Browsing by Subject "Arctic"

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  • Arppe, Laura; Kurki, Eija; Wooller, Matthew J.; Luoto, Tomi P.; Zajaczkowski, Marek; Ojala, Antti E. K. (2017)
    The oxygen isotope composition of chironomid head capsules in a sediment core spanning the past 5500 years from Lake Svartvatnet in southern Spitsbergen was used to reconstruct the oxygen isotope composition of lake water (O-18(lw)) and local precipitation. The O-18(lw) values display shifts from the baseline variability consistent with the timing of recognized historical climatic episodes, such as the Roman Warm Period, the Dark Ages Cold Period and the Little Ice Age'. The highest values of the record, ca. 3 parts per thousand above modern O-18(lw) values, occur at ca. 1900-1800 cal. yr BP. Three negative excursions increasing in intensity toward the present, at 3400-3200, 1250-1100, and 350-50 cal. yr BP, are tentatively linked to roughly synchronous episodes of increased glacier activity and general cold spells around the northern North Atlantic. Their manifestation in the Svartvatnet O-18(lw) record not only testify to the sensitivity and potential of high Arctic lacustrine O-18(chir) records in tracking terrestrial climate evolution but also highlight nonlinear dynamics within the northern North Atlantic hydroclimatic system. The Little Ice Age' period at 350-50 cal. yr BP displays a remarkable 8-9 parts per thousand drop in O-18(lw) values, construed to predominantly represent significantly decreased winter temperatures during a period of increased seasonal differences and extended sea ice cover inducing changes in moisture source regions.
  • Thomas, David Neville; Arévalo-Martínez, Damian; Crocket, Kirsty; Große, Fabian; Grosse, Julia; Schulz, Kirstin; Sühring, Roxana; Tessin, Allyson (2022)
    The Arctic is the fastest changing region on the planet. It is also intrinsically tied to global processes, whether they are climatic, environmental or socio-economic. The impacts of climate change on the vast and multiple interacting Arctic systems are inherently complex, although can be broadly summarised as an increase in temperature and the subsequent loss of sea-ice cover. This will ultimately result in the emergence of new physical and ecological states
  • Kirchner, Nina; Kuttenkeuler, Jakob; Rosqvist, Gunhild; Hancke, Marnie; Granebeck, Annika; Weckström, Jan; Weckström, Kaarina; Schenk, Frederik; Korhola, Atte; Eriksson, Pia (2021)
    Arctic lakes are exposed to warming during increasingly longer ice-free periods and, if located in glaciated areas, to increased inflow of meltwater and sediments. However, direct monitoring of how such lakes respond to changing environmental conditions is challenging not only because of their remoteness but also because of the scarcity of present and previously observed lake states. At the glacier-proximal Lake Tarfala in the Kebnekaise Mountains, northern Sweden, temperatures throughout the water column at its deepest part (50 m) were acquired between 2016 and 2019. This three-year record shows that Lake Tarfala is dimictic and is overturning during spring and fall, respectively. Timing, duration, and intensity of mixing processes, as well as of summer and winter stratification, vary between years. Glacial meltwater may play an important role regarding not only mixing processes but also cooling of the lake. Attribution of external environmental factors to (changes in) lake mixing processes and thermal states remains challenging owing to for example, timing of ice-on and ice-off but also reflection and absorption of light, both known to play a decisive role for lake mixing processes, are not (yet) monitored in situ at Lake Tarfala.
