Future Arctic climate changes: Adaptation and mitigation time scales

Science.gov (United States)

Overland, James E.; Wang, Muyin; Walsh, John E.; Stroeve, Julienne C.

2014-02-01

The climate in the Arctic is changing faster than in midlatitudes. This is shown by increased temperatures, loss of summer sea ice, earlier snow melt, impacts on ecosystems, and increased economic access. Arctic sea ice volume has decreased by 75% since the 1980s. Long-lasting global anthropogenic forcing from carbon dioxide has increased over the previous decades and is anticipated to increase over the next decades. Temperature increases in response to greenhouse gases are amplified in the Arctic through feedback processes associated with shifts in albedo, ocean and land heat storage, and near-surface longwave radiation fluxes. Thus, for the next few decades out to 2040, continuing environmental changes in the Arctic are very likely, and the appropriate response is to plan for adaptation to these changes. For example, it is very likely that the Arctic Ocean will become seasonally nearly sea ice free before 2050 and possibly within a decade or two, which in turn will further increase Arctic temperatures, economic access, and ecological shifts. Mitigation becomes an important option to reduce potential Arctic impacts in the second half of the 21st century. Using the most recent set of climate model projections (CMIP5), multimodel mean temperature projections show an Arctic-wide end of century increase of +13°C in late fall and +5°C in late spring for a business-as-usual emission scenario (RCP8.5) in contrast to +7°C in late fall and +3°C in late spring if civilization follows a mitigation scenario (RCP4.5). Such temperature increases demonstrate the heightened sensitivity of the Arctic to greenhouse gas forcing.

Arctic security in an age of climate change

Energy Technology Data Exchange (ETDEWEB)

Kraska, James (ed.)

2013-03-01

Publisher review: This book examines Arctic defense policy and military security from the perspective of all eight Arctic states. In light of climate change and melting ice in the Arctic Ocean, Canada, Russia, Denmark (Greenland), Norway and the United States, as well as Iceland, Sweden and Finland, are grappling with an emerging Arctic security paradigm. This volume brings together the world's most seasoned Arctic political-military experts from Europe and North America to analyze how Arctic nations are adapting their security postures to accommodate increased shipping, expanding naval presence, and energy and mineral development in the polar region. The book analyzes the ascent of Russia as the first 'Arctic superpower', the growing importance of polar security for NATO and the Nordic states, and the increasing role of Canada and the United States in the region.(Author)

Vulnerability to climate change in the Arctic: a case study from Arctic Bay, Canada

Energy Technology Data Exchange (ETDEWEB)

Ford, J.D.; Smit, B.; Wandel, J. [University of Guelph, Ontario (Canada). Department of Geography

2006-05-15

This paper develops a vulnerability-based approach to characterize the human implications of climate change in Arctic Bay, Canada. It focuses on community vulnerabilities associated with resource harvesting and the processes through which people adapt to them in the context of livelihood assets, constraints, and outside influences. Inuit in Arctic Bay have demonstrated significant adaptability in the face of changing climate-related exposures. This adaptability is facilitated by traditional Inuit knowledge, strong social networks, flexibility in seasonal hunting cycles, some modern technologies, and economic support. Changing Inuit livelihoods, however, have undermined certain aspects of adaptive capacity, and have resulted in emerging vulnerabilities in certain sections of the community. (author)

Changes in Arctic and Antarctic Sea Ice as a Microcosm of Global Climate Change

Science.gov (United States)

Parkinson, Claire L.

2014-01-01

Polar sea ice is a key element of the climate system and has now been monitored through satellite observations for over three and a half decades. The satellite observations reveal considerable information about polar ice and its changes since the late 1970s, including a prominent downward trend in Arctic sea ice coverage and a much lesser upward trend in Antarctic sea ice coverage, illustrative of the important fact that climate change entails spatial contrasts. The decreasing ice coverage in the Arctic corresponds well with contemporaneous Arctic warming and exhibits particularly large decreases in the summers of 2007 and 2012, influenced by both preconditioning and atmospheric conditions. The increasing ice coverage in the Antarctic is not as readily explained, but spatial differences in the Antarctic trends suggest a possible connection with atmospheric circulation changes that have perhaps been influenced by the Antarctic ozone hole. The changes in the polar ice covers and the issues surrounding those changes have many commonalities with broader climate changes and their surrounding issues, allowing the sea ice changes to be viewed in some important ways as a microcosm of global climate change.

Dangerous climate change and the importance of adaptation for the Arctic's Inuit population

Energy Technology Data Exchange (ETDEWEB)

Ford, James D [Department of Geography, McGill University, 805 Sherbrooke Street West, Montreal, QC, H3A 2K6 (Canada)], E-mail: james.ford@mcgill.ca

2009-04-15

The Arctic's climate is changing rapidly, to the extent that 'dangerous' climate change as defined by the United Nations Framework on Climate Change might already be occurring. These changes are having implications for the Arctic's Inuit population and are being exacerbated by the dependence of Inuit on biophysical resources for livelihoods and the low socio-economic-health status of many northern communities. Given the nature of current climate change and projections of a rapidly warming Arctic, climate policy assumes a particular importance for Inuit regions. This paper argues that efforts to stabilize and reduce greenhouse gas emissions are urgent if we are to avoid runaway climate change in the Arctic, but unlikely to prevent changes which will be dangerous for Inuit. In this context, a new policy discourse on climate change is required for Arctic regions-one that focuses on adaptation. The paper demonstrates that states with Inuit populations and the international community in general has obligations to assist Inuit to adapt to climate change through international human rights and climate change treaties. However, the adaptation deficit, in terms of what we know and what we need to know to facilitate successful adaptation, is particularly large in an Arctic context and limiting the ability to develop response options. Moreover, adaptation as an option of response to climate change is still marginal in policy negotiations and Inuit political actors have been slow to argue the need for adaptation assistance. A new focus on adaptation in both policy negotiations and scientific research is needed to enhance Inuit resilience and reduce vulnerability in a rapidly changing climate.

Collaborative Proposal: Improving Decadal Prediction of Arctic Climate Variability and Change Using a Regional Arctic System Model (RASM)

Energy Technology Data Exchange (ETDEWEB)

Maslowski, Wieslaw [Naval Postgraduate School, Monterey, CA (United States)

2016-10-17

This project aims to develop, apply and evaluate a regional Arctic System model (RASM) for enhanced decadal predictions. Its overarching goal is to advance understanding of the past and present states of arctic climate and to facilitate improvements in seasonal to decadal predictions. In particular, it will focus on variability and long-term change of energy and freshwater flows through the arctic climate system. The project will also address modes of natural climate variability as well as extreme and rapid climate change in a region of the Earth that is: (i) a key indicator of the state of global climate through polar amplification and (ii) which is undergoing environmental transitions not seen in instrumental records. RASM will readily allow the addition of other earth system components, such as ecosystem or biochemistry models, thus allowing it to facilitate studies of climate impacts (e.g., droughts and fires) and of ecosystem adaptations to these impacts. As such, RASM is expected to become a foundation for more complete Arctic System models and part of a model hierarchy important for improving climate modeling and predictions.

Reduced arctic tundra productivity linked with landform and climate change interactions

Science.gov (United States)

Lara, Mark J.; Nitze, Ingmar; Grosse, Guido; Martin, Philip; McGuire, A. David

2018-01-01

Arctic tundra ecosystems have experienced unprecedented change associated with climate warming over recent decades. Across the Pan-Arctic, vegetation productivity and surface greenness have trended positively over the period of satellite observation. However, since 2011 these trends have slowed considerably, showing signs of browning in many regions. It is unclear what factors are driving this change and which regions/landforms will be most sensitive to future browning. Here we provide evidence linking decadal patterns in arctic greening and browning with regional climate change and local permafrost-driven landscape heterogeneity. We analyzed the spatial variability of decadal-scale trends in surface greenness across the Arctic Coastal Plain of northern Alaska (~60,000 km²) using the Landsat archive (1999–2014), in combination with novel 30 m classifications of polygonal tundra and regional watersheds, finding landscape heterogeneity and regional climate change to be the most important factors controlling historical greenness trends. Browning was linked to increased temperature and precipitation, with the exception of young landforms (developed following lake drainage), which will likely continue to green. Spatiotemporal model forecasting suggests carbon uptake potential to be reduced in response to warmer and/or wetter climatic conditions, potentially increasing the net loss of carbon to the atmosphere, at a greater degree than previously expected.

Climate-driven changes in functional biogeography of Arctic marine fish communities.

Science.gov (United States)

Frainer, André; Primicerio, Raul; Kortsch, Susanne; Aune, Magnus; Dolgov, Andrey V; Fossheim, Maria; Aschan, Michaela M

2017-11-14

Climate change triggers poleward shifts in species distribution leading to changes in biogeography. In the marine environment, fish respond quickly to warming, causing community-wide reorganizations, which result in profound changes in ecosystem functioning. Functional biogeography provides a framework to address how ecosystem functioning may be affected by climate change over large spatial scales. However, there are few studies on functional biogeography in the marine environment, and none in the Arctic, where climate-driven changes are most rapid and extensive. We investigated the impact of climate warming on the functional biogeography of the Barents Sea, which is characterized by a sharp zoogeographic divide separating boreal from Arctic species. Our unique dataset covered 52 fish species, 15 functional traits, and 3,660 stations sampled during the recent warming period. We found that the functional traits characterizing Arctic fish communities, mainly composed of small-sized bottom-dwelling benthivores, are being rapidly replaced by traits of incoming boreal species, particularly the larger, longer lived, and more piscivorous species. The changes in functional traits detected in the Arctic can be predicted based on the characteristics of species expected to undergo quick poleward shifts in response to warming. These are the large, generalist, motile species, such as cod and haddock. We show how functional biogeography can provide important insights into the relationship between species composition, diversity, ecosystem functioning, and environmental drivers. This represents invaluable knowledge in a period when communities and ecosystems experience rapid climate-driven changes across biogeographical regions. Copyright © 2017 the Author(s). Published by PNAS.

Climate Change Impacts on Environmental and Human Exposure to Mercury in the Arctic

Science.gov (United States)

Sundseth, Kyrre; Pacyna, Jozef M.; Banel, Anna; Pacyna, Elisabeth G.; Rautio, Arja

2015-01-01

This paper reviews information from the literature and the EU ArcRisk project to assess whether climate change results in an increase or decrease in exposure to mercury (Hg) in the Arctic, and if this in turn will impact the risks related to its harmful effects. It presents the state-of-the art of knowledge on atmospheric mercury emissions from anthropogenic sources worldwide, the long-range transport to the Arctic, and it discusses the likely environmental fate and exposure effects on population groups in the Arctic under climate change conditions. The paper also includes information about the likely synergy effects (co-benefits) current and new climate change polices and mitigation options might have on mercury emissions reductions in the future. The review concludes that reductions of mercury emission from anthropogenic sources worldwide would need to be introduced as soon as possible in order to assure lowering the adverse impact of climate change on human health. Scientific information currently available, however, is not in the position to clearly answer whether climate change will increase or decrease the risk of exposure to mercury in the Arctic. New research should therefore be undertaken to model the relationships between climate change and mercury exposure. PMID:25837201

Climate change impacts on environmental and human exposure to mercury in the arctic.

Science.gov (United States)

Sundseth, Kyrre; Pacyna, Jozef M; Banel, Anna; Pacyna, Elisabeth G; Rautio, Arja

2015-03-31

This paper reviews information from the literature and the EU ArcRisk project to assess whether climate change results in an increase or decrease in exposure to mercury (Hg) in the Arctic, and if this in turn will impact the risks related to its harmful effects. It presents the state-of-the art of knowledge on atmospheric mercury emissions from anthropogenic sources worldwide, the long-range transport to the Arctic, and it discusses the likely environmental fate and exposure effects on population groups in the Arctic under climate change conditions. The paper also includes information about the likely synergy effects (co-benefits) current and new climate change polices and mitigation options might have on mercury emissions reductions in the future. The review concludes that reductions of mercury emission from anthropogenic sources worldwide would need to be introduced as soon as possible in order to assure lowering the adverse impact of climate change on human health. Scientific information currently available, however, is not in the position to clearly answer whether climate change will increase or decrease the risk of exposure to mercury in the Arctic. New research should therefore be undertaken to model the relationships between climate change and mercury exposure.

 Climate Change and the Arctic Discourses

DEFF Research Database (Denmark)

Bjørst, Lill Rastad

2009-01-01

  It is now a fact that global warming and climate change are on the public agenda and will remain there for a long time to come. The Arctic has been portrayed as a thermometer for the world mostly because it is very vulnerable to the climatic changes and the subsequent consequences. Inuit are used...... as an example and included as the first witnesses to ‘the big catastrophe'. My hypothesis is that the newly emerging climate debate can establish an unexpected and unique political platform where Inuit can get influence on local as well as global questions. My investigating focus concerning these matters...

The Climate Science Special Report: Arctic Changes and their Effect on Alaska and the Rest of the United States

Science.gov (United States)

Taylor, P. C.

2017-12-01

Rapid and visible climate change is happening across the Arctic, outpacing global change. Annual average near-surface air temperatures across the Arctic are increasing at more than twice the rate of global average surface temperature. In addition to surface temperature, all components of the Arctic climate system are responding in kind, including sea ice, mountain glaciers and the Greenland Ice sheet, snow cover, and permafrost. Many of these changes with a discernable anthropogenic imprint. While Arctic climate change may seem physically remote to those living in other regions of the planet, Arctic climate change can affect the global climate influencing sea level, the carbon cycle, and potentially atmospheric and oceanic circulation patterns. As an Arctic nation, United States' adaptation, mitigation, and policy decisions depend on projections of future Alaskan and Arctic climate. This chapter of the Climate Science Special Report documents significant scientific progress and knowledge about how the Alaskan and Arctic climate has changed and will continue to change.

Arctic climate change in an ensemble of regional CORDEX simulations

Directory of Open Access Journals (Sweden)

Torben Koenigk

2015-03-01

Full Text Available Fifth phase Climate Model Intercomparison Project historical and scenario simulations from four global climate models (GCMs using the Representative Concentration Pathways greenhouse gas concentration trajectories RCP4.5 and RCP8.5 are downscaled over the Arctic with the regional Rossby Centre Atmosphere model (RCA. The regional model simulations largely reflect the circulation bias patterns of the driving global models in the historical period, indicating the importance of lateral and lower boundary conditions. However, local differences occur as a reduced winter 2-m air temperature bias over the Arctic Ocean and increased cold biases over land areas in RCA. The projected changes are dominated by a strong warming in the Arctic, exceeding 15°K in autumn and winter over the Arctic Ocean in RCP8.5, strongly increased precipitation and reduced sea-level pressure. Near-surface temperature and precipitation are linearly related in the Arctic. The wintertime inversion strength is reduced, leading to a less stable stratification of the Arctic atmosphere. The diurnal temperature range is reduced in all seasons. The large-scale change patterns are dominated by the surface and lateral boundary conditions so future response is similar in RCA and the driving global models. However, the warming over the Arctic Ocean is smaller in RCA; the warming over land is larger in winter and spring but smaller in summer. The future response of winter cloud cover is opposite in RCA and the GCMs. Precipitation changes in RCA are much larger during summer than in the global models and more small-scale change patterns occur.

The Arctic: between climatic change, economic development and security issues

International Nuclear Information System (INIS)

Degeorges, Damien

2016-01-01

The Arctic is a perfect illustration of how climate change is impacting international relations, in particular because it triggers new economic and safety issues. Since every major economic power has interests in the region, it has now become the stage of many rivalries, including between China and the United-States. Whether it is because its extreme climate conditions or the growing international pressure, the Arctic sets a new challenge for investors: securing a sustainable economic growth in the region

Climate change effects on human health in a gender perspective: some trends in Arctic research.

Science.gov (United States)

Natalia, Kukarenko

2011-01-01

Climate change and environmental pollution have become pressing concerns for the peoples in the Arctic region. Some researchers link climate change, transformations of living conditions and human health. A number of studies have also provided data on differentiating effects of climate change on women's and men's well-being and health. To show how the issues of climate and environment change, human health and gender are addressed in current research in the Arctic. The main purpose of this article is not to give a full review but to draw attention to the gaps in knowledge and challenges in the Arctic research trends on climate change, human health and gender. A broad literature search was undertaken using a variety of sources from natural, medical, social science and humanities. The focus was on the keywords. Despite the evidence provided by many researchers on differentiating effects of climate change on well-being and health of women and men, gender perspective remains of marginal interest in climate change, environmental and health studies. At the same time, social sciences and humanities, and gender studies in particular, show little interest towards climate change impacts on human health in the Arctic. As a result, we still observe the division of labour between disciplines, the disciplinary-bound pictures of human development in the Arctic and terminology confusion. Efforts to bring in a gender perspective in the Arctic research will be successful only when different disciplines would work together. Multidisciplinary research is a way to challenge academic/disciplinary homogeneity and their boundaries, to take advantage of the diversity of approaches and methods in production of new integrated knowledge. Cooperation and dialogue across disciplines will help to develop adequate indicators for monitoring human health and elaborating efficient policies and strategies to the benefit of both women and men in the Arctic. Global Health Action 2011. © 2011 Kukarenko

The state of climate change adaptation in the Arctic

International Nuclear Information System (INIS)

Ford, James D; McDowell, Graham; Jones, Julie

2014-01-01

The Arctic climate is rapidly changing, with wide ranging impacts on natural and social systems. A variety of adaptation policies, programs and practices have been adopted to this end, yet our understanding of if, how, and where adaptation is occurring is limited. In response, this paper develops a systematic approach to characterize the current state of adaptation in the Arctic. Using reported adaptations in the English language peer reviewed literature as our data source, we document 157 discrete adaptation initiatives between 2003 and 2013. Results indicate large variations in adaptation by region and sector, dominated by reporting from North America, particularly with regards to subsistence harvesting by Inuit communities. Few adaptations were documented in the European and Russian Arctic, or have a focus on the business and economy, or infrastructure sectors. Adaptations are being motivated primarily by the combination of climatic and non-climatic factors, have a strong emphasis on reducing current vulnerability involving incremental changes to existing risk management processes, and are primarily initiated and led at the individual/community level. There is limited evidence of trans-boundary adaptations or initiatives considering potential cross-scale/sector impacts. (letter)

Patterns and processes influencing helminth parasites of Arctic coastal communities during climate change.

Science.gov (United States)

Galaktionov, K V

2017-07-01

This review analyses the scarce available data on biodiversity and transmission of helminths in Arctic coastal ecosystems and the potential impact of climate changes on them. The focus is on the helminths of seabirds, dominant parasites in coastal ecosystems. Their fauna in the Arctic is depauperate because of the lack of suitable intermediate hosts and unfavourable conditions for species with free-living larvae. An increasing proportion of crustaceans in the diet of Arctic seabirds would result in a higher infection intensity of cestodes and acanthocephalans, and may also promote the infection of seabirds with non-specific helminths. In this way, the latter may find favourable conditions for colonization of new hosts. Climate changes may alter the composition of the helminth fauna, their infection levels in hosts and ways of transmission in coastal communities. Immigration of boreal invertebrates and fish into Arctic seas may allow the circulation of helminths using them as intermediate hosts. Changing migratory routes of animals would alter the distribution of their parasites, facilitating, in particular, their trans-Arctic transfer. Prolongation of the seasonal 'transmission window' may increase the parasitic load on host populations. Changes in Arctic marine food webs would have an overriding influence on the helminths' circulation. This process may be influenced by the predicted decreased of salinity in Arctic seas, increased storm activity, coastal erosion, ocean acidification, decline of Arctic ice, etc. Greater parasitological research efforts are needed to assess the influence of factors related to Arctic climate change on the transmission of helminths.

Is climate change affecting wolf populations in the high Arctic?

Science.gov (United States)

Mech, L.D.

2004-01-01

Gobal climate change may affect wolves in Canada's High Arctic (80?? N) acting through three trophic levels (vegetation, herbivores, and wolves). A wolf pack dependent on muskoxen and arctic hares in the Eureka area of Ellesmere Island denned and produced pups most years from at least 1986 through 1997. However, when summer snow covered vegetation in 1997 and 2000 for the first time since records were kept, halving the herbivore nutrition-replenishment period, muskox and hare numbers dropped drastically, and the area stopped supporting denning wolves through 2003. The unusual weather triggering these events was consistent with global-climate-change phenomena. ?? 2004 Kluwer Academic Publishers.

Arctic Climate Change, Economy and Society (ACCESS): Integrated perspectives.

Science.gov (United States)

Crépin, Anne-Sophie; Karcher, Michael; Gascard, Jean-Claude

2017-12-01

This introduction to the special issue presents an overview of the wide range of results produced during the European Union project Arctic Climate Change, Economy and Society (ACCESS). This project assessed the main impacts of climate change on Arctic Ocean's geophysical variables and how these impending changes could be expected to impact directly and indirectly on socio-economic activities like transportation, marine sea food production and resource exploitation. Related governance issues were examined. These results were used to develop several management tools that can live on beyond ACCESS. In this article, we synthesize most of the project results in the form of tentative responses to questions raised during the project. By doing so, we put the findings of the project in a broader perspective and introduce the contributions made in the different articles published in this special issue.

Boundary layer stability and Arctic climate change: a feedback study using EC-Earth

Energy Technology Data Exchange (ETDEWEB)

Bintanja, R.; Linden, E.C. van der; Hazeleger, W. [Royal Netherlands Meteorological Institute (KNMI), De Bilt (Netherlands)

2012-12-15

Amplified Arctic warming is one of the key features of climate change. It is evident in observations as well as in climate model simulations. Usually referred to as Arctic amplification, it is generally recognized that the surface albedo feedback governs the response. However, a number of feedback mechanisms play a role in AA, of which those related to the prevalent near-surface inversion have received relatively little attention. Here we investigate the role of the near-surface thermal inversion, which is caused by radiative surface cooling in autumn and winter, on Arctic warming. We employ idealized climate change experiments using the climate model EC-Earth together with ERA-Interim reanalysis data to show that boundary-layer mixing governs the efficiency by which the surface warming signal is 'diluted' to higher levels. Reduced vertical mixing, as in the stably stratified inversion layer in Arctic winter, thus amplifies surface warming. Modelling results suggest that both shortwave - through the (seasonal) interaction with the sea ice feedback - and longwave feedbacks are affected by boundary-layer mixing, both in the Arctic and globally, with the effect on the shortwave feedback dominating. The amplifying effect will decrease, however, with climate warming because the surface inversion becomes progressively weaker. We estimate that the reduced Arctic inversion has slowed down global warming by about 5% over the past 2 decades, and we anticipate that it will continue to do so with ongoing Arctic warming. (orig.)

