Search

The cloud feedback may result in amplification or damping of Arctic warming. Two common techniques used to diagnose the top‐of‐the‐atmosphere cloud feedback are the Adjusted Cloud Radiative Effect (AdjCRE) method and the Cloud Radiative Kernel (CRK) method. We apply both to CMIP5 and CMIP6 model data, finding that the AdjCRE calculated Arctic shortwave cloud feedback is twice as correlated with sea ice loss in CMIP5, and four times in CMIP6, as the CRK method. We find that the CRK method produces Arctic all‐sky residual percentages exceeding 20% in 15 of 18 models. We use the CRK method to decompose the feedback in CMIP5 and CMIP6 finding that its median value changed from negative to positive driven by a less‐negative cloud optical depth feedback. Despite its lack of closure, we conclude that the CRK method is better suited for Arctic SW feedbacks as it is less impacted by surface albedo changes. Plain Language Summary: The cloud feedback is the process by which cloud property changes in a warming climate can either further enhance warming or damp it. The Arctic is warming faster than the rest of the globe, and one of the largest sources of uncertainty in its climate projections is the cloud feedback. There are two popular methods to calculate the cloud feedback: the Adjusted Cloud Radiative Effect technique, and the Cloud Radiative Kernel technique. In this paper we compare the two methods in a suite of climate models by considering the extent to which changes in Arctic sea ice impact the cloud feedbacks. From this analysis we conclude that the Cloud Radiative Kernel method is less affected by sea ice loss. We then apply the Cloud Radiative Kernel technique to data from the two most recent generations of global climate models to investigate how polar day Arctic cloud feedbacks have changed between these generations. We find that the median value of these Arctic feedbacks is slightly positive in the newest generation of models, a change from slightly negative in the previous generation that is largely fueled by a weakening of the feedback associated with changes in cloud optical depth. Key Points: The Cloud Radiative Kernel method is less sensitive to surface albedo changes than the Adjusted Cloud Radiative Effect techniqueThe Cloud Radiative Kernel method provides poor radiative closure in a suite of global climate modelsThe median shortwave Arctic cloud feedback in recent climate models is slightly positive due to a weakened cloud optical depth feedback [ABSTRACT FROM AUTHOR]

The sea ice albedo can amplify global climate change and affect the surface energy in the Arctic. In this paper, the data from Visible and Infra-Red Radiometer (VIRR) onboard Fengyun-3C satellite are applied to derive the Arctic sea ice albedo. Two radiative transfer models, namely, 6S and FluxNet, are used to simulate the reflectance and albedo in the shortwave band. Clear sky sea ice albedo in the Arctic region (60°~90°N) from 2016 to 2019 is derived through the physical process, including data preprocessing, narrowband to broadband conversion, anisotropy correction, and atmospheric correction. The results are compared with aircraft measurements and AVHRR Polar Pathfinder-Extended (APP-x) albedo product and OLCI MPF product. The bias and standard deviation of the difference between VIRR albedo and aircraft measurements are −0.040 and 0.071, respectively. Compared with APP-x product and OLCI MPF product, a good consistency of albedo is shown. And analyzed together with melt pond fraction, an obvious negative relationship can be seen. After processing the 4-year data, an obvious annual trend can be observed. Due to the influence of snow on the ice surface, the average surface albedo of the Arctic in March and April can reach more than 0.8. Starting in May, with the ice and snow melting and melt ponds forming, the albedo drops rapidly to 0.5–0.6. Into August, the melt ponds begin to freeze and the surface albedo increases. [ABSTRACT FROM AUTHOR]

After describing how the marine environment is tottering in the face of the triple environmental crisis, this article explores the limited governance progressions at the global and regional levels in addressing the threats of pollution, climate change and biodiversity loss in the especially vulnerable Arctic. For pollution, key limitations include slow and arduous processes to add chemicals for control under the Stockholm and Rotterdam Conventions and reliance at the regional level on a fragmented array of pollution studies and projects but without specific region-wide legally binding pollution standards. For climate change, the world is not on track to meet the Paris Agreement's temperature targets which is especially problematic for the Arctic cryosphere while the Arctic Council has largely been limited to providing general statements of concern and aspirational calls for enhanced climate mitigation and adaptation actions. For marine biodiversity losses, a pan-Arctic network of marine protected areas has yet to be developed and various implementation challenges surround the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean including the need to ensure adequate financial, human resource and technical support. The paper concludes by highlighting some promising future governance directions. They include: the conclusion of a global treaty on plastic pollution; implementation of a new Global Framework on Chemicals – For a Planet Free of Harm from Chemicals and Waste; expected further clarifications from international tribunals on State responsibilities to address climate change; and regional implementation of the Kunming-Montreal Global Biodiversity Framework and the new agreement under the UN Convention on Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction. [ABSTRACT FROM AUTHOR]

This paper analyzes the importance of the melting of the Arctic ice for Mexico. The research examines the impacts of this process, the Mexican government’s environmental policies, citizen’s perception and the media’s approach to climate change and the melting of the Arctic ice. To obtain the results, an exploratory analysis was carried out, from which it was concluded that, despite the importance of the Arctic melting in the current climate crisis affecting all countries, and specifically Mexico, within the political agendas of the nation, the citizenry and the mass media, both climate change and the Arctic melting are secondary issues. [ABSTRACT FROM AUTHOR]

Space observations (1979–2020) have shown that, over the past 40 years, years with a decrease in the area of summer ice and their thickness prevailed. Over 10 years, negative trends of anomalies in the area and thickness of the ice are –13 and –15%, respectively. A rapid reduction in the area of old ice (>4-year-old) is also noted, because in 1985 it was estimated at 2.7 million km2, while in March 2010 it was 0.34 million km2. The paper analyses paleo sea ice extent during the Holocene (the last 12 000 years) based on empirical IP25 biomarkers (a sea ice proxy with 25 carbon atoms synthesized by the specific Arctic sea ice diatoms Hasleaspp, which have been proven to be a suitable proxy for paleo-sea ice reconstructions) obtained from deep-sea cores from the North Atlantic. The data showed that, during the warm periods of the Early and Middle Holocene, the area of summer sea ice was reduced to a minimum. This confirms the conclusion made earlier in (Kinnard et al., 2011) that the current trend of reducing the area and thickness of ice is unprecedented over the past 1500 years. There is no complete analogue of the climate in the past corresponding to the current level of the CO2 concentration in the atmosphere. The period with CO2 concentrations in the atmosphere similar to the current level was the warm part of the Middle Pliocene between 3 and 4 million years ago with level of the CO2 concentration 450–500 ppm against approximately 420 ppm at present. Paleo-climate reconstructions for this period estimate the global temperature to be 3.0–3.5 ± 0.5°C higher than at the end of the 19th century. Summer air temperatures in the high latitudes of the Northern Hemisphere exceeded the current ones by 8–10°C, and the sea ice in the Arctic shelf seas was completely absent in the summer. Empirical data and model simulations have shown that presently the main driver of the reduction of the Arctic sea ice area is the increase in concentration of CO2 in the atmosphere. At the present time, old sea ice tends to be replaced by seasonal ice, demonstrating a natural shift from the predominance of permanent ice to an ice-free Arctic. In the case of a continuous increase in CO2 concentration in the atmosphere despite emission control measures, one of the scenarios that happened in the past may occur again. [ABSTRACT FROM AUTHOR]