  • Mingfeng, Wang; Jie, Su; Landy, Jack; Leppäranta, Matti; Lei, Guan (2020)
    Abstract Melt ponds occupy a large fraction of the Arctic sea ice surface during spring and summer. The fraction and distribution of melt ponds have considerable impacts on Arctic climate and ecosystem by reducing the albedo. There is an urgency to obtain improved accuracy and a wider coverage of melt pond fraction (MPF) data for studying these processes. MPF information has generally been acquired from optical imagery. Conventional MPF algorithms based on high-resolution optical sensors have treated melt ponds as features with constant reflectance; however, the spectral reflectance of ponds can vary greatly, even at a local scale. Here we use Sentinel-2 imagery to demonstrate those previous algorithms assuming fixed melt pond-reflectance greatly underestimate MPF. We propose a new algorithm (?LinearPolar?) based on the polar coordinate transformation that treats melt ponds as variable-reflectance features and calculates MPF across the vector between melt pond and bare ice axes. The angular coordinate ? of the polar coordinate system, which is only associated with pond fraction rather than reflectance, is used to determinate MPF. By comparing the new algorithm and previous methods with IceBridge optical imagery data, across a variety of Sentinel-2 images with melt ponds at various stages of development, we show that the RMSE value of the LinearPolar algorithm is about 30% lower than for the previous algorithms. Moreover, based on a sensitivity test, the new algorithm is also less sensitive to the subjective threshold for melt pond reflectance than previous algorithms.
  • Abrego, Nerea; Roslin, Tomas; Huotari, Tea; Tack, Ayco J. M.; Lindahl, Bjorn D.; Tikhonov, Gleb; Somervuo, Panu; Schmidt, Niels Martin; Ovaskainen, Otso (2020)
    Understanding the role of interspecific interactions in shaping ecological communities is one of the central goals in community ecology. In fungal communities, measuring interspecific interactions directly is challenging because these communities are composed of large numbers of species, many of which are unculturable. An indirect way of assessing the role of interspecific interactions in determining community structure is to identify the species co-occurrences that are not constrained by environmental conditions. In this study, we investigated co-occurrences among root-associated fungi, asking whether fungi co-occur more or less strongly than expected based on the environmental conditions and the host plant species examined. We generated molecular data on root-associated fungi of five plant species evenly sampled along an elevational gradient at a high arctic site. We analysed the data using a joint species distribution modelling approach that allowed us to identify those co-occurrences that could be explained by the environmental conditions and the host plant species, as well as those co-occurrences that remained unexplained and thus more probably reflect interactive associations. Our results indicate that not only negative but also positive interactions play an important role in shaping microbial communities in arctic plant roots. In particular, we found that mycorrhizal fungi are especially prone to positively co-occur with other fungal species. Our results bring new understanding to the structure of arctic interaction networks by suggesting that interactions among root-associated fungi are predominantly positive.
  • Abrego, Nerea; Roslin, Tomas; Huotari, Tea; Ji, Yinqiu; Schmidt, Niels Martin; Wang, Jiaxin; Yu, Douglas W.; Ovaskainen, Otso (2021)
    Species interactions are known to structure ecological communities. Still, the influence of climate change on biodiversity has primarily been evaluated by correlating individual species distributions with local climatic descriptors, then extrapolating into future climate scenarios. We ask whether predictions on arctic arthropod response to climate change can be improved by accounting for species interactions. For this, we use a 14-year-long, weekly time series from Greenland, resolved to the species level by mitogenome mapping. During the study period, temperature increased by 2 degrees C and arthropod species richness halved. We show that with abiotic variables alone, we are essentially unable to predict species responses, but with species interactions included, the predictive power of the models improves considerably. Cascading trophic effects thereby emerge as important in structuring biodiversity response to climate change. Given the need to scale up from species-level to community-level projections of biodiversity change, these results represent a major step forward for predictive ecology.
  • Luoto, Tomi P.; Kivila, E. Henriikka; Kotrys, Bartosz; Plociennik, Mateusz; Rantala, Marttiina; Nevalainen, Liisa (2020)
    Independent Arctic records of temperature and precipitation from the same proxy archives are rare. Nevertheless, they are important for providing detailed information on long-term climate changes and temperature-precipitation relationships in the context of large-scale atmospheric dynamics. Here, we used chironomid and cladoceran fossil assemblages to reconstruct summer air-temperature and water-level changes, during the past 400 years, in a small lake located in Finnish Lapland. Temperatures remained persistently cold over the Little Ice Age (LIA), but increased in the 20th century. After a cooler phase in the 1970s, the climate rapidly warmed to the record-high temperatures of the most recent decades. The lake-level reconstruction suggested persistently wet conditions for the LIA, followed by a dry period between similar to 1910 and 1970 CE, when the lake apparently became almost dry. Since the 1980s, the lake level has returned to a similar position as during the IAA. The temperature development was consistent with earlier records, but a significant local feature was found in the lake-level reconstruction the LIA appears to have been continuously wet, without the generally depicted dry phase during the 18th and 19th centuries. Therefore, the results suggest local precipitation patterns and enforce the concept of spatially divergent LIA conditions.