Evidence and implications of recent climate change in Northern Alaska and other Arctic regions

Science.gov (United States)

Hinzman, L.D.; Bettez, N.D.; Bolton, W.R.; Chapin, F.S.; Dyurgerov, M.B.; Fastie, C.L.; Griffith, B.; Hollister, R.D.; Hope, A.; Huntington, H.P.; Jensen, A.M.; Jia, G.J.; Jorgenson, T.; Kane, D.L.; Klein, D.R.; Kofinas, G.; Lynch, A.H.; Lloyd, A.H.; McGuire, A.D.; Nelson, Frederick E.; Oechel, W.C.; Osterkamp, T.E.; Racine, C.H.; Romanovsky, V.E.; Stone, R.S.; Stow, D.A.; Sturm, M.; Tweedie, C.E.; Vourlitis, G.L.; Walker, M.D.; Walker, D.A.; Webber, P.J.; Welker, J.M.; Winker, K.S.; Yoshikawa, K.

2005-01-01

The Arctic climate is changing. Permafrost is warming, hydrological processes are changing and biological and social systems are also evolving in response to these changing conditions. Knowing how the structure and function of arctic terrestrial ecosystems are responding to recent and persistent climate change is paramount to understanding the future state of the Earth system and how humans will need to adapt. Our holistic review presents a broad array of evidence that illustrates convincingly; the Arctic is undergoing a system-wide response to an altered climatic state. New extreme and seasonal surface climatic conditions are being experienced, a range of biophysical states and processes influenced by the threshold and phase change of freezing point are being altered, hydrological and biogeochemical cycles are shifting, and more regularly human sub-systems are being affected. Importantly, the patterns, magnitude and mechanisms of change have sometimes been unpredictable or difficult to isolate due to compounding factors. In almost every discipline represented, we show how the biocomplexity of the Arctic system has highlighted and challenged a paucity of integrated scientific knowledge, the lack of sustained observational and experimental time series, and the technical and logistic constraints of researching the Arctic environment. This study supports ongoing efforts to strengthen the interdisciplinarity of arctic system science and improve the coupling of large scale experimental manipulation with sustained time series observations by incorporating and integrating novel technologies, remote sensing and modeling. ?? Springer 2005.

Relevance of hydro-climatic change projection and monitoring for assessment of water cycle changes in the Arctic.

Science.gov (United States)

Bring, Arvid; Destouni, Georgia

2011-06-01

Rapid changes to the Arctic hydrological cycle challenge both our process understanding and our ability to find appropriate adaptation strategies. We have investigated the relevance and accuracy development of climate change projections for assessment of water cycle changes in major Arctic drainage basins. Results show relatively good agreement of climate model projections with observed temperature changes, but high model inaccuracy relative to available observation data for precipitation changes. Direct observations further show systematically larger (smaller) runoff than precipitation increases (decreases). This result is partly attributable to uncertainties and systematic bias in precipitation observations, but still indicates that some of the observed increase in Arctic river runoff is due to water storage changes, for example melting permafrost and/or groundwater storage changes, within the drainage basins. Such causes of runoff change affect sea level, in addition to ocean salinity, and inland water resources, ecosystems, and infrastructure. Process-based hydrological modeling and observations, which can resolve changes in evapotranspiration, and groundwater and permafrost storage at and below river basin scales, are needed in order to accurately interpret and translate climate-driven precipitation changes to changes in freshwater cycling and runoff. In contrast to this need, our results show that the density of Arctic runoff monitoring has become increasingly biased and less relevant by decreasing most and being lowest in river basins with the largest expected climatic changes.

COLLABORATIVE RESEARCH: TOWARDS ADVANCED UNDERSTANDING AND PREDICTIVE CAPABILITY OF CLIMATE CHANGE IN THE ARCTIC USING A HIGH-RESOLUTION REGIONAL ARCTIC CLIMATE SYSTEM MODEL

Energy Technology Data Exchange (ETDEWEB)

Gutowski, William J.

2013-02-07

The motivation for this project was to advance the science of climate change and prediction in the Arctic region. Its primary goals were to (i) develop a state-of-the-art Regional Arctic Climate system Model (RACM) including high-resolution atmosphere, land, ocean, sea ice and land hydrology components and (ii) to perform extended numerical experiments using high performance computers to minimize uncertainties and fundamentally improve current predictions of climate change in the northern polar regions. These goals were realized first through evaluation studies of climate system components via one-way coupling experiments. Simulations were then used to examine the effects of advancements in climate component systems on their representation of main physics, time-mean fields and to understand variability signals at scales over many years. As such this research directly addressed some of the major science objectives of the BER Climate Change Research Division (CCRD) regarding the advancement of long-term climate prediction.

Sensitivity of the carbon cycle in the Arctic to climate change

Science.gov (United States)

A.D. McGuire; L.G. Anderson; T.R. Christensen; S. Dallimore; L. Guo; D.J. Hayes; M. Heimann; T.D. Lorenson; R.W. Macdonald; N. Roulet

2009-01-01

The recent warming in the Arctic is affecting a broad spectrum of physical, ecological, and human/cultural systems that may be irreversible on century time scales and have the potential to cause rapid changes in the earth system. The response of the carbon cycle of the Arctic to changes in climate is a major issue of global concern, yet there has not been a...

Climate Change and Risk Management Challenges in the Arctic

DEFF Research Database (Denmark)

Jakobsen, Uffe

Climate change or global warming results in melting ice in the Arctic, both inland and sea ice. This opens up opportunities of natural ressource extraction and possibilities of new shipping routes, that opens up opportunities for increased maritime activities. However, with these opportunies come...... also the challenges of increased maritime activities that result in several risks in the Arctic such as the risk of pollution and the risks of accidents, which produce a need for preparedness towards oil spill and towards search and rescue (SAR) and institutions for SAR. Since the Arctic is such a huge...... possibilies of transborder risk management and partnership building....

Building Partnerships and Research Collaborations to Address the Impacts of Arctic Change: The North Atlantic Climate Change Collaboration (NAC3)

Science.gov (United States)

Polk, J.; North, L. A.; Strenecky, B.

2015-12-01

Changes in Arctic warming influence the various atmospheric and oceanic patterns that drive Caribbean and mid-latitude climate events, including extreme events like drought, tornadoes, and flooding in Kentucky and the surrounding region. Recently, the establishment of the North Atlantic Climate Change Collaboration (NAC3) project at Western Kentucky University (WKU) in partnership with the University of Akureyri (UNAK), Iceland Arctic Cooperation Network (IACN), and Caribbean Community Climate Change Centre (CCCCC) provides a foundation from which to engage students in applied research from the local to global levels and more clearly understand the many tenets of climate change impacts in the Arctic within both a global and local community context. The NAC3 project encompasses many facets, including joint international courses, student internships, economic development, service learning, and applied research. In its first phase, the project has generated myriad outcomes and opportunities for bridging STEM disciplines with other fields to holistically and collaboratively address specific human-environmental issues falling under the broad umbrella of climate change. WKU and UNAK students desire interaction and exposure to other cultures and regions that are threatened by climate change and Iceland presents a unique opportunity to study influences such as oceanic processes, island economies, sustainable harvest of fisheries, and Arctic influences on climate change. The project aims to develop a model to bring partners together to conduct applied research on the complex subject of global environmental change, particularly in the Arctic, while simultaneously focusing on changing how we learn, develop community, and engage internationally to understand the impacts and find solutions.

Climate change and natural hazards in the Arctic

Science.gov (United States)

Eichelberger, J. C.; Eichelberger, L. P.

2015-12-01

Climate change is motivating much of the science research in the Arctic. Natural hazards, which have always been with us and can be influenced by climate, also pose a serious threat to sustainability of Arctic communities, the Native cultures they support, and the health and wellbeing of their residents. These are themes of the US Chairship of the Arctic Council. For example, repetitive floods, often associated with spring ice jams, are a particularly severe problem for river communities. People live near rivers because access to food, water and river transportation support an indigenous subsistence lifestyle. Some settlement sites for Indigenous Peoples were mandated by distant authorities without regard to natural hazards, in Alaska no less than in other countries. Thus bad policy of the past casts a long shadow into the future. Remote communities are subject to multiple challenges, including natural hazards, access to education, and limited job opportunities. These intersect to reproduce structural vulnerability and have over time created a need for substantial support from government. In the past 40 years, the themes of "sustainability" and "self reliance" have become prominent strategies for governance at both state and local levels. Communities now struggle to demonstrate their sustainability while grappling with natural hazards and chronic poverty. In the extreme, the shifting of responsibility to resource-poor communities can be called "structural violence". Accepting the status quo can mean living without sanitation and reliable water supply, leading to the high observed rates of disease not normally encountered in developed countries. Many of the efforts to address climate change and natural hazards are complementary: monitoring the environment; forecasting extreme events; and community-based participatory research and planning. Natural disaster response is complementary to the Arctic Council's Search and Rescue (SAR) initiative, differing in that those

Climate Change and Arctic Issues in the Marine and Environmental Science Curriculum at the U.S. Coast Guard Academy

Science.gov (United States)

Vlietstra, L.; McConnell, M. C.; Bergondo, D. L.; Mrakovcich, K. L.; Futch, V.; Stutzman, B. S.; Fleischmann, C. M.

2016-02-01

As global climate change becomes more evident, demand will likely increase for experts with a detailed understanding of the scientific basis of climate change, the ocean's role in the earth-atmosphere system, and forecasted impacts, especially in Arctic regions where effects may be most pronounced. As a result, programs in marine and environmental sciences are uniquely poised to prepare graduates for the formidable challenges posed by changing climates. Here we present research evaluating the prevalence and themes of courses focusing on anthropogenic climate change in 125 Marine Science and Environmental Science undergraduate programs at 86 institutions in the United States. These results, in addition to the increasing role of the Coast Guard in the Arctic, led to the development of two new courses in the curriculum. Climate Change Science, a one-credit seminar, includes several student-centered activities supporting key learning objectives. Polar Oceanography, a three-credit course, incorporates a major outreach component to Coast Guard units and members of the scientific community. Given the importance of climate change in Arctic regions in particular, we also propose six essential "Arctic Literacy Principles" around which courses or individual lesson plans may be organized. We show how these principles are incorporated into an additional new three-credit course, Model Arctic Council, which prepares students to participate in a week-long simulation exercise of Arctic Council meetings, held in Fairbanks, Alaska. Students examine the history and mission of the Arctic Council and explore some of the issues on which the council has deliberated. Special attention is paid to priorities of the current U.S. chairmanship of the Arctic Council which include climate change impacts on, and stewardship of, the Arctic Ocean.

Climate and man in the Arctic

International Nuclear Information System (INIS)

1997-01-01

The ever-changing climate shapes the Arctic landscape, influences life conditions for plants and animals and alters the availability of the living resources that play such and important part in the economy of Arctic peoples. It is essential that we try to understand the nature of climatic change and its effects on man and his environment. Only this way can we hope to be able to predict future changes that may have great consequences for the well-being of northern residents. In recent years many research projects have been addressing the subject and important advances have been made. At the same time it has become increasingly evident that the complexity of the whole issue calls for an integration of scientific approaches and for interdisciplinary collaboration. The seminar 'Climate and Man in the Arctic' provided an opportunity both to highlight important areas of climate related research and to discuss more general aspects of arctic research. Eight papers presented at the seminar are published in this volume. (au) 22 refs

Climate of the Arctic marine environment.

Science.gov (United States)

Walsh, John E

2008-03-01

The climate of the Arctic marine environment is characterized by strong seasonality in the incoming solar radiation and by tremendous spatial variations arising from a variety of surface types, including open ocean, sea ice, large islands, and proximity to major landmasses. Interannual and decadal-scale variations are prominent features of Arctic climate, complicating the distinction between natural and anthropogenically driven variations. Nevertheless, climate models consistently indicate that the Arctic is the most climatically sensitive region of the Northern Hemisphere, especially near the sea ice margins. The Arctic marine environment has shown changes over the past several decades, and these changes are part of a broader global warming that exceeds the range of natural variability over the past 1000 years. Record minima of sea ice coverage during the past few summers and increased melt from Greenland have important implications for the hydrographic regime of the Arctic marine environment. The recent changes in the atmosphere (temperature, precipitation, pressure), sea ice, and ocean appear to be a coordinated response to systematic variations of the large-scale atmospheric circulation, superimposed on a general warming that is likely associated with increasing greenhouse gases. The changes have been sufficiently large in some sectors (e.g., the Bering/Chukchi Seas) that consequences for marine ecosystems appear to be underway. Global climate models indicate an additional warming of several degrees Celsius in much of the Arctic marine environment by 2050. However, the warming is seasonal (largest in autumn and winter), spatially variable, and closely associated with further retreat of sea ice. Additional changes predicted for 2050 are a general decrease of sea level pressure (largest in the Bering sector) and an increase of precipitation. While predictions of changes in storminess cannot be made with confidence, the predicted reduction of sea ice cover will

Arctic ecosystem responses to a warming climate

DEFF Research Database (Denmark)

Mortensen, Lars O.

sheet, loss of multiannual sea-ice and significant advances in snowmelt days. The biotic components of the arctic ecosystem have also been affected by the rapid changes in climate, for instance resulting in the collapse of the collared lemming cycle, advances in spring flowering and changes in the intra...... biotic interactions. Hence, through the use of up-to-date multivariate statistical tools, this Ph.D. study has been concerned with analyzing how the observed rapid climate changes are affecting the arctic ecosystems. The primary tool has been the implementation of structural equation modeling (SEM) which....... Additionally, the study demonstrated that climate effects had distinct direct and indirect effects on different trophic levels, indicating cascading effects of climate through the trophic system. Results suggest that the Arctic is being significantly affected by the observed climate changes and depending...

Regional Arctic System Model (RASM): A Tool to Advance Understanding and Prediction of Arctic Climate Change at Process Scales

Science.gov (United States)

Maslowski, W.; Roberts, A.; Osinski, R.; Brunke, M.; Cassano, J. J.; Clement Kinney, J. L.; Craig, A.; Duvivier, A.; Fisel, B. J.; Gutowski, W. J., Jr.; Hamman, J.; Hughes, M.; Nijssen, B.; Zeng, X.

2014-12-01

The Arctic is undergoing rapid climatic changes, which are some of the most coordinated changes currently occurring anywhere on Earth. They are exemplified by the retreat of the perennial sea ice cover, which integrates forcing by, exchanges with and feedbacks between atmosphere, ocean and land. While historical reconstructions from Global Climate and Global Earth System Models (GC/ESMs) are in broad agreement with these changes, the rate of change in the GC/ESMs remains outpaced by observations. Reasons for that stem from a combination of coarse model resolution, inadequate parameterizations, unrepresented processes and a limited knowledge of physical and other real world interactions. We demonstrate the capability of the Regional Arctic System Model (RASM) in addressing some of the GC/ESM limitations in simulating observed seasonal to decadal variability and trends in the sea ice cover and climate. RASM is a high resolution, fully coupled, pan-Arctic climate model that uses the Community Earth System Model (CESM) framework. It uses the Los Alamos Sea Ice Model (CICE) and Parallel Ocean Program (POP) configured at an eddy-permitting resolution of 1/12° as well as the Weather Research and Forecasting (WRF) and Variable Infiltration Capacity (VIC) models at 50 km resolution. All RASM components are coupled via the CESM flux coupler (CPL7) at 20-minute intervals. RASM is an example of limited-area, process-resolving, fully coupled earth system model, which due to the additional constraints from lateral boundary conditions and nudging within a regional model domain facilitates detailed comparisons with observational statistics that are not possible with GC/ESMs. In this talk, we will emphasize the utility of RASM to understand sensitivity to variable parameter space, importance of critical processes, coupled feedbacks and ultimately to reduce uncertainty in arctic climate change projections.

Globalization and climate change challenges the Arctic communities adaptability and increases vulnerability

DEFF Research Database (Denmark)

Hendriksen, Kåre

2011-01-01

Globalization and climate change challenges the Arctic communities adaptability and increases vulnerability Kåre Hendriksen, PhD student, Aalborg University, Denmark The previous isolation of the Arctic will change as a wide range of areas increasingly are integrated into the globalized world....... Coinciding climate changes cause an easier access for worldwide market as well as for the extraction of coastal oil and mineral resources. In an attempt to optimize the fishing fleet by economic measures it is centralized to larger units, and the exports of unprocessed fish and shellfish to low wage...... in contemporary developments leaving them with a feeling of being powerless. The consequences of contemporary policies and the problems arising will be illustrated through examples from traditional hunting and fishing districts in Greenland....

Changing Arctic ecosystems: resilience of caribou to climatic shifts in the Arctic

Science.gov (United States)

Gustine, David D.; Adams, Layne G.; Whalen, Mary E.; Pearce, John M.

2014-01-01

The U.S. Geological Survey (USGS) Changing Arctic Ecosystems (CAE) initiative strives to inform key resource management decisions for Arctic Alaska by providing scientific information and forecasts for current and future ecosystem response to a warming climate. Over the past 5 years, a focal area for the USGS CAE initiative has been the North Slope of Alaska. This region has experienced a warming trend over the past 60 years, yet the rate of change has been varied across the North Slope, leading scientists to question the future response and resilience of wildlife populations, such as caribou (Rangifer tarandus), that rely on tundra habitats for forage. Future changes in temperature and precipitation to coastal wet sedge and upland low shrub tundra are expected, with unknown consequences for caribou that rely on these plant communities for food. Understanding how future environmental change may affect caribou migration, nutrition, and reproduction is a focal question being addressed by the USGS CAE research. Results will inform management agencies in Alaska and people that rely on caribou for food.

Climatic and biotic extreme events moderate long-term responses of above- and belowground sub-Arctic heathland communities to climate change

NARCIS (Netherlands)

Bokhorst, S.F.; Phoenix, G.K.; Berg, M.P.; Callaghan, T.V.; Kirby-Lambert, C.; Bjerke, J.W.

2015-01-01

Climate change impacts are not uniform across the Arctic region because interacting factors causes large variations in local ecosystem change. Extreme climatic events and population cycles of herbivores occur simultaneously against a background of gradual climate warming trends and can redirect

The influence of human activity in the Arctic on climate and climate impacts

Energy Technology Data Exchange (ETDEWEB)

Huntington, H.P. [23834 The Clearing Dr., Eagle River, AK 99577 (United States); Boyle, M. [Institute for Resources, Environment and Sustainability, University of British Columbia, 2202 Main Mall, Vancouver, BC, V6S 1K4 (Canada); Flowers, G.E. [Department of Earth Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6 (Canada); Weatherly, J.W. [Snow and Ice Division, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH 03755 (United States); Hamilton, L.C. [Department of Sociology, University of New Hampshire, 20 College Road, Durham, NH 03824 (United States); Hinzman, L. [Water and Environment Research Center, University of Alaska Fairbanks, P.O. Box 755860, Fairbanks, AK 99775 (United States); Gerlach, C. [Department of Anthropology, University of Alaska Fairbanks, P.O. Box 757720, Fairbanks, AK 99775 (United States); Zulueta, R. [Department of Biology, Global Change Research Group, San Diego State University, 5500 Campanile Drive, PS-240, San Diego, CA 92182 (United States); Nicolson, C. [Department of Natural Resources Conservation, University of Massachusetts, 160 Holdsworth Way, Amherst, MA , 01003 (United States); Overpeck, J. [Institute for the Study of Planet Earth, University of Arizona, 715 North Park Avenue, 2nd Floor, Tucson, AZ, 85721 (United States)

2007-05-15

Human activities in the Arctic are often mentioned as recipients of climate-change impacts. In this paper we consider the more complicated but more likely possibility that human activities themselves can interact with climate or environmental change in ways that either mitigate or exacerbate the human impacts. Although human activities in the Arctic are generally assumed to be modest, our analysis suggests that those activities may have larger influences on the arctic system than previously thought. Moreover, human influences could increase substantially in the near future. First, we illustrate how past human activities in the Arctic have combined with climatic variations to alter biophysical systems upon which fisheries and livestock depend. Second, we describe how current and future human activities could precipitate or affect the timing of major transitions in the arctic system. Past and future analyses both point to ways in which human activities in the Arctic can substantially influence the trajectory of arctic system change.

Climate change and environmental impacts on maternal and newborn health with focus on Arctic populations

Directory of Open Access Journals (Sweden)

Torkjel M. Sandanger

2011-11-01

Full Text Available In 2007, the Intergovernmental Panel on Climate Change (IPCC presented a report on global warming and the impact of human activities on global warming. Later the Lancet commission identified six ways human health could be affected. Among these were not environmental factors which are also believed to be important for human health. In this paper we therefore focus on environmental factors, climate change and the predicted effects on maternal and newborn health. Arctic issues are discussed specifically considering their exposure and sensitivity to long range transported contaminants.Considering that the different parts of pregnancy are particularly sensitive time periods for the effects of environmental exposure, this review focuses on the impacts on maternal and newborn health. Environmental stressors known to affects human health and how these will change with the predicted climate change are addressed. Air pollution and food security are crucial issues for the pregnant population in a changing climate, especially indoor climate and food security in Arctic areas.The total number of environmental factors is today responsible for a large number of the global deaths, especially in young children. Climate change will most likely lead to an increase in this number. Exposure to the different environmental stressors especially air pollution will in most parts of the world increase with climate change, even though some areas might face lower exposure. Populations at risk today are believed to be most heavily affected. As for the persistent organic pollutants a warming climate leads to a remobilisation and a possible increase in food chain exposure in the Arctic and thus increased risk for Arctic populations. This is especially the case for mercury. The perspective for the next generations will be closely connected to the expected temperature changes; changes in housing conditions; changes in exposure patterns; predicted increased exposure to Mercury

Climate change on arctic environment, ecosystem services and society (CLICHE)

Science.gov (United States)

Weckström, J.; Korhola, A.; Väliranta, M.; Seppä, H.; Luoto, M.; Tuittila, E.-S.; Leppäranta, M.; Kahilainen, K.; Saarinen, J.; Heikkinen, H.

