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This paper engages an Indigenous and a non-Indigenous researcher in discussion about collaboration and co-creation between researchers and Indigenous communities that include and prioritise Indigenous knowledge. It places a focus on the preconditions for respectful and goal-oriented research relationships. The paper is structured around ‘small moments’ in research, as a means of analysing the need for commonality and relationality. Indigenous understandings of relationality include connection to place as a living practice with a responsibility to kin. Relationality and commonality focus on friendship, shared visioning and communication across long distances. Through discourse, Dr Charleen Fisher (Gwich’in, Tl’eeyegge Hʉt’aane, Dena’ina) and Dr Nina Doering (German) focus on positionality, relationality, communication and co-creation in a variety of communication landscapes. Long-term critical discussions during the Covid-19 pandemic about ethical research with Indigenous philosophy, epistemology and ontology normalised virtual meetings as a contemporary practice. The paper addresses research in the social and natural sciences and humanities. [ABSTRACT FROM AUTHOR]

Participatory scenario methodologies are increasingly used for studying possible future developments in the Arctic. They have the potential to contribute to several high-priority tasks for Arctic research, such as integration of indigenous and local knowledge in futures studies, providing a platform for activating Arctic youth in shaping their futures, identifying Arctic-relevant indicators for sustainable development, and supporting decision-making towards sustainable futures. Yet, to achieve this potential, several methodological challenges need to be addressed. These include attention to whose voices are amplified or silenced in participatory research practices, with special attention to diversification and the engagement of youth. Given the historic and potential future role of disruptive events for Arctic development trajectories, methods are needed in participatory scenario exercises to include attention to the dynamics and consequences of such events and regime shifts. Participatory scenarios can also be further improved through approaches that effectively combine qualitative and quantitative information. Finally, there is a need for systematic studies of how the results of scenario exercises influence decision-making processes. This article elaborates on ways in which attention to these aspects can help make scenarios more robust for assessing a diversity of potential Arctic futures in times of rapid environmental and social change. [ABSTRACT FROM AUTHOR]

Arctic sea ice incorporates and transports sediment, releasing it back into the water column during the melting season. This process constitutes an important aspect of marine sediment transport and biogeochemical cycling. Sediment incorporation into sea ice is considered to occur mainly through underwater interaction between frazil ice and resuspended sediment, referred to as suspension freezing. However, harsh environmental conditions have greatly limited field observations of this phenomenon. Analysis of mooring data from a coastal polynya in the northeastern Chukchi Sea, in conjunction with coastal ice radar and meteorological data, indicates that suspension freezing is a key mechanism for sediment entrainment into sea ice. During polynya episodes, acoustic backscatter data obtained by an Acoustic Doppler Current Profiler showed the presence of frazil ice from the surface down to 20‐ to 25‐m depth, coinciding with in situ and potential supercooling. Underwater frazil ice persisted over 1 week under windy, turbulent water column conditions. A combination of the turbidity and Acoustic Doppler Current Profiler backscatter data revealed upward sediment dispersion associated with strong currents during the polynya episodes. The fact that frazil ice and resuspended sediment were detected at the same depth and time strongly suggests the interaction between ice crystals and sediment particles, that is, suspension freezing. Plain Language Summary: Sea ice incorporates, transports, and releases particulate matter. These processes constitute an important aspect of the biology, biogeochemical cycling, and pollutant transport in polar oceans. Seafloor sediments serve as the most important source of such particulate matter; however, the process of sediment incorporation into sea ice remains poorly explored. We conducted a year‐long study of sediment resuspension and entrainment processes, using underwater sensors deployed in the Chukchi Sea. During winter, wind‐driven offshore transport of sea ice created area of open water and newly grown thin ice that persisted for several days, so‐called coastal polynya or flaw lead system. Our sensors recorded small ice crystals, so‐called frazil ice, that formed in the water column when water temperatures were below freezing point (supercooling). During some of these episodes, sediment was resuspended from the seafloor and dispersed upward by the strong currents, bringing it into water depths at which frazil ice was encountered. Such conditions provide for opportunities that allow frazil ice crystals or aggregates to capture resuspended sediment, a process referred to as suspension freezing. Based on this study, we propose that suspension freezing commonly occurs in shallow Arctic polynyas, serving as a key process of sediment incorporation into sea ice. Key Points: ADCP data provided evidence of frazil ice penetrating to ~25 m in the water column during supercooling episodes in a coastal polynyaThe combination of acoustic and optical measurements revealed underwater frazil ice‐sediment interaction at water depths of 10–25 mSuspension freezing can often occur in shallow polynyas and is suggested to be the dominant process of sediment incorporation into sea ice [ABSTRACT FROM AUTHOR]