This paper explores the potential of ground-penetrating radar (GPR) monitoring for an advanced understanding of snow cover processes and structure. For this purpose, the study uses the Hansbreen (SW Spitsbergen) records that are among the longest and the most comprehensive snow-cover GPR monitoring records available on Svalbard. While snow depth (HS) is frequently the only feature derived from high-frequency radio-echo sounding (RES), this study also offers an analysis of the physical characteristics (grain shape, size, hardness, and density) of the snow cover structure. We demonstrate that, based on GPR data (800 MHz) and a single snow pit, it is possible to extrapolate the detailed features of snow cover to the accumulation area. Field studies (snow pits and RES) were conducted at the end of selected accumulation seasons in the period 2008–2019, under dry snow conditions and HS close to the maximum. The paper shows that although the snow cover structure varies in space and from season to season, a single snow pit site can represent the entire center line of the accumulation zone. Numerous hard layers (HLs) (up to 30% of the snow column) were observed that reflect progressive climate change, but there is no trend in quantity, thickness, or percentage contribution in total snow depth in the study period. HLs with strong crystal bonds create a "framework" in the snowpack, which reduces compaction and, consequently, the ice formation layers slow down the rate of snowpack metamorphosis. The extrapolation of snow pit data through radar profiling is a novel solution that can improve spatial recognition of snow cover characteristics and the accuracy of calculation of snow water equivalent (SWE). [ABSTRACT FROM AUTHOR]

This paper examines teleconnections between the Arctic and the Baltic Sea region and is based on two cases of CESM-LE climate model simulations': the stationary case with pre-industrial radiative forcing and the climate change case with measured and RCP8.5 radiative forcing. Stationary control simulation 1800-year long time-series were used for stationary teleconnection and 40-member ensemble from the period 1920-2100 for teleconnections during ongoing climate change. We analyzed seasonal temperature at a 2-meter level, sea-level pressure, sea ice concentration, precipitations, geopotential height and 10-meter level wind speed. The Arctic was divided into seven areas. the Baltic Sea region climate has strong teleconnections with the Arctic climate; the strongest connections are with Svalbard and Greenland region. There is high seasonality in the teleconnections, with the strongest correlations in winter and the lowest correlations in summer, when the local factors are stronger. The majority of teleconnections in winter and spring can be explained by climate indexes NAO and AO. During ongoing climate change, the teleconnection patterns did not show remarkable developments by the end of the 21st century. Minor pattern changes are between the Baltic Sea region temperature and the sea ice concentration. To estimate different Arctic regions' collective statistical connections with the Baltic Sea region, we calculated the correlation between the parameter and its Ridge regression estimation. Seasonal coefficient of determination, R2, were highest for winter: for temperature R2 = 0.64, for surface pressure R2 = 0.44 and for precipitation R2 = 0.35. When doing the same for the seasons' previous month values in the Arctic, the relations are considerably weaker with the highest R2 = 0.09 for temperature in the spring. Hence, the forecasting capacity of Arctic climate data for the Baltic Sea region is weak. Although there are statistically significant teleconnections between the Arctic and Baltic Sea region, the Arctic impacts are regional and mostly connected with climate indexes. There are no simple cause-and-effect pathways. By the end of the 21st century, the Arctic ice concentration has significantly decreased. Still, the general teleconnections pattern between the Arctic and the Baltic Sea region will not change considerably by the end of the 21st century. [ABSTRACT FROM AUTHOR]

The Arctic is rapidly warming posing a significant threat to underlying permafrost. Permafrost degradation has already resulted in extensive damage to the Arctic's built infrastructure, putting communities and industries at risk. Projected climate warming will further reduce the capacity of permafrost to support infrastructure, thereby requiring a rethinking of construction and development of permafrost regions in the future. This paper focuses on three Arctic regions with a substantial presence of population and infrastructure on permafrost: USA (Alaska), Canada, and Russia. The three regions' permafrost construction practices are examined in order to identify best practices and major gaps. We identify a lack of standardized, codified construction guidelines; an absence of permafrost-geotechnical monitoring in communities; barriers to integrating climate scenarios into future planning; limited data sharing; and low numbers of permafrost professionals as major constraints limiting the region's resilience in the face of climate change. Refining building practices and standards, implementing operational permafrost monitoring systems, developing downscaled climate projections, and integrating local knowledge will minimize the impacts of permafrost degradation under rapidly warming climatic conditions. [ABSTRACT FROM AUTHOR]

Keywords: Arctic; alaska; climate change; bering Sea; wildfires; permafrost; carbon emissions EN Arctic alaska climate change bering Sea wildfires permafrost carbon emissions 129 132 4 05/12/20 20200501 NES 200501 Anyone who has ever tried to convince a hesitant friend or family member that climate change is really happening can attest to the difficulty of the task. In 2018, sea ice in the Bering Sea hit record low levels, and you coauthored an academic paper about this event and how strongly we can attribute it to climate change (Thoman et al. [5]). B BB b :There are a few types of sea ice that we should distinguish. The formation of that ice becomes entirely dependent on the water temperature in the Bering Sea and the air temperature during the cold season. Arctic, alaska, climate change, bering Sea, wildfires, permafrost, carbon emissions. [Extracted from the article]

Arctic sea ice change is one of the critical factors affecting the global climate environment; hence, it is crucial to obtain sea ice thickness with high accuracy while studying polar and global climate change. In the process of using altimetry data to estimate sea ice thickness, the mean sea surface height will bring greater uncertainty to the extraction of sea ice freeboard, which will affect the accuracy of sea ice thickness. Also, the influence of snow cover on radar signal penetration will bring greater uncertainty to sea ice thickness. In this paper, we present a processing chain for sea ice thickness estimation. First, we compare the effect of four different MSS models on the freeboard estimation. Then, considering the incomplete penetration of radar signals and the different speeds of radar signals penetrating the snow layer and the vacuum, the traditional sea ice thickness model is optimized to obtain the sea ice thickness. Compared with the Operation IceBridge (OIB) sea ice thickness, the accuracy of sea ice thickness obtained by the optimized model is better than 0.350 m, with a root mean square error of 0.260 m and a mean bias of 0.048 m. The comparison results show that the combination of the latest DTU18 MSS model and sea ice thickness optimization model effectively improve the accuracy of sea ice thickness. [ABSTRACT FROM AUTHOR]

As one of the best indicators of the periglacial environment, ice-wedge polygons (IWPs) are important for arctic landscapes, hydrology, engineering, and ecosystems. Thus, a better understanding of the spatiotemporal dynamics and evolution of IWPs is key to evaluating the hydrothermal state and carbon budgets of the arctic permafrost environment. In this paper, the dynamics of ground surface deformation (GSD) in IWP zones (2018–2019) and their influencing factors over the last 20 years in Saskylakh, northwestern Yakutia, Russia were investigated using the Interferometric Synthetic Aperture Radar (InSAR) and Google Earth Engine (GEE). The results show an annual ground surface deformation rate (AGSDR) in Saskylakh at −49.73 to 45.97 mm/a during the period from 1 June 2018 to 3 May 2019. All the selected GSD regions indicate that the relationship between GSD and land surface temperature (LST) is positive (upheaving) for regions with larger AGSDR, and negative (subsidence) for regions with lower AGSDR. The most drastic deformation was observed at the Aeroport regions with GSDs rates of −37.06 mm/a at tower and 35.45 mm/a at runway. The GSDs are negatively correlated with the LST of most low-centered polygons (LCPs) and high-centered polygons (HCPs). Specifically, the higher the vegetation cover, the higher the LST and the thicker the active layer. An evident permafrost degradation has been observed in Saskylakh as reflected in higher ground temperatures, lusher vegetation, greater active layer thickness, and fluctuant numbers and areal extents of thermokarst lakes and ponds. [ABSTRACT FROM AUTHOR]

