Sea-ice floating in the Arctic ocean is a constantly moving, growing and melting layer. The seasonal cycle of sea-ice volume has an average amplitude of $10\,000\,\mathrm{km}^3$ or 9 trillion tonnes of sea ice. The role of dynamic redistribution of sea ice is observable during winter growth by the incorporation of satellite remote sensing of ice thickness, concentration and drift. Recent advances in the processing of CryoSat-2 radar altimetry data have allowed for the retrieval of summer sea-ice thickness. This allows for a full year of a purely remote sensing-derived ice volume budget analysis.

Here, we present the closed volume budget of Arctic sea ice over the period October 2010–May 2022 revealing the key contributions to summer melt and minimum sea-ice volume and extent. We show the importance of ice drift to the inter-annual variability in Arctic sea-ice volume and the regional distribution of sea ice. The estimates of specific areas of sea-ice growth and melt provide key information on sea-ice over-production, the excess volume of ice growth compared to melt. The statistical accuracy of each key region of the Arctic is presented, revealing the current accuracy of knowledge of Arctic sea-ice volume from observational sources.

Since the emergence of the Thule culture (AD 1200), dog sledding has been perceived as a central means of transportation in traditional Inuit life in the Arctic. However, there is an absence of research concerning Inuit dog-sled technology and the tradition of the craft. This study investigates the Inuit dog-sled technocomplex using enskilment methodologiesby employing experimental and ethno-archaeological observations to explore the relationship between knowledge and technical practice. It involves the reconstruction of a historical West Greenlandic dog sled, shedding light on carpentry techniques and construction processes. This method emphasizes the interaction between humans, technology, and time, providing essential practical data for future archaeological and historical research, particularly for comprehending fragmented archaeological remains. By focusing on process rather than end product, this research provides insight into understanding Inuit dog sled technology and the complexity of the practice. The connection between artifacts and materially situated practice is demonstrated through the reconstruction of a dog sled, which illustrates the value of physicality in enskilment. It highlights how experimental archaeology can improve our insights into the historical and prehistoric Arctic societies’ technologies, economies, and practices.

Passive microwave measurements of Arctic sea ice have been conducted over the last 50 years from space and during airborne, ship- and ground-based measurement campaigns. The different radiometric signatures of distinct surface types have led to satellite retrievals of, e.g., sea-ice concentration. In contrast, ground-based upward-viewing radiometers measure radiation emitted from the atmosphere and are used to retrieve atmospheric variables. Here, we present results from a ship-based radiometer setup with a mirror construction, which allows us to switch between atmospheric and surface measurements flexibly. This way, in summer 2022, surface observations in the Arctic marginal sea-ice zone could be performed from the research vessel Polarstern by two radiometers covering the frequency range from 22 to 243 GHz. At low frequencies, the brightness temperatures show clear signatures of different surface conditions. We estimate emissivities at 53∘ zenith angle from infrared-based skin temperatures. Predominantly vertically polarized 22–31 GHz emissivities are between 0.51 and 0.55 for open ocean and around 0.95 for sea ice. Predominantly horizontally polarized 243 GHz ocean emissivities are around 0.78 and ice surfaces exhibit a large variability from 0.67 to 0.82. Our results can improve the characterization of surface emissions in satellite retrieval algorithms.

The global population and status of Snowy Owls Bubo scandiacus are particularly challenging to assess because individuals are irruptive and nomadic, and the breeding range is restricted to the remote circumpolar Arctic tundra. The International Union for Conservation of Nature (IUCN) uplisted the Snowy Owl to “Vulnerable” in 2017 because the suggested population estimates appeared considerably lower than historical estimates, and it recommended actions to clarify the population size, structure, and trends. Here we present a broad review and status assessment, an effort led by the International Snowy Owl Working Group (ISOWG) and researchers from around the world, to estimate population trends and the current global status of the Snowy Owl. We use long-term breeding data, genetic studies, satellite-GPS tracking, and survival estimates to assess current population trends at several monitoring sites in the Arctic and we review the ecology and threats throughout the Snowy Owl range. An assessment of the available data suggests that current estimates of a worldwide population of 14,000–28,000 breeding adults are plausible. Our assessment of population trends at five long-term monitoring sites suggests that breeding populations of Snowy Owls in the Arctic have decreased by more than 30% over the past three generations and the species should continue to be categorised as Vulnerable under the IUCN Red List Criterion A2. We offer research recommendations to improve our understanding of Snowy Owl biology and future population assessments in a changing world.