  • Salonen, Hilma (2021)
    In the middle of accelerating climate change and global energy transition from fossil fuels towards low-carbon alternatives, Russia has set a course for mitigating the negative effects of these phenomena while seeking to profit from the supposed positive prospects of warming climate conditions: for example, the expected opening of the Northern Sea Route for commercial traffic or producing renewable energy technologies for export. To reach these goals, Russia wields a policy tool known as "mega projects", centralized development interventions, which should bypass structural problems like the high cost of fuel deliveries that have plagued the Arctic socioeconomic development for decades. How do new mega projects aim to find quick solutions for complex problems, and why are outdated energy systems so resistant to change? The article analyzes two recent energy projects in the Republic of Sakha: building a wind park in Tiksi and establishing a company to manage fossil fuel deliveries, from the viewpoint of a pragmatist understanding of habits and their interconnected relationship with institutions. Main research questions examine what parts of the established ways of fossil fuel usage are most resistant to change in this context and what we may expect of renewable energy development in the area. Although challenges caused by the accelerating climate change are unpredictable, Russia answers to them by using the same toolkit as with other national mega projects, involving centralized decision-making and one-size-fits-all solutions. Therefore, any actors wishing to further new energy solutions in the region must do so by supplementing and supporting the dominant ones.
  • Yagodin, Dmitry (2018)
    In July 2016, Russian media reported on an anthrax outbreak on the Yamal peninsula. The extremely hot weather was first to blame, followed by numerous references to global climate change. High temperatures were seen causing permafrost melting and the “awakening” of anthrax bacteria that infected thousands of reindeer. Dozens of children had to be hospitalized, at least one child died. While climate-related explanations in the media lowered liabilities of the local officials, a number of competing versions, including about improper vaccinations and excessive commercialization of reindeer herding, were widely discussed too. Based on the content analysis of local, regional, and national media outlets, this study clarifies the role of mass media in raising public awareness about climate-induced health threats. I use methods of discourse analysis to investigate the ways media had framed potential causes of the emergency, as well as the immediate solutions and future preventive measures. My research looks at these aspects from a standpoint of communication policy networks wherein a guiding theoretical question is how local public issues transform into media and policy agenda, potentially also rearticulating the problem of climate change. Previous research has shown quite convincingly that environmental journalism and especially the theme of climate change are at a rather low level in the professional and news hierarchy of Russian media. This is particularly visible in the results of international comparisons.
  • Jenkins, Jamie (Helsingin yliopisto, 2020)
    The Arctic environment is unique and hosts many economic opportunities. The environment is fragile and is home to many different animals, plants and indigenous people. The area has undergone periods of remilitarisation since the end of the cold war, and this is impacting local communities economically, environmentally and their social development. This research has been undertaken to assess the impact that military activity is having on these local communities. A literature review was undertaken in 3 key areas: Arctic sustainability, military sustainability and Arctic militarisation to identify relevant indicators that impact sustainable development. Sustainable development was defined using the 3 pillars from the Brundtland report, as economic, environmental and social. These indicators were collated to create a conceptual framework that was used to analyse two case study cities in the Arctic. These two cities were Fairbanks, in Alaska, and Severomorsk in Russia. These were chosen as economically and socially, they are very different, but they share the main similarity of being militarised Arctic cities. This meant the framework was tested on two different cities and in two different environments to test the validity and usefulness. The two case studies were built from reports, census information, statistical information and government reports. Although quantification was outside the scope of this research, observations were found from the data. Economically, the impact is positive. Military activity generates jobs, growth, infrastructure and military spending. The environmental impact is clearly negative. Military activity contaminates groundwater, soil, water and the local environment. The social impact is more ambiguous. Military activity helps foster community development but can impact personnel health. A discussion was undertaken on the effectiveness of the framework and improvement areas. The framework provided a good overall picture of activity but could be improved in some areas. These areas include reducing subjectivity in the construction phase, improved environmental data and time series data. The research was limited by time constraints and data availability in some impact areas.