2012-04-01

The predicted climate warming has raised many questions and concerns about its impacts on the environment and society. As a respond to the need of holistic studies comprising both of these areas, The Academy of Finland launched The Finnish Research Programme on Climate Change (FICCA 2011-2014) in spring 2010 with the main aim to focus on the interaction between the environment and society. Ultimately 11 national consortium projects were funded (total budget 12 million EUR). Here we shortly present the main objectives of the largest consortium project "Climate change on arctic environment, ecosystem services and society" (CLICHE). The CLICHE consortium comprises eight interrelated work packages (treeline, diversity, peatlands, snow, lakes, fish, tourism, and traditional livelihoods), each led by a prominent research group and a team leader. The research consortium has three main overall objectives: 1) Investigate, map and model the past, present and future climate change-induced changes in central ecosystems of the European Arctic with unprecedented precision 2) Deepen our understanding of the basic principles of ecosystem and social resilience and dynamics; identify key taxa, structures or processes that clearly indicate impending or realised global change through their loss, occurrence or behaviour, using analogues from the past (e.g. Holocene Thermal Maximum, Medieval Warm Period), experiments, observations and models 3) Develop adaptation and mitigation strategies to minimize the adverse effects of climate change on local communities, traditional livelihoods, fisheries, and tourism industry, and promote sustainable development of local community structures and enhance the quality of life of local human populations. As the project has started only recently no final results are available yet. However, the fieldwork as well as the co-operation between the research teams has thus far been very successful. Thus, the expectations for the final outcome of the project

Past Changes in Arctic Terrestrial Ecosystems, Climate and UV Radiation

Energy Technology Data Exchange (ETDEWEB)

Callaghan, Terry V. [Abisko Scientific Research Station, Abisko (Sweden); Bjoern, Lars Olof [Lund Univ. (Sweden). Dept. of Cell and Organism Biology; Chernov, Yuri [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Severtsov Inst. of Evolutionary Morphology and Animal Ecology] (and others)

2004-11-01

At the last glacial maximum, vast ice sheets covered many continental areas. The beds of some shallow seas were exposed thereby connecting previously separated landmasses. Although some areas were ice-free and supported a flora and fauna, mean annual temperatures were 10-13 deg C colder than during the Holocene. Within a few millennia of the glacial maximum, deglaciation started, characterized by a series of climatic fluctuations between about 18,000 and 11,400 years ago. Following the general thermal maximum in the Holocene, there has been a modest overall cooling trend, superimposed upon which have been a series of millennial and centennial fluctuations in climate such as the 'Little Ice Age' spanning approximately the late 13th to early 19th centuries. Throughout the climatic fluctuations of the last 150,000 years, Arctic ecosystems and biota have been close to their minimum extent within the most recent 10,000 years. They suffered loss of diversity as a result of extinctions during the most recent large-magnitude rapid global warming at the end of the last glacial stage. Consequently, Arctic ecosystems and biota such as large vertebrates are already under pressure and are particularly vulnerable to current and projected future global warming. Evidence from the past indicates that the treeline will very probably advance, perhaps rapidly, into tundra areas, as it did during the early Holocene, reducing the extent of tundra and increasing the risk of species extinction. Species will very probably extend their ranges northwards, displacing Arctic species as in the past. However, unlike the early Holocene, when lower relative sea level allowed a belt of tundra to persist around at least some parts of the Arctic basin when treelines advanced to the present coast, sea level is very likely to rise in future, further restricting the area of tundra and other treeless Arctic ecosystems. The negative response of current Arctic ecosystems to global climatic

Long-term bird study records Arctic climate change

Science.gov (United States)

Zielinski, Sarah

Alaska's summer of 2005 was the second warmest on record there, with a record retreat of arctic pack ice. As Alaskan temperatures gradually increase, artic birds, such as the black guillemots of Cooper Island, near Barrow, Alaska, are experiencing drastic habitat changes. Though these small black and white birds—the subjects of a long-term study of climate change—fared better this year than they have in the recent past (due to local cool conditions), they are nonetheless struggling to adapt as their artic island summer home becomes subarctic.George Divokyan ornithologist at the Institute of Arctic Biology, University of Alaska Fairbanks, discovered the Cooper Island colony of guillemots in the early 1970s and has spent every summer since 1975 there studying these birds. He presented his latest research during a 3 November talk in Washington, D.C.

Toward Process-resolving Synthesis and Prediction of Arctic Climate Change Using the Regional Arctic System Model

Science.gov (United States)

Maslowski, W.

2017-12-01

The Regional Arctic System Model (RASM) has been developed to better understand the operation of Arctic System at process scale and to improve prediction of its change at a spectrum of time scales. RASM is a pan-Arctic, fully coupled ice-ocean-atmosphere-land model with marine biogeochemistry extension to the ocean and sea ice models. The main goal of our research is to advance a system-level understanding of critical processes and feedbacks in the Arctic and their links with the Earth System. The secondary, an equally important objective, is to identify model needs for new or additional observations to better understand such processes and to help constrain models. Finally, RASM has been used to produce sea ice forecasts for September 2016 and 2017, in contribution to the Sea Ice Outlook of the Sea Ice Prediction Network. Future RASM forecasts, are likely to include increased resolution for model components and ecosystem predictions. Such research is in direct support of the US environmental assessment and prediction needs, including those of the U.S. Navy, Department of Defense, and the recent IARPC Arctic Research Plan 2017-2021. In addition to an overview of RASM technical details, selected model results are presented from a hierarchy of climate models together with available observations in the region to better understand potential oceanic contributions to polar amplification. RASM simulations are analyzed to evaluate model skill in representing seasonal climatology as well as interannual and multi-decadal climate variability and predictions. Selected physical processes and resulting feedbacks are discussed to emphasize the need for fully coupled climate model simulations, high model resolution and sensitivity of simulated sea ice states to scale dependent model parameterizations controlling ice dynamics, thermodynamics and coupling with the atmosphere and ocean.

Food and water security in a changing arctic climate

International Nuclear Information System (INIS)

White, Daniel M; Gerlach, S Craig; Loring, Philip; Tidwell, Amy C; Chambers, Molly C

2007-01-01

In the Arctic, permafrost extends up to 500 m below the ground surface, and it is generally just the top metre that thaws in summer. Lakes, rivers, and wetlands on the arctic landscape are normally not connected with groundwater in the same way that they are in temperate regions. When the surface is frozen in winter, only lakes deeper than 2 m and rivers with significant flow retain liquid water. Surface water is largely abundant in summer, when it serves as a breeding ground for fish, birds, and mammals. In winter, many mammals and birds are forced to migrate out of the Arctic. Fish must seek out lakes or rivers deep enough to provide good overwintering habitat. Humans in the Arctic rely on surface water in many ways. Surface water meets domestic needs such as drinking, cooking, and cleaning as well as subsistence and industrial demands. Indigenous communities depend on sea ice and waterways for transportation across the landscape and access to traditional country foods. The minerals, mining, and oil and gas industries also use large quantities of surface water during winter to build ice roads and maintain infrastructure. As demand for this limited, but heavily-relied-upon resource continues to increase, it is now more critical than ever to understand the impacts of climate change on food and water security in the Arctic

Arctic Climate Variability and Trends from Satellite Observations

Directory of Open Access Journals (Sweden)

Xuanji Wang

2012-01-01

Full Text Available Arctic climate has been changing rapidly since the 1980s. This work shows distinctly different patterns of change in winter, spring, and summer for cloud fraction and surface temperature. Satellite observations over 1982–2004 have shown that the Arctic has warmed up and become cloudier in spring and summer, but cooled down and become less cloudy in winter. The annual mean surface temperature has increased at a rate of 0.34°C per decade. The decadal rates of cloud fraction trends are −3.4%, 2.3%, and 0.5% in winter, spring, and summer, respectively. Correspondingly, annually averaged surface albedo has decreased at a decadal rate of −3.2%. On the annual average, the trend of cloud forcing at the surface is −2.11 W/m2 per decade, indicating a damping effect on the surface warming by clouds. The decreasing sea ice albedo and surface warming tend to modulate cloud radiative cooling effect in spring and summer. Arctic sea ice has also declined substantially with decadal rates of −8%, −5%, and −15% in sea ice extent, thickness, and volume, respectively. Significant correlations between surface temperature anomalies and climate indices, especially the Arctic Oscillation (AO index, exist over some areas, implying linkages between global climate change and Arctic climate change.

Arctic sea ice area changes in CMIP3 and CMIP5 climate models’ ensembles

Directory of Open Access Journals (Sweden)

V. A. Semenov

2017-01-01

Full Text Available The shrinking Arctic sea ice cover observed during the last decades is probably the clearest manifestation of ongoing climate change. While climate models in general reproduce the sea ice retreat in the Arctic during the 20th century and simulate further sea ice area loss during the 21st century in response to anthropogenic forcing, the models suffer from large biases and the results exhibit considerable spread. Here, we compare results from the two last generations of climate models, CMIP3 and CMIP5, with respect to total and regional Arctic sea ice change. Different characteristics of sea ice area (SIA in March and September have been analysed for the Entire Arctic, Central Arctic and Barents Sea. Further, the sensitivity of SIA to changes in Northern Hemisphere (NH temperature is investigated and dynamical links between SIA and some atmospheric variability modes are assessed.CMIP3 (SRES A1B and CMIP5 (RCP8.5 models not only simulate a coherent decline of the Arctic SIA but also depict consistent changes in the SIA seasonal cycle. The spatial patterns of SIC variability improve in CMIP5 ensemble, most noticeably in summer when compared to HadISST1 data. A better simulation of summer SIA in the Entire Arctic by CMIP5 models is accompanied by a slightly increased bias for winter season in comparison to CMIP3 ensemble. SIA in the Barents Sea is strongly overestimated by the majority of CMIP3 and CMIP5 models, and projected SIA changes are characterized by a high uncertainty. Both CMIP ensembles depict a significant link between the SIA and NH temperature changes indicating that a part of inter-ensemble SIA spread comes from different temperature sensitivity to anthropogenic forcing. The results suggest that, in general, a sensitivity of SIA to external forcing is enhanced in CMIP5 models. Arctic SIA interannual variability in the end of the 20th century is on average well simulated by both ensembles. To the end of the 21st century, September

Modelling impact of climate change on atmospheric transport and fate of persistent organic pollutants in the Arctic

Science.gov (United States)

Hansen, K. M.; Christensen, J. H.; Geels, C.; Silver, J. D.; Brandt, J.

2015-03-01

The Danish Eulerian Hemispheric Model (DEHM) was applied to investigate how projected climate changes will affect the atmospheric transport of 13 persistent organic pollutants (POPs) to the Artic and their environmental fate within the Arctic. Two sets of simulations were performed, one with initial environmental concentrations from a 20 year spin-up simulation and one with initial environmental concentrations set to zero. Each set of simulations consisted of two ten-year time slices representing the present (1990-2000) and future (2090-2100) climate conditions. The same POP emissions were applied in all simulations to ensure that the difference in predicted concentrations for each set of simulations only arises from the difference in climate input. DEHM was driven using meteorological input from the global circulation model, ECHAM/MPI-OM, simulating the SRES A1B climate scenario. Under the applied climate and emission scenarios, the total mass of all compounds was predicted to be up to 20% higher across the Northern Hemisphere. The mass of HCHs within the Arctic was predicted to be up to 39% higher, whereas the change in mass of the PCBs was predicted to range from 14% lower to 17% higher depending on the congener and the applied initial environmental concentrations. The results of this study also indicate that contaminants with no or a short emission history will be more rapidly transported to and build up in the arctic environment in a future warmer climate. The process that dominates the environmental behaviour of POPs in the Arctic under a future warmer climate scenario is the shift in mass of POPs from the surface media to the atmosphere induced by the higher mean temperature. This is to some degree counteracted by higher degradation rates also following the higher mean temperature. The more dominant of these two processes depend on the physical-chemical properties of the compounds. Previous model studies have predicted that the effect of a changed climate on

Climate change and consequences in the Arctic: perception of climate change by the Nenets people of Vaigach Island.

Science.gov (United States)

Davydov, Alexander N; Mikhailova, Galina V

2011-01-01

Arctic climate change is already having a significant impact on the environment, economic activity, and public health. For the northern peoples, traditions and cultural identity are closely related to the natural environment so any change will have consequences for society in several ways. A questionnaire was given to the population on the Vaigach island, the Nenets who rely to a large degree on hunting, fishing and reindeer herding for survival. Semi-structured interviews were also conducted about perception of climate change. Climate change is observed and has already had an impact on daily life according to more than 50% of the respondents. The winter season is now colder and longer and the summer season colder and shorter. A decrease in standard of living was noticeable but few were planning to leave. Climate change has been noticed in the region and it has a negative impact on the standard of living for the Nenets. However, as of yet they do not want to leave as cultural identity is important for their overall well-being.

Species interactions and response time to climate change: ice-cover and terrestrial run-off shaping Arctic char and brown trout competitive asymmetries

Science.gov (United States)

Finstad, A. G.; Palm Helland, I.; Jonsson, B.; Forseth, T.; Foldvik, A.; Hessen, D. O.; Hendrichsen, D. K.; Berg, O. K.; Ulvan, E.; Ugedal, O.

2011-12-01

There has been a growing recognition that single species responses to climate change often mainly are driven by interaction with other organisms and single species studies therefore not are sufficient to recognize and project ecological climate change impacts. Here, we study how performance, relative abundance and the distribution of two common Arctic and sub-Arctic freshwater fishes (brown trout and Arctic char) are driven by competitive interactions. The interactions are modified both by direct climatic effects on temperature and ice-cover, and indirectly through climate forcing of terrestrial vegetation pattern and associated carbon and nutrient run-off. We first use laboratory studies to show that Arctic char, which is the world's most northernmost distributed freshwater fish, outperform trout under low light levels and also have comparable higher growth efficiency. Corresponding to this, a combination of time series and time-for-space analyses show that ice-cover duration and carbon and nutrient load mediated by catchment vegetation properties strongly affected the outcome of the competition and likely drive the species distribution pattern through competitive exclusion. In brief, while shorter ice-cover period and decreased carbon load favored brown trout, increased ice-cover period and increased carbon load favored Arctic char. Length of ice-covered period and export of allochthonous material from catchments are major, but contrasting, climatic drivers of competitive interaction between these two freshwater lake top-predators. While projected climate change lead to decreased ice-cover, corresponding increase in forest and shrub cover amplify carbon and nutrient run-off. Although a likely outcome of future Arctic and sub-arctic climate scenarios are retractions of the Arctic char distribution area caused by competitive exclusion, the main drivers will act on different time scales. While ice-cover will change instantaneously with increasing temperature

Has prey availability for Arctic birds advanced with climate change? Hindcasting the abundance of tundra arthropods using weather and seasonal variations

NARCIS (Netherlands)

Tulp, I.; Schekkerman, H.

2008-01-01

Of all climatic zones on earth, Arctic areas have experienced the greatest climate change in recent decades. Predicted changes, including a continuing rise in temperature and precipitation and a reduction in snow cover, are expected to have a large impact on Arctic life. Large numbers of birds breed

Has prey availability for Arctic birds advanced with climate change? Hindcasting the abundance of tundra Arthropods using weather and seasonal variation

NARCIS (Netherlands)

Tulp, I.Y.M.; Schekkerman, H.

2008-01-01

Of all climatic zones on earth, Arctic areas have experienced the greatest climate change in recent decades. Predicted changes, including a continuing rise in temperature and precipitation and a reduction in snow cover, are expected to have a large impact on Arctic life. Large numbers of birds breed

Climate change and infectious diseases in the Arctic: establishment of a circumpolar working group

Directory of Open Access Journals (Sweden)

Alan J. Parkinson

2014-09-01

Full Text Available The Arctic, even more so than other parts of the world, has warmed substantially over the past few decades. Temperature and humidity influence the rate of development, survival and reproduction of pathogens and thus the incidence and prevalence of many infectious diseases. Higher temperatures may also allow infected host species to survive winters in larger numbers, increase the population size and expand their habitat range. The impact of these changes on human disease in the Arctic has not been fully evaluated. There is concern that climate change may shift the geographic and temporal distribution of a range of infectious diseases. Many infectious diseases are climate sensitive, where their emergence in a region is dependent on climate-related ecological changes. Most are zoonotic diseases, and can be spread between humans and animals by arthropod vectors, water, soil, wild or domestic animals. Potentially climate-sensitive zoonotic pathogens of circumpolar concern include Brucella spp., Toxoplasma gondii, Trichinella spp., Clostridium botulinum, Francisella tularensis, Borrelia burgdorferi, Bacillus anthracis, Echinococcus spp., Leptospira spp., Giardia spp., Cryptosporida spp., Coxiella burnetti, rabies virus, West Nile virus, Hantaviruses, and tick-borne encephalitis viruses.

Climate change and infectious diseases in the Arctic: establishment of a circumpolar working group

Science.gov (United States)

Parkinson, Alan J.; Evengard, Birgitta; Semenza, Jan C.; Ogden, Nicholas; Børresen, Malene L.; Berner, Jim; Brubaker, Michael; Sjöstedt, Anders; Evander, Magnus; Hondula, David M.; Menne, Bettina; Pshenichnaya, Natalia; Gounder, Prabhu; Larose, Tricia; Revich, Boris; Hueffer, Karsten; Albihn, Ann

2014-01-01

The Arctic, even more so than other parts of the world, has warmed substantially over the past few decades. Temperature and humidity influence the rate of development, survival and reproduction of pathogens and thus the incidence and prevalence of many infectious diseases. Higher temperatures may also allow infected host species to survive winters in larger numbers, increase the population size and expand their habitat range. The impact of these changes on human disease in the Arctic has not been fully evaluated. There is concern that climate change may shift the geographic and temporal distribution of a range of infectious diseases. Many infectious diseases are climate sensitive, where their emergence in a region is dependent on climate-related ecological changes. Most are zoonotic diseases, and can be spread between humans and animals by arthropod vectors, water, soil, wild or domestic animals. Potentially climate-sensitive zoonotic pathogens of circumpolar concern include Brucella spp., Toxoplasma gondii, Trichinella spp., Clostridium botulinum, Francisella tularensis, Borrelia burgdorferi, Bacillus anthracis, Echinococcus spp., Leptospira spp., Giardia spp., Cryptosporida spp., Coxiella burnetti, rabies virus, West Nile virus, Hantaviruses, and tick-borne encephalitis viruses. PMID:25317383

Arctic cloud-climate feedbacks: On relationships between Arctic clouds, sea ice, and lower tropospheric stability

Science.gov (United States)

Taylor, P. C.; Boeke, R.; Hegyi, B.

2017-12-01

Arctic low clouds strongly affect the Arctic surface energy budget. Through this impact Arctic low clouds influence other important aspects of the Arctic climate system, namely surface and atmospheric temperature, sea ice extent and thickness, and atmospheric circulation. Arctic clouds are in turn influenced by these Arctic climate system elements creating the potential for Arctic cloud-climate feedbacks. To further our understanding of the potential for Arctic cloud-climate feedbacks, we quantify the influence of atmospheric state on the surface cloud radiative effect (CRE). In addition, we quantify the covariability between surface CRE and sea ice concentration (SIC). This paper builds on previous research using instantaneous, active remote sensing satellite footprint data from the NASA A-Train. First, the results indicate significant differences in the surface CRE when stratified by atmospheric state. Second, a statistically insignificant covariability is found between CRE and SIC for most atmospheric conditions. Third, we find a statistically significant increase in the average surface longwave CRE at lower SIC values in fall. Specifically, a +3-5 W m-2 larger longwave CRE is found over footprints with 0% versus 100% SIC. Because systematic changes on the order of 1 W m-2 are sufficient to explain the observed long-term reductions in sea ice extent, our results indicate a potentially significant amplifying sea ice-cloud feedback that could delay the fall freeze-up and influence the variability in sea ice extent and volume, under certain meteorological conditions. Our results also suggest that a small change in the frequency of occurrence of atmosphere states may yield a larger Arctic cloud feedback than any cloud response to sea ice.

Climate change and water security with a focus on the Arctic

Directory of Open Access Journals (Sweden)

Birgitta Evengard

2011-10-01

Full Text Available Water is of fundamental importance for human life; access to water of good quality is of vital concern for mankind. Currently however, the situation is under severe pressure due to several stressors that have a clear impact on access to water. In the Arctic, climate change is having an impact on water availability by melting glaciers, decreasing seasonal rates of precipitation, increasing evapotranspiration, and drying lakes and rivers existing in permafrost grounds. Water quality is also being impacted as manmade pollutants stored in the environment are released, lowland areas are flooded with salty ocean water during storms, turbidity from permafrost-driven thaw and erosion is increased, and the growth or emergence of natural pollutants are increased. By 2030 it is estimated that the world will need to produce 50% more food and energy which means a continuous increase in demand for water. Decisionmakers will have to very clearly include life quality aspects of future generations in the work as impact of ongoing changes will be noticeable, in many cases, in the future. This article will focus on effects of climate-change on water security with an Arctic perspective giving some examples from different countries how arising problems are being addressed.

Detecting and Understanding Changing Arctic Carbon Emissions

Science.gov (United States)

Bruhwiler, L.

2017-12-01

Warming in the Arctic has proceeded faster than anyplace on Earth. Our current understanding of biogeochemistry suggests that we can expect feedbacks between climate and carbon in the Arctic. Changes in terrestrial fluxes of carbon can be expected as the Arctic warms, and the vast stores of organic carbon frozen in Arctic soils could be mobilized to the atmosphere, with possible significant impacts on global climate. Quantifying trends in Arctic carbon exchanges is important for policymaking because greater reductions in anthropogenic emissions may be required to meet climate goals. Observations of greenhouse gases in the Arctic and globally have been collected for several decades. Analysis of this data does not currently support significantly changed Arctic emissions of CH4, however it is difficult to detect changes in Arctic emissions because of transport from lower latitudes and large inter-annual variability. Unfortunately, current space-based remote sensing systems have limitations at Arctic latitudes. Modeling systems can help untangle the Arctic budget of greenhouse gases, but they are dependent on underlying prior fluxes, wetland distributions and global anthropogenic emissions. Also, atmospheric transport models may have significant biases and errors. For example, unrealistic near-surface stability can lead to underestimation of emissions in atmospheric inversions. We discuss our current understanding of the Arctic carbon budget from both top-down and bottom-up approaches. We show that current atmospheric inversions agree well on the CH4 budget. On the other hand, bottom-up models vary widely in their predictions of natural emissions, with some models predicting emissions too large to be accommodated by the budget implied by global observations. Large emissions from the shallow Arctic ocean are also inconsistent with atmospheric observations. We also discuss the sensitivity of the current atmospheric network to what is likely small, gradual increases in

Specificities of Spatial System Transformation and Strategies of the Russian Arctic Redevelopment under the Conditions of Climate Changes

Directory of Open Access Journals (Sweden)

Vladimir Nikolaevich Leksin

2017-09-01

Full Text Available A bunch of papers has been published by foreign and Russian researchers on climate change impact on the environment and regional socioeconomic development. The bulk of them is focused on analyzing drivers and impact assessments for the Arctic region characterized by the most intensive climate change worldwide. The paper puts to the fore a nontrivial issue of considering the climate change impact factor within the methodology and practice of the strategic process of the Russian Arctic redevelopment. The issue above is complicated by the imperative of ranking of the salience of the climate change socioeconomic implications as priorities of the governance and public administration of the comprehensive development of the macro-region under consideration. The lack of the effective tools for consolidation of the needed resources further exacerbates it. The summary of the findings of the national and international researchers in the area of climate change impact on environment, settlements and economic activity in the Arctic Zone of the Russian Federation (AZRF is introduced to substantiate the policy decisions made. We have specified the methodological issues related to peculiarities and role of the climate change factor plays in policy decisions within the context of contemporary knowledge on patterns of spatial systems transformation, their capabilities of selforganization and adaptation to externalities. The authors have revealed the general regularities and specificity of the AZRF transformation as a spatial system and the impact of climate change produced on this process. We have particularly emphasized the issues of adaptation to climate change of the AZRF indigenous population whose health and economic activities experience increased risks associated with high intensiveness of the climatic fluctuations. Recommendations for using scenario (variation approach to redesigning strategies and programs of AZRF development are substantiated

Modelling the impact of climate change on the atmospheric transport and the fate of persistent organic pollutants in the Arctic

Science.gov (United States)

Hansen, K. M.; Christensen, J. H.; Geels, C.; Silver, J. D.; Brandt, J.