The French–German Arctic research base AWIPEV (the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research – AWI – and the French Polar Institute Paul Emile Victor – PEV) at Ny-Ålesund, Svalbard, is a unique station for monitoring cloud-related processes in the Arctic. For the first time, data from a set of ground-based instruments at the AWIPEV observatory are analyzed to characterize the vertical structure of clouds. For this study, a 14-month dataset from Cloudnet combining observations from a ceilometer, a 94 GHz cloud radar, and a microwave radiometer is used. A total cloud occurrence of ∼81 %, with 44.8 % multilayer and 36 % single-layer clouds, was found. Among single-layer clouds the occurrence of liquid, ice, and mixed-phase clouds was 6.4 %, 9 %, and 20.6 %, respectively. It was found that more than 90 % of single-layer liquid and mixed-phase clouds have liquid water path (LWP) values lower than 100 and 200 g m -2 , respectively. Mean values of ice water path (IWP) for ice and mixed-phase clouds were found to be 273 and 164 g m -2 , respectively. The different types of single-layer clouds are also related to in-cloud temperature and the relative humidity under which they occur. Statistics based on observations are compared to ICOsahedral Non-hydrostatic (ICON) model output. Distinct differences in liquid-phase occurrence in observations and the model at different environmental temperatures lead to higher occurrence of pure ice clouds. A lower occurrence of mixed-phase clouds in the model at temperatures between -20 and -5 ∘ C becomes evident. The analyzed dataset is useful for satellite validation and model evaluation. [ABSTRACT FROM AUTHOR]

Most of the world's permafrost is located in the Arctic, where its frozen organic carbon content makes it a potentially important influence on the global climate system. The Arctic climate appears to be changing more rapidly than the lower latitudes, but observational data density in the region is low. Permafrost thaw and carbon release into the atmosphere, as well as snow cover changes, are positive feedback mechanisms that have the potential for climate warming. It is therefore particularly important to understand the links between the energy balance, which can vary rapidly over hourly to annual timescales, and permafrost conditions, which changes slowly on decadal to centennial timescales. This requires long-term observational data such as that available from the Samoylov research site in northern Siberia, where meteorological parameters, energy balance, and subsurface observations have been recorded since 1998. This paper presents the temporal data set produced between 2002 and 2017, explaining the instrumentation, calibration, processing, and data quality control. Furthermore, we present a merged data set of the parameters, which were measured from 1998 onwards. Additional data include a high-resolution digital terrain model (DTM) obtained from terrestrial lidar laser scanning. Since the data provide observations of temporally variable parameters that influence energy fluxes between permafrost, active-layer soils, and the atmosphere (such as snow depth and soil moisture content), they are suitable for calibrating and quantifying the dynamics of permafrost as a component in earth system models. The data also include soil properties beneath different microtopographic features (a polygon centre, a rim, a slope, and a trough), yielding much-needed information on landscape heterogeneity for use in land surface modelling. For the record from 1998 to 2017, the average mean annual air temperature was -12.3 ∘ C, with mean monthly temperature of the warmest month (July) recorded as 9.5 ∘ C and for the coldest month (February) -32.7 ∘ C. The average annual rainfall was 169 mm. The depth of zero annual amplitude is at 20.75 m. At this depth, the temperature has increased from -9.1 ∘ C in 2006 to -7.7 ∘ C in 2017. The presented data are freely available through the PANGAEA (10.1594/PANGAEA.891142) and Zenodo (https://zenodo.org/record/2223709 , last access: 6 February 2019) websites. [ABSTRACT FROM AUTHOR]