  • Toivanen, Reetta; Fabritius, Nora (2020)
    This article presents research on contradictory representations of the Arctic and its inhabitants from the point of view of sustainable development. Indigenous peoples are repeatedly presented as connected to nature but outside politics, while business and state stakeholders portray the Arctic as uninhabited and utilizable for extractivism. These depictions diminish the agency of indigenous Sámi in political decision-making, agency that is integral to achieving a sustainable future both for Arctic lands and cultures. Contrary to what older generations fear, research from this decade shows that youth — who are increasingly moving to urban centers — are not necessarily leaving Sámi culture and lands. They are finding new modes of agency by transcending the discursive boundaries of periphery and center, nature and culture.
  • Naakka, Tuomas (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Finnish Meteorological Institute Contributions 179
    Water vapour is an effective greenhouse gas, but clouds, which are formed when water vapour condenses into water droplets or ice crystals, may have an even greater effect on radiative energy transfer through the atmosphere. In addition, absorption or release of the latent heat of vaporization and transport of water vapour are part of the heat transport from the Tropics towards the Poles. Thus, atmospheric water vapour greatly affects the energy balance of the atmosphere and is also an important component of the water cycle. This thesis addresses the subject of atmospheric moisture and the processes affecting it in the Arctic and Antarctic. The studies comprising the thesis are mostly based on atmospheric reanalyses. In the polar regions, meteorological observation networks are sparse, due to their remoteness and the harsh environment, and therefore traditional observations have not provided a comprehensive picture of atmospheric conditions in the polar regions. In recent years, atmospheric reanalyses have also become more accurate in remote areas, which has enabled detailed studies of atmospheric moisture in the polar regions. In the polar regions, the mostly negative radiation budget of Earth’s atmosphere-surface system shapes the distribution of water vapour in the atmosphere, especially the vertical structure of specific humidity. The polar regions are sinks for atmospheric water vapour, due to their typically small local evaporation, and even condensation of moisture on the surface. Therefore, moisture transport from the lower latitudes balances the moisture budget in the polar regions. This type of moisture budget favours the formation of specific humidity inversions. Our results show that specific humidity inversions are common in the polar regions, and their occurrence near Earth’s surface is linked with surface conditions: radiative surface cooling, occurrence of temperature inversions in winter and cold sea surfaces or melting of sea ice in summer. Advection of warm, moist air masses over a cold surface in summer is vital for formation of specific humidity inversions. Below the approximately 800-hPa level, interactions between the atmosphere and Earth’s surface clearly affect both the atmospheric moisture content and moisture transport. Our results show that the northward moisture transport near the surface is mostly balanced by southward transport. Moisture transport clearly shapes the spatial distribution of the atmospheric moisture content. Regional trends in atmospheric moisture content in the Arctic are also mostly the results of long-term variations in atmospheric circulation. The negative net radiation budget, weak evaporation and extensive contribution of moisture transport to atmospheric moisture content also characterize moisture conditions in the Antarctic. The results show that, due to geographical conditions, specific humidity inversions in Antarctica are even more persistent than those in the Arctic. This is associated with stronger isolation of air masses in inner Antarctica from advection of warm, moist air masses than in the Arctic. The results also show that when a cold, dry air mass flows from the continent towards the ocean, it undergoes adiabatic warming, which together with downward sensible heat fluxes enables evaporation on Antarctic slopes. Overall, this thesis contributes to our understanding of how the spatial distribution of atmospheric moisture content interacts with moisture transport and with physical processes such as evaporation and condensation in polar regions.