Understanding and predicting Arctic change and its impacts on global climate requires broad, sustained observations of the atmosphere-ice-ocean system, yet technological and logistical challenges severely restrict the temporal and spatial scope of observing efforts. Satellite remote sensing provides unprecedented, pan-Arctic measurements of the surface, but complementary in situ observations are required to complete the picture. Over the past few decades, a diverse range of autonomous platforms have been developed to make broad, sustained observations of the ice-free ocean, often with near-real-time data delivery. Though these technologies are well suited to the difficult environmental conditions and remote logistics that complicate Arctic observing, they face a suite of additional challenges, such as limited access to satellite services that make geolocation and communication possible. This paper reviews new platform and sensor developments, adaptations of mature technologies, and approaches for their use, placed within the framework of Arctic Ocean observing needs. [ABSTRACT FROM AUTHOR]

Climate change has increasing visible effects on the environment, particularly in the Arctic, where the sea-ice melted faster in 2020 than any time before. It directly threatens the Inuit people's survival, whose livelihood is mainly based on traditional modes of subsistence (hunting, fishing and gathering). In light of the environmental crisis, this paper carries out a critical analysis of the Nunavut (Canada) legal framework, granting Inuit specific rights regarding their traditional way of life. While recognizing that this framework implements international human rights legal standards, we argue that the human right lens presents limitations in addressing climate change impacts on Inuit livelihood. By acknowledging the developments following the adoption of the United Nations Declarations on the Rights of Indigenous Peoples and on the Rights of Peasants and Other Peoples Living in Rural Areas, leading to the recognition of some collective rights to communities and people living of the land, we address the gaps of human rights –which are mainly individual –to reflect the importance of recognizing collective rights in the adaptation to the global climate change challenge. Indeed, the paper argues for the necessity to recognize the community level in the climate international governance scene. [ABSTRACT FROM AUTHOR]

The currently-observed increase in human activity in the Arctic accelerates the negative impact on the environment as well as increases the risk of threats to mankind itself. This paper reviews and summarises a selection of studies on the interaction between humans and the environment in the Arctic coastal zone, which is impacted by a warming climate and associated geohazards. The paper presents a general description of human presence in the Arctic, identifies and describes the processes that are threatening the infrastructure, and the anthropogenic processes that have a negative impact on the Arctic. It considers the possible future economic opportunities, and presents the sustainable requirements for modern human activity in the Arctic. The paper demonstrates the urgent need to develop a common, Arctic-wide strategy based on sustainable development. The time has come to change human perception of the Arctic because, in the near future, it may be considered as a refuge for climate change refugees. [ABSTRACT FROM AUTHOR]

This paper examines the processes that drive Arctic anomalous surface warming and sea ice loss during winter-season tropospheric energy flux events, synoptic periods of increased tropospheric energy flux convergence (Ftrop), using the NASA MERRA-2 reanalysis. During an event, a poleward anomaly in Ftrop initially increases the sensible and latent energy of the Arctic troposphere; as the warm and moist troposphere loses heat, the anomalous energy source is balanced by a flux upward across the tropopause and a downward net surface flux. A new metric for the Arctic surface heating efficiency (Etrop) is defined, which measures the fraction of the energy source that reaches the surface. Composites of high-, medium-, and low-efficiency events help identify key physical factors, including the vertical structure of Ftrop and Arctic surface preconditioning. In high-efficiency events (Etrop ≥ 0.63), a bottom-heavy poleward Ftrop occurs in the presence of an anomalously warm and unstratified Arctic—a consequence of decreased sea ice—resulting in increased vertical mixing, enhanced near-surface warming and moistening, and further sea ice loss. Smaller Etrop, and thus weaker surface impacts, are found in events with anomalously large initial sea ice extent and more vertically uniform Ftrop. These differences in Etrop are manifested primarily through turbulent heat fluxes rather than downward longwave radiation. The frequency of high-efficiency events has increased from the period 1980–99 to the period 2000–19, contributing to Arctic surface warming and sea ice decline. [ABSTRACT FROM AUTHOR]

This paper reviews some of the highlights of selected topics in ocean acoustics during the thirty years that have passed since the founding of the Journal of Theoretical and Computational Acoustics. Advances in computational methods and computers helped to make computational ocean acoustics a vibrant area of research during that period. The parabolic equation method provides an unrivaled combination of accuracy and efficiency for propagation problems in which the bathymetry, sound speed, and other environmental parameters vary in the horizontal directions. The extension of this approach to cases involving layers that support shear waves has been an active area of research throughout the thirty year period. Interest in basin-scale and global-scale propagation was stimulated by the Heard Island Feasibility Test for monitoring climate change in terms of changes in travel time that occur as the temperature of the ocean rises. Diminishing ice cover in the Arctic, which is one of the consequences of climate change, has stimulated renewed interest in Arctic acoustics during the past decade. Reverberation is a challenging problem that was the topic of a major research program during the beginning of the thirty year period. An innovative approach for making it feasible to solve such problems was applied to data for reverberation from the seafloor and from schools of fish, and some of the findings were featured in Science and Nature. Source localization is one of the core problems in ocean acoustics. When applied on a 2-D array of receivers, an approach based on the eigenvectors of the covariance matrix is capable of separating the signals from different sources from each other, determining when this partitioning step is successful, and tracking sources that cross each other in bearing; one of the advantages of this approach is that it does not require environmental information or solutions of the wave equation. Geoacoustic inversion for estimating the layer structure, wave speeds, density, and other parameters of ocean bottoms has also been a topic of interest throughout the thirty year period. [ABSTRACT FROM AUTHOR]

Arctic Ocean freshwater storage increased since the mid‐1990s, but the cause was unknown. Jahn and Laiho (2020, https://doi.org/10.1029/2020GL088854) use ensemble runs of a coupled climate model to suggest that the observed increase is anthropogenic. The paper quantifies when the anthropogenic signals should emerge from the noise of natural variability. This result contextualizes research on the Arctic Ocean freshwater system and sketches an unprecedented opportunity. Future work should elucidate mechanisms, seek to observe the anthropogenic freshwater changes, and investigate the impacts on biogeochemistry and the North Atlantic Ocean circulation. Plain Language Summary: The Arctic is a region of clear man‐made climate change. Changes in the Arctic Ocean salinity and currents have been seen, but the cause was unknown. A new paper shows that the changes are probably due to man‐made climate change. The reason is they only occur in a climate model with man‐made climate forcing. This is an important result because it helps scientists focus their research into how the changes work. It also points to a valuable opportunity to watch the Arctic Ocean respond to man‐made climate change. There might be important future impacts on North Atlantic oceanography and North Atlantic climate that scientists can now look for. Key Points: A recent paper shows that observed increases in Arctic Ocean freshwater storage are anthropogenicThe paper anticipates future anthropogenic changes, which are testable predictions for observersThere are widespread impacts of anthropogenic freshwater change, both within the Arctic and the North Atlantic Oceans [ABSTRACT FROM AUTHOR]

In recent years, International Relations' research area has expanded including terrorism, environmental issues, ethnic-politics-denomination based local disputes besides energy geopolitics. Particularly in the light of climate change, one of new regions driven by environmental factors, security and energy geopolitics, the Arctic has been getting more substantial during the last century. Through navigation, strategic base, mine and seafood prosperity, and scientific research besides its explored energy resources, the Arctic has been facing a political and juristicial sovereignty struggle at recent years. Within this paper, it is aimed to assess the centennial struggle over the Arctic in terms of energy geopolitics, different political perceptions and sovereignty disputes among the Arctic states. Through interdependent relations among the coastal states and using descriptive analysis as a method, the paper is concluded with the claim that cooperation is preferable in the region. [ABSTRACT FROM AUTHOR]