Climate change provides opportunities in the surrounding areas of North Pole to commercial shipping activities, but which also poses risks to ship strikes, oil spills, chronic marine environmental pollution, etc. However, the public product supply of Arctic environmental emergency response and governance is seriously insufficient. As such, a collective and effective system should be established to protect the Arctic environment. In the present paper, a complex network model of Arctic environmental emergency response and governance system is developed. The strategy of each country in the complex network is demonstrated by evolutionary game simulations of this system model. Computational results indicate that the benefit of environmental emergency response and governance affects the cooperation strategy of each country. Moreover, Long-term benefit and return intensity are the key parameters of environmental emergency response and governance benefit. These findings extend theoretical research in the sustainable development Arctic routes and provide reference for the participation of other countries beyond the Arctic Council. [ABSTRACT FROM AUTHOR]

Winter 2016/2017 saw record warmth over the Arctic Ocean, leading to the least amount of freezing degree days north of 70° N since at least 1979. The impact of this warmth was evaluated using model simulations from the Los Alamos sea ice model (CICE) and CryoSat-2 thickness estimates from three different data providers. While CICE simulations show a broad region of anomalously thin ice in April 2017 relative to the 2011-2017 mean, analysis of three CryoSat-2 products show more limited regions with thin ice and do not always agree with each other, both in magnitude and direction of thickness anomalies. CICE is further used to diagnose feedback processes driving the observed anomalies, showing 11-13 cm reduced thermodynamic ice growth over the Arctic domain used in this study compared to the 2011-2017 mean, and dynamical contributions of C1 to C4 cm. Finally, CICE model simulations from 1985 to 2017 indicate the negative feedback relationship between ice growth and winter air temperatures may be starting to weaken, showing decreased winter ice growth since 2012, as winter air temperatures have increased and the freeze-up has been further delayed. [ABSTRACT FROM AUTHOR]

Using thresholds of physical climate variables developed from community observations, together with two large-scale datasets, we have produced local indices directly relevant to the impacts of a reduced sea ice cover on Alaska coastal communities. The indices include the number of "false freeze-ups" defined by transient exceedances of ice concentration prior to a corresponding exceedance that persists, "false break-ups", timing of freeze-up and break-up, length of the open water duration, number of days when the winds preclude hunting via boat (wind speed threshold exceedances), the number of wind events conducive to geomorphological work or damage to infrastructure from ocean waves, and the number of these wind events with onand along-shore components promoting water setup along the coastline. We demonstrate how community observations can inform use of large-scale datasets to derive these locally relevant indices. The two primary large-scale datasets are the Historical Sea Ice Atlas for Alaska and the atmospheric output from a regional climate model used to downscale the ERA-Interim atmospheric reanalysis. We illustrate the variability and trends of these indices by application to the rural Alaska communities of Kotzebue, Shishmaref, and Utqiaġgvik (previously Barrow), although the same procedure and metrics can be applied to other coastal communities. Over the 1979-2014 time period, there has been a marked increase in the number of combined false freeze-ups and false break-ups as well as the number of days too windy for hunting via boat for all three communities, especially Utqiaġvik. At Utqiaġvik, there has been an approximate tripling of the number of wind events conducive to coastline erosion from 1979 to 2014. We have also found a delay in freeze-up and earlier break-up, leading to a lengthened open water period for all of the communities examined. [ABSTRACT FROM AUTHOR]

Results from ground-penetrating radar (GPR) measurements and shallow ice cores carried out during a scientific traverse between Dome Concordia (DC) and Vostok stations are presented in order to infer both spatial and temporal characteristics of snow accumulation over the East Antarctic Plateau. Spatially continuous accumulation rates along the traverse are computed from the identification of three equally spaced radar reflections spanning about the last 600 years. Accurate dating of these internal reflection horizons (IRHs) is obtained from a depth-age relationship derived from volcanic horizons and bomb testing fallouts on a DC ice core and shows a very good consistency when tested against extra ice cores drilled along the radar profile. Accumulation rates are then inferred by accounting for density profiles down to each IRH. For the latter purpose, a careful error analysis showed that using a single and more accurate density profile along a DC core provided more reliable results than trying to include the potential spatial variability in density from extra (but less accurate) ice cores distributed along the profile. The most striking feature is an accumulation pattern that remains constant through time with persistent gradients such as a marked decrease from 26mmw.e. yr-1 at DC to 20mmw.e. yr-1 at the south-west end of the profile over the last 234 years on average (with a similar decrease from 25 to 19mmw.e. yr-1 over the last 592 years). As for the time dependency, despite an overall consistency with similar measurements carried out along the main East Antarctic divides, interpreting possible trends remains difficult. Indeed, error bars in our measurements are still too large to unambiguously infer an apparent time increase in accumulation rate. For the proposed absolute values, maximum margins of error are in the range 4mmw.e. yr-1 (last 234 years) to 2mmw.e. yr-1 (last 592 years), a decrease with depth mainly resulting from the time-averaging when computing accumulation rates. [ABSTRACT FROM AUTHOR]