  • Sigrist, Jonathan (Helsingin yliopisto, 2021)
    This thesis analyses the development of Danish foreign and security policy towards the Arctic ever since the end of the Second World War up until today. It draws primarily on Denmark’s relation to the United States, having been Denmark’s main ally for the last 75 years on all security related matters - but especially since the end of the Cold War. Both Denmark and the US are considered Arctic coastal states, with Denmark accessing the Arctic ocean through its sovereign claim over Greenland, and the US through the state of Alaska. The thesis supports other scholarly studies that argue that a ‘new Cold War’ has been taking place in the years following the election of Donald Trump as President of the United States in 2016 between the US, China and Russia, with potentially grave ramifications for Arctic regional security, given its growing importance as a region for resource extraction and commercial passage through the Northern Sea Route. For Denmark, this new Cold War threatens its sovereign claim over Greenland – a crucial geostrategic location for a potential Arctic militarization - being challenged as a small nation by the great power competitions accelerating in the Arctic. The thesis divides the last 75 years into three categorized eras: 1) The Cold War (1945-1991); 2) The post-Cold War era (1991-2017); 3) The ‘new Cold War’ as a developing era (2017 - ; denoted in the thesis), and analyses for each era the fundamentals of Denmark – US relations, first providing a more general overview of their political relations as security partners on non-Arctic related matters, in order to then draw parallels to the development of Denmark – US relations in the Arctic and their roles as state actors in shaping the geopolitical climate of the region. As I show, a lot can be learned from the Cold War to understand what is and may happen in the Arctic in the new Cold War. The thesis makes use of foreign policy analysis, as well as two variations of discourse analysis – poststructuralist discourse analysis and critical discourse analysis – as tools to engage with the empirical data available and answer the thesis’s main research questions: what is the perceived effect of the Trump administration's policy to the position of Denmark in the Arctic? The question is answered on the basis of two main theoretical frameworks: Securitization Theory and Region-Building Theory. These frameworks build the necessary foundation which along with the mentioned methodologies can provide a holistic overview and perspective on the matter with scientific validity. The thesis ends by discussing what can be expected in the near future, based on the knowledge acquired and the answers provided to the research question. A new administration led by president elect Joe Biden took over the White House on January 20st, and with it many new questions are yet to be answered, regarding the future of Denmark – US relations, the future of Arctic governance and the course of the new Cold War. I ponder on what options Denmark might have that could guarantee its security while also maintaining its sovereignty over Greenland – one option being a potential turn towards the EU as its new main security partner. Yet doing so would mean breaking a long-lasting relationship with the US while standing up to the world’s biggest economic and military superpower.