2015-06-01

The Danish Eulerian Hemispheric Model (DEHM) was applied to investigate how projected climate changes will affect the atmospheric transport of 13 persistent organic pollutants (POPs) to the Arctic and their environmental fate within the Arctic. Three sets of simulations were performed, one with present day emissions and initial environmental concentrations from a 20-year spin-up simulation, one with present day emissions and with initial environmental concentrations set to zero and one without emissions but with initial environmental concentrations from the 20-year spin-up simulation. Each set of simulations consisted of two 10-year time slices representing the present (1990-2000) and future (2090-2100) climate conditions. DEHM was driven using meteorological input from the global circulation model, ECHAM/MPI-OM, simulating the SRES (Special Report on Emissions Scenarios) A1B climate scenario. Under the applied climate and emission scenarios, the total mass of all compounds was predicted to be up to 55 % lower across the Northern Hemisphere at the end of the 2090s than in the 1990s. The mass of HCHs within the Arctic was predicted to be up to 38 % higher, whereas the change in mass of the PCBs was predicted to range from 38 % lower to 17 % higher depending on the congener and the applied initial environmental concentrations. The results of this study also indicate that contaminants with no or a short emission history will be more rapidly transported to and build up in the arctic environment in a future warmer climate. The process that dominates the environmental behaviour of POPs in the Arctic under a future warmer climate scenario is the shift in mass of POPs from the surface media to the atmosphere induced by the higher mean temperature. This is to some degree counteracted by higher degradation rates also following the higher mean temperature. The more dominant of these two processes depends on the physical-chemical properties of the compounds. Previous model

Globalising the Arctic Climate:

DEFF Research Database (Denmark)

Corry, Olaf

2017-01-01

This chapter uses an object-oriented approach to explore how the Arctic is being constituted as an object of global governance within an emerging ‘global polity’, partly through geoengineering plans and political visions ('imaginaries'). It suggests that governance objects—the socially constructed...... on world politics. The emergence of the Arctic climate as a potential target of governance provides a case in point. The Arctic climate is becoming globalised, pushing it up the political agenda but drawing it away from its local and regional context....

Global and Arctic climate engineering: numerical model studies.

Science.gov (United States)

Caldeira, Ken; Wood, Lowell

2008-11-13

We perform numerical simulations of the atmosphere, sea ice and upper ocean to examine possible effects of diminishing incoming solar radiation, insolation, on the climate system. We simulate both global and Arctic climate engineering in idealized scenarios in which insolation is diminished above the top of the atmosphere. We consider the Arctic scenarios because climate change is manifesting most strongly there. Our results indicate that, while such simple insolation modulation is unlikely to perfectly reverse the effects of greenhouse gas warming, over a broad range of measures considering both temperature and water, an engineered high CO2 climate can be made much more similar to the low CO2 climate than would be a high CO2 climate in the absence of such engineering. At high latitudes, there is less sunlight deflected per unit albedo change but climate system feedbacks operate more powerfully there. These two effects largely cancel each other, making the global mean temperature response per unit top-of-atmosphere albedo change relatively insensitive to latitude. Implementing insolation modulation appears to be feasible.

Quantifying Direct and Indirect Impact of Future Climate on Sub-Arctic Hydrology

Science.gov (United States)

Endalamaw, A. M.; Bolton, W. R.; Young-Robertson, J. M.; Morton, D.; Hinzman, L. D.

2016-12-01

Projected future climate will have a significant impact on the hydrology of interior Alaskan sub-arctic watersheds, directly though the changes in precipitation and temperature patterns, and indirectly through the cryospheric and ecological impacts. Although the latter is the dominant factor controlling the hydrological processes in the interior Alaska sub-arctic, it is often overlooked in many climate change impact studies. In this study, we aim to quantify and compare the direct and indirect impact of the projected future climate on the hydrology of the interior Alaskan sub-arctic watersheds. The Variable Infiltration Capacity (VIC) meso-scale hydrological model will be implemented to simulate the hydrological processes, including runoff, evapotranspiration, and soil moisture dynamics in the Chena River Basin (area = 5400km2), located in the interior Alaska sub-arctic region. Permafrost and vegetation distribution will be derived from the Geophysical Institute Permafrost Lab (GIPL) model and the Lund-Potsdam-Jena Dynamic Global Model (LPJ) model, respectively. All models will be calibrated and validated using historical data. The Scenario Network for Alaskan and Arctic Planning (SNAP) 5-model average projected climate data products will be used as forcing data for each of these models. The direct impact of climate change on hydrology is estimated using surface parameterization derived from the present day permafrost and vegetation distribution, and future climate forcing from SNAP projected climate data products. Along with the projected future climate, outputs of GIPL and LPJ will be incorporated into the VIC model to estimate the indirect and overall impact of future climate on the hydrology processes in the interior Alaskan sub-arctic watersheds. Finally, we will present the potential hydrological and ecological changes by the end of the 21st century.

The effects of climate changes on soil methane oxidation in a dry Arctic tundra

Science.gov (United States)

D'Imperio, Ludovica

2014-05-01

The effects of climate changes on soil methane oxidation in a dry Arctic tundra. Ludovica D'Imperio1, Anders Michelsen1, Christian J. Jørgensen1, Bo Elberling1 1Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark At Northern latitudes climatic changes are predicted to be most pronounced resulting in increasing active layer depth and changes in growing season length, vegetation cover and nutrient cycling. As a consequence of increased temperature, large stocks of carbon stored in the permafrost-affected soils could become available for microbial transformations and under anoxic conditions result in increasing methane production affecting net methane (CH4) budget. Arctic tundra soils also serves as an important sink of atmospheric CH4 by microbial oxidation under aerobic conditions. While several process studies have documented the mechanisms behind both production and emissions of CH4 in arctic ecosystems, an important knowledge gap exists with respect to the in situ dynamics of microbial-driven uptake of CH4 in arctic dry lands which may be enhanced as a consequence of global warming and thereby counterbalancing CH4 emissions from Arctic wetlands. In-situ methane measurements were made in a dry Arctic tundra in Disko Island, Western Greenland, during the summer 2013 to assess the role of seasonal and inter-annual variations in temperatures and snow cover. The experimental set-up included snow fences installed in 2012, allowed investigations of the emissions of GHGs from soil under increased winter snow deposition and ambient field conditions. The soil fluxes of CH4 and CO2 were measured using closed chambers in manipulated plots with increased summer temperatures and shrub removal with or without increased winter precipitation. At the control plots, the averaged seasonal CH4 oxidation rates ranged between -0.05 mg CH4 m-2 hr-1 (end of August) and -0.32 mg CH4 m-2 hr-1 (end of June). In the

The Impact of Climate Change on an Archaeological Site in the Arctic

DEFF Research Database (Denmark)

Hollesen, Jørgen; Matthiesen, H.; Elberling, Bo

2017-01-01

Climate change may accelerate the degradation of archaeological sites in the Arctic and lead to a loss of important historical information. This study assesses the current preservation conditions and the processes controlling the physical and chemical stability of the Qajaa kitchen midden......, thermal and hydrological erosion and oxygen exposure may lead to substantial loss of archaeological evidence before the end of the 21st century....

Impacts of northern climate changes on Arctic engineering practice

International Nuclear Information System (INIS)

Esch, D.C.

1993-01-01

Potential impacts of climate changes on engineering design practices in the Arctic are discussed with reference to permafrost engineering aspects, hydrology, and coastal and sea ice processes. Permafrost generally remains thermally stable only when mean annual air temperature remains 2-4 degrees below zero and the original surface conditions remain unchanged. It has been demonstrated that a temperature rise of only 1-2 degrees is very critical. The many different climate change forecasts make it difficult to design structures in permafrost with definite levels of confidence over a project's lifetime (i.e. up to 50 years). Consequences of climate warming on transportation-related structures can be estimated to a certain degree by examining experience with natural permafrost surfaces affected by land clearing or with structures built in permafrost. Melting of permafrost will be accompanied by surface settlements, slumping of slopes and banks, and creation of thaw pits and ponds, with eventual distress to many surface structures such as pavements and foundations. Designing for a warmer climate is illustrated for the case of the Bethel Highway, the first in Alaska to be designed for a progressively warmer climate. Increased water flows both from ice melting and increased precipitation in a warmer climate will make forecasting of discharge levels in drainage basins a difficult task. Of great concern to engineers is the potential for increased erosion and sediment loadings in streams. In coastal engineering, the effects of rising sea levels, increased open-water areas, and more severe storms foreseen in a warmer climate will require heavier and more elevated shore protection. On the other hand, shipping and offshore operations will be made easier. 9 refs., 4 figs

Transformational Change and Regime Shifts in the Circumpolar Arctic

Directory of Open Access Journals (Sweden)

Annika E. Nilsson

2016-11-01

Full Text Available The Arctic is changing rapidly, and there are many indications that the region is in the midst of transformational change. While some of the focus relates to impacts of climate change, rapid economic development and the potential for shifts in political and social structures in the region have also been in the limelight. This article looks at the circumpolar Arctic as a potential case of a regime shift in a large-scale social–ecological system that includes reinforcing feedbacks. A special focus is placed on governance structures, as these play an important role in social negotiations on the relationship between societies and the environment. While climate change is often portrayed as a driver of social change in the Arctic, it does not appear that the ongoing changes in the biophysical features of the Arctic region have rocked current circumpolar governance structures out of kilter. On the contrary, the ongoing climate-related changes, in particular sea ice decline, appear to have reinforced political commitment to existing legal structures. Major past social regime shifts have mainly been related to access to resources and national identity ideology, with political dynamics reinforced at times by military security considerations.

One Health – a strategy for resilience in a changing arctic

Directory of Open Access Journals (Sweden)

Bruce A. Ruscio

2015-09-01

Full Text Available The circumpolar north is uniquely vulnerable to the health impacts of climate change. While international Arctic collaboration on health has enhanced partnerships and advanced the health of inhabitants, significant challenges lie ahead. One Health is an approach that considers the connections between the environment, plant, animal and human health. Understanding this is increasingly critical in assessing the impact of global climate change on the health of Arctic inhabitants. The effects of climate change are complex and difficult to predict with certainty. Health risks include changes in the distribution of infectious disease, expansion of zoonotic diseases and vectors, changing migration patterns, impacts on food security and changes in water availability and quality, among others. A regional network of diverse stakeholder and transdisciplinary specialists from circumpolar nations and Indigenous groups can advance the understanding of complex climate-driven health risks and provide community-based strategies for early identification, prevention and adaption of health risks in human, animals and environment. We propose a regional One Health approach for assessing interactions at the Arctic human–animal–environment interface to enhance the understanding of, and response to, the complexities of climate change on the health of the Arctic inhabitants.

Climate change alters the structure of arctic marine food webs due to poleward shifts of boreal generalists.

Science.gov (United States)

Kortsch, Susanne; Primicerio, Raul; Fossheim, Maria; Dolgov, Andrey V; Aschan, Michaela

2015-09-07

Climate-driven poleward shifts, leading to changes in species composition and relative abundances, have been recently documented in the Arctic. Among the fastest moving species are boreal generalist fish which are expected to affect arctic marine food web structure and ecosystem functioning substantially. Here, we address structural changes at the food web level induced by poleward shifts via topological network analysis of highly resolved boreal and arctic food webs of the Barents Sea. We detected considerable differences in structural properties and link configuration between the boreal and the arctic food webs, the latter being more modular and less connected. We found that a main characteristic of the boreal fish moving poleward into the arctic region of the Barents Sea is high generalism, a property that increases connectance and reduces modularity in the arctic marine food web. Our results reveal that habitats form natural boundaries for food web modules, and that generalists play an important functional role in coupling pelagic and benthic modules. We posit that these habitat couplers have the potential to promote the transfer of energy and matter between habitats, but also the spread of pertubations, thereby changing arctic marine food web structure considerably with implications for ecosystem dynamics and functioning. © 2015 The Authors.

Habitat-specific effects of climate change on a low-mobility Arctic spider species

DEFF Research Database (Denmark)

Bowden, Joseph James; Hansen, Rikke Reisner; Olsen, Kent

2015-01-01

Abstract Terrestrial ecosystems are heterogeneous habitat mosaics of varying vegetation types that are differentially affected by climate change. Arctic plant communities, for example, are changing faster in moist habitats than in dry habitats and abiotic changes like snowmelt vary locally among...... was significantly related to the timing of snowmelt and differed significantly between the sexes and habitats with the spiders in the mesic habitat showing a stronger temporal response to later snowmelt. Juvenile/ female ratios also differed significantly between habitats; as did the overall abundance...

Collaborative Research: Towards Advanced Understanding and Predictive Capability of Climate Change in the Arctic Using a High-Resolution Regional Arctic Climate Model

Energy Technology Data Exchange (ETDEWEB)

Cassano, John [Principal Investigator

2013-06-30

The primary research task completed for this project was the development of the Regional Arctic Climate Model (RACM). This involved coupling existing atmosphere, ocean, sea ice, and land models using the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM) coupler (CPL7). RACM is based on the Weather Research and Forecasting (WRF) atmospheric model, the Parallel Ocean Program (POP) ocean model, the CICE sea ice model, and the Variable Infiltration Capacity (VIC) land model. A secondary research task for this project was testing and evaluation of WRF for climate-scale simulations on the large pan-Arctic model domain used in RACM. This involved identification of a preferred set of model physical parameterizations for use in our coupled RACM simulations and documenting any atmospheric biases present in RACM.

Marine Mammals and Climate Change in the Pacific Arctic: Impacts & Resilience

Science.gov (United States)

Moore, S. E.

2014-12-01

Extreme reductions in Arctic sea ice extent and thickness have become a hallmark of climate change, but impacts to the marine ecosystem are poorly understood. As top predators, marine mammals must adapt to biological responses to physical forcing and thereby become sentinels to ecosystem variability and reorganization. Recent sea ice retreats have influenced the ecology of marine mammals in the Pacific Arctic sector. Walruses now often haul out by the thousands along the NW Alaska coast in late summer, and reports of harbor porpoise, humpback, fin and minke whales in the Chukchi Sea demonstrate that these temperate species routinely occur there. In 2010, satellite tagged bowhead whales from Atlantic and Pacific populations met in the Northwest Passage, an overlap thought precluded by sea ice since the Holocene. To forage effectively, baleen whales must target dense patches of zooplankton and small fishes. In the Pacific Arctic, bowhead and gray whales appear to be responding to enhanced prey availability delivered both by new production and advection pathways. Two programs, the Distributed Biological Observatory (DBO) and the Synthesis of Arctic Research (SOAR), include tracking of marine mammal and prey species' responses to ecosystem shifts associated with sea ice loss. Both programs provide an integrated-ecosystem baseline in support of the development of a web-based Marine Mammal Health Map, envisioned as a component of the U.S. Integrated Ocean Observing System (IOOS). An overarching goal is to identify ecological patterns for marine mammals in the 'new' Arctic, as a foundation for integrative research, local response and adaptive management.

Biodiversity of Arctic marine ecosystems and responses to climate change

DEFF Research Database (Denmark)

Michel, C.; Bluhm, B.; Gallucci, V.

2012-01-01

The Arctic Ocean is undergoing major changes in many of its fundamental physical constituents, from a shift from multi- to first-year ice, shorter ice-covered periods, increasing freshwater runoff and surface stratification, to warming and alteration in the distribution of water masses....... These changes have important impacts on the chemical and biological processes that are at the root of marine food webs, influencing their structure, function and biodiversity. Here we summarise current knowledge on the biodiversity of Arctic marine ecosystems and provide an overview of fundamental factors...... that structure ecosystem biodiversity in the Arctic Ocean. We also discuss climateassociated effects on the biodiversity of Arctic marine ecosystems and discuss implications for the functioning of Arctic marine food webs. Based on the complexity and regional character of Arctic ecosystem reponses...

Arctic Ice Management: an integrated approach to climate engineering

Science.gov (United States)

Desch, S. J.; Hartnett, H. E.; Groppi, C. E.; Romaniello, S. J.

2017-12-01

The warming climate is having the most rapid and pronounced effects in the high Arctic. The loss of Arctic sea ice is not only changing the physical oceanography of the Arctic Ocean and its coastlines; it is also promoting new conversations about the dangers and benefits for trade, transportation, and industry in the Arctic. The rate of decrease of summer sea ice in the Arctic is currently -300 km3 yr-1, a rate that will lead to complete loss of end-summer sea ice as soon as 2030. Preventing the strong positive feedbacks and increased warming due to sea ice albedo loss must be an important component of climate mitigation strategies. Here, we explore a direct engineering approach we call Arctic Ice Management (AIM) to reduce the loss of Arctic sea ice. We predict that pumping seawater onto the ice surface during the Arctic winter using wind-powered pumps can thicken sea ice by up to 1 m per year, reversing the current loss rates and prolonging the time until the Arctic Ocean is ice-free. Thickening sea ice would not change CO2 levels, which are the underlying cause of ice loss, but it would prevent some of the strongest feedbacks and would buy time to develop the tools and governance systems necessary to achieve carbon-neutrality. We advocate exploration of AIM as a mitigation strategy employed in parallel with CO2 reduction efforts. The opportunity and risk profiles of AIM differ from other geoengineering proposals. While similar in principle to solar radiation management, AIM may present fewer large-scale environmental risks. AIM is separate from greenhouse gas emission reduction or sequestration, but might help prevent accelerated release of methane from thawing permafrost. Further, AIM might be usefully employed at regional and local scales to preserve Arctic ecosystems and possibly reduce the effects of ice-loss induced coastal erosion. Through presentation of the AIM concept, we hope to spark new conversations between scientists, stakeholders, and decision

Assessing STEM content learning: using the Arctic's changing climate to develop 21st century learner

Science.gov (United States)

Henderson, G. R.; Durkin, S.; Moran, A.

2016-12-01

In recent years the U.S. federal government has called for an increased focus on science, technology, engineering, and mathematics (STEM) in the educational system to ensure that there will be sufficient technical expertise to meet the needs of business and industry. As a direct result of this STEM emphasis, the number of outreach activities aimed at actively engaging these students in STEM learning has surged. Such activities, frequently in the form of summer camps led by university faculty, have targeted primary and secondary school students with the goal of growing student interest in STEM majors and STEM careers. This study assesses short-term content learning using a climate module that highlights rapidly changing Arctic climate conditions to illustrate concepts of radiative energy balance and climate feedback. Hands-on measurement of short and longwave radiation using simple instrumentation is used to demonstrate concepts that are then related back to the "big picture" Arctic issue. Pre and post module questionnaires were used to assess content learning, as this learning type has been identified as the basis for STEM literacy and the vehicle by which 21st century learning skills are usually developed. In this instance, students applied subject knowledge they gained by taking radiation measurements to better understand the real-world problem of climate change.

Variations in the Sensitivity of Shrub Growth to Climate Change along Arctic Environmental and Biotic Gradients

Science.gov (United States)

Beck, P. S. A.; Myers-Smith, I. H.; Elmendorf, S.; Georges, D.

2015-12-01

Despite evidence of rapid shrub expansion at many Arctic sites and the profound effects this has on ecosystem structure, biogeochemical cycling, and land-atmosphere feedbacks in the Arctic, the drivers of shrub growth remain poorly understood. The compilation of 41,576 annual shrub growth measurements made around the Arctic, allowed for the first systematic evaluation of the climate sensitivity of Arctic shrub growth, i.e. the strength of the relationship between annual shrub growth and monthly climate variables. The growth measurements were taken on 1821 plants of 25 species at 37 arctic and alpine sites, either as annual ring widths or as stem increments. We evaluated climate sensitivity of shrub growth for each genus-by-site combination in this data set based on the performance and parameters of linear mixed models that used CRU TS3.21 climate data as predictors of shrub growth between 1950 and 2010. 76% of genus-by-site combinations showed climate sensitive growth, but climate-growth relationships varied with soil moisture, species canopy height, and geographic position within the species ranges. Shrubs growing at sites with more soil moisture showed greater climate sensitivity, suggesting that water availability might limit shrub growth if continued warming isn't matched by a steady increase in soil moisture. Tall shrub species growing at their northern range limit were particularly climate sensitive causing climate sensitivity of shrubs to peak at the transition between Low and High Arctic, where carbon storage in permafrost is greatest. Local and regional studies have documented matching spatial and temporal patterns in dendrochronological measurements and satellite observations of vegetation indices both in boreal and Arctic regions. Yet the circumarctic comparison of patterns in dendrochronological and remote sensing data sets yielded poor levels of agreement. In much of the Arctic, steep environmental gradients generate fine spatial patterns of vegetation

Collaborative Proposal: Improving Decadal Prediction of Arctic Climate Variability and Change Using a Regional Arctic System Model (RASM)

Energy Technology Data Exchange (ETDEWEB)

Robertson, William [Univ. of Texas, El Paso, TX (United States)

2016-11-18

RASM is a multi-disciplinary project, which brings together researchers from six state universities, one military postgraduate school, and one DoE laboratory to address the core modeling objectives of the arctic research community articulated in the Arctic System Modeling report by Roberts et al. (2010b). This report advocates the construction of a regional downscaling tool to generate probabilistic decadal projections of Greenland ice sheet retreat, evolution of arctic sea ice cover, changes in land surface vegetation, and regional processes leading to arctic amplification. Unified coupled models such as RASM are ideal for this purpose because they simulate fine-scale physics, essential for the realistic representation of intra-annual variability, in addition to processes fundamental to long term climatic shifts (Hurrell et al. 2009). By using RASM with boundary conditions from a global model, we can generate many-member ensembles essential for understanding uncertainty in regional climate projections (Hawkins and Sutton 2009). This probabilistic approach is computationally prohibitive for high-resolution global models in the foreseeable future, and also for regional models interactively nested within global simulations. Yet it is fundamental for quantifying uncertainty in decadal forecasts to make them useful for decision makers (Doherty et al. 2009). For this reason, we have targeted development of ensemble generation techniques as a core project task (Task 4.5). Environmental impact assessment specialists need high-fidelity regional ensemble projections to improve the accuracy of their work (Challinor et al. 2009; Moss et al. 2010). This is especially true of the Arctic, where economic, social and national interests are rapidly reshaping the high north in step with regional climate change. During the next decade, considerable oil and gas discoveries are expected across many parts of the marine and terrestrial Arctic (Gautier et al. 2009), the economics of the

Consistency and discrepancy in the atmospheric response to Arctic sea-ice loss across climate models

Science.gov (United States)

Screen, James A.; Deser, Clara; Smith, Doug M.; Zhang, Xiangdong; Blackport, Russell; Kushner, Paul J.; Oudar, Thomas; McCusker, Kelly E.; Sun, Lantao

2018-03-01

The decline of Arctic sea ice is an integral part of anthropogenic climate change. Sea-ice loss is already having a significant impact on Arctic communities and ecosystems. Its role as a cause of climate changes outside of the Arctic has also attracted much scientific interest. Evidence is mounting that Arctic sea-ice loss can affect weather and climate throughout the Northern Hemisphere. The remote impacts of Arctic sea-ice loss can only be properly represented using models that simulate interactions among the ocean, sea ice, land and atmosphere. A synthesis of six such experiments with different models shows consistent hemispheric-wide atmospheric warming, strongest in the mid-to-high-latitude lower troposphere; an intensification of the wintertime Aleutian Low and, in most cases, the Siberian High; a weakening of the Icelandic Low; and a reduction in strength and southward shift of the mid-latitude westerly winds in winter. The atmospheric circulation response seems to be sensitive to the magnitude and geographic pattern of sea-ice loss and, in some cases, to the background climate state. However, it is unclear whether current-generation climate models respond too weakly to sea-ice change. We advocate for coordinated experiments that use different models and observational constraints to quantify the climate response to Arctic sea-ice loss.