Major ions were analysed in firn and ice cores located at Fimbul Ice Shelf (FIS), Dronning Maud Land - DML, Antarctica. FIS is the largest ice shelf in the Haakon VII Sea, with an extent of approximately 36 500 km². Three shallow firn cores (about 20m deep) were retrieved in different ice rises, Kupol Ciolkovskogo (KC), Kupol Moskovskij (KM), and Blåskimen Island (BI), while a 100m long core (S100) was drilled near the FIS edge. These sites are distributed over the entire FIS area so that they provide a variety of elevation (50-400ma.s.l.) and distance (3-42 km) to the sea. Sea-salt species (mainly Na+ and Cl-) generally dominate the precipitation chemistry in the study region.We associate a significant sixfold increase in median sea-salt concentrations, observed in the S100 core after the 1950s, to an enhanced exposure of the S100 site to primary sea-salt aerosol due to a shorter distance from the S100 site to the ice front, and to enhanced sea-salt aerosol production from blowing salty snow over sea ice, most likely related to the calving of Trolltunga occurred during the 1960s. This increase in seasalt concentrations is synchronous with a shift in non-seasalt sulfate (nssSO42- ) toward negative values, suggesting a possible contribution of fractionated aerosol to the sea-salt load in the S100 core most likely originating from salty snow found on sea ice. In contrast, there is no evidence of a significant contribution of fractionated sea salt to the ice-rises sites, where the signal would be most likely masked by the large inputs of biogenic sulfate estimated for these sites. In summary, these results suggest that the S100 core contains a sea-salt record dominated by the proximity of the site to the ocean, and processes of sea ice formation in the neighbouring waters. In contrast, the ice-rises firn cores register a larger-scale signal of atmospheric flow conditions and a less efficient transport of sea-salt aerosols to these sites. These findings are a contribution to the understanding of the mechanisms behind sea-salt aerosol production, transport and deposition at coastal Antarctic sites, and the improvement of the current Antarctic sea ice reconstructions based on seasalt chemical proxies obtained from ice cores. [ABSTRACT FROM AUTHOR]

We propose a waveform mixture algorithm to detect leads from CryoSat-2 data, which is novel and different from the existing threshold-based lead detection methods. The waveform mixture algorithm adopts the concept of spectral mixture analysis, which is widely used in the field of hyperspectral image analysis. This lead detection method was evaluated with high-resolution (250 m) MODIS images and showed comparable and promising performance in detecting leads when compared to the previous methods. The robustness of the proposed approach also lies in the fact that it does not require the rescaling of parameters (i.e., stack standard deviation, stack skewness, stack kurtosis, pulse peakiness, and backscatter σ0), as it directly uses L1B waveform data, unlike the existing threshold-based methods. Monthly lead fraction maps were produced by the waveform mixture algorithm, which shows interannual variability of recent sea ice cover during 2011-2016, excluding the summer season (i.e., June to September).We also compared the lead fraction maps to other lead fraction maps generated from previously published data sets, resulting in similar spatiotemporal patterns. [ABSTRACT FROM AUTHOR]

The field of Arctic studies is becoming increasingly rich in empirical material across a broad array of topics and relationships, encompassing multiple international actors, both littoral and extra-regional. This article reviews three recent books on the Arctic, focusing on the evaluation of the potential for conflict in the region. Climate change will have long-ranging repercussions in the Arctic, where complex situations and choices will loom large, creating scope for international tensions. The scholarship demonstrates that there is much 'old' in the 'new' narratives of the North but at the same time posits that the region has been significantly less confrontational in the post-Cold War era than many observers predicted. Yet the Arctic is not hermetically sealed from other regions: international developments as well as the foreign policy ambitions of individual states, sometimes as remote as China, have been affecting emerging governance arrangements. In combination, the 'spill-over effect' of international crises and efforts by individual states to engage in sovereignty-enhancing exercises risk reducing cooperation among the states which have until now managed to maintain stability in the region. [ABSTRACT FROM AUTHOR]