Hunting pits are common archaeological features in northern landscapes, mainly researched from a morphological perspective, as dateable material is scarce. This has resulted in a limited and generalized understanding of hunting pits. While human land use in non-agrarian settings is often subtle, it can still be understood in terms of distribution and management by using relational approaches that address spatial organization and the nature of land use. This study, based on extensive field surveys and GIS analyses and guided by the concept of landscape domestication, has identified the characteristics of approximately 1500 previously unrecorded hunting pits in the Arctic region of Sweden. It examines how hunting pit systems, their selective spatial distribution, and strategic arrangement can be seen as expressions of landscape domestication. The author concludes that, through profound knowledge and deliberate resource management, communities invested in the landscape, generating dense spatial and temporal manifestations in the form of hunting pits. These systems reflect an elaborate hunting technique involving the whole landscape.

Bortolanite, a rare mineral of the rinkite group, seidozerite supergroup occurs in two different associations in the Lovozero massif in the Kola Peninsula, Russia: (1) together with ferri-katophorite and phlogopite, it forms porous or mesh aggregates (symplectitic accretions) with euhedral contours in the contact zone of a volcano–sedimentary xenolith and eudialyte lujavrite at Kuamdespakhk Mt and (2) in intergrowths with titanite and fluorcaphite in the poikilitic feldspathoid syenites at Sengischorr Mt. In both cases, bortolanite was found in association with rosenbuschite that is close to it in chemical composition, but unlike bortolanite, it contains no REEs. The mineral is triclinic, space group P$\bar{1}$, a = 9.5807(5), b = 5.6943(4), c = 7.2813(4) Å, α = 89.891(5)°, β = 100.959(4)°, γ = 101.241(5)°, V = 382.25(4) Å3 and Z = 1.

The Lovozero bortolanite differs from the Brazilian holotype sample from de Caldas alkaline massif, Minas Gerais, due to the presence of (OH)-groups in its composition, which is indicated by Raman data. A combination of single-crystal X-ray diffraction data and electron microprobe data provides the following crystal-chemical formula: (Ca1.97Ce0.01Nd0.01Th0.01)Σ2(Ca1.39Zr0.61)Σ2(Na0.72Ca0.28)Σ1(Na1.36Ca0.56Mn0.03Zn0.01)Σ1.96(Ti0.78Zr0.08Nb0.05Mg0.05Fe0.04)Σ1Si4O14((OH)0.92O0.87F0.21)Σ2F2.

While much work on expertise has explored the mobilisation and production of knowledge, the development of epistemic communities, and the mechanisms through which expertise operates – little work has been done exploring how expertise is understood across academic literature on particular regional cases such as the Arctic. In this article, I scope a broad literature review of the Arctic, seeking out how expertise has been depicted and framed in academic and theoretical literature. The results are framed around five different themes: (1) expertise serving the interests of great powers, (2) recognition of the overall importance of expertise in Arctic governance, (3) the purpose of experts, (4) science diplomacy and expertise: a murky barrier, and (5) how to study experts, but also find that Indigenous knowledge is often left out of literature that relies upon Western frameworks of expertise. This incongruity suggests that there are two competing conceptualizations of Arctic expertise, one in theory and another in practice – which has consequences for how the region and its expertise are narrated.

This study investigates the impacts of the timing of an extreme cyclone that occurred in August 2012 on the sea-ice volume evolution based on the Arctic Ice Ocean Prediction System (ArcIOPS). By applying a novel cyclone removal algorithm to the atmospheric forcing during 4–12 August 2012, we superimpose the derived cyclone component onto the atmospheric forcing one month later or earlier. This study finds that although the extreme cyclone leads to strong sea-ice volume loss in all runs, large divergence occurs in sea-ice melting mechanism in response to various timing of the cyclone. The extreme cyclone occurred in August, when enhanced ice volume loss is attributed to ice bottom melt primarily and ice surface melt secondarily. If the cyclone occurs one month earlier, ice surface melt dominates ice volume loss, and earlier appearance of open water within the ice zone initiates positive ice-albedo feedback, leading to a long lasting of the cyclone-induced impacts for approximately one month, and eventually a lower September ice volume. In contrast, if the cyclone occurs one month later, ice bottom melt entirely dominates ice volume loss, and the air-open water heat flux in the ice zone tends to offset ice volume loss.

Interferometric synthetic aperture radar (InSAR) data suffer from an elevation bias due to signal penetration into the firn and ice surface, rendering the height information unusable for elevation and mass-change detection. This study estimates the penetration bias in X-band InSAR data to quantify its impact on elevation and mass-change detection and to demonstrate the applicability of TanDEM-X digital elevation models (DEMs) for cryosphere research. To achieve this, a multiple linear regression model is applied to a time series of four TanDEM-X DEMs acquired between 2010 and 2018 over the Sverdrup Glacier basin (SGB), Devon Ice Cap, Canada. The resulting penetration corrected TanDEM-X DEMs agreed to within ±14 cm of spatially and temporally coincident precise in situ kinematic dGPS data (±10 cm RMSE). Additionally, multi-year estimations of mass change for the SGB derived from differencing TanDEM-X DEMs over multi-year periods between 2010 and 2018, showed good agreement with mean deviation of 338 ± 166 mm w.e. with independent measurements of mass change derived from annual in situ surface mass balance over the same time periods. The results show that the penetration bias can vary significantly, leading to random under- and overestimations in the detection of elevation and mass changes.

