Polar Science最新文献

The total area covered by permafrost has been continually decreasing over the past decades. This study investigates the effect of various temperature increases on the microbiome of permafrost sampled at the Cold Regions Research and Engineering Laboratory (CRREL) Permafrost Tunnel site in Fox, Alaska, USA, corresponding to the Holocene (around 8000 years before present (ybp)) and Pleistocene (around 36,000 ybp), respectively. The soil was subjected to two thawing time courses, with temperature increasing from −4 °C to either +4 °C or +25 °C, and total nucleic acid was extracted at each time point. Consistent with previous 16S rRNA amplicon sequencing studies on the Permafrost Tunnel, the Pleistocene was dominated by Clostridia, while the Holocene was mainly composed of Clostridia, Bacteroidia and Alphaproteobacteria at −4 °C. Thawing at +25 °C resulted in divergent microbial profiles for permafrost of both ages, with the Pleistocene becoming more similar to the active layer, while the Holocene was relatively less impacted. Prediction of metabolic function revealed that bacteria from the Holocene permafrost activated degradation pathways upon thawing at +25 °C, while bacteria from the Pleistocene were more involved in amino-acid biosynthesis pathways, suggesting different mechanisms of adaptation.

Cold storage of food using a natural cold environment (i.e., frozen ground, ice, snow, and freezing air) is globally found to be compatible with the local environment, and within the cultural traditions of communities. Our interdisciplinary project, focusing on four areas from Beringia (Alaska and easternmost Siberia) to the middle latitudes (Mongolia and Japan) of the northern hemisphere, aims to 1) document the variations and commonalities in the history, present situations, and future concerns of cold storage facilities, 2) review the roles and functionalities of the practice through the “Food Life History” concept, a new framework to address local food issues in a global context on the history of interactions between humanity and the environment, and 3) co-produce knowledge and strategies to facilitate cold storage practices for local adaptation to environmental and economic challenges. In this preliminary study conducted from 2021 to 2023, we initiated communication with local leaders and knowledge-bearers, examined current conditions, and installed temperature monitors in cold storage structures where available. The results illustrate the presence of practices of various types, specifications, and conditions, commonly challenged by environmental changes both natural (e.g., permafrost thawing and ground wetting) and social (e.g., modern technologies, education, and economy).

Qaanaaq, a remote community in Greenland, faces significant challenges in achieving sustainable development goals (SDGs) due to its extremely high heating demands, reliance on diesel fuel, limited transportation options, declining population, and shortage of skilled labor in the construction industry. Addressing these issues is particularly complex due to the harsh climate and limited resources. In this study, we propose a strategy to achieve SDGs in Qaanaaq by replacing 263 single-family homes with 66 highly insulated multi-family nearly zero-energy apartment houses (n-ZEAHs) and installing rooftop solar photovoltaic (PV) systems. Simulation results indicate that replacing homes with n-ZEAHs could reduce annual heating energy consumption by 9575 MWh and that the rooftop PV systems could offset approximately 57% of annual electricity sales, significantly improving Qaanaaq's energy security. However, field measurements revealed that indoor humidity in n-ZEAHs was low and that CO₂ and PM₁₀ levels occasionally exceeded standards. Additionally, the rooftop PV systems may not fully meet monthly electricity demands during certain seasons. To address these issues, it will be necessary to introduce appropriate ventilation systems and consider the implementation of combined systems that integrate other renewable energy sources and batteries. Given the limited availability of skilled technicians in Qaanaaq, simple and user-friendly systems are preferred. The findings of this study provide valuable insights on how to achieve SDGs in cold and remote climate communities like Qaanaaq.