Circumpolar arctic tundra biomass and productivity dynamics in response to projected climate change and herbivory.

Science.gov (United States)

Yu, Qin; Epstein, Howard; Engstrom, Ryan; Walker, Donald

2017-09-01

Satellite remote sensing data have indicated a general 'greening' trend in the arctic tundra biome. However, the observed changes based on remote sensing are the result of multiple environmental drivers, and the effects of individual controls such as warming, herbivory, and other disturbances on changes in vegetation biomass, community structure, and ecosystem function remain unclear. We apply ArcVeg, an arctic tundra vegetation dynamics model, to estimate potential changes in vegetation biomass and net primary production (NPP) at the plant community and functional type levels. ArcVeg is driven by soil nitrogen output from the Terrestrial Ecosystem Model, existing densities of Rangifer populations, and projected summer temperature changes by the NCAR CCSM4.0 general circulation model across the Arctic. We quantified the changes in aboveground biomass and NPP resulting from (i) observed herbivory only; (ii) projected climate change only; and (iii) coupled effects of projected climate change and herbivory. We evaluated model outputs of the absolute and relative differences in biomass and NPP by country, bioclimate subzone, and floristic province. Estimated potential biomass increases resulting from temperature increase only are approximately 5% greater than the biomass modeled due to coupled warming and herbivory. Such potential increases are greater in areas currently occupied by large or dense Rangifer herds such as the Nenets-occupied regions in Russia (27% greater vegetation increase without herbivores). In addition, herbivory modulates shifts in plant community structure caused by warming. Plant functional types such as shrubs and mosses were affected to a greater degree than other functional types by either warming or herbivory or coupled effects of the two. © 2017 John Wiley & Sons Ltd.

Can regional climate engineering save the summer Arctic sea ice?

Science.gov (United States)

Tilmes, S.; Jahn, Alexandra; Kay, Jennifer E.; Holland, Marika; Lamarque, Jean-Francois

2014-02-01

Rapid declines in summer Arctic sea ice extent are projected under high-forcing future climate scenarios. Regional Arctic climate engineering has been suggested as an emergency strategy to save the sea ice. Model simulations of idealized regional dimming experiments compared to a business-as-usual greenhouse gas emission simulation demonstrate the importance of both local and remote feedback mechanisms to the surface energy budget in high latitudes. With increasing artificial reduction in incoming shortwave radiation, the positive surface albedo feedback from Arctic sea ice loss is reduced. However, changes in Arctic clouds and the strongly increasing northward heat transport both counteract the direct dimming effects. A 4 times stronger local reduction in solar radiation compared to a global experiment is required to preserve summer Arctic sea ice area. Even with regional Arctic dimming, a reduction in the strength of the oceanic meridional overturning circulation and a shut down of Labrador Sea deep convection are possible.

The Arctic as a test case for an assessment of climate impacts on national security.

Energy Technology Data Exchange (ETDEWEB)

Taylor, Mark A.; Zak, Bernard Daniel; Backus, George A.; Ivey, Mark D.; Boslough, Mark Bruce Elrick

2008-11-01

The Arctic region is rapidly changing in a way that will affect the rest of the world. Parts of Alaska, western Canada, and Siberia are currently warming at twice the global rate. This warming trend is accelerating permafrost deterioration, coastal erosion, snow and ice loss, and other changes that are a direct consequence of climate change. Climatologists have long understood that changes in the Arctic would be faster and more intense than elsewhere on the planet, but the degree and speed of the changes were underestimated compared to recent observations. Policy makers have not yet had time to examine the latest evidence or appreciate the nature of the consequences. Thus, the abruptness and severity of an unfolding Arctic climate crisis has not been incorporated into long-range planning. The purpose of this report is to briefly review the physical basis for global climate change and Arctic amplification, summarize the ongoing observations, discuss the potential consequences, explain the need for an objective risk assessment, develop scenarios for future change, review existing modeling capabilities and the need for better regional models, and finally to make recommendations for Sandia's future role in preparing our leaders to deal with impacts of Arctic climate change on national security. Accurate and credible regional-scale climate models are still several years in the future, and those models are essential for estimating climate impacts around the globe. This study demonstrates how a scenario-based method may be used to give insights into climate impacts on a regional scale and possible mitigation. Because of our experience in the Arctic and widespread recognition of the Arctic's importance in the Earth climate system we chose the Arctic as a test case for an assessment of climate impacts on national security. Sandia can make a swift and significant contribution by applying modeling and simulation tools with internal collaborations as well as with

Shift in the United States Climate Policy and the Arctic Council Agenda

Directory of Open Access Journals (Sweden)

Sakharov A.

2018-03-01

Full Text Available Environmental issues form the basis of the Arctic Council’s agenda. Since the first Senior Arctic Officials (SAOs meeting in 1996, issues related to ecology and climate have been raised at almost every event under the aegis of the forum. A substantial number of structures within the forum’s institutional framework were created to engage in monitoring exercises and scientific research, as well as to harmonize the positions of Arctic Council members on the most pressing environmental and climate change concerns in the region. In this regard, the change in the general course of U.S. environmental policy under the administration of Donald Trump could significantly complicate the interaction between members in key areas of the Council’s agenda. The United States’ withdrawal from the Paris Agreement and the lifting of the moratorium on oil and gas exploitation in the Arctic seabed will certainly impede dialogue within the Council. Nevertheless, there are several aspects of U.S foreign and internal politics which could work to preserve its long-term environmental policy trend despite changes brought about by the Trump administration. Even in the short term, the activities of the U.S. within the Arctic Council and the provisions of the Fairbanks Ministerial Declaration differ from the president’s statements on climate change. The U.S.’s new environmental policy is compared to the priorities of Finland’s 2017–2019 chairmanship which maintains the traditional environmental focus of the forum’s agenda while intensifying cooperation with other international institutions on climate change issues. Thus, the institutional basis established in previous years, and more importantly, the stable agenda and concrete work by the forum’s bodies ensure the effective use and functioning of the Arctic Council. The Finnish presidency and the secretariat of the Arctic Council are not adjusting the agenda to accommodate policy changes of individual

The Immediacy of Arctic Change: New 2016-17 Extremes

Science.gov (United States)

Overland, J. E.; Kattsov, V.; Olsen, M. S.; Walsh, J. E.

2017-12-01

Additional recent observations add increased certainty to cryospheric Arctic changes, and trends are very likely to continue past mid-century. Observed and projected Arctic changes are large compared with those at mid-latitude, driven by greenhouse gas (GHG) increase and Arctic feedbacks. Sea ice has undergone a regime shift from mostly multi-year to first-year sea ice, and summer sea ice is likely to be esentially gone within the next few decades. Spring snow cover is decreasing, and Arctic greening is increasing, although somewhat variable. There are potential emerging impacts of Arctic change on mid-latitude weather and sea level rise. Model assessments under different future GHG concentration scenarios show that stabilizing global temperatures near 2° C compliant with Paris agreement could slow, but not halt further major changes in the Arctic before mid- 21st century; foreseeable Arctic temperature changes are 4-5° C for fall/winter by 2040-2050. Substantial and immediate mitigation reductions in GHG emissions (at least at the level of the RCP 4.5 emission scenario) should reduce the risk of further change for most cryospheric components after mid-century, and reduce the likelyhood of potential runaway loss of ice sheets and glaciers and their impact on sea level rise. Extreme winter 2016 Arctic temperatures and a large winter 2017 sea ice deficit demonstrate contemporary climate states outside the envelope of previous experience. While there is confidence in the sign of Arctic changes, recent observations increase uncertainty in projecting the rate for future real world scenarios. Do events return to mean conditions, represent irreversible changes, or contribute to accelerating trends beyond those provided by climate models? Such questions highlight the need for improved quantitative prediction of the cryosphere and its global impacts, crucial for adaptation actions and risk management at local to global scales.

Decadal Climate Change in Ny-Ålesund, Svalbard, A Representative Area of the Arctic

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Minghu Ding

2018-04-01

Full Text Available In recent decades, global warming hiatus/slowdown has attracted considerable attention and has been strongly debated. Many studies suggested that the Arctic is undergoing rapid warming and significantly contributes to a continual global warming trend rather than a hiatus. In this study, we evaluated the climate changes of Ny-Ålesund, Svalbard, a representative location of the northern North Atlantic sector of the Arctic, based on observational records from 1975–2014. The results showed that the annual warming rate was four times higher than the global mean (+0.76 °C·decade−1 and was also much greater than Arctic average. Additionally, the warming trend of Ny-Ålesund started to slow down since 2005–2006, and our estimates showed that there is a 8–9 years-lagged, but significant, correlation between records of Ny-Ålesund and global HadCRUT4 datasets. This finding indicates that the Arctic was likely experiencing a hiatus pattern, which just appeared later than the low-mid latitudes due to transport processes of atmospheric circulations and ocean currents, heat storage effect of cryospheric components, multidecadal variability of Arctic cyclone activities, etc. This case study provides a new perspective on the global warming hiatus/slowdown debate.

Climate change and Arctic ecosystems: 2. Modeling, paleodata-model comparisons, and future projections

Science.gov (United States)

Kaplan, J.O.; Bigelow, N.H.; Prentice, I.C.; Harrison, S.P.; Bartlein, P.J.; Christensen, T.R.; Cramer, W.; Matveyeva, N.V.; McGuire, A.D.; Murray, D.F.; Razzhivin, V.Y.; Smith, B.; Walker, D.A.; Anderson, P.M.; Andreev, A.A.; Brubaker, L.B.; Edwards, M.E.; Lozhkin, A.V.

2003-01-01

Large variations in the composition, structure, and function of Arctic ecosystems are determined by climatic gradients, especially of growing-season warmth, soil moisture, and snow cover. A unified circumpolar classification recognizing five types of tundra was developed. The geographic distributions of vegetation types north of 55??N, including the position of the forest limit and the distributions of the tundra types, could be predicted from climatology using a small set of plant functional types embedded in the biogeochemistry-biogeography model BIOME4. Several palaeoclimate simulations for the last glacial maximum (LGM) and mid-Holocene were used to explore the possibility of simulating past vegetation patterns, which are independently known based on pollen data. The broad outlines of observed changes in vegetation were captured. LGM simulations showed the major reduction of forest, the great extension of graminoid and forb tundra, and the restriction of low- and high-shrub tundra (although not all models produced sufficiently dry conditions to mimic the full observed change). Mid-Holocene simulations reproduced the contrast between northward forest extension in western and central Siberia and stability of the forest limit in Beringia. Projection of the effect of a continued exponential increase in atmospheric CO2 concentration, based on a transient ocean-atmosphere simulation including sulfate aerosol effects, suggests a potential for larger changes in Arctic ecosystems during the 21st century than have occurred between mid-Holocene and present. Simulated physiological effects of the CO2 increase (to > 700 ppm) at high latitudes were slight compared with the effects of the change in climate.

Human adaptation responses to a rapidly changing Arctic: A research context for building system resilience

Science.gov (United States)

Chapin, T.; Brinkman, T. J.

2016-12-01

Although human behavior accounts for more uncertainty in future trajectories in climate change than do biophysical processes, most climate-change research fails to include human actions in research design and implementation. This is well-illustrated in the Arctic. At the global scale, arctic processes strongly influence the strength of biophysical feedbacks between global human emissions and the rate of climate warming. However, most human actions in the arctic have little effect on these feedbacks, so research can contribute most effectively to reduction in arctic warming through improved understanding of the strength of arctic-global biophysical feedbacks, as in NASA's ABoVE program, and its effective communication to policy makers and the public. In contrast, at the local to regional scale within the arctic, human actions may influence the ecological and societal consequences of arctic warming, so research benefits from active stakeholder engagement in research design and implementation. Human communities and other stakeholders (government and NGOs) respond heterogeneously to socioeconomic and environmental change, so research that documents the range of historical and current adaptive responses to change provides insights on the resilience (flexibility of future options) of social-ecological processes in the arctic. Alaskan communities have attempted a range of adaptive responses to coastal erosion (e.g., seasonal migration, protection in place, relocation), wildfire (fire suppression to use of fire to manage wildlife habitat or landscape heterogeneity), declining sea ice (e.g., new hunting technology, sea ice observations and predictions), and changes in wildlife and fish availability (e.g., switch to harvest of alternative species, harvest times, or harvest locations). Research that draws on both traditional and western knowledge facilitates adaptation and predictions of the likely societal consequences of climate change in the Arctic. Effective inclusion of

Changes in the seasonality of Arctic sea ice and temperature

Science.gov (United States)

Bintanja, R.

2012-04-01

Observations show that the Arctic sea ice cover is currently declining as a result of climate warming. According to climate models, this retreat will continue and possibly accelerate in the near-future. However, the magnitude of this decline is not the same throughout the year. With temperatures near or above the freezing point, summertime Arctic sea ice will quickly diminish. However, at temperatures well below freezing, the sea ice cover during winter will exhibit a much weaker decline. In the future, the sea ice seasonal cycle will be no ice in summer, and thin one-year ice in winter. Hence, the seasonal cycle in sea ice cover will increase with ongoing climate warming. This in itself leads to an increased summer-winter contrast in surface air temperature, because changes in sea ice have a dominant influence on Arctic temperature and its seasonality. Currently, the annual amplitude in air temperature is decreasing, however, because winters warm faster than summer. With ongoing summer sea ice reductions there will come a time when the annual temperature amplitude will increase again because of the large seasonal changes in sea ice. This suggests that changes in the seasonal cycle in Arctic sea ice and temperature are closely, and intricately, connected. Future changes in Arctic seasonality (will) have an profound effect on flora, fauna, humans and economic activities.

The Arctic

International Nuclear Information System (INIS)

Petersen, H.; Meltofte, H.; Rysgaard, S.; Rasch, M.; Jonasson, S.; Christensen, T.R.; Friborg, T.; Soegaard, H.; Pedersen, S.A.

2001-01-01

Global climate change in the Arctic is a growing concern. Research has already documented pronounced changes, and models predict that increases in temperature from anthropogenic influences could be considerably higher than the global average. The impacts of climate change on Arctic ecosystems are complex and difficult to predict because of the many interactions within ecosystem, and between many concurrently changing environmental variables. Despite the global consequences of change in the Arctic climate the monitoring of basic abiotic as well as biotic parameters are not adequate to assess the impact of global climate change. The uneven geographical location of present monitoring stations in the Arctic limits the ability to understand the climate system. The impact of previous variations and potential future changes to ecosystems is not well understood and need to be addressed. At this point, there is no consensus of scientific opinion on how much of the current changes that are due to anthropogenic influences or to natural variation. Regardless of the cause, there is a need to investigate and assess current observations and their effects to the Arctic. In this chapter examples from both terrestrial and marine ecosystems from ongoing monitoring and research projects are given. (LN)

A dynamical link between the Arctic and the global climate system

DEFF Research Database (Denmark)

Dethloff, K.; Rinke, A.; Benkel, A.

2006-01-01

and snow albedo treatment changes the ice-albedo feedback and the radiative exchange between the atmosphere and the ocean-sea-ice system. The planetary wave energy fluxes in the middle troposphere of mid-latitudes between 30 and 50°N are redistributed, which induces perturbations in the zonal...... and meridional planetary wave trains from the tropics over the mid-latitudes into the Arctic. It is shown, that the improved parameterization of Arctic sea-ice and snow albedo can trigger changes in the Arctic and North Atlantic Oscillation pattern with strong implications for the European climate.......By means of simulations with a global coupled AOGCM it is shown that changes in the polar energy sink region can exert a strong influence on the mid- and high-latitude climate by modulating the strength of the mid-latitude westerlies and storm tracks. It is found, that a more realistic sea-ice...

Sub-arctic hydrology and climate change : a case study of the Tana River Basin in Northern Fennoscandia

NARCIS (Netherlands)

Dankers, Rutger

2002-01-01

The most significant changes in climate, due to the well-known enhanced greenhouse effect, are generally expected to occur at northern high latitudes. Sub-arctic environments, that are dominated by the presence of a seasonal snow cover, may therefore be particularly sensitive to global warming. The

Public Perceptions of Arctic Change

Science.gov (United States)

Hamilton, L.

2014-12-01

What does the general US public know, or think they know, about Arctic change? Two broad nationwide surveys in 2006 and 2010 addressed this topic in general terms, before and after the International Polar Year (IPY). Since then a series of representative national or statewide surveys have carried this research farther. The new surveys employ specific questions that assess public knowledge of basic Arctic facts, along with perceptions about the possible consequences of future Arctic change. Majorities know that late-summer Arctic sea ice area has declined compared with 30 years ago, although substantial minorities -- lately increasing -- believe instead that it has now recovered to historical levels. Majorities also believe that, if the Arctic warms in the future, this will have major effects on the weather where they live. Their expectation of local impacts from far-away changes suggests a degree of global thinking. On the other hand, most respondents do poorly when asked whether melting Arctic sea ice, melting Greenland/Antarctic land ice, or melting Himalayan glaciers could have more effect on sea level. Only 30% knew or guessed the right answer to this question. Similarly, only 33% answered correctly on a simple geography quiz: whether the North Pole could best be described as ice a few feet or yards thick floating over a deep ocean, ice more than a mile thick over land, or a rocky, mountainous landscape. Close analysis of response patterns suggests that people often construct Arctic "knowledge" on items such as sea ice increase/decrease from their more general ideology or worldview, such as their belief (or doubt) that anthropogenic climate change is real. When ideology or worldviews provide no guidance, as on the North Pole or sealevel questions, the proportion of accurate answers is no better than chance. These results show at least casual public awareness and interest in Arctic change, unfortunately not well grounded in knowledge. Knowledge problems seen on

Projected Impact of Climate Change on the Water and Salt Budgets of the Arctic Ocean by a Global Climate Model

Science.gov (United States)

Miller, James R.; Russell, Gary L.

1996-01-01

The annual flux of freshwater into the Arctic Ocean by the atmosphere and rivers is balanced by the export of sea ice and oceanic freshwater. Two 150-year simulations of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. Relative to the control, the last 50-year period of the GHG experiment indicates that the total inflow of water from the atmosphere and rivers increases by 10% primarily due to an increase in river discharge, the annual sea-ice export decreases by about half, the oceanic liquid water export increases, salinity decreases, sea-ice cover decreases, and the total mass and sea-surface height of the Arctic Ocean increase. The closed, compact, and multi-phased nature of the hydrologic cycle in the Arctic Ocean makes it an ideal test of water budgets that could be included in model intercomparisons.

Sensitivity of simulated regional Arctic climate to the choice of coupled model domain

Directory of Open Access Journals (Sweden)

Dmitry V. Sein

2014-07-01

Full Text Available The climate over the Arctic has undergone changes in recent decades. In order to evaluate the coupled response of the Arctic system to external and internal forcing, our study focuses on the estimation of regional climate variability and its dependence on large-scale atmospheric and regional ocean circulations. A global ocean–sea ice model with regionally high horizontal resolution is coupled to an atmospheric regional model and global terrestrial hydrology model. This way of coupling divides the global ocean model setup into two different domains: one coupled, where the ocean and the atmosphere are interacting, and one uncoupled, where the ocean model is driven by prescribed atmospheric forcing and runs in a so-called stand-alone mode. Therefore, selecting a specific area for the regional atmosphere implies that the ocean–atmosphere system can develop ‘freely’ in that area, whereas for the rest of the global ocean, the circulation is driven by prescribed atmospheric forcing without any feedbacks. Five different coupled setups are chosen for ensemble simulations. The choice of the coupled domains was done to estimate the influences of the Subtropical Atlantic, Eurasian and North Pacific regions on northern North Atlantic and Arctic climate. Our simulations show that the regional coupled ocean–atmosphere model is sensitive to the choice of the modelled area. The different model configurations reproduce differently both the mean climate and its variability. Only two out of five model setups were able to reproduce the Arctic climate as observed under recent climate conditions (ERA-40 Reanalysis. Evidence is found that the main source of uncertainty for Arctic climate variability and its predictability is the North Pacific. The prescription of North Pacific conditions in the regional model leads to significant correlation with observations, even if the whole North Atlantic is within the coupled model domain. However, the inclusion of the

Arctic Climate Systems Analysis

Energy Technology Data Exchange (ETDEWEB)

Ivey, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boslough, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peterson, Kara J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); van Bloemen Waanders, Bart G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Swiler, Laura Painton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Desilets, Darin Maurice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reinert, Rhonda Karen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-03-01

This study began with a challenge from program area managers at Sandia National Laboratories to technical staff in the energy, climate, and infrastructure security areas: apply a systems-level perspective to existing science and technology program areas in order to determine technology gaps, identify new technical capabilities at Sandia that could be applied to these areas, and identify opportunities for innovation. The Arctic was selected as one of these areas for systems level analyses, and this report documents the results. In this study, an emphasis was placed on the arctic atmosphere since Sandia has been active in atmospheric research in the Arctic since 1997. This study begins with a discussion of the challenges and benefits of analyzing the Arctic as a system. It goes on to discuss current and future needs of the defense, scientific, energy, and intelligence communities for more comprehensive data products related to the Arctic; assess the current state of atmospheric measurement resources available for the Arctic; and explain how the capabilities at Sandia National Laboratories can be used to address the identified technological, data, and modeling needs of the defense, scientific, energy, and intelligence communities for Arctic support.

New views on changing Arctic vegetation

Science.gov (United States)

Kennedy, Robert E.

