Arctic Archipelago Research Articles

On the terrestrial and freshwater invertebrate diversity of the High Arctic archipelago of Svalbard: a revised species inventory and synopsis of the community composition

On the terrestrial and freshwater invertebrate diversity of the High Arctic archipelago of Svalbard: a revised species inventory and synopsis of the community composition

Vertical stratification of arctic microbial communities near potential hydrocarbon seepage off Cape Dyer, Nunavut

AbstractClimate change disproportionately affects the Arctic, where warming is up to four times greater than the global annual average experienced in southern regions. Baffin Bay in the Canadian Arctic Archipelago is an ecologically and biologically significant area that will likely experience an increase in marine vessel traffic as a result of consistent declines in annual sea ice coverage. Along the western coast of Baffin Bay is known to be a region of active, natural hydrocarbon seeps where elevated levels of methane have been detected in previous surveys. Petroleum hydrocarbons released from the seafloor can fuel microbial production and shape the baseline microbiome. Establishing a microbial baseline is highly valuable as it contributes to a fundamental understanding of the existing microbial diversity that may be impacted in the future by anthropogenic stressors. In this study, 16S and 18S rRNA gene amplicon sequencing surveys revealed that the vertical stratification of the water column is largely driven by differences in depth, temperature, salinity, and inorganic nutrient concentrations. Chemical analysis provides further support that active petrogenic methane seepage occurs around Cape Dyer but not in areas targeted in this study. Presence of n-alkanes and toluene in association with hydrocarbon-synthesizing phytoplankton suggests biogenic production of these compounds. These findings provide a baseline for future environmental monitoring assessments to evaluate how the prokaryotic and eukaryotic microbiome may be impacted by ongoing climate change and anthropogenic stressors in western Baffin Bay.

A moderator of tropical impacts on climate in Canadian Arctic Archipelago during boreal summer

The Canadian Arctic Archipelago consists of important international trade routes, and local surface air temperatures (SAT) greatly control sea ice melting in situ during boreal summer (June-July-August-September). However, the drivers of the Arctic Archipelago summer SAT variability have not yet been fully elucidated. Here, we find that the impact of tropical Indo-Pacific convection on the Arctic Archipelago SAT through induced poleward-propagating Rossby wave train is strongly modulated by Russian Arctic sea surface temperature anomalies (SSTA). Negative Russian Arctic SSTA lead to a weakened East Asia westerly jet via equatorward Rossby wave activity. The weakened westerly jet enhances the meridional gradient of the potential vorticity over the North Pacific, guiding the poleward-propagating Rossby wave to the Arctic Archipelago and therefore affecting the local SAT. Conversely, positive Russian Arctic SSTA impede the northward-propagating Rossby wave via enhancing the East Asia westerly jet, resulting in a weakened relationship between the tropical Indo-Pacific convection and Arctic Archipelago SAT. The present study proposes a mechanism whereby changes in the Tropical-Arctic connection stem from thermal conditions elsewhere in the Arctic, through shaping poleward-propagating Rossby waves by changing the background mean flow.

Potential of the Arkhangelsk seismic network for European Arctic monitoring

The Arkhangelsk Seismic Network (ASN) of the N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, founded in 2003, includes 10 permanent seismic stations located on the coasts of the White, Barents, and Kara Seas and on the Arctic archipelagos of Novaya Zemlya, Franz Josef Land, and Severnaya Zemlya. The network is registered with the International Federation of Digital Seismograph Networks and the International Seismological Center. We used not only ASN data to process earthquakes but also the waveforms of various international seismic stations. The 13,000 seismic events were registered using ASN data for 2012–2022, and for 5,500 of them, we determined the parameters of the earthquake epicenters from the European Arctic. The spatial distribution of epicenters shows that the ASN monitors not only the main seismically active zones but also weak seismicity on the shelf of the Barents and Kara Seas. The representative magnitude of ASN was ML, rep=3.5. The level of microseismic noise has seasonal variations that affect the registration capabilities of each station included in the ASN and the overall sensitivity of the network as a whole. In summer, the sensitivity of the ASN decreased owing to the increasing microseismic and ambient noises, whereas in winter, the sensitivity of the ASN increased significantly because of the decrease.