  • Abbott, Benjamin W.; Jones, Jeremy B.; Schuur, Edward A. G.; Chapin, F. Stuart; Bowden, William B.; Bret-Harte, M. Syndonia; Epstein, Howard E.; Flannigan, Michael D.; Harms, Tamara K.; Hollingsworth, Teresa N.; Mack, Michelle C.; McGuire, A. David; Natali, Susan M.; Rocha, Adrian V.; Tank, Suzanne E.; Turetsky, Merritt R.; Vonk, Jorien E.; Wickland, Kimberly P.; Aiken, George R.; Alexander, Heather D.; Amon, Rainer M. W.; Benscoter, Brian W.; Bergeron, Yves; Bishop, Kevin; Blarquez, Olivier; Bond-Lamberty, Ben; Breen, Amy L.; Buffam, Ishi; Cai, Yihua; Carcaillet, Christopher; Carey, Sean K.; Chen, Jing M.; Chen, Han Y. H.; Christensen, Torben R.; Cooper, Lee W.; Cornelissen, J. Hans C.; de Groot, William J.; DeLuca, Thomas H.; Dorrepaal, Ellen; Fetcher, Ned; Finlay, Jacques C.; Forbes, Bruce C.; French, Nancy H. F.; Gauthier, Sylvie; Girardin, Martin P.; Goetz, Scott J.; Goldammer, Johann G.; Gough, Laura; Grogan, Paul; Guo, Laodong; Higuera, Philip E.; Hinzman, Larry; Hu, Feng Sheng; Hugelius, Gustaf; Jafarov, Elchin E.; Jandt, Randi; Johnstone, Jill F.; Karlsson, Jan; Kasischke, Eric S.; Kattner, Gerhard; Kelly, Ryan; Keuper, Frida; Kling, George W.; Kortelainen, Pirkko; Kouki, Jari; Kuhry, Peter; Laudon, Hjalmar; Laurion, Isabelle; Macdonald, Robie W.; Mann, Paul J.; Martikainen, Pertti J.; McClelland, James W.; Molau, Ulf; Oberbauer, Steven F.; Olefeldt, David; Pare, David; Parisien, Marc-Andre; Payette, Serge; Peng, Changhui; Pokrovsky, Oleg S.; Rastetter, Edward B.; Raymond, Peter A.; Raynolds, Martha K.; Rein, Guillermo; Reynolds, James F.; Robards, Martin; Rogers, Brendan M.; Schaedel, Christina; Schaefer, Kevin; Schmidt, Inger K.; Shvidenko, Anatoly; Sky, Jasper; Spencer, Robert G. M.; Starr, Gregory; Striegl, Robert G.; Teisserenc, Roman; Tranvik, Lars J.; Virtanen, Tarmo; Welker, Jeffrey M.; Zimov, Sergei (2016)
    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
  • Mori, Tatsuhiro; Goto-Azuma, Kumiko; Kondo, Yutaka; Ogawa-Tsukagawa, Yoshimi; Miura, Kazuhiko; Hirabayashi, Motohiro; Oshima, Naga; Koike, Makoto; Kupiainen, Kaarle; Moteki, Nobuhiro; Ohata, Sho; Sinha, P.R.; Sugiura, Konosuke; Aoki, Teruo; Schneebeli, Martin; Steffen, Konrad; Sato, Atsushi; Tsushima, Akane; Makarov, Vladimir; Omiya, Satoshi; Sugimoto, Atsuko; Takano, Shinya; Nagatsuka, Naoko (Wiley & Sons, 2019)
    Journal of Geophysical Research : Atmospheres
    Black carbon (BC) deposited on snow lowers its albedo, potentially contributing to warming in the Arctic. Atmospheric distributions of BC and inorganic aerosols, which contribute directly and indirectly to radiative forcing, are also greatly influenced by depositions. To quantify these effects, accurate measurement of the spatial distributions of BC and ionic species representative of inorganic aerosols (ionic species hereafter) in snowpack in various regions of the Arctic is needed, but few such measurements are available. We measured mass concentrations of size-resolved BC (CMBC) and ionic species in snowpack by using a single-particle soot photometer and ion chromatography, respectively, over Finland, Alaska, Siberia, Greenland, and Spitsbergen during early spring in 2012–2016. Total BC mass deposited per unit area (DEPMBC) during snow accumulation periods was derived from CMBC and snow water equivalent (SWE). Our analyses showed that the spatial distributions of anthropogenic BC emission flux, total precipitable water, and topography strongly influenced latitudinal variations of CMBC, BC size distributions, SWE, and DEPMBC. The average size distributions of BC in Arctic snowpack shifted to smaller sizes with decreasing CMBC due to an increase in the removal efficiency of larger BC particles during transport from major sources. Our measurements of CMBC were lower by a factor of ~13 than previous measurements made with an Integrating Sphere/Integrating Sandwich spectrophotometer due mainly to interference from coexisting non-BC particles such as mineral dust. The SP2 data presented here will be useful for constraining climate models that estimate the effects of BC on the Arctic climate.