At the Arctic Council's Iqaluit Ministerial Meeting in April 2015, the eight Arctic States decided to extend the mandate of the Task Force on Enhancing Scientific Cooperation in the Arctic (SCTF) in order to work toward a legally binding agreement on scientific cooperation. Based on the Oslo Draft of February 2015, this paper finds that the Agreement may improve the legal environment for Arctic science beyond current international law, including the law of the sea. The Agreement would lower the hurdles heretofore identified in international Arctic scientific cooperation, for example, the difficulties in accessing research areas and research facilities; and, the delays in border crossing procedures for entry and exit of scientists and their equipment and materials. Such an agreement is a good idea and should be promoted. However, non-Arctic States and their scientists may have an issue because the improved legal environment that is sought may benefit only the eight Arctic States and their scientists. In effect, the Agreement may create a two-category system where non-Arctic States and their scientists do not benefit from such improved environment. This paper examines whether they have substantial interests recognized under international law or by the Arctic scientific community by which they can claim certain benefits of the Agreement. We argue that the degree of benefits to non-Arctic States and their scientists under the Agreement should be commensurate with the degree of substantial interests accorded them by international law and by the Arctic scientific community. [ABSTRACT FROM AUTHOR]

The United Kingdom has a longstanding interest in the Arctic and has recently begun to develop a set of guiding principles for its engagement in the region. Although the UK has a great deal to offer in terms of scientific research and expertise, it is missing an opportunity to engage more fully with issues of importance to the Arctic region. [ABSTRACT FROM AUTHOR]

The Arctic is among the world’s regions most affected by ongoing and increasing cultural, socio-economic, environmental and climatic changes. Over the last two decades, scholars, policymakers, extractive industries, local, regional and national governments, intergovernmental forums, and non-governmental organizations have turned their attention to the Arctic, its peoples and resources, and to challenges and benefits of impending transformations. The International Conference on Arctic Research Planning (ICARP) has now transpired three times, most recently in April 2015 with ICARP III. Arctic sustainability is an issue of increasing concern within the Arctic and beyond it, including in ICARP endeavors. This paper reports some of the key findings of a white paper prepared by an international and interdisciplinary team as part of the ICARP-III process, with support from the International Arctic Science Committee Social and Human Sciences Working Group, the International Arctic Social Sciences Association and the Arctic-FROST research coordination network. Input was solicited through sharing the initial draft with a broader network of researchers, including discussion and feedback at several academic and community venues. This paper presents a progress report on Arctic sustainability research, identifies related knowledge gaps and provides recommendations for prioritizing research for the next decade. [ABSTRACT FROM AUTHOR]

The article discusses the Arctic Council that aims to develop the Arctic as a region of peace and raise awareness of environmental, development and economic issues affecting the Arctic and its peoples, the International Conference on Arctic Research Planning (ICARP) and collaboration related to it.

Climate change, ocean acidification (OA) and the subsequent changes in marine productivity may affect fisheries and eventually the whole economy in the Arctic. We analysed how changes in climate and ocean pH under scenarios of anthropogenic CO2 emissions are likely to affect the economics of marine fisheries in the Arctic. We applied a Dynamic Bioclimate Envelope Model (DBEM) and outputs from four different Earth System Models (ESMs) to project future changes in the distribution and maximum catch potential of exploited marine fishes and invertebrates. We projected that total fisheries revenue in the Arctic region may increase by 39% (14-59%) by 2050 relative to 2000 under the Special Reports on Emission Scenario (SRES) A2. Simultaneously, total fishing costs, fishers' incomes, household incomes and economy-wide impacts in the Arctic are also projected to increase. Climate change with OA is expected to reduce the potential increases in catch and the economic indicators studied herein. Although the projections suggest that Arctic countries are likely to be 'winners' under climate change in comparison with tropical developing countries, the effects of OA will lower the expected future benefits in the Arctic. The predicted impacts are likely to be conservative as we consider only the direct effects of OA on fishes and calcifiers, of which there are only a few in the Arctic. Results of this study would be useful for designing effective adaptation strategies to climate change and measures to mitigate the potential negative impacts of OA in the Arctic. [ABSTRACT FROM AUTHOR]