2012-03-01

As climate changes, how will terrestrial vegetation respond? Because the fates of many biogeochemical, hydrological and economic cycles depend on vegetation, this question is fundamental to climate change science but extremely challenging to address. This is particularly true in the Arctic, where temperature change has been most acute globally (IPCC 2007) and where potential feedbacks to carbon, energy and hydrological cycles have important implications for the rest of the Earth system (Chapin et al 2000). It is well known that vegetation is tightly coupled to precipitation and temperature (Whittaker 1975), but predicting the response of vegetation to changes in climate involves much more than invoking the limitations of climate envelopes (Thuiller et al 2008). Models must also consider efficacy of dispersal, soil constraints, ecological interactions, possible CO2 fertilization impacts and the changing impact of other, more proximal anthropogenic effects such as pollution, disturbance, etc (Coops and Waring 2011, Lenihan et al 2008, Scheller and Mladenoff 2005). Given this complexity, a key test will be whether models can match empirical observations of changes that have already occurred. The challenge is finding empirical observations of change that are appropriate to test hypothesized impacts of climate change. As climate gradually changes across broad bioclimatic gradients, vegetation condition may change gradually as well. To capture these gradual trends, observations need at least three characteristics: (1) they must quantify a vegetation attribute that is expected to change, (2) they must measure that attribute in exactly the same way over long periods of time, and (3) they must sample diverse communities at geographic scales commensurate with the scale of expected climatic shifts. Observation networks meeting all three criteria are rare anywhere on the globe, but particularly so in remote areas. For this reason, satellite images have long been used as a

Pävi Naskali, Marjaana Seppänen & Shahnaj Begum (eds., Ageing, Wellbeing and Climate Change in the Arctic. An interdisciplinary analysis (London: Routledge, 2015

Directory of Open Access Journals (Sweden)

Hermann Óskarsson

2016-03-01

Full Text Available Book review of: Pävi Naskali, Marjaana Seppänen and Shahnaj Begum (eds., Ageing, Wellbeing and Climate Change in the Arctic. An interdisciplinary analysis (London: Routledge’s series on advances in climate change research, 2015

Warm Arctic—cold continents: climate impacts of the newly open Arctic Sea

Directory of Open Access Journals (Sweden)

James E. Overland

2011-12-01

Full Text Available Recent Arctic changes are likely due to coupled Arctic amplification mechanisms with increased linkage between Arctic climate and sub-Arctic weather. Historically, sea ice grew rapidly in autumn, a strong negative radiative feedback. But increased sea-ice mobility, loss of multi-year sea ice, enhanced heat storage in newly sea ice-free ocean areas, and modified wind fields form connected positive feedback processes. One-way shifts in the Arctic system are sensitive to the combination of episodic intrinsic atmospheric and ocean variability and persistent increasing greenhouse gases. Winter 2009/10 and December 2010 showed a unique connectivity between the Arctic and more southern weather patterns when the typical polar vortex was replaced by high geopotential heights over the central Arctic and low heights over mid-latitudes that resulted in record snow and low temperatures, a warm Arctic—cold continents pattern. The negative value of the winter (DJF 2009/10 North Atlantic Oscillation (NAO index associated with enhanced meridional winds was the lowest observed value since the beginning of the record in 1865. Wind patterns in December 2007 and 2008 also show an impact of warmer Arctic temperatures. A tendency for higher geopotential heights over the Arctic and enhanced meridional winds are physically consistent with continued loss of sea ice over the next 40 years. A major challenge is to understand the interaction of Arctic changes with climate patterns such as the NAO, Pacific North American and El Niño–Southern Oscillation.

Climate change: Its possible impact on the environment and the people of northern regions

International Nuclear Information System (INIS)

Roots, F.

1993-01-01

A detailed overview is presented of the possible impacts of climate change on the Arctic environment, ecosystems, and human activities. The extent of global climate change is examined through the use of historical and paleoclimatologic records of temperature and stratospheric ozone. The effects of precipitation distribution and airborne particulates on climate change are also outlined. Changes in the Arctic are then examined, with an explanation of why global change in the Arctic is likely to be exaggerated. Likely scenarios of Arctic climate change involve milder winter temperatures, wetter and cloudier summers, more stormy weather and snowfall, greater variability in regional weather patterns, and dramatic changes in the extent of sea ice. Biological responses of wetland, northern forest, tundra, Arctic desert, below-ground, and marine ecosystems are assessed. Features of northern and Arctic ecosystems that may be particularly vulnerable to climate change are noted. Finally, the impacts of climate change on traditional activities and lifestyles, resource management and harvesting, agriculture, forestry, mining and fossil-fuel development, offshore operations, and human infrastructures are summarized. 5 figs

Climate change and the permafrost carbon feedback.

Science.gov (United States)

Schuur, E A G; McGuire, A D; Schädel, C; Grosse, G; Harden, J W; Hayes, D J; Hugelius, G; Koven, C D; Kuhry, P; Lawrence, D M; Natali, S M; Olefeldt, D; Romanovsky, V E; Schaefer, K; Turetsky, M R; Treat, C C; Vonk, J E

2015-04-09

Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.

Effect of recent climate change on Arctic Pb pollution: A comparative study of historical records in lake and peat sediments

International Nuclear Information System (INIS)

Liu Xiaodong; Jiang Shan; Zhang Pengfei; Xu Liqiang

2012-01-01

Historical changes of anthropogenic Pb pollution were reconstructed based on Pb concentrations and isotope ratios in lake and peat sediment profiles from Ny-Ålesund of Arctic. The calculated excess Pb isotope ratios showed that Pb pollution largely came from west Europe and Russia. The peat profile clearly reflected the historical changes of atmospheric deposition of anthropogenic Pb into Ny-Ålesund, and the result showed that anthropogenic Pb peaked at 1960s–1970s, and thereafter a significant recovery was observed by a rapid increase of 206 Pb/ 207 Pb ratios and a remarkable decrease in anthropogenic Pb contents. In contrast to the peat record, the longer lake record showed relatively high anthropogenic Pb contents and a persistent decrease of 206 Pb/ 207 Pb ratios within the uppermost samples, suggesting that climate-sensitive processes such as catchment erosion and meltwater runoff might have influenced the recent change of Pb pollution record in the High Arctic lake sediments. - Highlights: ► Historical changes of anthropogenic Pb pollution in Ny-Ålesund were reconstructed. ► Anthropogenic Pb in Ny-Ålesund was largely originated from W. European and Russia. ► Anthropogenic Pb recorded in peat sediments peaked at 1960–1970s and then declined. ► High anthropogenic fluxes were found in recent change of Pb record from lake sediments. ► Climate-sensitive processes might have influenced recent Pb accumulation rate in lakes. - This manuscript reports the effects of climate-sensitive processes on historical records of Pb pollution in sediments of Arctic lakes.

Cloud Response to Arctic Sea Ice Loss and Implications for Feedbacks in the CESM1 Climate Model

Science.gov (United States)

Morrison, A.; Kay, J. E.; Chepfer, H.; Guzman, R.; Bonazzola, M.

2017-12-01

Clouds have the potential to accelerate or slow the rate of Arctic sea ice loss through their radiative influence on the surface. Cloud feedbacks can therefore play into Arctic warming as clouds respond to changes in sea ice cover. As the Arctic moves toward an ice-free state, understanding how cloud - sea ice relationships change in response to sea ice loss is critical for predicting the future climate trajectory. From satellite observations we know the effect of present-day sea ice cover on clouds, but how will clouds respond to sea ice loss as the Arctic transitions to a seasonally open water state? In this study we use a lidar simulator to first evaluate cloud - sea ice relationships in the Community Earth System Model (CESM1) against present-day observations (2006-2015). In the current climate, the cloud response to sea ice is well-represented in CESM1: we see no summer cloud response to changes in sea ice cover, but more fall clouds over open water than over sea ice. Since CESM1 is credible for the current Arctic climate, we next assess if our process-based understanding of Arctic cloud feedbacks related to sea ice loss is relevant for understanding future Arctic clouds. In the future Arctic, summer cloud structure continues to be insensitive to surface conditions. As the Arctic warms in the fall, however, the boundary layer deepens and cloud fraction increases over open ocean during each consecutive decade from 2020 - 2100. This study will also explore seasonal changes in cloud properties such as opacity and liquid water path. Results thus far suggest that a positive fall cloud - sea ice feedback exists in the present-day and future Arctic climate.

Drivers of 2016 record Arctic warmth assessed using climate simulations subjected to Factual and Counterfactual forcing

Directory of Open Access Journals (Sweden)

Lantao Sun

2018-03-01

Full Text Available A suite of historical atmospheric model simulations is described that uses a hierarchy of global boundary forcings designed to inform research on the detection and attribution of weather and climate-related extremes. In addition to experiments forced by actual variations in sea surface temperature, sea ice concentration, and atmospheric chemical composition (so-called Factual experiments; additional (Counterfactual experiments are conducted in which the boundary forcings are adjusted by removing estimates of long-term climate change. A third suite of experiments are identical to the Factual runs except that sea ice concentrations are set to climatological conditions (Clim-Polar experiments. These were used to investigate the cause for extremely warm Arctic surface temperature during 2016.Much of the magnitude of surface temperature anomalies averaged poleward of 65°N in 2016 (3.2 ± 0.6 °C above a 1980–89 reference is shown to have been forced by observed global boundary conditions. The Factual experiments reveal that at least three quarters of the magnitude of 2016 annual mean Arctic warmth was forced, with considerable sensitivity to assumptions of sea ice thickness change. Results also indicate that 30–40% of the overall forced Arctic warming signal in 2016 originated from drivers outside of the Arctic. Despite such remote effects, the experiments reveal that the extreme magnitude of the 2016 Arctic warmth could not have occurred without consideration of the Arctic sea ice loss. We find a near-zero probability for Arctic surface temperature to be as warm as occurred in 2016 under late-19th century boundary conditions, and also under 2016 boundary conditions that do not include the depleted Arctic sea ice. Results from the atmospheric model experiments are reconciled with coupled climate model simulations which lead to a conclusion that about 60% of the 2016 Arctic warmth was likely attributable to human-induced climate change

Climate Change and Thawing Permafrost in Two Iñupiaq Communities of Alaska's Arctic: Observations, Implications, and Resilience

Science.gov (United States)

Woodward, A.; Kofinas, G.

2013-12-01

For thousands of years the Iñupiat of northern Alaska have relied on ecosystems underlain by permafrost for material and cultural resources. As permafrost thaws across the Arctic, these social-ecological systems are changing rapidly. Community-based research and extensive local knowledge of Iñupiaq villagers offer unique and valuable contributions to understanding permafrost change and its implications for humans. We partnered with two Iñupiaq communities in Alaska's Arctic to investigate current and potential effects of thawing permafrost on social-ecological systems. Anaktuvuk Pass is situated on thaw-stable consolidated gravel in the Brooks Range, while Selawik rests on ice-rich permafrost in Beringia lowland tundra. Using the transdisciplinary approach of resilience theory and mixed geophysical and ethnographic methods, we measured active layer thaw depths and documented local knowledge about climate and permafrost change. Thaw depths were greater overall in Selawik. Residents of both communities reported a variety of changes in surface features, hydrology, weather, flora, and fauna that they attribute to thawing permafrost and / or climate change. Overall, Selawik residents described more numerous and extreme examples of such changes, expressed higher degrees of certainty that change is occurring, and anticipated more significant and negative implications for their way of life than did residents of Anaktuvuk Pass. Of the two villages, Selawik faces greater and more immediate challenges to the resilience of its social-ecological system as permafrost thaws.

Evolution of anomalies of salinity of surface waters of Arctic Ocean and their possible influence on climate changes

Science.gov (United States)

Popov, A.; Rubchenia, A.

2009-04-01

Numerous of model simulations of ice extent in Arctic Ocean predict almost full disappearance of sea ice in Arctic regions by 2050. However, the nature, as against models, does not suffer the unidirectional processes. By means of various feedback responses system aspires to come in an equilibrium condition. In Arctic regions one of the most powerful generators of a negative feedback is the fresh-water stream to Greenland Sea and Northern Atlantic. Increasing or decreasing of a fresh-water volume from the Arctic basin to Greenland Sea and Northern Atlantic results in significant changes in climatic system. At the Oceanology department of Arctic and Antarctic Research Institute (AARI) (St-Petersburg, Russia) in 2007, on the basis of the incorporated Russian-American database of the oceanographic data, reconstruction of long-term time series of average salinity of ocean surface was executed. The received time series describes the period from 1950 to 1993. For allocation of the processes determining formation of changes of average salinity of surface waters in Arctic basin the correlation analysis of interrelation of the received time series and several physical parameters which could affect formation of changes of salinity was executed. We found counter-intuitive result: formation of long-term changes of average salinity of surface waters of Arctic basin in the winter period does not depend on changes of a Siberian rivers runoff. Factors of correlation do not exceed -0,31. At the same time, clear inverse relationship of salinity of surface waters from volumes of the ice formed in flaw lead polynyas of the Siberian shelf seas is revealed. In this case factors of correlation change from -0,56 to -0,7. The maximum factor of correlation is -0,7. It characterizes interrelation of total volume of the ice formed in flaw lead polynyas of all seas of the Siberian shelf and average salinity of surface waters of Arctic basin. Thus, at increase of volumes of the ice formed in

Arctic climate change in NORKLIMA

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The NORKLIMA programme is the national Norwegian initiative on climate research established for the period 2004-2013. The programme seeks to generate key knowledge about climate trends, the impacts of climate change, and how Norway can adapt to these changes. The NORKLIMA programme also encompasses research on instruments and policies for reducing emissions. Large-scale Programmes As part of the effort to meet national research-policy priorities, the Research Council has established a special funding instrument called the Large-scale Programmes. This initiative is designed to build long-term knowledge in order to encourage innovation and enhance value creation as well as to help find solutions to important challenges facing society.(Author)

Deglacial climate modulated by the storage and release of Arctic sea ice

Science.gov (United States)

Condron, A.; Coletti, A. J.; Bradley, R. S.

2017-12-01

Periods of abrupt climate cooling during the last deglaciation (20 - 8 kyr ago) are often attributed to glacial outburst floods slowing the Atlantic meridional overturning circulation (AMOC). Here, we present results from a series of climate model simulations showing that the episodic break-up and mobilization of thick, perennial, Arctic sea ice during this time would have released considerable volumes of freshwater directly to the Nordic Seas, where processes regulating large-scale climate occur. Massive sea ice export events to the North Atlantic are generated whenever the transport of sea ice is enhanced, either by changes in atmospheric circulation, rising sea level submerging the Bering land bridge, or glacial outburst floods draining into the Arctic Ocean from the Mackenzie River. We find that the volumes of freshwater released to the Nordic Seas are similar to, or larger than, those estimated to have come from terrestrial outburst floods, including the discharge at the onset of the Younger Dryas. Our results provide the first evidence that the storage and release of Arctic sea ice helped drive deglacial climate change by modulating the strength of the AMOC.

Climate change, future Arctic Sea ice, and the competitiveness of European Arctic offshore oil and gas production on world markets.

Science.gov (United States)

Petrick, Sebastian; Riemann-Campe, Kathrin; Hoog, Sven; Growitsch, Christian; Schwind, Hannah; Gerdes, Rüdiger; Rehdanz, Katrin

2017-12-01

A significant share of the world's undiscovered oil and natural gas resources are assumed to lie under the seabed of the Arctic Ocean. Up until now, the exploitation of the resources especially under the European Arctic has largely been prevented by the challenges posed by sea ice coverage, harsh weather conditions, darkness, remoteness of the fields, and lack of infrastructure. Gradual warming has, however, improved the accessibility of the Arctic Ocean. We show for the most resource-abundant European Arctic Seas whether and how a climate induced reduction in sea ice might impact future accessibility of offshore natural gas and crude oil resources. Based on this analysis we show for a number of illustrative but representative locations which technology options exist based on a cost-minimization assessment. We find that under current hydrocarbon prices, oil and gas from the European offshore Arctic is not competitive on world markets.

Resilience, human agency and climate change adaptation strategies in the Arctic

DEFF Research Database (Denmark)

Sejersen, Frank

2009-01-01

and work with a number of barriers for resilience. The objective of the article is first to address the position of institutional barriers in the studies and strategies. Second the article analyses the role human agency is ascribed in proposed strategies and projects in Nunavut and Greenland. With a focus......  In the Arctic, indigenous peoples, researchers and governments are working to develop climate change adaptation strategies due to the rapid changes in sea ice extent, weather conditions and in the ecosystem as such. These strategies are often based on specific perceptions of vulnerability...... on institutions and human agency the question is not only ‘how do people manage to adapt?' but moreover ‘what constrains people in pursuing a given adaptation strategy?' The article introduces the concept of double agency which stresses two different aspects of human agency that can be used to understand...

Does Arctic governance hold the key to achieving climate policy targets?

Science.gov (United States)

Forbis, Robert, Jr.; Hayhoe, Katharine

2018-02-01

Arctic feedbacks are increasingly viewed as the wild card in the climate system; but their most unpredictable and potentially dangerous aspect may lie in the human, rather than the physical, response to a warming climate. If Arctic policy is driven by agendas based on domestic resource development, the ensuing oil and gas extraction will ensure the failure of the Paris Agreement. If Arctic energy policy can be framed by the Arctic Council, however, its environmental agenda and fragmented governance structure offers the scientific community a fighting chance to determine the region’s energy future. Connecting Arctic climate science to resource economics via its unique governance structure is one of the most powerful ways the scientific community can protect the Arctic region’s environmental, cultural, and scientific resources, and influence international energy and climate policy.

Impacts of projected sea ice changes on trans-Arctic navigation

Science.gov (United States)

Stephenson, S. R.; Smith, L. C.

2012-12-01

Reduced Arctic sea ice continues to be a palpable signal of global change. Record lows in September sea ice extent from 2007 - 2011 have fueled speculation that trans-Arctic navigation routes may become physically viable in the 21st century. General Circulation Models project a nearly ice-free Arctic Ocean in summer by mid-century; however, how reduced sea ice will realistically impact navigation is not well understood. Using the ATAM (Arctic Transportation Accessibility Model) we present simulations of 21st-century trans-Arctic voyages as a function of climatic (ice) conditions and vessel class. Simulations are based on sea ice projections for three climatic forcing scenarios (RCP 4.5, 6.0, and 8.5 W/m^2) representing present-day and mid-century conditions, assuming Polar Class 6 (PC6) and open-water vessels (OW) with medium and no ice-breaking capability, respectively. Optimal least-cost routes (minimizing travel time while avoiding ice impassible to a given vessel class) between the North Atlantic and the Bering Strait were calculated for summer months of each time window. While Arctic navigation depends on other factors besides sea ice including economics, infrastructure, bathymetry, current, and weather, these projections should be useful for strategic planning by governments, regulatory and environmental agencies, and the global maritime industry to assess potential changes in the spatial and temporal ranges of Arctic marine operations.

Simulations of Vegetation Impacts on Arctic Climate

Science.gov (United States)

Bonfils, C.; Phillips, T. J.; Riley, W. J.; Post, W. M.; Torn, M. S.

2009-12-01

Because global warming disproportionately influences high-latitude climate, changes in arctic vegetation are in progress. These land-cover changes include redistribution of local vegetation types as well as northward migration of lower-latitude species in response to the increasing warming. The resulting displacement of low-lying tundra vegetation by shrubs and trees darkens the surface, thus accelerating regional warming. As participants in the U.S. Department of Energy IMPACTS Project, we are investigating the potential for abrupt arctic climatic change resulting from such variations in vegetation, among other mechanisms. To estimate the relative magnitudes of effects to be expected from changes in high-latitude land cover, we are conducting several numerical experiments with the Community Climate System Model (CCSM). These experiments include: 1) A “present-day-climate” control experiment with current atmospheric greenhouse-gas concentrations and climatological monthly sea surface temperatures and sea ice extents prescribed, and with “standard” CLM plant functional types (PFTs) specified; 2) A “changed-vegetation-type” experiment that is the same as 1), except that the “standard” PFTs are augmented by additional vegetation types (forbs, sedges, shrubs, mosses, and lichens) that are not presently represented in CLM. This experiment will require information on the location, fractional cover, and physiological parameterizations of these new PFTs. 3) A “changed-vegetation-extent experiment” that is the same as 2), except that the spatial extents of selected PFTs (e.g. shrubs or boreal forest PFTs) are shifted northward from their present locations in the CLM. We will report on the atmospheric climate and land-surface feedbacks associated with these vegetation changes, with emphasis on local and regional surface energy and moisture fluxes and near-surface temperature, humidity, and clouds. Acknowledgments This work was performed under the auspices

Changes in Arctic vegetation amplify high-latitude warming through the greenhouse effect.

Science.gov (United States)

Swann, Abigail L; Fung, Inez Y; Levis, Samuel; Bonan, Gordon B; Doney, Scott C

2010-01-26

Arctic climate is projected to change dramatically in the next 100 years and increases in temperature will likely lead to changes in the distribution and makeup of the Arctic biosphere. A largely deciduous ecosystem has been suggested as a possible landscape for future Arctic vegetation and is seen in paleo-records of warm times in the past. Here we use a global climate model with an interactive terrestrial biosphere to investigate the effects of adding deciduous trees on bare ground at high northern latitudes. We find that the top-of-atmosphere radiative imbalance from enhanced transpiration (associated with the expanded forest cover) is up to 1.5 times larger than the forcing due to albedo change from the forest. Furthermore, the greenhouse warming by additional water vapor melts sea-ice and triggers a positive feedback through changes in ocean albedo and evaporation. Land surface albedo change is considered to be the dominant mechanism by which trees directly modify climate at high-latitudes, but our findings suggest an additional mechanism through transpiration of water vapor and feedbacks from the ocean and sea-ice.

Climate sensitivity to Arctic seaway restriction during the early Paleogene

Science.gov (United States)

Roberts, Christopher D.; LeGrande, Allegra N.; Tripati, Aradhna K.

2009-09-01

The opening and closing of ocean gateways affects the global distribution of heat, salt, and moisture, potentially driving climatic change on regional to global scales. Between 65 and 45 million years ago (Ma), during the early Paleogene, exchange between the Arctic and global oceans occurred through two narrow and shallow seaways, the Greenland-Norway seaway and the Turgai Strait. Sediments from the Arctic Ocean suggest that, during this interval, the surface ocean was warm, brackish, and episodically enabled the freshwater fern Azolla to bloom. The precise mechanisms responsible for the development of these conditions in the Paleogene Arctic remain uncertain. Here we show results from an isotope-enabled, atmosphere-ocean general circulation model, which indicate that Northern Hemisphere climate would have been very sensitive to the degree of oceanic exchange through the Arctic seaways. We also present modelled estimates of seawater and calcite δ18O for the Paleogene. By restricting these seaways, we simulate freshening of the surface Arctic Ocean to ~ 6 psu and warming of sea-surface temperatures by 2 °C in the North Atlantic and 5-10 °C in the Labrador Sea. Our results may help explain the occurrence of low-salinity tolerant taxa in the Arctic Ocean during the Eocene and provide a mechanism for enhanced warmth in the north western Atlantic. We propose that the formation of a volcanic land-bridge between Greenland and Europe could have caused increased ocean convection and warming of intermediate waters in the Atlantic. If true, this result is consistent with the theory that bathymetry changes may have caused thermal destabilisation of methane clathrates and supports a tectonic trigger hypothesis for the Paleocene Eocene Thermal Maximum (PETM).