The marine methane cycle in the Canadian Arctic Archipelago during summer.

In the Arctic Ocean, methane concentrations surpassing global averages are prevalent, especially along sub-Arctic and Arctic continental shelf margins. Despite elevated dissolved methane levels, the Arctic Ocean exhibits minimal methane fluxes to the atmosphere, indicating a potential role of water column oxidation in methane processing. During the Northwest Passage Project in the summer of 2019, we integrated thermohaline, chemical, and biological data with in-situ and in-vitro methane data in Canadian Arctic Archipelago (CAA) waters. Elevated in-situ dissolved methane was prominent in near-surface Pacific waters (between 2 and 7m), particularly in meltwater regions, with av. concentrations of 5.8±2.5 nM within the upper 30m. While methane oxidation constants were generally low (av. 0.006±0.002 d-1), surface waters in Wellington Channel and Croker Bay exhibited higher rates (av. 0.01±0.0004 d-1), associated with Pacific-origin microbial taxa like Oleispira and Aurantivirga. Deeper layers (>200m) displayed lower methane concentrations (av. 3.1±1.1 nM) and oxidation rates (av. 0.005±0.001 d-1). Sea ice showed elevated dissolved methane concentrations (av. 9.2±5 nM). Waters in the western CAA exhibited a 25% increase in methane concentrations compared to ice-free areas. The overall picture suggested supersaturation of in-situ methane in shallow waters (between 2 and 50m), coupled with faster oxidation rates in meltwater and Pacific dominant layers, suggesting rapid seasonal cycling of methane and prevention of the methane migration into the atmosphere.

Passage and removal of the Amundsen Gulf Ice Stream, NW Laurentide Ice Sheet, recorded by the glacial and sea level history of southern Banks Island, Arctic Canada

Earlier reconstructions of the glacial history of the western Canadian Arctic Archipelago, commonly portrayed Banks Island as an ice-free biological refugium during the Last Glacial Maximum, ostensibly constituting the northeast extremity of Beringia. This has now been contradicted by widespread fieldwork across the northern and western coasts documenting their inundation by the northwest Laurentide Ice Sheet that extended onto the polar continental shelf. Here we report the surficial geology and deglacial sea levels across southern Banks Island completing the island-wide evidence for a pervasive ice cover during the Late Wisconsinan.Moraines and erratics confirm the passage of an ice stream at least 1.1 km thick through Amundsen Gulf that onlapped the south coast of the island. The inland margin of the ice stream is marked by a prominent 80 km long shear moraine (Sachs moraine) that contacted thin, cold-based Laurentide ice crossing the island's interior. Subsequent thinning and retreat of the Amundsen Gulf Ice Stream from the Sachs moraine occurred in concert with its separation from topographically-confined ice lobes in the interior recorded by prominent ice-marginal meltwater channels. As the ice stream retreated offshore, a prominent kettled outwash plain was deposited along the coast marking marine limit at 20 m asl. From an unknown position offshore, the ice stream readvanced deforming the south shore of the kettled lowland marked by the 40 km long ‘Sand Hills moraine’. Based on updated field mapping, the 'Sand Hills moraine' is now recognized as the westward extension of the more widespread Jesse moraine belt.Deglacial marine limit rises eastward across the island from 11 to 40 m asl, bordering Prince of Wales Strait. Marine limit and all lower shorelines across the island's south coast (for ∼ 200 km) are barren of marine shells. This is because sea level had regressed from marine limit to a lowstand offshore before Pacific molluscs recolonized the western Canadian Arctic at 13.7 cal ka BP, their entry occasioned by the resubmergence of Bering Strait. This requires that the breakup of the western Amundsen Gulf Ice Stream (including the M'Clure Strait Ice Stream along northern Banks Island) occurred before 14 cal ka BP, documenting that the NW Laurentide Ice Sheet must have contributed to Meltwater-Pulse-1A. Although the retreat from the outermost parts of the Jesse moraine belt also pre-date the arrival of shells, we show that the youngest (central) segment along eastern Amundsen Gulf dates to ∼12.9 cal ka BP, documenting that the Jesse moraine belt is highly time transgressive (spanning >13.7 to 12.9 cal ka BP). Radiocarbon dates on woody plants and bryophytes demonstrate that the island was biologically viable as early as 12.6 cal ka BP and that all coastlines were submergent soon afterwards and remain so today.