  • Young, T. Kue; Kelly, Janet J.; Friborg, Jeppe; Soininen, Leena; Wong, Kai O. (2016)
    Objectives. To determine and compare the incidence of cancer among the 8 Arctic States and their northern regions, with special focus on 3 cross-national indigenous groups - Inuit, Athabaskan Indians and Sami. Methods. Data were extracted from national and regional statistical agencies and cancer registries, with direct age-standardization of rates to the world standard population. For comparison, the "world average'' rates as reported in the GLOBOCAN database were used. Findings. Age-standardized incidence rates by cancer sites were computed for the 8 Arctic States and 20 of their northern regions, averaged over the decade 2000 - 2009. Cancer of the lung and colon/rectum in both sexes are the commonest in most populations. We combined the Inuit from Alaska, Northwest Territories, Nunavut and Greenland into a "Circumpolar Inuit'' group and tracked cancer trends over four 5-year periods from 1989 to 2008. There has been marked increase in lung, colorectal and female breast cancers, while cervical cancer has declined. Compared to the GLOBOCAN world average, Inuit are at extreme high risk for lung and colorectal cancer, and also certain rare cancers such as nasopharyngeal cancer. Athabaskans (from Alaska and Northwest Territories) share some similarities with the Inuit but they are at higher risk for prostate and breast cancer relative to the world average. Among the Sami, published data from 3 cohorts in Norway, Sweden and Finland show generally lower risk of cancer than non-Sami. Conclusions. Cancer among certain indigenous people in the Arctic is an increasing public health concern, especially lung and colorectal cancer.
  • Chetelat, John; McKinney, Melissa A.; Amyot, Marc; Dastoor, Ashu; Douglas, Thomas A.; Heimburger-Boavida, Lars-Eric; Kirk, Jane; Kahilainen, Kimmo K.; Outridge, Peter M.; Pelletier, Nicolas; Skov, Henrik; St Pierre, Kyra; Vuorenmaa, Jussi; Wang, Feiyue (2022)
    Dramatic environmental shifts are occuring throughout the Arctic from climate change, with consequences for the cycling of mercury (Hg). This review summarizes the latest science on how climate change is influencing Hg transport and biogeochemical cycling in Arctic terrestrial, freshwater and marine ecosystems. As environmental changes in the Arctic continue to accelerate, a clearer picture is emerging of the profound shifts in the climate and cryosphere, and their connections to Hg cycling. Modeling results suggest climate influences seasonal and interannual variability of atmospheric Hg deposition. The clearest evidence of current climate change effects is for Hg transport from terrestrial catchments, where widespread permafrost thaw, glacier melt and coastal erosion are increasing the export of Hg to downstream environments. Recent estimates suggest Arctic permafrost is a large global reservoir of Hg, which is vulnerable to degradation with climate warming, although the fate of permafrost soil Hg is unclear. The increasing development of thermokarst features, the formation and expansion of thaw lakes, and increased soil erosion in terres- trial landscapes are increasing river transport of particulate-bound Hg and altering conditions for aquatic Hg transfor- mations. Greater organic matter transport may also be influencing the downstream transport and fate of Hg. More severe and frequent wildfires within the Arctic and across boreal regions may be contributing to the atmospheric pool of Hg. Climate change influences on Hg biogeochemical cycling remain poorly understood. Seasonal evasion and retention of inorganic Hg may be altered by reduced sea-ice cover and higher chloride content in snow. Experi- mental evidence indicates warmer temperatures enhance methylmercury production in ocean and lake sediments as well as in tundra soils. Improved geographic coverage of measurements and modeling approaches are needed to better evaluate net effects of climate change and long-term implications for Hg contamination in the Arctic.