A review of many studies published since the late 1920s reveals that the main driving mechanisms responsible for the early-twentieth-century Arctic warming (ETCAW) are not fully recognized. The main obstacle seems to be our limited knowledge about the climate of this period and some forcings. A deeper knowledge based on greater spatial and temporal resolution data is needed. The article provides new (or improved) knowledge about surface air temperature (SAT) conditions (including their extreme states) in the Arctic during the ETCAW. Daily and subdaily data have been used (mean daily air temperature, maximum and minimum daily temperature, and diurnal temperature range). These were taken from 10 individual years (selected from the period 1934–50) for six meteorological stations representing parts of five Arctic climatic regions. Standard SAT characteristics were analyzed (monthly, seasonal, and yearly means), as were rarely investigated aspects of SAT characteristics (e.g., number of characteristic days, day-to-day temperature variability, and the onset, end, and duration of thermal seasons). The results were compared with analogical calculations done for data taken from the contemporary Arctic warming (CAW) period (2007–16). The Arctic experienced warming between the ETCAW and the CAW. The magnitude of warming was greatest in the Pacific (2.7°C) and Canadian Arctic (1.9°C) regions. A shortening of winter and lengthening of summer were noted. Furthermore, the climate was also a little more continental (except the Russian Arctic) and less stable (greater day-to-day variability and diurnal temperature range) during the ETCAW than during the CAW. Significance Statement: It is well established that human activity (particularly increased greenhouse gas emissions) is the primary driving mechanism of the recent dramatic warming in the Arctic. However, the causes of a similar warming here in the first half of the twentieth century remain uncertain. The limited knowledge about the climate of that period—which mainly results from the low resolution of data—is a significant obstacle to a definitive determination of the forcing mechanisms. Therefore, the main aim of our paper is to improve our understanding of specific aspects of weather and climate (including extremes) using long-term series of daily and subdaily data that have rarely been applied for this purpose. This new, more comprehensive knowledge about the historical Arctic climate should allow the scientific community (particularly climate modelers) to better validate both climate models and reanalysis products and, consequently, to more precisely identify the causes of the early-twentieth-century Arctic warming. [ABSTRACT FROM AUTHOR]

In early studies, northern vegetation response to global warming recognised both increases in biomass/cover and shrinking of species' distributional ranges. Subsequent field measurements focussed on vegetation cover and biomass increases ("greening"), and more recently decreases ("browning"). However, satellite observations show that more than 50% of arctic vegetation has not changed significantly despite rapid warming. While absence of change in remote sensing data does not necessarily mean no ecological change on the ground, the significant proportion of the Arctic that appears to be stable in the face of considerable climate change points to a greater need to understand Arctic ecosystem stability. In this paper, we performed an extensive review of the available literature to seek balances or imbalances between research focussing on "greening", "browning" and "stability/no change". We find that greening studies dominate the literature though two relatively small areas of the Arctic are disproportionately represented for this main change process. Critically, there are too few studies anywhere investigating stability. We highlight the need to understand the mechanisms driving Arctic ecosystem stability, and the potential longer-term consequences of remaining stable in a rapidly changing climate. [ABSTRACT FROM AUTHOR]

Sea ice continues to decline across many regions of the Arctic, with remaining ice becoming increasingly younger and more dynamic. These changes alter the habitats of microbial life that live within the sea ice, which support healthy functioning of the marine ecosystem and provision of resources for human-consumption, in addition to influencing biogeochemical cycles (e.g. air–sea CO2 exchange). With the susceptibility of sea ice ecosystems to climate change, there is a pressing need to fill knowledge gaps surrounding sea ice habitats and their microbial communities. Of fundamental importance to this goal is the development of new methodologies that permit effective study of them. Based on outcomes from the DiatomARCTIC project, this paper integrates existing knowledge with case studies to provide insight on how to best document sea ice microbial communities, which contributes to the sustainable use and protection of Arctic marine and coastal ecosystems in a time of environmental change. [ABSTRACT FROM AUTHOR]

The Canadian Arctic is a complex and fragile region which is currently experiencing unprecedented environmental degradation due to climate change. The effects of climate change on the Canadian Arctic is just one example where we're seeing the decline of ecosystems and socio-culture-environmental traditions. Mineral development in this already fragile ecosystem is indeed a contentious and high-risk endeavour. However, mining is currently one of the few industries and economic development opportunities in the Canadian Arctic, which is one of the poorest regions in Canada. Unfortunately, mining struggles to achieve environmental sustainability due to mineral development's inherent trade-off of short-term economic gains for long-term environmental impacts. Local communities are usually left with trying to find this balance. This paper analyzes how we can apply decision-making techniques and environmental management tools for the Canadian Arctic's mining industry to promote better environmental sustainability, understanding of environmental-economic trade-offs, and community involvement. Specific decision-making methodologies and management tools are analyzed to develop, discuss, and explore their application for the Canadian Arctic. This paper concludes with a framework that brings together the analyzed methods and Arctic specificities; to prioritize environmental issues and to ensure long-term thriving communities in the Arctic. [ABSTRACT FROM AUTHOR]

The data obtained during the recent decades indicate large-scale climatic changes in the Arctic Ocean, especially in the Siberian shelf seas. The impact of shrinking of the Arctic ice cover on marine net primary production (PP) was mostly studied using satellite-derived estimates of chlorophyll-a (Chl a), sea surface temperature, and sea ice concentrations, as well as various modeling approaches. However, no data are available on the quantitative relations between phytoplankton production and heterotrophic bacterioplankton activity in the broadest and shallowest shelf of the World Ocean - the East Siberian Arctic seas (ESAS). In this paper we present a full set of in situ measurements of main PP and microbial heterotrophy characteristics required for better understanding and further validation of the satellite and modeling approaches. In September–October 2011, during the 57th cruise of RV Akademik M.A. Lavrent'ev , PP, bacterioplankton abundance (BA) and bacterioplankton production (BP), as well the rates of dark CO 2 assimilation (DCA) were determined in the Chukchi, East Siberian, and Laptev seas and in the Gulf of Anadyr of the Bering Sea (a total of 26 stations) by in situ measurements using radiolabeled bicarbonate. All three important production indicators exhibited significant variance within the studied water areas of the Arctic (РР from 0.98 to 54.7 μg C L−1 day−1), (ВР from 1.1 to 17.1 μg C L−1 day−1), and (DCA from 0.23 to 8.7 μg C L−1 day−1). The state of phyto- and bacterioplankton was determined by analysis of the BP/PP and DCA/PP ratios. Active photosynthesis with efficient incorporation of inorganic carbon into the biomass was observed in the Chukchi Sea coastal eastern waters and in the Gulf of Anadyr. On the contrary, the phytoplankton primary production was extremely low in oligotrophic basins of the East Siberian and Laptev seas, while the activity of heterotrophic bacterioplankton consuming organic matter of phytoplankton origin was relatively high. The data of direct measurements can be used for further adjustment of the indirect assessments of production obtained by satellite observations. Glossary East Siberian Arctic seas (ESAS), net primary production (PP), bacterioplankton abundance (BA), bacterial biomass (BB), bacterial production (BP), Arctic Ocean PP (AO-PP), organic matter (OM), dissolved organic matter (DOM), colored dissolved organic matter (CDOM), light CO 2 assimilation (LCA), dark (heterotrophic + chemotrophic) CO 2 assimilation (DCA), production indicators of the surface water layer (PP surf , DCA surf , BP surf), estimated production indicators for the entire depth of the sea (PP int , DCA int , BP int ; mg C m−2 day−1). [Display omitted] • The Arctic seas are characterized by high heterogeneity of phyto- and bacterioplankton activity. • In the Chukchi and Bering seas, autotrophic production is higher than heterotrophic. • In the East Siberian and Laptev Seas, heterotrophic production is similar and higher than autotrophic. • The balance of autotrophic and heterotrophic plankton activity determines the direction of CO 2 flow. [ABSTRACT FROM AUTHOR]