Biodiversity, Distributions and Adaptations of Arctic Species in the Context of Environmental Change

Energy Technology Data Exchange (ETDEWEB)

Callaghan, Terry V. [Abisko Scientific Research Station, Abisko (Sweden); Bjoern, Lars Olof [Lund Univ. (Sweden). Dept. of Cell and Organism Biology; Chernov, Yuri [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Severtsov Inst. of Evolutionary Morphology and Animal Ecology] (and others)

2004-11-01

The individual of a species is the basic unit which responds to climate and UV-B changes, and it responds over a wide range of time scales. The diversity of animal, plant and microbial species appears to be low in the Arctic, and decreases from the boreal forests to the polar deserts of the extreme North but primitive species are particularly abundant. This latitudinal decline is associated with an increase in superdominant species that occupy a wide range of habitats. Climate warming is expected to reduce the abundance and restrict the ranges of such species and to affect species at their northern range boundaries more than in the South: some Arctic animal and plant specialists could face extinction. Species most likely to expand into tundra are boreal species that currently exist as outlier populations in the Arctic. Many plant species have characteristics that allow them to survive short snow-free growing seasons, low solar angles, permafrost and low soil temperatures, low nutrient availability and physical disturbance. Many of these characteristics are likely to limit species' responses to climate warming, but mainly because of poor competitive ability compared with potential immigrant species. Terrestrial Arctic animals possess many adaptations that enable them to persist under a wide range of temperatures in the Arctic. Many escape unfavorable weather and resource shortage by winter dormancy or by migration. The biotic environment of Arctic animal species is relatively simple with few enemies, competitors, diseases, parasites and available food resources. Terrestrial Arctic animals are likely to be most vulnerable to warmer and drier summers, climatic changes that interfere with migration routes and staging areas, altered snow conditions and freeze-thaw cycles in winter, climate-induced disruption of the seasonal timing of reproduction and development, and influx of new competitors, predators, parasites and diseases. Arctic microorganisms are also well

Projected Impact of Climate Change on the Energy Budget of the Arctic Ocean by a Global Climate Model

Science.gov (United States)

Miller, James R.; Russell, Gary L.; Hansen, James E. (Technical Monitor)

2001-01-01

The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air-sea interface that is balanced by oceanic heat transport into the Arctic. The energy loss at the air-sea interface is due to the combined effects of radiative, sensible, and latent heat fluxes. The inflow of heat by the ocean can be divided into two components: the transport of water masses of different temperatures between the Arctic and the Atlantic and Pacific Oceans and the export of sea ice, primarily through Fram Strait. Two 150-year simulations (1950-2099) of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. One is a control simulation for the present climate with constant 1950 atmospheric composition, and the other is a transient experiment with observed GHGs from 1950 to 1990 and 0.5% annual compounded increases of CO2 after 1990. For the present climate the model agrees well with observations of radiative fluxes at the top of the atmosphere, atmospheric advective energy transport into the Arctic, and surface air temperature. It also simulates the seasonal cycle and summer increase of cloud cover and the seasonal cycle of sea-ice cover. In addition, the changes in high-latitude surface air temperature and sea-ice cover in the GHG experiment are consistent with observed changes during the last 40 and 20 years, respectively. Relative to the control, the last 50-year period of the GHG experiment indicates that even though the net annual incident solar radiation at the surface decreases by 4.6 W(per square meters) (because of greater cloud cover and increased cloud optical depth), the absorbed solar radiation increases by 2.8 W(per square meters) (because of less sea ice). Increased cloud cover and warmer air also cause increased downward thermal radiation at the surface so that the net radiation into the ocean increases by 5.0 Wm-2. The annual increase in radiation into the ocean, however, is

Mammalian herbivores confer resilience of Arctic shrub-dominated ecosystems to changing climate.

Science.gov (United States)

Kaarlejärvi, Elina; Hoset, Katrine S; Olofsson, Johan

2015-09-01

Climate change is resulting in a rapid expansion of shrubs in the Arctic. This expansion has been shown to be reinforced by positive feedbacks, and it could thus set the ecosystem on a trajectory toward an alternate, more productive regime. Herbivores, on the other hand, are known to counteract the effects of simultaneous climate warming on shrub biomass. However, little is known about the impact of herbivores on resilience of these ecosystems, that is, the capacity of a system to absorb disturbance and still remain in the same regime, retaining the same function, structure, and feedbacks. Here, we investigated how herbivores affect resilience of shrub-dominated systems to warming by studying the change of shrub biomass after a cessation of long-term experimental warming in a forest-tundra ecotone. As predicted, warming increased the biomass of shrubs, and in the absence of herbivores, shrub biomass in tundra continued to increase 4 years after cessation of the artificial warming, indicating that positive effects of warming on plant growth may persist even over a subsequent colder period. Herbivores contributed to the resilience of these systems by returning them back to the original low-biomass regime in both forest and tundra habitats. These results support the prediction that higher shrub biomass triggers positive feedbacks on soil processes and microclimate, which enable maintaining the rapid shrub growth even in colder climates. Furthermore, the results show that in our system, herbivores facilitate the resilience of shrub-dominated ecosystems to climate warming. © 2015 John Wiley & Sons Ltd.

Climate-derived tensions in Arctic security.

Energy Technology Data Exchange (ETDEWEB)

Backus, George A.; Strickland, James Hassler

2008-09-01

Globally, there is no lack of security threats. Many of them demand priority engagement and there can never be adequate resources to address all threats. In this context, climate is just another aspect of global security and the Arctic just another region. In light of physical and budgetary constraints, new security needs must be integrated and prioritized with existing ones. This discussion approaches the security impacts of climate from that perspective, starting with the broad security picture and establishing how climate may affect it. This method provides a different view from one that starts with climate and projects it, in isolation, as the source of a hypothetical security burden. That said, the Arctic does appear to present high-priority security challenges. Uncertainty in the timing of an ice-free Arctic affects how quickly it will become a security priority. Uncertainty in the emergent extreme and variable weather conditions will determine the difficulty (cost) of maintaining adequate security (order) in the area. The resolution of sovereignty boundaries affects the ability to enforce security measures, and the U.S. will most probably need a military presence to back-up negotiated sovereignty agreements. Without additional global warming, technology already allows the Arctic to become a strategic link in the global supply chain, possibly with northern Russia as its main hub. Additionally, the multinational corporations reaping the economic bounty may affect security tensions more than nation-states themselves. Countries will depend ever more heavily on the global supply chains. China has particular needs to protect its trade flows. In matters of security, nation-state and multinational-corporate interests will become heavily intertwined.

Adapting to the impacts of climate change on food security among Inuit in the Western Canadian Arctic.

Science.gov (United States)

Wesche, Sonia D; Chan, Hing Man

2010-09-01

This study examined critical impacts of climate change on Inuit diet and nutritional health in four Inuit communities in the Inuvialuit Settlement Region, Western Arctic, Canada. The first objective was to combine data from community observation studies and dietary interview studies to determine potential climate change impacts on nutritional quality. The second objective was to address the scale of data collection and/or availability to compare local versus regional trends, and identify implications for adaptation planning. Information was compiled from 5 reports (4 community reports and 1 synthesis report) of climate change observations, impacts and adaptations in 12 Inuit communities (2005-2006), and from a dietary report of food use from 18 Inuit communities (1997-2000). Changing access to, availability of, quality of, and ability to use traditional food resources has implications for quality of diet. Nutritional implications of lower traditional food use include likely reductions in iron, zinc, protein, vitamin D, and omega-3 fatty acids, among others. The vulnerability of each community to changing food security is differentially influenced by a range of factors, including current harvesting trends, levels of reliance on individual species, opportunities for access to other traditional food species, and exposure to climate change hazards. Understanding linkages between climate change and traditional food security provides a basis for strengthening adaptive capacity and determining effective adaptation options to respond to future change.

The expedition ARCTIC `96 of RV `Polarstern` (ARK XII) with the Arctic Climate System Study (ACSYS). Cruise report; Die Expedition ARCTIC `96 des FS `Polarstern` (ARK XII) mit der Arctic Climate System Study (ACSYS). Fahrtbericht

Energy Technology Data Exchange (ETDEWEB)

Augstein, E.

1997-11-01

The multinational expedition ARCTIC `96 was carried out jointly by two ships, the German RV POLARSTERN and the Swedish RV ODEN. The research programme was developed by scientists from British, Canadian, Finish, German, Irish, Norwegian, Russian, Swedish and US American research institutions and universities. The physical programme on POLARSTERN was primarily designed to foster the Arctic Climte System Study (ACSYS) in the framework of the World Climate Research Programme (WCRP). Investigations during the recent years have provided substantial evidence that the Arctic Ocean and the adjacent shelf seas play a significant role in the thermohaline oceanic circulation and may therefore have a distinct influence on global climate. Consequently the main ACSYS goals are concerned with studies of the governing oceanic, atmospheric and hydrological processes in the entire Arctic region. (orig.) [Deutsch] Die Expedition ARCTIC `96 wurde von zwei Forschungsschiffen, der deutschen POLARSTERN und der schwedischen ODEN unter Beteiligung von Wissenschaftlern und Technikern aus Deutschland, Finnland, Grossbritannien, Irland, Kanada, Norwegen, Russland, Schweden und den Vereinigten Staaten von Amerika durchgefuehrt. Die physikalischen Projekte auf der POLARSTERN dienten ueberwiegend der Unterstuetzung der Arctic Climate System Study (ACSYS) des Weltklimaforschungsprogramms, die auf die Erforschung der vorherrschenden ozeanischen, atmosphaerischen, kryosphaerischen und hydrologischen Prozesse der Arktisregion ausgerichtet ist. (orig.)

Human-induced Arctic moistening.

Science.gov (United States)

Min, Seung-Ki; Zhang, Xuebin; Zwiers, Francis

2008-04-25

The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming in the Arctic, and fluctuations of regional fresh water inflow to the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence. By comparing observations to simulations from 22 coupled climate models, we find influence from anthropogenic greenhouse gases and sulfate aerosols in the space-time pattern of precipitation change over high-latitude land areas north of 55 degrees N during the second half of the 20th century. The human-induced Arctic moistening is consistent with observed increases in Arctic river discharge and freshening of Arctic water masses. This result provides new evidence that human activity has contributed to Arctic hydrological change.

High-Arctic Plant-Herbivore Interactions under Climate Influence

DEFF Research Database (Denmark)

Berg, Thomas B.; Schmidt, Niels M.; Høye, Toke Thomas

production upon which the herbivores depend, and snow may be the most important climatic factor affecting the different trophic levels and the interactions between them. Hence, the spatio-temporal distribution of snow, as well as thawing events during winter, may have considerable effects on the herbivores...... by both the timing of onset and the duration of winter snow-cover. Musk oxen significantly reduced the productivity of arctic willow, while high densities of collared lemmings during winter reduced the production of mountain averts flowers in the following summer. Under a deep snow-layer scenario, climate...... and the previous year's density of musk oxen had a negative effect on the present year's production of arctic willow. Previous year's primary production of arctic willow, in turn, significantly affected the present year's density of musk oxen positively. Climatic factors that affect primary production of plants...

Impact of prescribed Arctic sea ice thickness in simulations of the present and future climate

Energy Technology Data Exchange (ETDEWEB)

Krinner, Gerhard [Alfred Wegener Institute for Polar and Marine Research, Potsdam (Germany); INSU-CNRS and UJF Grenoble, Laboratoire de Glaciologie et Geophysique de l' Environnement (LGGE), 54 rue Moliere, BP 96, Saint Martin d' Heres Cedex (France); Rinke, Annette; Dethloff, Klaus [Alfred Wegener Institute for Polar and Marine Research, Potsdam (Germany); Gorodetskaya, Irina V. [INSU-CNRS and UJF Grenoble, Laboratoire de Glaciologie et Geophysique de l' Environnement (LGGE), 54 rue Moliere, BP 96, Saint Martin d' Heres Cedex (France)

2010-09-15

This paper describes atmospheric general circulation model climate change experiments in which the Arctic sea-ice thickness is either fixed to 3 m or somewhat more realistically parameterized in order to take into account essentially the spatial variability of Arctic sea-ice thickness, which is, to a first approximation, a function of ice type (perennial or seasonal). It is shown that, both at present and at the end of the twenty-first century (under the SRES-A1B greenhouse gas scenario), the impact of a variable sea-ice thickness compared to a uniform value is essentially limited to the cold seasons and the lower troposphere. However, because first-year ice is scarce in the Central Arctic today, but not under SRES-A1B conditions at the end of the twenty-first century, and because the impact of a sea-ice thickness reduction can be masked by changes of the open water fraction, the spatial and temporal patterns of the effect of sea-ice thinning on the atmosphere differ between the two periods considered. As a consequence, not only the climate simulated at a given period, but also the simulated Arctic climate change over the twenty-first century is affected by the way sea-ice thickness is prescribed. (orig.)

Collaborative Proposal: Improving Decadal Prediction of Arctic Climate Variability and Change Using a Regional Arctic System Model (RASM)

Energy Technology Data Exchange (ETDEWEB)

Maslowski, Wieslaw [Naval Postgraduate School, Monterey, CA (United States). Dept. of Oceanography; Cassano, John J. [Univ. of Colorado, Boulder, CO (United States); Gutowski, Jr., William J. [Iowa State Univ., Ames, IA (United States); Lipscomb, William H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nijssen, Bart [Univ. of Washington, Seattle, WA (United States); Roberts, Andrew [Naval Postgraduate School, Monterey, CA (United States). Dept. of Oceanography; Robertson, William [Univ. of Texas, El Paso, TX (United States); Tulaczyk, Slawek [Univ. of California, Santa Cruz, CA (United States); Zeng, Xubin [Univ. of Arizona, Tucson, AZ (United States)

2011-05-15

The primary outcome of the project was the development of the Regional Arctic System Model (RASM) and evaluation of its individual model components, coupling among them and fully coupled model results. Overall, we have demonstrated that RASM produces realistic mean and seasonal surface climate as well as its interannual and decadal variability and trends.

Dependence of Arctic climate on the latitudinal position of stationary waves and to high-latitudes surface warming

Science.gov (United States)

Shin, Yechul; Kang, Sarah M.; Watanabe, Masahiro

2017-12-01

Previous studies suggest large uncertainties in the stationary wave response under global warming. Here, we investigate how the Arctic climate responds to changes in the latitudinal position of stationary waves, and to high-latitudes surface warming that mimics the effect of Arctic sea ice loss under global warming. To generate stationary waves in an atmospheric model coupled to slab ocean, a series of experiments is performed where the thermal forcing with a zonal wavenumber-2 (with zero zonal-mean) is prescribed at the surface at different latitude bands in the Northern Hemisphere. When the stationary waves are generated in the subtropics, the cooling response dominates over the warming response in the lower troposphere due to cloud radiative effects. Then, the low-level baroclinicity is reduced in the subtropics, which gives rise to a poleward shift of the eddy driven jet, thereby inducing substantial cooling in the northern high latitudes. As the stationary waves are progressively generated at higher latitudes, the zonal-mean climate state gradually becomes more similar to the integration with no stationary waves. These differences in the mean climate affect the Arctic climate response to high-latitudes surface warming. Additional surface heating over the Arctic is imposed to the reference climates in which the stationary waves are located at different latitude bands. When the stationary waves are positioned at lower latitudes, the eddy driven jet is located at higher latitude, closer to the prescribed Arctic heating. As baroclinicity is more effectively perturbed, the jet shifts more equatorward that accompanies a larger reduction in the poleward eddy transport of heat and momentum. A stronger eddy-induced descending motion creates greater warming over the Arctic. Our study calls for a more accurate simulation of the present-day stationary wave pattern to enhance the predictability of the Arctic warming response in a changing climate.

Impacts of climate change on resource management in the north

International Nuclear Information System (INIS)

1993-01-01

A Canada/USA symposium was held to communicate with people of the Arctic regions of North America about current issues in climate and climatic change; to promote dialogue between northern groups about various aspects of the climate problem relevant to northern people; and to discuss and formulate recommendations regarding management of northern resources that might be affected by global warming and associated regional climatic change. Papers were presented on the impacts of climatic change on water resources and hydrology, snow cover and sea ice, forest ecosystems, wildlife and marine resources, offshore petroleum operations, engineered structures, and the socio-economic system in the north. Arctic research programs and international initiatives on climatic change were also described. Separate abstracts have been prepared for 21 papers from this symposium

Climate change hotspots in the CMIP5 global climate model ensemble.

Science.gov (United States)

Diffenbaugh, Noah S; Giorgi, Filippo

2012-01-10

We use a statistical metric of multi-dimensional climate change to quantify the emergence of global climate change hotspots in the CMIP5 climate model ensemble. Our hotspot metric extends previous work through the inclusion of extreme seasonal temperature and precipitation, which exert critical influence on climate change impacts. The results identify areas of the Amazon, the Sahel and tropical West Africa, Indonesia, and the Tibetan Plateau as persistent regional climate change hotspots throughout the 21 st century of the RCP8.5 and RCP4.5 forcing pathways. In addition, areas of southern Africa, the Mediterranean, the Arctic, and Central America/western North America also emerge as prominent regional climate change hotspots in response to intermediate and high levels of forcing. Comparisons of different periods of the two forcing pathways suggest that the pattern of aggregate change is fairly robust to the level of global warming below approximately 2°C of global warming (relative to the late-20 th -century baseline), but not at the higher levels of global warming that occur in the late-21 st -century period of the RCP8.5 pathway, with areas of southern Africa, the Mediterranean, and the Arctic exhibiting particular intensification of relative aggregate climate change in response to high levels of forcing. Although specific impacts will clearly be shaped by the interaction of climate change with human and biological vulnerabilities, our identification of climate change hotspots can help to inform mitigation and adaptation decisions by quantifying the rate, magnitude and causes of the aggregate climate response in different parts of the world.

Marine distribution of arctic seabirds over six decades: changes and conservation applications

DEFF Research Database (Denmark)

Wong, SNP; Johansen, Kasper Lambert; Lieske, DJ

Climate change is causing rapid changes in Arctic marine ecosystems and understanding its impacts on wildlife is critical for conservation management, especially as the decline in sea ice leads to increased development and vessel traffic. The Arctic supports hundreds of millions of seabirds, which...... collected from 1988 to 2015 and covering a combined 185,000 linear km, we examined the marine distribution of seabirds in sub-arctic and Arctic waters between Canada and Greenland, an area covering over 5,000,000 km2. We developed a predictive model to investigate how ice cover and ocean processes influence...... the distribution of arctic seabirds in summer and autumn and identified existing areas of high density. Comparing these results to at-sea surveys conducted in the same waters from 1966 - 1987, we examined how seabird distribution has changed over the last six decades. Understanding how changes in the marine...

An estimated cost of lost climate regulation services caused by thawing of the Arctic cryosphere.

Science.gov (United States)

Euskirchen, Eugénie S; Goodstein, Eban S; Huntington, Henry P

2013-12-01

Recent and expected changes in Arctic sea ice cover, snow cover, and methane emissions from permafrost thaw are likely to result in large positive feedbacks to climate warming. There is little recognition of the significant loss in economic value that the disappearance of Arctic sea ice, snow, and permafrost will impose on humans. Here, we examine how sea ice and snow cover, as well as methane emissions due to changes in permafrost, may potentially change in the future, to year 2100, and how these changes may feed back to influence the climate. Between 2010 and 2100, the annual costs from the extra warming due to a decline in albedo related to losses of sea ice and snow, plus each year's methane emissions, cumulate to a present value cost to society ranging from US$7.5 trillion to US$91.3 trillion. The estimated range reflects uncertainty associated with (1) the extent of warming-driven positive climate feedbacks from the thawing cryosphere and (2) the expected economic damages per metric ton of CO2 equivalents that will be imposed by added warming, which depend, especially, on the choice of discount rate. The economic uncertainty is much larger than the uncertainty in possible future feedback effects. Nonetheless, the frozen Arctic provides immense services to all nations by cooling the earth's temperature: the cryosphere is an air conditioner for the planet. As the Arctic thaws, this critical, climate-stabilizing ecosystem service is being lost. This paper provides a first attempt to monetize the cost of some of those lost services.

City of Iqaluit's climate change impacts, infrastructure risks and adaptive capacity project

International Nuclear Information System (INIS)

Nielsen, D.; Kronenberger, J.

2007-03-01

The City of Iqaluit is an Arctic community that is very susceptible to the stresses of climate change. The city is challenged by increased flooding, coastal erosion and ground instability caused by melting of the permafrost layer. In response, the City of Iqaluit has created policies to reduce greenhouse gases and act on climate change. A project has also been launched to develop adaptation strategies, with particular focus on infrastructure vulnerability given the environmental and climate change in the Canadian Arctic. The purpose of the study is to evaluate the biophysical exposure and hazards on Arctic coasts subject to effects of climate change, identify past and current management strategies used to manage risks in coastal communities which have already experienced environmental change, and to evaluate the adaptive capacity of communities for dealing with coastal hazards throughout the Arctic. This document identified the risks to Iqaluit's infrastructure, including buildings, roads, water supply, wastewater treatment and waste disposal systems. Adaptation options were also developed. These ranged from educational programs and retrofits to policy changes and building standard amendments. refs., tabs., figs

Squaring the Arctic Circle: connecting Arctic knowledge with societal needs

Science.gov (United States)

Wilkinson, J.

2017-12-01

Over the coming years the landscape of the Arctic will change substantially- environmentally, politically, and economically. Furthermore, Arctic change has the potential to significantly impact Arctic and non-Arctic countries alike. Thus, our science is in-demand by local communities, politicians, industry leaders and the public. During these times of transition it is essential that the links between science and society be strengthened further. Strong links between science and society is exactly what is needed for the development of better decision-making tools to support sustainable development, enable adaptation to climate change, provide the information necessary for improved management of assets and operations in the Arctic region, and and to inform scientific, economic, environmental and societal policies. By doing so tangible benefits will flow to Arctic societies, as well as for non-Arctic countries that will be significantly affected by climate change. Past experience has shown that the engagement with a broad range of stakeholders is not always an easy process. Consequently, we need to improve collaborative opportunities between scientists, indigenous/local communities, private sector, policy makers, NGOs, and other relevant stakeholders. The development of best practices in this area must build on the collective experiences of successful cross-sectorial programmes. Within this session we present some of the outreach work we have performed within the EU programme ICE-ARC, from community meetings in NW Greenland through to sessions at the United Nations Framework Convention on Climate Change COP Conferences, industry round tables, and an Arctic side event at the World Economic Forum in Davos.

Changing Arctic snow cover: A review of recent developments and assessment of future needs for observations, modelling, and impacts

NARCIS (Netherlands)

Bokhorst, Stef; Pedersen, Stine Højlund; Brucker, Ludovic; Anisimov, Oleg; Bjerke, Jarle W.; Brown, Ross D.; Ehrich, Dorothee; Essery, Richard L. H.; Heilig, Achim; Ingvander, Susanne; Johansson, Cecilia; Johansson, Margareta; Jónsdóttir, Ingibjörg Svala; Inga, Niila; Luojus, Kari; Macelloni, Giovanni; Mariash, Heather|info:eu-repo/dai/nl/41327697X; Mclennan, Donald; Rosqvist, Gunhild Ninis; Sato, Atsushi; Savela, Hannele; Schneebeli, Martin; Sokolov, Aleksandr; Sokratov, Sergey A.; Terzago, Silvia; Vikhamar-schuler, Dagrun; Williamson, Scott; Qiu, Yubao; Callaghan, Terry V.

