enterococcus spp., Salmonella spp., potentially pathogenic Vibrio spp., and Staphylococcus aureus), small volumes were inoculated into selective culture media using aspread plate directly or after enrichment. Screening of the antibiotic susceptibility profiles of the bacterial isolates was performed to assess the presence of antibiotic-resistant bacteria. The culturable heterotrophic bacterial community was dominated by members of the phyla Gammaproteobacteria and Actinobacteria, with bacterial isolates assigned to the genera Psychrobacter, Pseudoalteromonas, Shewanella, and Arthrobacter. Selective enrichments resulted in the detection of target bacterial pathogens, mostly identified as potentially pathogenic Vibrios spp., in the examined samples. The antibiotic susceptibility profiles pointed out that multiple antibiotic-resistant bacteria were also isolated, suggesting the need to shed light on the potential risks to human and animal health deriving from the plastisphere in remote cold regions as well. Full article
(This article belongs to the Special Issue Assessment of Marine Microbial Risks from Plastic Pollution)
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