It is apparent that Biocatalysts are shaping the future by providing a more sustainable approach to established chemical processes. Industrial processes rely heavily on the use of toxic compounds and high energy or pH reactions, factors that both contributes to the worsening climate crisis. Enzymes found in bacterial systems and other microorganisms, from the glaciers of the Arctic to the sandy deserts of Abu Dhabi, provide key tools and understanding as to how we can progress in the biotechnology sector. These extremophilic bacteria harness the adaptive enzymes capable of withstanding harsh reaction conditions in terms of stability and reactivity. Carbohydrate-active enzymes, including glycoside hydrolases or carbohydrate esterases, are extremely beneficial for the presence and future of biocatalysis. Their involvement in the industry spans from laundry detergents to paper and pulp treatment by degrading oligo/polysaccharides into their monomeric products in almost all detrimental environments. This includes exceedingly high temperatures, pHs or even in the absence of water. In this review, we discuss the structure and function of different glycoside hydrolases from extremophiles, and how they can be applied to industrial-scale reactions to replace the use of harsh chemicals, reduce waste, or decrease energy consumption. [ABSTRACT FROM AUTHOR]

Climate change is predicted to have dramatic effects on Arctic freshwater ecosystems through changes to the abiotic template that are expected to influence biodiversity. Changes are already ongoing in Arctic systems, but there is a lack of coordinated monitoring of Arctic freshwaters that hinders our ability to assess changes in biodiversity.To address the need for coordinated monitoring on a circumpolar scale, the Arctic Council working group, Conservation of Arctic Flora and Fauna, established the Circumpolar Biodiversity Monitoring Program, which is an adaptive monitoring program for the Arctic centred around four ecosystem themes (i.e., Freshwater, Terrestrial, Coastal, Marine). The freshwater theme developed a monitoring plan for Arctic freshwater biodiversity and recently completed the first assessment of status and trends in Arctic freshwater biodiversity.Circumpolar Biodiversity Monitoring Program–Freshwater has compiled and analysed a database of Arctic freshwater monitoring data to form the first report of the state of circumpolar Arctic freshwater biodiversity. This special issue presents the scientific analyses that underlie the Circumpolar Biodiversity Monitoring Program–Freshwater report and provides analyses of spatial and temporal diversity patterns and the multiple‐stressor scenarios that act on the biological assemblages and biogeochemistry of Arctic lakes and rivers.This special issue includes regional patterns for selected groups of organisms in Arctic rivers and lakes of northern Europe, Russia, and North America. Circumpolar assessments for benthic diatoms, macrophytes, plankton, benthic macroinvertebrates, and fish demonstrate how climate change and associated environmental drivers affect freshwater biodiversity. Also included are papers on spatial and temporal trends in water chemistry across the circumpolar region, and a systematic review of documented Indigenous Knowledge that demonstrates its potential to support assessment and conservation of Arctic freshwaters.This special issue includes the first circumpolar assessment of trends in Arctic freshwater biodiversity and provides important baseline information for future assessments and studies. It represents the largest compilation and assessment of Arctic freshwater biodiversity data to date and strives to provide a holistic view of ongoing change in these ecosystems to support future monitoring efforts. By identifying gaps in monitoring data across the circumpolar region, as well as identifying best practices for monitoring and assessment, this special issue presents an important resource for researchers, policy makers, and Indigenous and local communities that can support future assessments of ecosystem change. [ABSTRACT FROM AUTHOR]

Indigenous Peoples in the Arctic have for millennia relied on freshwaters for drinking water and freshwater species that comprise important subsistence harvests, which promotes a strong connection to the land and unique understanding of organisms and ecosystem processes and changes. Despite the importance of freshwater biodiversity and ecosystem services to Arctic Indigenous communities, there have been limited attempts to summarise available Indigenous Knowledge (IK) regarding Arctic freshwater systems and to understand how conservation can benefit from this knowledge base.This paper presents a systematic review of literature documenting circumpolar Arctic IK with a focus on freshwater biodiversity in Canada, Greenland, Fennoscandia (Norway, Sweden, and Finland), Russia, and the U.S.A. (Alaska). Standardised search terms and methodologies were used to locate relevant documents using Google Scholar and Google Advanced search engines. Thematic coding was used to identify freshwater biodiversity themes within the identified documents.Documented IK of freshwater biodiversity was found from all five geographic regions and included data on both species presence and habitat changes with potential to affect biodiversity. Canada had the highest number of relevant documents (n = 127), followed by the U.S.A. (Alaska; n = 116), Fennoscandia (n = 38), Russia (n = 27), and Greenland (n = 5). The number of relevant documents with IK published per year was highest in most recent years, from 2010 onwards, in all geographic regions.Fish represented the highest number of faunal observations with 59 species observed, approximately half of which were Salmonidae (29 species). Local‐scale assessment of fish diversity found observations of the highest number of species (11–25) in Alaska, and individual observations of 6–10 species were found throughout Alaska, mainland areas of Canada, and the Kola Peninsula in Russia. Documented IK also contributed new information on historical fish diversity and indicated local‐scale loss or gain of species. Such information is of vital importance to provide long‐term records of fish composition and abundance, especially when this information does not exist in other knowledge bases such as western science datasets.Indigenous Knowledge included observations of changes in freshwater and terrestrial habitat associated with a warming climate, such as: decreasing water levels and more draining/drying of lakes and rivers, a shorter period of ice cover (late freeze and early break‐up), decreasing ice thickness, and increasing occurrence of permafrost thaw and eroding banks. Such observations by those who actively rely on Arctic freshwater ecosystem services are important because they signify that change is occurring and that action is needed to mitigate the impacts on freshwater habitats and the biodiversity therein.This study demonstrates that previously documented IK provides valuable information towards determining freshwater biodiversity baselines and patterns of change in the circumpolar Arctic. However, these results do not sufficiently cover the depth and breadth of IK on freshwater biodiversity and ecology held by Indigenous communities. Further work incorporating Indigenous worldviews around freshwater ecology would provide context to the knowledge collected and a deeper understanding of Arctic circumpolar freshwater environments. [ABSTRACT FROM AUTHOR]

This paper provides an assessment of long-term trends in total cloud cover in the Arctic for the period 1985-2020 based on surface observations. Analysis shows that total cloud cover exhibits a substantial variation both between seasons and from year to year. Two areas of positive trends were found in the total cloud cover from October to April over the Arctic: one in the North Atlantic from 20° W up to 90° E and another from 150° E up to 150° W, which may be a result of atmospheric heat and moisture transport through the Atlantic and Pacific gates. Throughout the year, positive trends dominate over the Arctic Ocean and its seas (except for the Laptev Sea). Negative trends prevail over the continental parts of the Arctic. [ABSTRACT FROM AUTHOR]

A global problem facing humanity today is the changing planetary climate. The Earth's northern regions play an important role in processes that affect the environment on a global scale and serve as indicators of global natural changes, especially climate change. The currently observed climate changes in the Arctic, such as rising air temperature, shrinking ice cover, increased river runoff, and permafrost degradation, have already shown that the Arctic is experiencing the greatest changes in comparison with other regions of the Earth. The response of the Arctic to all climatic change occurring on the planet is the strongest. The strong and rapid changes in the Arctic climate in recent years require comprehensive studies of their causes with assessment of the role of natural and anthropogenic factors. This paper analyzes the temporal changes in a number of Arctic climate indicators based on its main components (air temperature and oscillations in the atmospheric circulation, ocean waters, and ice cover extent) at time intervals of the 20th century, the period of anthropogenic impact on the climate, the last 2000 years, and the Holocene period, as well as the role of solar activity (cyclical changes and insolation) in climate change on the Earth. Trends in the variation in natural climate indicators are traced. Problems of prime importance for an understanding of the nature of current climate change and the main physical processes responsible for these changes are discussed. The goal of the study is to summarize the current understanding of Arctic climate change. [ABSTRACT FROM AUTHOR]