The value of theory in drawing lessons from empirical cases remains elusive in the Arctic. In the introduction to this special issue, we develop broad theoretical underpinnings to consider how frame analysis can better inform Arctic research. We build on a research synthesis from a collaborative anthology focused on diplomacy in polar regions [Pincus, R., & Ali, S. H. (Eds.). (2015).Diplomacy on ice: Energy and the environment in the Arctic and Antarctic. New Haven, CT: Yale University Press]. Here, we review aspects of media and communication theory, in particular frame theory, and contextualize theoretically the common tropes of Arctic political conflict, centered on the so-called race or scramble for the Arctic. After introducing and identifying concepts of framing and discourse and discussing how these concepts are relevant to Arctic issues, the paper will address why these concepts are important to policy-makers, stakeholders, and the public. What are the impacts of conflict-driven frames as applied to Arctic sovereignty or development questions? We explore how frames impact diplomacy in contested spaces, such as the Arctic, and how to draw cooperative lessons from these discourses. Finally, the papers that make up this special edition are placed in relation to the broader topic. [ABSTRACT FROM AUTHOR]

DNA sequences offer powerful tools for describing the members and interactions of natural communities. In this study, we establish the to-date most comprehensive library of DNA barcodes for a terrestrial site, including all known macroscopic animals and vascular plants of an intensively studied area of the High Arctic, the Zackenberg Valley in Northeast Greenland. To demonstrate its utility, we apply the library to identify nearly 20 000 arthropod individuals from two Malaise traps, each operated for two summers. Drawing on this material, we estimate the coverage of previous morphology-based species inventories, derive a snapshot of faunal turnover in space and time and describe the abundance and phenology of species in the rapidly changing arctic environment. Overall, 403 terrestrial animal and 160 vascular plant species were recorded by morphology-based techniques. DNA barcodes ( CO1) offered high resolution in discriminating among the local animal taxa, with 92% of morphologically distinguishable taxa assigned to unique Barcode Index Numbers ( BINs) and 93% to monophyletic clusters. For vascular plants, resolution was lower, with 54% of species forming monophyletic clusters based on barcode regions rbcL a and ITS2. Malaise catches revealed 122 BINs not detected by previous sampling and DNA barcoding. The insect community was dominated by a few highly abundant taxa. Even closely related taxa differed in phenology, emphasizing the need for species-level resolution when describing ongoing shifts in arctic communities and ecosystems. The DNA barcode library now established for Zackenberg offers new scope for such explorations, and for the detailed dissection of interspecific interactions throughout the community. [ABSTRACT FROM AUTHOR]

The paper presents the first data on the geology of a series of mafic dikes emplaced in the volcanogenic sedimentary sequence composing the structure of Jeannette Island. We show that the island hosts two generations of dikes consisting of fine-grained dolerites. Both magmatic stages were followed by fold deformations. The youngest and weakly deformed dikes are none the less chloritized and serpentinized. However, we were able to obtain the first ever precise geochronological Ar/Ar data for them. According to this analysis, the emplacement age of the intrusive complex of Jeannette Island is close to the Ediacaran (553.6 ± 10.3 Ma). The ages of several superimposed tectonothermal events were determined: Middle Ordovician (463.3 ± 11.7 Ma), Late Silurian (425.3 ± 8.7 Ma), Late Devonian (360.7 ± 8.3 Ma) and Early Carboniferous (341.3 ± 6.8 Ma). [ABSTRACT FROM AUTHOR]

We use demographic and economic indicators to analyze spatial differences and temporal trends across 18 regions surrounding the Arctic Ocean. Multifactor and cluster analysis were used on 10 indicators reflecting income, employment and demography from 1995 to 2008. The main difference is between regions with high population densities, low natural growth rate, and low unemployment (Russia, Norway and Iceland) and regions with high unemployment rate and high natural growth rate (mainly North American regions). However, once those parameters were accounted for sub-regional differences start to emerge. Variation among the regions was a result of national policies and regional differences such as access and presence of natural resources (i.e. oil, gas, mining, etc.). We found only weak temporal trends, but regions with resource extraction show some signs of higher volatility. Overall, the Arctic has experienced out-migration with only Iceland and two regions in Canada experiencing in-migration. [ABSTRACT FROM PUBLISHER]