The article presents three perspectives on how Russia's full-scale invasion of Ukraine has impacted international relations and security in the Arctic: a North European, a pan-Arctic and a Japanese-cum-North Pacific. We find a significant impact on the security situation in Northern Europe, including the European Arctic, notably in the Finish and Swedish decisions to join NATO. The consequences have been more limited from the circumpolar Arctic perspective, with the interruption of cooperation in the Arctic Council and in the international use of the Northern Sea Route as the most significant. Also from the Japanese perspective, the direct impact of the war has been more limited than in Northern Europe. Our analysis of Japan confirms, however, that both Arctic states and stakeholders seem to have adopted a wait and see approach to key issues, notably the future of the Arctic Council. The aim is likely to preserve the important gains made in Arctic governance in the last decades. How much reengagement with Russia will be politically palatable, and how long Russia's constructive approach to Arctic cooperation will last, remains to be seen, however. The political winds in the north are cold, but like the climate, not as cold as one could expect.

Accelerating Arctic permafrost thaw results in increasing methane emissions affecting regional and global climates, but the rate of permafrost disappearance can be difficult to estimate with remote sensing, field surveys and modelling. Here we investigate if the annual growth rings of the shrub Betula nana (dwarf birch) may be used to detect and monitor near-surface permafrost degradation. Whole B. nana samples were collected at Latnjajávri and Corrvosjávri, northernmost Sweden, and their annual growth rings were analysed regarding their potential as permafrost indicators. Permafrost disappeared in Latnjajávri between 1993 and 2001, whereas Corrvosjávri lost its frozen ground decades earlier. Annual growth rings from more than twenty B. nana shrubs at each site were measured and crossdated by serial sectioning, and then averaged into two separate shrub-ring chronologies. Growth rates were higher at Corrvosjávri than at Latnjajávri. Analysing the 1972–2015 period disclosed a stronger climate-growth relationship at Corrvosjávri, with significant correlations with summer temperatures. In Latnjajávri the association with climate was much weaker before the permafrost disappeared, but afterwards reached similar levels as at Corrvosjávri. Our results suggest that changes in the B. nana growth-climate relationship may be used to indicate permafrost degradation. Moreover, the strong correlation between summer temperature and shrub growth after disappearance of permafrost supports previous research that B. nana ring widths are useful climate proxies.

The Arctic region has been experiencing an extensive transformation and several economic opportunities have emerged due to the shrinking sea ice. While the Arctic Ocean has become more convenient for navigation, both Arctic and non-Arctic states have updated their Arctic policies according to recent developments. There has been a substantial increase in the number of studies studying three main Arctic sea routes: Northwest Passage (NWP), Northeast Passage (NEP), and Trans-Polar Sea Route (TSR). Albeit the existence of contradictory results, the interest in Arctic shipping presents a growing trend. The Turkish shipyards increasingly participate in tenders as well. While Çelik Tekne Shipyard stands out as the first Turkish shipyard to win the shipbuilding tender in accordance with polar conditions, a significant increase has been observed in the number of shipyards within the Arctic shipping tenders since 2018. In addition to Atlas and Akdeniz Shipyards, producing ice-class vehicles in accordance with the requirements of the Polar Code, it is possible to multiply examples from Beşiktaş Shipyard, which built ice class fuel ships, Sanmar Shipyard, which won the icebreaker tugboat tender, and Sefine and Kuzey Star Shipyards, which participated in the icebreaker tenders. Besides, the participation of Turkish shipyards as sole contractors in the Russian Arctic as of 2021 indicates their determination to become active actors in the Arctic shipping industry. Accordingly, this paper discusses the opportunities and challenges of Arctic shipping based on the Turkish case.

Russia's invasion of Ukraine in 2022 put to test the North Pacific regional governance structure, with environmental cooperation overshadowed by security concerns. In this paper, the central government, subnational and non-state actors' potential in finding ways out of environmental governance crises is explored. The authors turn for possible clues to the Northern fur seal conservation and management regimes, which existed in 1911–40 and 1957–84 and laid the groundwork for marine wildlife conservation and management in the North Pacific, in the century replete with military conflicts and international tension. The focus is on Japan and Russia's subnational and non-state actors (private companies, experts, NGOs and indigenous communities), who have received much less attention than their US and Canadian counterparts. Their roles in negotiation, operation and dismantlement of these regimes, are analyzed in domestic and international contexts by applying Putnam's “two-level game” metaphor. Their motives and tactics, interconnections and clout are examined in the light of both states' domestic and foreign policy goals and constraints, and regional and global trends in environmental governance. The recent multi-actor undertakings for marine mammal conservation and management in Japan and Russia are also explored from the multilevel governance perspective. It is hoped that the current diplomatic deadlock may be overcome by utilizing sub-state and supra-state frameworks and channels for communication.