Changes in climate, land-use and pollution are having disproportionate impacts on ecosystems and biodiversity of arctic and mountain ecosystems. While these impacts are well-documented for many areas of the Arctic and alpine regions, some isolated and inaccessible mountain areas are poorly studied. Furthermore, even in well-studied regions, assessments of biodiversity and species responses to environmental change are biased towards vascular plants and cryptogams, particularly bryophytes are far less represented. This paper aims to document the environments of the remote and inaccessible Altai-Sayan mountain mires and particularly their bryofloras where threatened species exist and species new to the regional flora are still being found. As these mountain mires are relatively inaccessible, changes in drivers of change and their ecosystem and biodiversity impacts have not been monitored. However, the remoteness of the mires has so far protected them and their species. In this study, we describe the mires, their bryophyte species and the expected impacts of environmental stressors to bring attention to the urgency of documenting change and conserving these pristine ecosystems. [ABSTRACT FROM AUTHOR]

Institutions are influential in mediating the impact of adaptation initiatives at the local level, yet there are disconnects between the goals of multi-scale planning initiatives and community priorities. Research to address this challenge primarily focuses on reform to formal institutions in environmental governance. Meanwhile, knowledge of the specific role informal institutions play in governance processes remains limited. This study increases understanding of the interactions between informal institutions and adaptation using a case study of the Native Village of Wainwright on Alaska's North Slope. Qualitative contextual analysis was employed to identify patterns of informal institution and adaptation associations in historic and contemporary situations in Wainwright. The Adaptation Institutional Analysis Framework developed in this paper extends Elinor Ostrom's Institutional Analysis and Development Framework and is used as a tool to analyse and describe these dynamics. Four primary findings resulted from this analysis (1) identification of informal institutions that have a bearing on adaptation to environmental change and adaptive capacity in Wainwright, (2) insight into how the identified institutions relate to each other and to different aspects of local adaptation, (3) identification of changes in informal institutions that have occurred over time and the potential implications of these changes for local adaptive capacity, and (4) potential opportunities to leverage knowledge of informal institution and adaptation relationships in targeted formal initiatives. The outcomes of this study contribute to an improved understanding of the function and potential of informal institutions in adaptation processes, the benefits of which extend beyond the local context of Wainwright. [ABSTRACT FROM AUTHOR]

Climate change and global warming strongly impact the cryosphere. The rise of air temperature and change of precipitation patterns lead to dramatic responses of snow and ice heat and mass balance. Sustainable field observations on lake air–snow–ice–water temperature regime have been carried out in Lake Orajärvi in the vicinity of the Finnish Space Centre, a Flagship Supersite in Sodankylä in Finnish Lapland since 2009. A thermistor-string-based snow and ice mass balance buoy called "Snow and ice mass balance apparatus (SIMBA)" was deployed in the lake at the beginning of each ice season. In this paper, we describe snow and ice temperature regimes, snow depth, ice thickness, and ice compositions retrieved from SIMBA observations as well as meteorological variables based on high-quality observations at the Finnish Space Centre. Ice thickness in Lake Orajärvi showed an increasing trend. During the decade of data collection (1) the November–May mean air temperature had an increasing trend of 0.16 ∘ C per year, and the interannual variations were highly correlated (r = 0.93) with the total seasonal accumulated precipitation; (2) the maximum granular ice thickness ranged from 15 % to 80 % of the maximum total ice thickness; and (3) the snow depth on lake ice was not correlated (r = 0.21) with the total precipitation. The data set can be applied to investigate the lake ice surface heat balance and the role of snow in lake ice mass balance and to improve the parameterization of snow to ice transformation in snow and ice models. The data are archived at 10.5281/zenodo.4559368 (Cheng et al., 2021). [ABSTRACT FROM AUTHOR]

Throughout his tenure as Prime Minster of Canada (2006-2015), Stephen Harper had a particular fascination with the Canadian North, illustrated in part by his annual tours of the Canadian Arctic and Subarctic region. Using these tours as a case study, this paper argues that state discourses of sovereignty, resource development, and climate change are intertwined with the simultaneous production of a tourist landscape. This tourist landscape is established in part through the circulation of affect within state discourses, like those engaged by Harper on his northern tours. The affective economies of tourism in the Canadian Arctic are heavily intertwined with both market-focused policy objectives and the moral imperative established by climate change. The result is a discourse of northern Canada that puts it within the purview of southern Canada. In particular, the affective, economic, and ecological dynamics in northern Canada produce an image of the North as both a playground for southern desires and a place in danger that is in need of saving. This moral economy in the North proposes market-based solutions and ethics for both economic and environmental problems. [ABSTRACT FROM AUTHOR]

Climate change threatens many well‐preserved archaeological sites in the Arctic. The paper presents the first Arctic multi‐threat assessment focusing on the Nuuk region of Greenland. The results suggest that the majority of the 336 known archaeological sites are already exposed to impacts from microbial degradation, permafrost thaw and vegetation, and that these impacts will increase over the next 80 years. Additional impacts from coastal erosion are only noted at a limited number of sites due to a predominant consolidated and uplifting coast. The applied methods represent an important first step to identify threatened sites and emphasize important data limitations. [ABSTRACT FROM AUTHOR]

Recent research has focused on the impacts of environmental change to tourism. In particular, the perceived costs of climate change have been increasingly studied. However, the relationship between costs and benefits resulting from the changing environmental conditions for the industry has been less examined. This paper identifies the locally observed changes in the natural and socio-economic environments and aims to analyse the financial costs and benefits to tourism businesses in two tourism-dependent communities in northern Finland. The specific focus is on adaptation and adaptive management in a tourist destination scale. Adaption is understood as an investment creating not only implementation costs, but potentially also benefits for tourism operations. Research materials were collected among tourism and tourism-related businesses through 41 semi-structured thematic interviews. Results indicate that the evaluated benefits of environmental change seem to exceed those of costs. This conforms to the on-going discourse of climate change-tourism relations associated with the Arctic region where both awareness and vulnerability to change are considered relatively high but the level of responses, i.e. adaptation, low. These results can help to further identify the most vulnerable sectors in tourism and assist entrepreneurs preparing for environmental and climate change. However, the paper concludes that while global environmental change, with specific adaptive management strategies, may create local short-term direct benefits for the industry, a long-term sustainability of tourism in the Arctic calls for mitigation responses to climate change. [ABSTRACT FROM AUTHOR]

A space in rapid flux, environmentally as well as geopolitically, the Arctic region has not tended to be seen as part of the imagined national “homeland” of the eight states with Arctic territories. Yet, in a time of climate change and increasing international attention to the region, the Arctic is at present re-narrated as a space embedded in sovereign statehood and national identity. Recognising the powerful purchase of identity discourses, of emotional attachment, and feelings of belonging, this paper asks: What does it mean to “be” or represent an Arctic state; how do identity discourses permeate among those tasked with the state's enactment on a daily basis, state personnel? This paper explores articulations of state identity by state practitioners in three of the eight Arctic states: Norway, Iceland, and Canada. In so doing, it develops an understanding of discourses of state identity as spatiotemporally regulated, articulated as geography and history; and yet, it shows how it always comes about through relations and encounters – across, beyond, and exceeding scales, from international relations to the intimately personal. Focusing on the performance of politics, the paper thereby highlights the constitutive role of the diverse practitioners behind the practice, the articulators, and performers. In short, it argues for “peopling” political geographical conceptualisations of the state, statecraft, and political practices. By seeing the state for its people, new avenues for interaction and dialogue may open up – new, radical ways of relating and participating in politics as, of, and by people. [ABSTRACT FROM AUTHOR]