Chromosomal-level reference genome assembly of muskox (Ovibos moschatus) from Banks Island in the Canadian Arctic, a resource for conservation genomics

The muskox (Ovibos moschatus), an integral component and iconic symbol of arctic biocultural diversity, is under threat by rapid environmental disruptions from climate change. We report a chromosomal-level haploid genome assembly of a muskox from Banks Island in the Canadian Arctic Archipelago. The assembly has a contig N50 of 44.7 Mbp, a scaffold N50 of 112.3 Mbp, a complete representation (100%) of the BUSCO v5.2.2 set of 9225 mammalian marker genes and is anchored to the 24 chromosomes of the muskox. Tabulation of heterozygous single nucleotide variants in our specimen revealed a very low level of genetic diversity, which is consistent with recent reports of the muskox having the lowest genome-wide heterozygosity among the ungulates. While muskox populations are currently showing no overt signs of inbreeding depression, environmental disruptions are expected to strain the genomic resilience of the species. One notable impact of rapid climate change in the Arctic is the spread of emerging infectious and parasitic diseases in the muskox, as exemplified by the range expansion of muskox lungworms, and the recent fatal outbreaks of Erysipelothrix rhusiopathiae, a pathogen normally associated with domestic swine and poultry. As a genomics resource for conservation management of the muskox against existing and emerging disease modalities, we annotated the genes of the major histocompatibility complex on chromosome 2 and performed an initial assessment of the genetic diversity of this complex. This resource is further supported by the annotation of the principal genes of the innate immunity system, genes that are rapidly evolving and under positive selection in the muskox, genes associated with environmental adaptations, and the genes associated with socioeconomic benefits for Arctic communities such as wool (qiviut) attributes. These annotations will benefit muskox management and conservation.

Change of global land extreme temperature in the future

Understanding future temperature extremes is pivotal to preparing for and mitigating the impacts of climate change. This study proposed machine learning techniques to develop a multi-model ensemble model for high-resolution projection of global land temperature extremes under different emission scenarios, hence providing enhanced precision over previous climate model projections. By utilizing the NEX-GDDP-CMIP6 dataset with bias adjustment and the Gradient Booster algorithm, we reduced the biases that existed in Global Climate Models. The model significantly reduces the root mean square errors (RMSEs) for both the daily maximum and daily minimum temperature extremes. A future scenario analysis revealed that global temperature extremes would substantially increase under high-emission scenarios, highlighting the urgency for stringent emission reduction commitments. This study also identified regions like Greenland, the Tibetan Plateau, and the regional Arctic Archipelago as potential hotspots of temperature extremes under these scenarios. The multi-model ensemble approach, tuned with machine learning and driven by high-resolution data, contributes to climate science by providing refined insights into future temperature extremes, thereby offering direction to climate change mitigation and adaptation strategies.

Shelf-to-basin shuttle of highly fractionated chromium isotopes in the Arctic Ocean