  • Svensson, Jonas (Finnish Meteorological Institute, 2017)
    Finnish Meteorological Institute Contributions 140
    Snow and ice are essential components of the Earth system, modulating the energy budget by reflecting sunlight back into the atmosphere, and through its importance in the hydrological cycle by being a reservoir for fresh water. Light-absorbing impurities (LAI), such as black carbon (BC) and mineral dust (MD), have a unique role in influencing the reflectance of the cryosphere. Deposition of the anthropogenic and natural LAI constituents onto these bright surfaces initiates powerful albedo feedbacks that will accelerate melt. This is important globally, but especially for regions such as the Arctic and the Himalaya. In this thesis, observations from both ambient and laboratory experiments are presented. The overarching research goal has been to better understand the climatic effect of LAI on snow. More specifically, an emphasis has been placed on exploring the process-level interactions between LAI and snow, which will enable better comprehension of LAI affecting the cryosphere. Key findings in this thesis involves the investigations on the horizontal variability of BC concentrations in the surface snow that indicate a larger variability on the order of meter scale at a pristine Arctic site compared to a polluted site nearby a major urban area. In outdoor experiments, where LAI were used to artificially dope natural snow surfaces, the snow albedo was observed to decrease following LAI deposition. The albedo decrease was on the same order as in situ measurements of LAI and albedo conducted elsewhere. As snow melted during the experiment, the snow density was observed to decrease with increasing LAI concentration, while this effect was not observed in non-melting snow. The water retention capacity in melting snow is likely to be decreased by the presence of LAI. Measurements examining the absorption of BC indicate that BC particles in the snow have less absorbing potential compared to BC particles generated in the laboratory. The LAI content of snow pit investigations from two glaciers in the Sunderdhunga valley, northern India, an area not previously examined for LAI, presented high BC and MD content, affecting the radiative balance of the glacier snow. At different points, MD may be greater than BC in absorbing light at the snow surface. A continued monitoring of LAI in the cryosphere, both on the detailed scale explored here, as well as on the larger modelling perspective is needed in order to understand the overall response of the cryosphere to climate change.
  • Lundell, Richard Viking; Wuorimaa, Tomi; Räisänen-Sokolowski, Anne; Sundholm, Johnny K. M.; Rintamäki, Hannu; Rissanen, Sirkka; Parkkola, Kai (2019)
    Introduction: It is vital to protect divers from the cold, particularly in Arctic conditions. The insulating gas layer within the drysuit is crucial for reducing heat loss. The technical diving community has long claimed the superiority of argon over air as an insulating gas. Although argon is widely used, previous studies have shown no significant differences between the two gases. Owing to its lower heat conductivity, argon should be a better thermal insulating gas than air. Methods: The study aimed to determine whether argon is beneficial for reducing heat loss in divers during development of military drysuit diving equipment in Arctic water temperatures. Four divers completed 14 dives, each lasting 45 minutes: seven dives used air insulation and seven used argon insulation. Rectal and eight skin temperatures were measured from which changes in calculated mean body temperature (MBT) were assessed. Results: There was a significant reduction in area weighted skin temperature over time (0-45 minute) on air dives (Delta T-skin = -4.16 degrees C, SE = 0.445, P <0.001). On argon dives the reduction was significantly smaller compared to air dives (difference between groups = 2.26 degrees C, SE = 0.358, P Conclusion: Compared to air, argon may be superior as a drysuit insulating gas in Arctic water temperatures for some divers. Argon used as insulating gas can make diving safer and may diminish the risks of fatal diving accidents and occupational hazard risks in professional diving.
  • Panov, Alexey; Prokushkin, Anatoly; Kubler, Karl Robert; Korets, Mikhail; Urban, Anastasiya; Bondar, Mikhail; Heimann, Martin (2021)
    Atmospheric observations of sources and sinks of carbon dioxide (CO2) and methane (CH4) in the pan-Arctic domain are highly sporadic, limiting our understanding of carbon turnover in this climatically sensitive environment and the fate of enormous carbon reservoirs buried in permafrost. Particular gaps apply to the Arctic latitudes of Siberia, covered by the vast tundra ecosystems underlain by permafrost, where only few atmospheric sites are available. The paper presents the first results of continuous observations of atmospheric CO2 and CH4 dry mole fractions at a newly operated station "DIAMIS" (73.506828 degrees N, 80.519869 degrees E) deployed on the edge of the Dikson settlement on the western coast of the Taimyr Peninsula. Atmospheric mole fractions of CO2, CH4, and H2O are measured by a CRDS analyzer Picarro G2301-f, which is regularly calibrated against WMO-traceable gases. Meteorological records permit screening of trace gas series. Here, we give the scientific rationale of the site, describe the instrumental setup, analyze the local environments, examine the seasonal footprint, and show CO2 and CH4 fluctuations for the daytime mixed atmospheric layer that is representative over a vast Arctic domain (-500-1000 km), capturing both terrestrial and oceanic signals.