Although “urban” and “fisheries” are not commonly paired in the analyses of either urbanism or fisheries governance, today’s large-scale fisheries are often closely organised in connection with cities. In this paper, I build on a feminist perspective and urban studies to examine the makings of a city through contemporary fisheries. Drawing upon observations and interviews conducted in Tromsø, Norway, which is a key site for Arctic fisheries, I review how fish and fisheries are simultaneously made visible and invisible in urban spheres. By analysing the gendered structures and valuations that organise the city–fisheries relations, I introduce three “fishy” windows to demonstrate the kinds of development and future pathways for fisheries that are considered relevant and rational in and for the city. In particular, I discuss how the historical, techno-masculine narratives of mastering Arctic nature frame and legitimise fisheries practices as they expand throughout Tromsø. The study builds on the emerging research on Arctic urbanism to highlight the need to better integrate gendered analyses of the “urban” into social science research on natural resource extraction.

Much has been written about the so-called Franklin expedition (1845–), but not about the master mariners, who joined as “Greenland pilots,” as experienced whaling masters on Royal Navy expeditions were usually called in the 19th century. Having been on Royal Navy expeditions to the Arctic before, Thomas Blanky, the ice master of HMS Terror, was mentioned here and there in contemporary sources. But who he was and how and why he joined the expedition are still widely unanswered questions, to be dealt with for the first time here.

China’s role in the Arctic regime remains a debatable topic in the expert discourse on the High North. Currently, in view of the aggravated conflicts in other regions that include Russia as the largest Arctic state, and China as its strategic partner, the Arctic regimes are experiencing salient disturbances. Against this backdrop, an understanding of China’s opportunities to affect Arctic affairs is urgently needed. We address this issue by combining political and legal analyses. We used the regime theory approach to outline the Arctic regime complex (ARC), and through this lens, we discuss the recent changes that are being observed. Based on this, we determine China’s actual potential for making amendments to the ARC. We conclude that China has no capacity to make a crucial shift in the ARC, but it is still able to alter particular rules, like those related to Arctic Ocean management and scientific cooperation. The further efficient operation of the Arctic Council will play a decisive role in envisaging China’s behaviour in the region.

Russia’s Arctic policy since 2008 has been influenced by two competing foreign policy lines (discourses): the “Arctic as a resource base” and the “sovereignty discourse”. The “Arctic as a resource base” has been the dominant one since the first Russian Arctic Strategy in 2008. It is primarily about exploiting the vast oil and gas resources estimated to be located there, as well as turn the Northern Sea Route into a “global transport corridor”. In Russia’s Arctic Strategy of 2020, however, there is enhanced emphasis on sovereignty and power balancing in Russian Arctic policy. And the focus on sovereignty was heightened with the amendments to Russia’s Arctic Strategy in March 2023. This increased emphasis on sovereignty, territorial defence and balance of power in Russian Arctic policy is likely to be further reinforced by the growing great-power competition between the USA and Russia, which has gained new momentum following Russia’s invasion of Ukraine in 2022.

In 1866, Charles F. Hall recorded testimony from a Pelly Bay native named Sŭ-pung-er who reported that together with his uncle, they had visited the Northwest coast of King William Island 4 years prior in search of materials abandoned by the Franklin Expedition. Sŭ-pung-er told Hall that he had identified a site which Hall believed was a “vault” which might contain documents and speculated that it could have been a burial site for a high-ranking officer. Sŭ-pung-er’s testimony also included the description of a wooden “pillar, stick or post” which marked the spot of the vault. The location of this site and the pillar have never been found. Yet they remain sought-after for both their significance and the potential bonanza of information about the expedition. Any clue or artefact, which could provide clarity for this site, is therefore of great value. This paper describes a model of the pillar seen on King Williams Island, replicated by Sŭ-pung-er, which Hall brought back from the Arctic and included in his list of Franklin relics. The model, now housed in the Smithsonian Museum of American History, was first featured in a drawing of relics appearing in 1869 in Harper’s Weekly magazine. The fact that this artefact has been in plain sight for so long, but unrecognised for what it is, is significant. The pillar model both provides clarity and continues the mystery surrounding the Franklin Expedition.