The oceanic chromium (Cr) cycle is mainly governed by the interconversion and the distribution of Cr(VI) and Cr(III) species and their stable isotopic ratios (δ53Cr) in the water column. As a result, the Cr cycle generates a strong correlation between the natural logarithm of its dissolved concentration and δ53Cr regardless of the location of sampling. A few studies have reported the Cr composition of certain regions falling off the global Cr array, highlighting the local prevalence of underlying mechanisms participating in the Cr cycle in the oceans. In an effort to better constrain the global Cr array, this study presents an extensive dataset for total dissolved Cr concentration ([Cr]T) and δ53Cr in the Arctic Ocean in regions meeting the environmental conditions where Cr was observed to fall off the global Cr array (e.g. continental shelves, restricted water circulation, sea ice melting). We find that more than 70% of the Arctic seawater collected plot below the global Cr array due to a small addition of highly fractionated Cr (−2.8 ‰ to −1.1 ‰) and its transport across all the Arctic regions sampled. We identify the Chukchi Shelf as the region where highly fractionated Cr is produced, from where a Cr shuttle could work in tandem with the Arctic Fe and Mn shuttles to explain the production and widespread export of isotopically light Cr in the Arctic waters. We identify a second non-reductive release of highly fractionated Cr in the Canadian Arctic Archipelago, Baffin Bay and potentially the Labrador Sea via sediment resuspension, alongside addition of isotopically light Cr originating from crustal rocks. These findings demonstrate that the Arctic-modified outflow signature of Cr isotopes modify the Cr isotopic signature of the North Atlantic waters, and that the North Atlantic waters may deviate from the global Cr array depending on whether the isotopically light Cr added to the Arctic Ocean is Cr(III) that has not been scavenged or Cr(III) that has oxidized to Cr(VI).

Atmospheric-river-induced foehn events drain glaciers on Novaya Zemlya

Recently, climate extremes have been grabbing attention as important drivers of environmental change. Here, we assemble an observational inventory of energy and mass fluxes to quantify the ice loss from glaciers on the Russian High Arctic archipelago of Novaya Zemlya. Satellite altimetry reveals that 70 ± 19% of the 149 ± 29 Gt mass loss between 2011 and 2022 occurred in just four high-melt years. We find that 71 ± 3% of the melt, including the top melt cases, are driven by extreme energy imports from atmospheric rivers. The majority of ice loss occurs on leeward slopes due to foehn winds. 45 of the 54 high-melt days (>1 Gt d−1) in 1990 to 2022 show a combination of atmospheric rivers and foehn winds. Therefore, the frequency and intensity of atmospheric rivers demand accurate representation for reliable future glacier melt projections for the Russian High Arctic.

Rethinking the exercise of sovereignty in the Anthropocene: From extraction to environmental protection in Arctic Svalbard

This paper explores the implications of the Anthropocene and its associated planetary awareness on the concept and exercise of sovereignty, particularly through the lens of the Svalbard Treaty. The Arctic archipelago of Svalbard is not only a space undergoing rapid environmental change today, but its treaty-based governance arrangements are based on an early-twentieth century spatial imaginary of fishery, coal, and resource extraction. By examining Norway's governance shift from resource extraction to environmental stewardship on Svalbard, this paper reflects on transformations of the practice of sovereignty in response to global environmental challenges. Through interviews with local stakeholders, the research highlights the contentious nature of these shifts, revealing how increased environmental regulations, while necessary, may paradoxically entrench existing power structures and complicate the presence of non-Norwegian entities. This case study of the Svalbard Treaty serves as a normative microcosm for broader issues of sovereignty, treaty obligations, and international governance as they may evolve due to planetary change, pointing to the urgent need to rethink these evolving dynamics. The paper underscores the pressing and complex challenges facing the international system in the Anthropocene, suggesting that while Svalbard's geopolitical stability may be maintained and Norwegian sovereignty remains uncontested, the instability of global environmental realities is already leading to changes to the ways in which sovereignty is exercised in the present.

Power and interests in environmental policy processes: the Svalbard case

ABSTRACT Climate and environmental changes pose tremendous challenges to ecosystems worldwide. While this underscores the need for more significant conservation efforts, these measures often clash with human activities. Participation and transparency may be key to reducing conflict and ensuring high-quality decisions, but facilitating such processes has proven difficult with many interests and stakeholders involved. This often leads to disputes over environmental policies but may also reflect a more profound debate about the definition of wilderness and who it is for. This article, therefore, explores what interests prevail and why in environmental policy processes and how this relates to perceptions of wilderness. Drawing on Lukes’ (2021) three-dimensional view of power and the case of the political process of new environmental regulations in the Arctic Archipelago of Svalbard, Norway, the author examines how the power to frame the public discourse about wilderness influences the issues and actors included in the discussion (see also McConnell and Hart 2019, 647). The insights provided are relevant not only to local stakeholders on Svalbard navigating the policy process but also to practitioners and academics elsewhere working in environmental governance, protected areas, and environmental policy and legislation.