Modern Arctic Indigenous peoples face many interconnected pressures, not the least of which is anthropogenic climate change, which is emerging as one of the most dramatic drivers of social and economic change in recent memory. In this paper, we investigate whether or not insights into premodern strategies for coping with climate change—and especially the "deeper histories" of traditional ways-of-knowing—can play a useful role in future planning, management and mitigation efforts. We do this in two ways. First, we assess this special issue's 17 archaeological case studies, in order to determine whether they are conducted within a framework that is consistent with approaches to resilience in studies of modern Arctic communities. Second, we focus on three climate-driven challenges faced by Canadian Arctic Inuit: safe travel, food security and food safety. For each, we identify specific ways in which studies of past social-ecological systems intersect with modern climate adaptation. We conclude that since archaeological insights highlight the operation of decision-making processes within long-term culture-adaptive trajectories, they can offer unique insights into the much shorter-term processes currently underway. While we highlight many potential directions for productive collaboration, much more work is required in local and regional settings to demonstrate the full potential of archaeology for future-oriented planning and mitigation efforts. [ABSTRACT FROM AUTHOR]

Most parts of the Circumpolar Arctic have only discontinuous evidence for long-term human settlement. In contrast, Northern Norway has an unbroken archaeological record that extends back to the early Holocene. Numerous high-resolution archaeological and palaeoenvironmental records have been generated by commercial excavations and surveys, offering archaeologists unique opportunities to investigate long-term human ecodynamics in an Arctic coastal setting. To date, however, deeper analysis of the new datasets has yet to be undertaken. This paper aims to present a new synthesis of early and mid Holocene archaeological and paleoenvironmental sequences for Western Finnmark (11500-2000 cal BP). This enables us to identify three major phases of culture change that broadly correlate with climatic and environmental shifts. We then present emerging results from our multi-scalar analysis of the processes driving these transformations. At supra-regional and regional scales, our palaeodemographic modelling indicates major population events centered around 6000 cal BP and 4000 cal BP. At intra-regional scales, we are identifying spatial clustering of prehistoric settlements into local socio-economic communities. At the scale of local settlements, our analysis of house-pit chronologies is clarifying the degree of simultaneous occupation and re-use. We also draw on recent research into rock art and ritual landscapes in an effort to reconstruct the relationship between settlement clusters and general interaction patterns. Integration of these diverse lines of evidence is generating a vivid picture of thriving Arctic coastal communities, with indications that the timing and pace of cultural responses to climatic and environmental changes were more complex than previously thought. [ABSTRACT FROM AUTHOR]

The article presents the climatological dataset from the Polish Polar Station Hornsund located in the southwest part of Spitsbergen – the biggest island of the Svalbard archipelago. Due to a general lack of long-term in situ measurements and observations, the High Arctic remains one of the largest climate-data-deficient regions on the Earth. Therefore, the described time series of observations in this paper are of unique value. To draw conclusions on the climatic changes in the Arctic, it is necessary to analyse and compare the long-term series of continuous, in situ observations from different locations, rather than relying on the climatic simulations only. In recent decades, rapid environmental changes occurring in the Atlantic sector of the Arctic are reflected in the data series collected by the operational monitoring conducted at the Hornsund station. We demonstrate the results of the 40-year-long series of observations. Climatological mean values or totals are given, and we also examined the variability of meteorological variables at monthly and annual scale using the modified Mann–Kendall test for trend and Sen's method. The relevant daily, monthly, and annual data are provided on the PANGAEA repository (10.1594/PANGAEA.909042, Wawrzyniak and Osuch, 2019). [ABSTRACT FROM AUTHOR]

Civil engineers design buildings, roads, and utility pipelines in the Arctic to rest on firm frozen ground. But as permafrost thaws due to increased air temperature, the ground subsides and infrastructure fails. This paper assesses the current tools used for mapping Arctic geohazard for civil infrastructure planning in the warming Arctic. We formulate an integrated framework to inform science-based decisions and policymaking in response to the ongoing environmental changes. This study first conducts a systematic review of the Arctic geohazard mapping tools. Tools used for Arctic geohazard mapping fall into three categories: analytical or statistical equations for geohazard assessment, modeling approaches for predicting the extent of permafrost degradation, and remote and in-situ sensing for monitoring the natural and built environments and data collection. A description of these tools, along with their limitations and applicability, is provided. Co-production of knowledge is important in developing a robust geohazard assessment tool. Based on the scientific and gray literature, however, we find that the literature of the use of knowledge co-production in the development of evaluation tools outside of health care and public governance is highly sparse. Through the review of Arctic geohazard mapping tools, we provide an integrated framework for Arctic high spatial-resolution multi-geohazards evaluation for civil infrastructure planning. Indigenous knowledge and local observations are included in the proposed framework. [ABSTRACT FROM AUTHOR]

This special issue of Cross-Cultural Research presents four papers each of which in their own way addresses the question of how Arctic populations tackle the high levels of unpredictability and risk associated with their environment. It takes as a starting point the evidence for and against aspects of disequilibrium between humans, animals, and their environment. The authors consider both contemporary and historical Indigenous Arctic populations and the dynamics of human–animal relations in the context of an ever-changing socioecology of the Arctic. Three overarching sources of disequilibrium are identified: (a) disruption in existing ecological networks due to climate and environmental upheaval, (b) effects of sociopolitical change (including migration and disease), and, finally, (c) changes to subsistence strategies. Based on contemporary field studies from across the Arctic, including the Ust'-Avam and Samoyed from the Taimyr Region in Russia, Sami in Finland, Yukagir and Chukchi from Siberia, and the historic Thule community from Greenland, the authors illustrate how, despite apparent disequilibria, there is nevertheless notable resilience evident in the coupling of human-environmental systems. Documenting past and present changes in local livelihoods, subsistence patterns, and sociocultural practices helps us understand the wider context in which these cultures persist. It also allows us to explore what factors are significant in supporting the long-term resilience of Indigenous communities, especially in the context of challenges, such as high levels of addiction, depression and suicide, facing contemporary arctic societies. [ABSTRACT FROM AUTHOR]

This paper examines search and rescue and backcountry medical response constraints in the Canadian Arctic and potential for unmanned aerial vehicles (UAV) to aid in response and preparedness. Semi-structured interviews (n = 18) were conducted with search and rescue responders, Elders, and emergency management officials to collect data on current emergency response and potential for UAV use. UAV test flights (n = 17) were undertaken with community members. We analyzed five years of weather data to examine UAV flight suitability. Numerous challenges face Arctic search and rescue and backcountry emergency response. Changing social and environmental conditions were described as increasing vulnerability to backcountry emergencies. Responders desired additional first aid and emergency training. Legal and weather restrictions were found to limit where, when and who could fly UAVs. UAVs were demonstrated to have potential benefits for hazard monitoring but not for SAR or medical response due to legal restrictions, weather margins, and local capacity. We find that communities are ill-prepared for ongoing SAR demands, let alone a larger disaster. There are numerous limitations to the use of consumer UAVs by Arctic communities. Prevention of backcountry medical emergencies, building resilience to disasters, and first responder training should be prioritized over introducing UAVs to the response system. [ABSTRACT FROM AUTHOR]