Among extreme environments, bioaerosol includes a wide range of primary atmospheric organic particles associated with and emitted by living and dead organisms. Bioaerosol samples were collected along two transects at a subArctic Atlantic spatial scale, including the eastern Fram Strait and the Greenland, Norwegian, and North Seas. This study was aimed at first estimating microscopically the prokaryotic abundance, biomass and phenotypic traits, along with the number of potential viable and respiring cells. Moreover, physiological profiles at community level were assessed. Prokaryotic abundance ranged from 10⁴ to 10⁷ cells m⁻³, with the predominance of small sized cells (0.1 μm³). Prokaryotic biomass reached higher values (mean value 233 μg C m⁻³) in relation to the occurrence of large sized rods. Overall, the percentage of the viable cells was lower than the dead ones, while respiring cells were in lower abundance than total cells. The physiological profiles revealed various potential metabolic pathways among the samples, highlighting the utilization of phosphate-carbon, carboxylic and amino acids. These first results on the metabolism and physiology of microbes, which survived transport in the atmosphere of the Northern Hemisphere, suggest that bioaerosol constitutes an extremely dynamic environment of remarkable ecological interest, also considering future global warming scenarios.

Northwest Greenland societies substantially rely on subsistence harvest, a part of which consists of little auks (Alle alle), an abundant seabird in the Arctic. Although little auks inhabit remote regions, they are prone to accumulating mercury (Hg) in their tissues and ingesting plastics from their environment while feeding. This entails a broad array of health-related issues, from the birds themselves to their local predators including humans. Here, we examined whether Hg and plastic contamination in little auks were influenced by the birds' age class and breeding status, mirrored by brood patch presence and size. Feather Hg concentrations were higher in birds with large brood patches (adults, currently breeding), compared to younger or non-breeding birds. Feather Hg concentrations also positively correlated with nitrogen stable isotope values in feathers, indicative of trophic position fed in the previous summer. Among the 13 examined auks’ gastrointestinal tract, two (15.4 %) contained large polyethylene fragments (6.55 × 4.10 mm, 49.45 mg on average); their occurrence was not found to relate to brood patch size. Although future research is needed on Hg accumulation in internal tissues, our results suggest that consuming adult little auks and the birds' gastrointestinal tracts may increase health-related risks for Arctic communities.

Future climate projections based on multi-model ensemble approach are seen as more reliable, but not all models are equally performant at reproducing climate features at a regional scale. An optimal regional GCM ensemble was developed for Sakha (Yakutia) Republic based on error statistics and spatial correlation metrics. Historical Coupled Model Intercomparison Project, version 6 (CMIP6) simulations from 48 global climate models (GCMs) were used to evaluate model quality compared to mean annual air temperature (MAAT) reanalysis data for 1961–1990, 1971–2000 and 1981–2010 reference periods, and the MAAT change between 1961-1990 and 1981–2010, ΔT_81-61. The best-performing reanalysis, GHCN-CAMS, was validated using observational data. This five-member ensemble includes CESM2-WACCM, CMCC-ESM2, CNRM-CM6-1-HR, INM-CM5-0, MPI-ESM1-2-HR models, weighted by Pearson's coefficient of spatial correlation between observed and modeled ΔT_81-61 fields. Model weighting based on spatial correlation metrics improved the performance of the developed multi-model regional ensemble, which can be used in projecting future climate under different climate change scenarios.