Shelf-break glaciation and an extensive ice shelf beyond northwest Greenland at the Last Glacial Maximum

The analysis of seafloor glacial landforms can provide important constraints on the past behaviour of ice sheets, including their extent at the Last Glacial Maximum and the controls on their subsequent retreat. The continental shelf and slope offshore of northwest Greenland have been sparsely surveyed, however, limiting our understanding of ice sheet extent and dynamics in this sector during the pre-satellite era. Here we use newly acquired high-resolution geophysical data to map and interpret the distribution of glacial landforms across the hitherto unexplored banks of northern Melville Bay and the adjacent slope and deep-sea basin. In contrast to previous conceptual models, our seafloor observations suggest that shelf-break glaciation was attained along the entire northwest Greenland margin at the Last Glacial Maximum, including beyond the shallow banks. The landforms that we map on the continental slope provide strong support for the existence of an ice shelf spanning northern Baffin Bay. Sub-ice shelf keel scours in water depths of down to 1220 m reveal that this ice shelf was at least 1100 m thick at its grounding zone. The orientation of sub-ice shelf landforms suggests that the ice shelf was fed mainly by the supply of ice to northern Baffin Bay from the Lancaster Sound Ice Stream of the Canadian Arctic Archipelago. The Baffin Bay ice shelf buttressed several large ice streams of the Greenland, Innuitian and Laurentide ice sheets at the Last Glacial Maximum, and its break-up may have contributed to instigating the deglacial retreat of these ice streams from the shelf edge.

Reconstructing Younger Dryas ground temperature and snow thickness from cave deposits

Abstract. The Younger Dryas stadial was characterised by a rapid shift towards cold-climate conditions in the North Atlantic realm during the last deglaciation. While some climate parameters including atmospheric temperature and glacier extent are widely studied, empirical constraints on permafrost temperature and snow thickness are limited. To address this, we present a regional dataset of cryogenic cave carbonates (CCCs) from three caves in Great Britain that formed at temperatures between −2 and 0 °C. Our CCC record indicates that these permafrost temperatures persisted for most of the Younger Dryas. By combining ground temperatures with surface temperatures from high-resolution ground-truthed model simulations, we demonstrate that ground temperatures were approximately 6.6 ± 2.3 °C warmer than the mean annual air temperature. Our results suggest that the observed temperature offset between permafrost and the atmosphere can be explained by an average snow thickness between 0.2 and 0.9 m, which persisted for 233 ± 54 d per year. By identifying modern analogues from climate reanalysis data, we demonstrate that the inferred temperature and snow cover characteristics for the British Isles during the Younger Dryas are best explained by extreme temperature seasonality, comparable to continental parts of today's Arctic Archipelago. Such a climate for the British Isles necessitates a winter sea ice margin at approximately 45° N in the North Atlantic Ocean.

Genomic characterization and virulence gene profiling of Erysipelothrix rhusiopathiae isolated from widespread muskox mortalities in the Canadian Arctic Archipelago