The Russian-American Long-term Census of the Arctic (RUSALCA) project provides a rare opportunity to study the Russian sector of the Pacific Arctic Region (PAR), which includes the Chukchi and East Siberian Seas. RUSALCA data from 2009 and 2012 allow fuller understanding of changes in ocean chemistry across this the region and, in particular, provide perspectives on the ocean carbon cycle, airsea CO2 gas exchange, and ocean acidification variability. Summertime surface waters of the western Chukchi Sea and East Siberian Sea mostly exhibited low pCO2 (<100 to 400 μatm) and high pH (8.0 to 8.4) conditions during sea ice retreat. As earlier studies of the adjacent eastern Chukchi Sea show, this area of the PAR had a strong potential for ocean uptake of atmospheric CO2, with saturation states for calcium carbonate (CaCO3) minerals such as calcite and aragonite (Ωcalcite and Ωaragonite, respectively) having values generally greater than two, thereby facilitating CaCO3 production. In contrast, fresher surface waters flowing into the Chukchi Sea from the East Siberian Sea and bottom waters on the PAR shelves exhibited high pCO2 and low pH, Ωcalcite, and Ωaragonite conditions. Low Ω surface waters near the Russian coast and nearly 70% of waters next to the seafloor were corrosive to CaCO3 minerals such as aragonite, with this change seemingly occurring at a more rapid rate than typical global open-ocean changes in ocean chemistry. The exposure of subsurface benthic communities and nearshore ecosystems near the Russian coast to potentially corrosive water is likely exacerbated by the ocean uptake of anthropogenic CO2 and gradual ocean acidification. The RUSALCA project also highlights the complexities and uncertainties in the physical and biogeochemical drivers of the ocean carbon cycle and ocean chemistry in this region of the Arctic. [ABSTRACT FROM AUTHOR]

An attempt has been made to derive sea ice freeboard from Ka-band Altimeter (SARAL/AltiKa) over Arctic region for 15 March–15 April 2013 (spring) and 15 September–15 October 2013 (autumn). A waveform template matching technique is employed for classification of leads and floe pixels. The estimated sea ice freeboards were found in close agreement with “Operation IceBridge quick look” freeboards (RMSD = 0.30 m). The differences between the two freeboards were largely due to snow layer over sea ice (R = 0.8). The estimated freeboards were of the order of 0.08–0.15 m during the two seasons. [ABSTRACT FROM PUBLISHER]

The article discusses the scientific publishing contributions of North America to the Nature Index database in 2014. Topics cited include the region's article and weight fractional count, the pattern of top five institutions' relative subject area distribution and collaborativeness and top three country collaborations, the initiative of the Canadian government to launch the Canadian High Arctic Research Station, and percentage of life science research in the U.S.

One of the challenging tasks in climate science is to understand the equator-to-pole temperature gradient. The poleward heat flux generated by baroclinic waves is known to be central in reducing the equator-to-pole temperature gradient from a state of radiative-convective equilibrium. However, invoking this relationship to explain the wide range of equator-to-pole temperature gradients observed in past climates is challenging because baroclinic waves tend to follow the flux-gradient relationship such that their poleward heat flux is proportional to the equator-to-pole temperature gradient and zonal available potential energy (ZAPE). With reanalysis data, the authors show the existence of poleward heat transport by planetary-scale waves that are independent of the flux-gradient relationship and baroclinic instability. This process arises from a forced tapping of atmospheric ZAPE by planetary-scale waves that are triggered by enhanced tropical convection over the Pacific warm pool region. The Rossby waves excited by this tropical convection propagate northeastward over the Pacific Ocean and constructively interfere with the climatological stationary waves at higher latitudes. During polar night, when the current warming is most rapid, the forced tapping of ZAPE by planetary-scale waves produces a substantially greater warming than that by the synoptic-scale eddy fluxes that presumably arise from baroclinic instability. [ABSTRACT FROM AUTHOR]