The paper presents results from a climate change detection and attribution study on the decline of Arctic sea ice extent in September for the 1953-2012 period. For this period three independently derived observational datasets and simulations from multiple climate models are available to attribute observed changes in the sea ice extent to known climate forcings. Here we direct our attention to the combined cooling effect from other anthropogenic forcing agents (mainly aerosols), which has potentially masked a fraction of greenhouse gas-induced Arctic sea ice decline. The presented detection and attribution framework consists of a regression model, namely, regularized optimal fingerprinting, where observations are regressed onto modelsimulated climate response patterns (i.e., fingerprints). We show that fingerprints from greenhouse gas, natural, and other anthropogenic forcings are detected in the three observed records of Arctic sea ice extent. Beyond that, our findings indicate that for the 1953-2012 period roughly 23% of the greenhouse gas-induced negative sea ice trend has been offset by a weak positive sea ice trend attributable to other anthropogenic forcing. We show that our detection and attribution results remain robust in the presence of emerging nonstationary internal climate variability acting upon sea ice using a perfect model experiment and data from two large ensembles of climate simulations. [ABSTRACT FROM AUTHOR]

Forty years ago, climate scientists predicted the Arctic to be one of Earth's most sensitive climate regions and thus extremely vulnerable to increased CO2. The rapid and unprecedented changes observed in the Arctic confirm this prediction. Especially significant, observed sea ice loss is altering the exchange of mass, energy, and momentum between the Arctic Ocean and atmosphere. As an important component of air-sea exchange, surface turbulent fluxes are controlled by vertical gradients of temperature and humidity between the surface and atmosphere, wind speed, and surface roughness, indicating that they respond to other forcing mechanisms such as atmospheric advection, ocean mixing, and radiative flux changes. The exchange of energy between the atmosphere and surface via surface turbulent fluxes in turn feeds back on the Arctic surface energy budget, sea ice, clouds, boundary layer temperature and humidity, and atmospheric and oceanic circulations. Understanding and attributing variability and trends in surface turbulent fluxes is important because they influence the magnitude of Arctic climate change, sea ice cover variability, and the atmospheric circulation response to increased CO2. This paper reviews current knowledge of Arctic Ocean surface turbulent fluxes and their effects on climate. We conclude that Arctic Ocean surface turbulent fluxes are having an increasingly consequential influence on Arctic climate variability in response to strong regional trends in the air-surface temperature contrast related to the changing character of the Arctic sea ice cover. Arctic Ocean surface turbulent energy exchanges are not smooth and steady but rather irregular and episodic, and consideration of the episodic nature of surface turbulent fluxes is essential for improving Arctic climate projections. [ABSTRACT FROM AUTHOR]

The ability to forecast sea ice (both extent and thickness) and weather conditions are the major factors when it comes to safe marine transportation in the Arctic Ocean. This paper presents findings focusing on sea ice and weather prediction in the Arctic Ocean for navigation purposes, in particular along the Northeast Passage. Based on comparison with the observed sea ice concentrations for validation, the best performing Earth system models from the Intergovernmental Panel on Climate Change (IPCC) program (CMIP5-Coupled Model Intercomparison Project phase 5) were selected to provide ranges of potential future sea ice conditions. Our results showed that, despite a general tendency toward less sea ice cover in summer, internal variability will still be large and shipping along the Northeast Passage might still be hampered by sea ice blocking narrow passages. This will make sea ice forecasts on shorter time and space scales and Arctic weather prediction even more important. [ABSTRACT FROM AUTHOR]

There is limited knowledge on institutional factors constraining and enabling climate change adaptation in Arctic regions, or the overall readiness of governing bodies and communities to develop, implement, and promote adaptation. This paper examines the preparedness of different levels of government to adapt in the Canadian Arctic territory of Nunavut, drawing upon semi-structured interviews with government personnel and organizations involved in adaptation. In the Government of Nunavut, there have been notable developments around adaptation planning and examples of adaptation champions, but readiness for adaptation is challenged by a number of factors including the existence of pressing socio-economic problems, and institutional and governmental barriers. Federally, there is evidence of high-level leadership on adaptation, the creation of adaptation programs, and allocation of funds for adaptation, although the focus has been mostly on researching adaptation options as opposed to supporting actual actions or policy change. The 2016 Pan-Canadian Framework on Clean Growth and Climate Change, and increasing emphasis on climate change federally and in the Government of Nunavut, offer opportunities for advancing adaptation, but concrete steps are needed to ensure readiness is enhanced. [ABSTRACT FROM AUTHOR]

In this paper an algorithm for ice/water classification of C- and L-band dual polarization synthetic aperture radar data is presented. A comparison of the two different frequencies is made in order to investigate the potential to improve classification results with multi-frequency data. The algorithm is based on backscatter intensities in co- and cross-polarization and autocorrelation as a texture feature. The mapping between image features and ice/water classification is made with a neural network. Accurate ice/water maps for both frequencies are produced by the algorithm and the results of two frequencies generally agree very well. Differences are found in the marginal ice zone, where the time difference between acquisitions causes motion of the ice pack. C-band reliably reproduces the outline of the ice edge, while L-band has its strengths for thin ice/calm water areas within the icepack. The classification shows good agreement with ice/water maps derived from met.no ice-charts and radiometer data from AMSR-2. Variations are found in the marginal ice zone where the generalization of the ice charts and lower accuracy of ice concentration from radiometer data introduce deviations. Usage of high-resolution dual frequency data could be beneficial for improving ice cover information for navigation and modelling. [ABSTRACT FROM AUTHOR]

With rapid and accelerated Arctic sea-ice loss, it is beneficial to update and baseline historical change on the regional scales from a consistent, intercalibrated, long-term time series of sea-ice data for understanding regional vulnerability and monitoring ice state for climate adaptation and risk mitigation. In this paper, monthly sea-ice extents (SIEs) derived from a passive microwave sea-ice concentration climate data record for the period of 1979–2015, are used to examine Arctic-wide and regional temporal variability of sea-ice cover and their decadal trends for 15 regions of the Arctic. Three unique types of SIE annual cycles are described. Regions of vulnerability within each of three types to further warming are identified. For the Arctic as a whole, the analysis has found significant changes in both annual SIE maximum and minimum, with −2.41 ± 0.56% per decade and −13.5 ± 2.93% per decade change relative to the 1979–2015 climate average, respectively. On the regional scale, the calculated trends for the annual SIE maximum range from +2.48 to −10.8% decade−1, while the trends for the annual SIE minimum range from 0 to up to −42% decade−1. [ABSTRACT FROM AUTHOR]

The Arctic cell as a reversed and closed loop next to the Polar cell has been recently revealed in the Northern Hemisphere (NH). In this paper, we study the interannual variability of the Arctic and Polar cell strengths during 1979-2012, and their influence on surface air temperature (SAT), precipitation, and sea-ice concentration (SIC) at mid- and high-latitudes of the NH. We show that there is a significant negative correlation between the Arctic and Polar cell strengths. Both the Arctic and Polar cell strengths can well indicate the recurring climatic anomalies of SAT, precipitation, and SIC in their extreme winters. The surface large-scale cold-warm and dry-wet anomalous patterns in these extreme winters are directly linked with the vertical structure of height and temperature anomalies in the troposphere. Results suggest that the past climatic anomalies are better indicated by the strength anomalies of the Polar and Arctic cells than the traditional indices of mid-high latitude pattern such as the Arctic Oscillation and North Atlantic Oscillation. This study illustrates a three-dimensional picture of atmospheric variable anomalies in the troposphere that result in surface climatic anomalies. [ABSTRACT FROM AUTHOR]