BackgroundMuskoxen are important ecosystem components and provide food, economic opportunities, and cultural well-being for Indigenous communities in the Canadian Arctic. Between 2010 and 2021, Erysipelothrix rhusiopathiae was isolated from carcasses of muskoxen, caribou, a seal, and an Arctic fox during multiple large scale mortality events in the Canadian Arctic Archipelago. A single strain (‘Arctic clone’) of E. rhusiopathiae was associated with the mortalities on Banks, Victoria and Prince Patrick Islands, Northwest Territories and Nunavut, Canada (2010–2017). The objectives of this study were to (i) characterize the genomes of E. rhusiopathiae isolates obtained from more recent muskox mortalities in the Canadian Arctic in 2019 and 2021; (ii) identify and compare common virulence traits associated with the core genome and mobile genetic elements (i.e. pathogenicity islands and prophages) among Arctic clone versus other E. rhusiopathiae genomes; and iii) use pan-genome wide association studies (GWAS) to determine unique genetic contents of the Arctic clone that may encode virulence traits and that could be used for diagnostic purposes.ResultsPhylogenetic analyses revealed that the newly sequenced E. rhusiopathiae isolates from Ellesmere Island, Nunavut (2021) also belong to the Arctic clone. Of 17 virulence genes analysed among 28 Arctic clone isolates, four genes – adhesin, rhusiopathiae surface protein-A (rspA), choline binding protein-B (cbpB) and CDP-glycerol glycerophosphotransferase (tagF) – had amino acid sequence variants unique to this clone when compared to 31 other E. rhusiopathiae genomes. These genes encode proteins that facilitate E. rhusiopathiae to attach to the host endothelial cells and form biofilms. GWAS analyses using Scoary found several unique genes to be overrepresented in the Arctic clone.ConclusionsThe Arctic clone of E. rhusiopathiae was associated with multiple muskox mortalities spanning over a decade and multiple Arctic islands with distances over 1000 km, highlighting the extent of its spatiotemporal spread. This clone possesses unique gene content, as well as amino acid variants in multiple virulence genes that are distinct from the other closely related E. rhusiopathiae isolates. This study establishes an essential foundation on which to investigate whether these differences are correlated with the apparent virulence of this specific clone through in vitro and in vivo studies.

The Cretaceous to Eocene: a biostratigraphical review and a new detailed palynostratigraphy of Greenland and adjacent areas

The present paper compile and correlate for the first time Cretaceous to Eocene palynostratigraphies across the Arctic. It focus on Greenland and adjacent areas, including the Labrador–Baffin Seaway, onshore Nuussuaq Basin in central West Greenland, onshore southern East Greenland, central East Greenland, North-East Greenland, eastern North Greenland and the Danmarkshavn Basin, but also extends to Canadian Arctic Archipelago and the Barents Sea region off Norway. The paper compile data from more than three decades of detailed Arctic palynological analyses, based mainly on dinoflagellate cysts. The paper gives a historical overview of the Cretaceous to Palaeogene paleontological studies of Greenland and presents an overview of 85 palynological intervals and numerous events. The palynological assemblages from the Labrador–Baffin Seaway, Nuussuaq Basin and north-east Baffin Bay reflect the opening of the Labrador–Baffin Seaway from brackish to freshwater environment in a large embayment in the Early Cretaceous to an open marine seaway in the Late Cretaceous. Assemblages reveal in dinoflagellate cyst provincialism between the opening stages of the Labrador–Baffin Seaway and the already opened Greenland–Norwegian–Barents seaway. The Upper Cretaceous global Oceanic Anoxic Event 2 (OAE2) spanning the Cenomanian/Turonian boundary is recognised from Arctic Canada, north-east Baffin Bay, Nuussuaq Basin in central West Greenland, and North-East Greenland, and is mapped and correlated based on dinoflagellate cyst stratigraphy and carbon isotope (δ13Corg) curves. The dinoflagellate cysts assemblages of the Cretaceous/Palaeogene boundary are correlated from the Labrador Sea across to the Nuussuaq Basin in central West Greenland; in both areas the earliest Danian palynological assemblage is represented by incoming warm-water species. The presence of the global Paleocene–Eocene Thermal Maximum (PETM) in the Palaeogene successions in North-East Greenland and in exploration wells in the Labrador–Baffin Seaway is indicated by the incoming of the warm-water dinoflagellate cyst species Axiodinium augustum.