Britain is no longer an Arctic nation, but it has a unique Arctic role. [ABSTRACT FROM PUBLISHER]

Eleven algorithms for the passive-microwave measurement of sea-ice were implemented and inter-compared. Daily, monthly and annual Arctic sea-ice concentration, area and extent were calculated by the algorithms using daily microwave brightness temperatures from SMMR, SSM/I, and SSMIS for the period 1979-2012. The differences between the 11 sea-ice concentration estimates-structural uncertainties-were quantified and analyzed spatially and seasonally. The algorithms differ in annual sea-ice area by 0.0-1.3 million km2 and in extent by 0.0-0.6 million km2. Linear trends for 34- and 21-year periods were calculated and compared for sea-ice concentration, area and extent. Low-frequency algorithms obtained annual Arctic sea-ice area decrease of 0.534-0.573 million km2 per decade (0.439-0.491 million km2 per decade for the extent) over the period 1979 to 2012, and a decrease of 0.866-0.975 million km2 per decade (0.767-0.812 million km2 per decade for the extent) for the 1992-2012 period. High-frequency algorithms obtained a decrease of 0.766-0.978 million km2 per decade in the area and 0.758-0.814 million km2 per decade in the extent over the period 1992-2012. Results for all the algorithms have close agreement on the strength of the negative trend in Arctic sea-ice area and extent, but are individually biased from the mean. The algorithms' ensemble mean and standard deviation in sea-ice concentration, describing part of the uncertainty, are presented to provide users with more insight into the uncertainties and potential biases of sea-ice concentration data. [ABSTRACT FROM PUBLISHER]

Korea implemented its Antarctic research program in 1987 and diversified to the Arctic in 2002. Since the development of the Joint Committee on Antarctic Data Management, Korea has acknowledged the importance of data management. The launch of the Korea Polar Research Institute in 2004 also saw establishment of the Korea Polar Data Center (KPDC), which outlines and executes a Polar Data Management Policy. KPDC has set up an Information Technology infrastructure and has developed a metadata management system. However, there is still a long way to go, especially in terms of raising researcher recognition for improving data registration and sharing. [ABSTRACT FROM AUTHOR]

The Polar Data Catalogue (PDC) is a growing Canadian archive and public access portal for Arctic and Antarctic research and monitoring data. In partnership with a variety of Canadian and international multi-sector research programs, the PDC encompasses the natural, social, and health sciences. From its inception, the PDC has adopted international standards and best practices to provide a robust infrastructure for reliable security, storage, discoverability, and access to Canada's polar data and metadata. Current efforts focus on developing new partnerships and incentives for data archiving and sharing and on expanding connections to other data centres through metadata interoperability protocols. [ABSTRACT FROM AUTHOR]

Localized permafrost disturbances such as active layer detachments (ALDs) are increasing in frequency and severity across the Canadian Arctic impacting terrestrial ecosystem functioning. However, the contribution of permafrost disturbance-carbon feedbacks to the carbon (C) balance of Arctic ecosystems is poorly understood. Here, we explore the short-term impact of active layer detachments (ALDs) on carbon dioxide (CO) exchange in a High Arctic semi-desert ecosystem by comparing midday C exchange between undisturbed areas, moderately disturbed areas (intact islands of vegetation within an ALD), and highly disturbed areas (non-vegetated areas due to ALD). Midday C exchange was measured using a static chamber method between June 23 and August 8 during the 2009 and 2010 growing seasons. Results show that areas of high disturbance had significantly reduced gross ecosystem exchange and ecosystem respiration ( R) compared to control and moderately disturbed areas. Moderately disturbed areas showed significantly enhanced net ecosystem exchange compared to areas of high disturbance, but were not significantly different from control areas. Disturbance did not significantly impact soil thermal, physical or chemical properties. According to average midday fluxes, ALDs as a whole (moderately disturbed areas: −1.942 μmol m s+ highly disturbed areas: 2.969 μmol m s) were a small CO source of 1.027 μmol m s which did not differ significantly from average midday fluxes in control areas 1.219 μmol m s. The findings of this study provide evidence that the short-term impacts of ALDs on midday, net C exchange and soil properties in a High Arctic semi-desert are minimal. [ABSTRACT FROM AUTHOR]