Norway’s research policy for Svalbard: intentions and perceptions

ABSTRACT Scholars of critical geography and geopolitics have long noted the intersection between research and strategic interest in the polar areas. This article focuses on how this link is displayed in the case of Svalbard, an Arctic archipelago under Norwegian sovereignty. While Norway’ research policy in Svalbard has traditionally been welcoming and supportive of international research activity with little interference in the organization of research, the Norwegian government recently introduced a new policy for the research community Ny-Ålesund. The article reviews the changes introduced as well as the response from involved research organizations. It shows interdependence between political ambitions and research priorities and, given the status of Svalbard, a more complex relationship than is the case for research in polar areas outside national jurisdiction.

Baroclinic Tide Generation at the Dolphin and Union Strait in the Southern Canadian Arctic Archipelago

We studied baroclinic tide generation at the Dolphin and Union Strait, a channel in the southern Canadian Arctic Archipelago that consists of a shallow sill. Utilizing both observational data and numerical simulations, we found that, due to the presence of strong stratification in the summertime, baroclinic tides are generated at both M2 and K1 frequencies as a result of the interaction between the amplified tidal currents and bottom topography. The M2 baroclinic current, which is comparable to the M2 barotropic current in terms of amplitude, is dominated by linear dynamics in the first baroclinic mode. The amplitude of the M2 baroclinic current increases as the strength of stratification increases. In contrast, the K1 baroclinic current has a smaller amplitude in general. Dynamics of the K1 baroclinic current are more complicated, possibly due to nonlinear effects as well as contributions from the higher baroclinic modes. On the other hand, increasing the strength of stratification leads to a noticeable reduction of K1 elevation in the nearby basin, but has a very minor effect on M2 elevation.

The myths of Svalbard geopolitics: An Arctic case study

The Arctic has become a victim of popularised geopolitical analyses. Common conceptions of ‘geopolitical rivalry’ being caused or even accelerated by sea ice melting are too simplistic. They under-estimate the complexity of the political and legal dynamics at play and over-estimate the explanatory power of geophysical change. Instead, we must examine the specific cases of geopolitics in the North. One such location is the Norwegian archipelago of Svalbard. Misconceptions and myths also concerning this archipelago abound in popular media and some academic scholarship – regarding everything from sovereignty disputes to its legal and military status. Such misconceptions are intertwined with the actual geopolitical issues that concern Svalbard or stem from different interpretations of the Svalbard Treaty from 1920. These include the (1) explicit challenges to Norwegian policies on land; the (2) disagreement over the geographic extension of the Svalbard Treaty to the archipelago’s maritime zones; and (3) the potential military use of Svalbard in a larger conflict with Russia. This article examines the geopolitical aspects of this Norwegian Arctic archipelago, in order to provide greater accuracy to the growing popular and academic discussion about Svalbard and the wider Arctic.

Detecting Melt Pond Onset on Landfast Arctic Sea Ice Using a Dual C-Band Satellite Approach

The presence of melt ponds on the surface of Arctic Sea ice affects its albedo, thermal properties, and overall melting rate; thus, the detection of melt pond onset is of significant importance for understanding the Arctic’s changing climate. This study investigates the utility of a novel method for detecting the onset of melt ponds on sea ice using a satellite-based, dual-sensor C-band approach, whereby Sentinel-1 provides horizontally polarized (HH) data and Advanced SCATterometer (ASCAT) provides vertically polarized (VV) data. The co-polarized ratio (VV/HH) is used to detect the presence of melt ponds on landfast sea ice in the Canadian Arctic Archipelago in 2017 and 2018. ERA-5 air temperature and wind speed re-analysis datasets are used to establish the VV/HH threshold for pond onset detection, which have been further validated by Landsat-8 reflectance. The co-polarized ratio threshold of three standard deviations from the late winter season (April) mean co-pol ratio values are used for assessing pond onset detection associated with the air temperature and wind speed data, along with visual observations from Sentinel-1 and cloud-free Sentinel-2 imagery. In 2017, the pond onset detection rates were 70.59% for FYI and 92.3% for MYI. Results suggest that this method, because of its dual-platform application, has potential for providing large-area coverage estimation of the timing of sea ice melt pond onset using different earth observation satellites.