2016-01-01

Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for

Adaptive strategies and life history characteristics in a warming climate: salmon in the Arctic?

Science.gov (United States)

Nielsen, Jennifer L.; Ruggerone, Gregory T.; Zimmerman, Christian E.

2013-01-01

In the warming Arctic, aquatic habitats are in flux and salmon are exploring their options. Adult Pacific salmon, including sockeye (Oncorhynchus nerka), coho (O. kisutch), Chinook (O. tshawytscha), pink (O. gorbuscha) and chum (O. keta) have been captured throughout the Arctic. Pink and chum salmon are the most common species found in the Arctic today. These species are less dependent on freshwater habitats as juveniles and grow quickly in marine habitats. Putative spawning populations are rare in the North American Arctic and limited to pink salmon in drainages north of Point Hope, Alaska, chum salmon spawning rivers draining to the northwestern Beaufort Sea, and small populations of chum and pink salmon in Canada’s Mackenzie River. Pacific salmon have colonized several large river basins draining to the Kara, Laptev and East Siberian seas in the Russian Arctic. These populations probably developed from hatchery supplementation efforts in the 1960’s. Hundreds of populations of Arctic Atlantic salmon (Salmo salar) are found in Russia, Norway and Finland. Atlantic salmon have extended their range eastward as far as the Kara Sea in central Russian. A small native population of Atlantic salmon is found in Canada’s Ungava Bay. The northern tip of Quebec seems to be an Atlantic salmon migration barrier for other North American stocks. Compatibility between life history requirements and ecological conditions are prerequisite for salmon colonizing Arctic habitats. Broad-scale predictive models of climate change in the Arctic give little information about feedback processes contributing to local conditions, especially in freshwater systems. This paper reviews the recent history of salmon in the Arctic and explores various patterns of climate change that may influence range expansions and future sustainability of salmon in Arctic habitats. A summary of the research needs that will allow informed expectation of further Arctic colonization by salmon is given.

Late-Middle Quaternary lithostratigraphy and sedimentation patterns on the Alpha Ridge, central Arctic Ocean: Implications for Arctic climate variability on orbital time scales

Science.gov (United States)

Wang, Rujian; Polyak, Leonid; Xiao, Wenshen; Wu, Li; Zhang, Taoliang; Sun, Yechen; Xu, Xiaomei

2018-02-01

We use sediment cores collected by the Chinese National Arctic Research Expeditions from the Alpha Ridge to advance Quaternary stratigraphy and paleoceanographic reconstructions for the Arctic Ocean. Our cores show a good litho/biostratigraphic correlation to sedimentary records developed earlier for the central Arctic Ocean, suggesting a recovered stratigraphic range of ca. 0.6 Ma, suitable for paleoclimatic studies on orbital time scales. This stratigraphy was tested by correlating the stacked Alpha Ridge record of bulk XRF manganese, calcium and zirconium (Mn, Ca, Zr), to global stable-isotope (LR04-δ18O) and sea-level stacks and tuning to orbital parameters. Correlation results corroborate the applicability of presumed climate/sea-level controlled Mn variations in the Arctic Ocean for orbital tuning. This approach enables better understanding of the global and orbital controls on the Arctic climate. Orbital tuning experiments for our records indicate strong eccentricity (100-kyr) and precession (∼20-kyr) controls on the Arctic Ocean, probably implemented via glaciations and sea ice. Provenance proxies like Ca and Zr are shown to be unsuitable as orbital tuning tools, but useful as indicators of glacial/deglacial processes and circulation patterns in the Arctic Ocean. Their variations suggest an overall long-term persistence of the Beaufort Gyre circulation in the Alpha Ridge region. Some glacial intervals, e.g., MIS 6 and 4/3, are predominated by material presumably transported by the Transpolar Drift. These circulation shifts likely indicate major changes in the Arctic climatic regime, which yet need to be investigated. Overall, our results demonstrate applicability of XRF data to paleoclimatic studies of the Arctic Ocean.

Arctic and Antarctic Sea Ice Changes and Impacts (Invited)

Science.gov (United States)

Nghiem, S. V.

2013-12-01

The extent of springtime Arctic perennial sea ice, important to preconditioning summer melt and to polar sunrise photochemistry, continues its precipitous reduction in the last decade marked by a record low in 2012, as the Bromine, Ozone, and Mercury Experiment (BROMEX) was conducted around Barrow, Alaska, to investigate impacts of sea ice reduction on photochemical processes, transport, and distribution in the polar environment. In spring 2013, there was further loss of perennial sea ice, as it was not observed in the ocean region adjacent to the Alaskan north coast, where there was a stretch of perennial sea ice in 2012 in the Beaufort Sea and Chukchi Sea. In contrast to the rapid and extensive loss of sea ice in the Arctic, Antarctic sea ice has a trend of a slight increase in the past three decades. Given the significant variability in time and in space together with uncertainties in satellite observations, the increasing trend of Antarctic sea ice may arguably be considered as having a low confidence level; however, there was no overall reduction of Antarctic sea ice extent anywhere close to the decreasing rate of Arctic sea ice. There exist publications presenting various factors driving changes in Arctic and Antarctic sea ice. After a short review of these published factors, new observations and atmospheric, oceanic, hydrological, and geological mechanisms contributed to different behaviors of sea ice changes in the Arctic and Antarctic are presented. The contribution from of hydrologic factors may provide a linkage to and enhance thermal impacts from lower latitudes. While geological factors may affect the sensitivity of sea ice response to climate change, these factors can serve as the long-term memory in the system that should be exploited to improve future projections or predictions of sea ice changes. Furthermore, similarities and differences in chemical impacts of Arctic and Antarctic sea ice changes are discussed. Understanding sea ice changes and

Comparative responses of phenology and reproductive development to simulated environmental change in sub-arctic and high arctic plants

Energy Technology Data Exchange (ETDEWEB)

Wookey, P A; Welker, J M; Callaghan, T V [Inst. of Terrestrial Ecology, Merlewood Research Station, Grange-over-Sands, Cumbria (United Kingdom); Parsons, A N; Potter, J A; Lee, J A; Press, M C [Dept. of Environmental Biology, Univ. of Manchester, Manchester (United Kingdom)

1993-01-01

The effects of temperature, precipitation and nutrient perturbations, and their interactions, are being assessed on two contrasting arctic ecosystems to simulate impacts of climate change. One, a high arctic polar semi-desert community, is characterized by a sparse, low and aggregated vegetation cover where plant proliferation is by seedlings, whereas the other, a sub-arctic dwarf shrub health, is characterized by a complete, vegetation cover of erect, clonal dwarf shrubs which spread vegetatively. The developmental processes of seed production were shown to be highly sensitive, even within one growing season to specific environmental perturbations which differed between sites. At the polar semi-desert site, there was a striking effect of the temperature enhancement treatments on phenology and seed-setting of Dryas octopetala ssp. octopetala, with almost no seed-setting occurring in plots experiencing ambient temperatures. By contrast, there were no significant effects of temperature enhancement alone on fruit production of Empetrum hermaphroditum at the sub-Arctic dwarf shrub heath site, although fruit production was significantly influenced by the application of nutrients and/or water. The response of dominant high arctic dwarf shrub to increased temperature suggests that any climate warming may stimulate seed-set. This could be particularly important in the high Arctic where colonization can proceed in areas dominated by bare ground and where genetic recombination may be needed to generate tolerance to predicted changes of great magnitude. In the sub-Arctic, however the closed vegetation is dominated by clonally-proliferating species. Plant fitness will increase here in response to any increased vegetative growth resulting from higher nutrient availability in warmer organic soils. (ua) (59 refs.)

Advancing NOAA NWS Arctic Program Development

Science.gov (United States)

Timofeyeva-Livezey, M. M.; Horsfall, F. M. C.; Meyers, J. C.; Churma, M.; Thoman, R.

2016-12-01

Environmental changes in the Arctic require changes in the way the National Oceanic and Atmospheric Administration (NOAA) delivers hydrological and meteorological information to prepare the region's societies and indigenous population for emerging challenges. These challenges include changing weather patterns, changes in the timing and extent of sea ice, accelerated soil erosion due to permafrost decline, increasing coastal vulnerably, and changes in the traditional food supply. The decline in Arctic sea ice is opening new opportunities for exploitation of natural resources, commerce, tourism, and military interest. These societal challenges and economic opportunities call for a NOAA integrated approach for delivery of environmental information including climate, water, and weather data, forecasts, and warnings. Presently the NOAA Arctic Task Force provides leadership in programmatic coordination across NOAA line offices. National Weather Service (NWS) Alaska Region and the National Centers for Environmental Prediction (NCEP) provide the foundational operational hydro-meteorological products and services in the Arctic. Starting in 2016, NOAA's NWS will work toward improving its role in programmatic coordination and development through assembling an NWS Arctic Task Team. The team will foster ties in the Arctic between the 11 NWS national service programs in climate, water, and weather information, as well as between Arctic programs in NWS and other NOAA line offices and external partners. One of the team outcomes is improving decision support tools for the Arctic. The Local Climate Analysis Tool (LCAT) currently has more than 1100 registered users, including NOAA staff and technical partners. The tool has been available online since 2013 (http://nws.weather.gov/lcat/ ). The tool links trusted, recommended NOAA data and analytical capabilities to assess impacts of climate variability and climate change at local levels. A new capability currently being developed will

Building Materials in Arctic Climate

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede

2005-01-01

Building in the artic requires special attention on the appropriateness of building materials. The harsh climate makes execution difficult and sets unusual requirements for the pure material properties. In addition, there is a lack of choice of good, natural building materials in the arctic...

Assessment of extreme flood events in a changing climate for a long-term planning of socio-economic infrastructure in the Russian Arctic

Science.gov (United States)

Shevnina, Elena; Kourzeneva, Ekaterina; Kovalenko, Viktor; Vihma, Timo

2017-05-01

Climate warming has been more acute in the Arctic than at lower latitudes and this tendency is expected to continue. This generates major challenges for economic activity in the region. Among other issues is the long-term planning and development of socio-economic infrastructure (dams, bridges, roads, etc.), which require climate-based forecasts of the frequency and magnitude of detrimental flood events. To estimate the cost of the infrastructure and operational risk, a probabilistic form of long-term forecasting is preferable. In this study, a probabilistic model to simulate the parameters of the probability density function (PDF) for multi-year runoff based on a projected climatology is applied to evaluate changes in extreme floods for the territory of the Russian Arctic. The model is validated by cross-comparison of the modelled and empirical PDFs using observations from 23 sites located in northern Russia. The mean values and coefficients of variation (CVs) of the spring flood depth of runoff are evaluated under four climate scenarios, using simulations of six climate models for the period 2010-2039. Regions with substantial expected changes in the means and CVs of spring flood depth of runoff are outlined. For the sites located within such regions, it is suggested to account for the future climate change in calculating the maximal discharges of rare occurrence. An example of engineering calculations for maximal discharges with 1 % exceedance probability is provided for the Nadym River at Nadym.

Changing times, changing stories: Generational differences in climate change perspectives from four remote indigenous communities in Subarctic Alaska

Science.gov (United States)

Herman-Mercer, Nicole M.; Matkin, Elli; Laituri, Melinda J.; Toohey, Ryan C; Massey, Maggie; Elder, Kelly; Schuster, Paul F.; Mutter, Edda A.

2016-01-01

Indigenous Arctic and Subarctic communities currently are facing a myriad of social and environmental changes. In response to these changes, studies concerning indigenous knowledge (IK) and climate change vulnerability, resiliency, and adaptation have increased dramatically in recent years. Risks to lives and livelihoods are often the focus of adaptation research; however, the cultural dimensions of climate change are equally important because cultural dimensions inform perceptions of risk. Furthermore, many Arctic and Subarctic IK climate change studies document observations of change and knowledge of the elders and older generations in a community, but few include the perspectives of the younger population. These observations by elders and older generations form a historical baseline record of weather and climate observations in these regions. However, many indigenous Arctic and Subarctic communities are composed of primarily younger residents. We focused on the differences in the cultural dimensions of climate change found between young adults and elders. We outlined the findings from interviews conducted in four indigenous communities in Subarctic Alaska. The findings revealed that (1) intergenerational observations of change were common among interview participants in all four communities, (2) older generations observed more overall change than younger generations interviewed by us, and (3) how change was perceived varied between generations. We defined “observations” as the specific examples of environmental and weather change that were described, whereas “perceptions” referred to the manner in which these observations of change were understood and contextualized by the interview participants. Understanding the differences in generational observations and perceptions of change are key issues in the development of climate change adaptation strategies.

Total Environment of Change: Impacts of Climate Change and Social Transitions on Subsistence Fisheries in Northwest Alaska

Directory of Open Access Journals (Sweden)

Katie J. Moerlein

2012-03-01

Full Text Available Arctic ecosystems are undergoing rapid changes as a result of global climate change, with significant implications for the livelihoods of Arctic peoples. In this paper, based on ethnographic research conducted with the Iñupiaq communities of Noatak and Selawik in northwestern Alaska, we detail prominent environmental changes observed over the past twenty to thirty years and their impacts on subsistence-based lifestyles. However, we suggest that it is ultimately insufficient to try to understand how Arctic communities are experiencing and responding to climate change in isolation from other stressors. During interviews and participant observation documenting local observations of climatic and related environmental shifts and impacts to subsistence fishing practices, we find the inseparability of environmental, social, economic, cultural, and political realms for community residents. Many of our informants, who live in a mixed economy based on various forms of income and widespread subsistence harvesting of fish and game, perceive and experience climate change as embedded among numerous other factors affecting subsistence patterns and practices. Changing lifestyles, decreasing interest by younger generations in pursuing subsistence livelihoods, and economic challenges are greatly affecting contemporary subsistence patterns and practices in rural Alaska. Observations of climate change are perceived, experienced, and articulated to researchers through a broader lens of these linked lifestyle and cultural shifts. Therefore, we argue that to properly assess and understand the impacts of climate change on the subsistence practices in Arctic communities, we must also consider the total environment of change that is dramatically shaping the relationship between people, communities, and their surrounding environments.

A Prince's tribute...and trial. Monaco's Prince Albert II followed the footsteps of his great great grandfather when he ventured the Arctic Archipelago to trace climate change, this time with IAEA Marine scientists

International Nuclear Information System (INIS)

Lodding, L.

2006-01-01

Monaco's Prince Albert II followed the footsteps of his great great grandfather when he ventured to the Arctic Archipelago to track climate change, this time with IAEA Marine scientists. He undertook this trip to draw global attention to the environmental damage to the Arctic regions caused by global warming. Although far away from industrialized areas, Svalbard Island is eminently suitable to observe the evolution of climate change and long-range pollutants transported from northern European countries by water currents and from North America by winds. Using nuclear techniques, it is hoped that some of the causes of climate change can be unlocked. The first of these studies was undertaken to evaluate the shell laminations of a very long-lived marine bivalve mollusc, the Ocean Quahog. The mollusc, with a life expectancy well over a century, acts as a recording of temperature variations and water chemistry. The second project aimed at determining levels of contaminates in marine zooplankton in remote arctic environments for comparison with other climatic regions

Obama states obligation to act on climate change

Science.gov (United States)

Showstack, Randy

2012-11-01

Obama states obligation to act on climate change Noting increased global temperatures, Arctic ice melt, and severe weather events, President Barack Obama said that climate change is real and called for a conversation across the country to determine what can be done about it.

The ocean's role in polar climate change: asymmetric Arctic and Antarctic responses to greenhouse gas and ozone forcing.

Science.gov (United States)

Marshall, John; Armour, Kyle C; Scott, Jeffery R; Kostov, Yavor; Hausmann, Ute; Ferreira, David; Shepherd, Theodore G; Bitz, Cecilia M

2014-07-13

In recent decades, the Arctic has been warming and sea ice disappearing. By contrast, the Southern Ocean around Antarctica has been (mainly) cooling and sea-ice extent growing. We argue here that interhemispheric asymmetries in the mean ocean circulation, with sinking in the northern North Atlantic and upwelling around Antarctica, strongly influence the sea-surface temperature (SST) response to anthropogenic greenhouse gas (GHG) forcing, accelerating warming in the Arctic while delaying it in the Antarctic. Furthermore, while the amplitude of GHG forcing has been similar at the poles, significant ozone depletion only occurs over Antarctica. We suggest that the initial response of SST around Antarctica to ozone depletion is one of cooling and only later adds to the GHG-induced warming trend as upwelling of sub-surface warm water associated with stronger surface westerlies impacts surface properties. We organize our discussion around 'climate response functions' (CRFs), i.e. the response of the climate to 'step' changes in anthropogenic forcing in which GHG and/or ozone-hole forcing is abruptly turned on and the transient response of the climate revealed and studied. Convolutions of known or postulated GHG and ozone-hole forcing functions with their respective CRFs then yield the transient forced SST response (implied by linear response theory), providing a context for discussion of the differing warming/cooling trends in the Arctic and Antarctic. We speculate that the period through which we are now passing may be one in which the delayed warming of SST associated with GHG forcing around Antarctica is largely cancelled by the cooling effects associated with the ozone hole. By mid-century, however, ozone-hole effects may instead be adding to GHG warming around Antarctica but with diminished amplitude as the ozone hole heals. The Arctic, meanwhile, responding to GHG forcing but in a manner amplified by ocean heat transport, may continue to warm at an accelerating rate.

Recent climate change in the Arctic and its impact on contaminant pathways and interpretation of temporal trend data

International Nuclear Information System (INIS)

Macdonald, R.W.; Harner, T.; Fyfe, J.

2005-01-01

possibility, presently difficult to predict, is combination of immune suppression together with expanding ranges of disease vectors. Finally, biotransport through migratory species is exceptionally vulnerable to changes in migration strength or in migration pathway-in the Arctic, change in the distribution of ice and temperature may already have caused such changes. Hydrocarbons, which tend to impact surfaces, will be mostly affected by change in the ice climate (distribution and drift tracks). Perhaps the most dramatic changes will occur because our view of the Arctic Ocean will change as it becomes more amenable to transport, tourism and mineral exploration on the shelves. Radionuclides have tended not to produce a radiological problem in the Arctic; nevertheless one pathway, the ice, remains a risk because it can accrue, concentrate and transport radio-contaminated sediments. This pathway is sensitive to where ice is produced, what the transport pathways of ice are, and where ice is finally melted-all strong candidates for change during the coming century. The changes that have already occurred in the Arctic and those that are projected to occur have an effect on contaminant time series including direct measurements (air, water, biota) or proxies (sediment cores, ice cores, archive material). Although these 'system' changes can alter the flux and concentrations at given sites in a number of obvious ways, they have been all but ignored in the interpretation of such time series. To understand properly what trends mean, especially in complex 'recorders' such as seals, walrus and polar bears, demands a more thorough approach to time series by collecting data in a number of media coherently. Presently, a major reservoir for contaminants and the one most directly connected to biological uptake in species at greatest risk-the ocean-practically lacks such time series

Density and climate influence seasonal population dynamics in an Arctic ungulate

DEFF Research Database (Denmark)

Mortensen, Lars O.; Moshøj, Charlotte; Forchhammer, Mads C.

2016-01-01

The locally migratory behavior of the high arctic muskox (Ovibos muschatus) is a central component of the breeding and winter survival strategies applied to cope with the highly seasonal arctic climate. However, altered climate regimes affecting plant growth are likely to affect local migration...... cover), forage availability (length of growth season), and the number of adult females available per male (operational sex ratio) influence changes in the seasonal density dependence, abundance, and immigration rate of muskoxen into the valley. The results suggested summer temperature as the major...... controlling factor in the seasonal, local-scale migration of muskoxen at Zackenberg. Specifically, higher summer temperatures, defined as the cumulative average daily positive degrees in June, July, and August, resulted in decreased density dependence and, consequently, increase in the seasonal abundance...

Cyclone Activity in the Arctic From an Ensemble of Regional Climate Models (Arctic CORDEX)

Science.gov (United States)

Akperov, Mirseid; Rinke, Annette; Mokhov, Igor I.; Matthes, Heidrun; Semenov, Vladimir A.; Adakudlu, Muralidhar; Cassano, John; Christensen, Jens H.; Dembitskaya, Mariya A.; Dethloff, Klaus; Fettweis, Xavier; Glisan, Justin; Gutjahr, Oliver; Heinemann, Günther; Koenigk, Torben; Koldunov, Nikolay V.; Laprise, René; Mottram, Ruth; Nikiéma, Oumarou; Scinocca, John F.; Sein, Dmitry; Sobolowski, Stefan; Winger, Katja; Zhang, Wenxin

2018-03-01

The ability of state-of-the-art regional climate models to simulate cyclone activity in the Arctic is assessed based on an ensemble of 13 simulations from 11 models from the Arctic-CORDEX initiative. Some models employ large-scale spectral nudging techniques. Cyclone characteristics simulated by the ensemble are compared with the results forced by four reanalyses (ERA-Interim, National Centers for Environmental Prediction-Climate Forecast System Reanalysis, National Aeronautics and Space Administration-Modern-Era Retrospective analysis for Research and Applications Version 2, and Japan Meteorological Agency-Japanese 55-year reanalysis) in winter and summer for 1981-2010 period. In addition, we compare cyclone statistics between ERA-Interim and the Arctic System Reanalysis reanalyses for 2000-2010. Biases in cyclone frequency, intensity, and size over the Arctic are also quantified. Variations in cyclone frequency across the models are partly attributed to the differences in cyclone frequency over land. The variations across the models are largest for small and shallow cyclones for both seasons. A connection between biases in the zonal wind at 200 hPa and cyclone characteristics is found for both seasons. Most models underestimate zonal wind speed in both seasons, which likely leads to underestimation of cyclone mean depth and deep cyclone frequency in the Arctic. In general, the regional climate models are able to represent the spatial distribution of cyclone characteristics in the Arctic but models that employ large-scale spectral nudging show a better agreement with ERA-Interim reanalysis than the rest of the models. Trends also exhibit the benefits of nudging. Models with spectral nudging are able to reproduce the cyclone trends, whereas most of the nonnudged models fail to do so. However, the cyclone characteristics and trends are sensitive to the choice of nudged variables.

Population dynamical responses to climate change

DEFF Research Database (Denmark)

Forchhammer, Mads; Schmidt, Niels Martin; Høye, Toke Thomas

2008-01-01

approaches, we analyse concurrently the influence of climatic variability and trophic interactions on the temporal population dynamics of species in the terrestrial vertebrate community at Zackenberg. We describe and contrast the population dynamics of three predator species (arctic fox Alopex lagopus, stoat...... of arctic fox were not significantly related to changes in lemming abundance, both the stoat and the breeding of long-tailed skua were mainly related to lemming dynamics. The predator-prey system at Zackenberg differentiates from previously described systems in high-arctic Greenland, which, we suggest...

The Influence of Climate Change on Atmospheric Deposition of Mercury in the Arctic—A Model Sensitivity Study

Science.gov (United States)

Hansen, Kaj M.; Christensen, Jesper H.; Brandt, Jørgen

2015-01-01

Mercury (Hg) is a global pollutant with adverse health effects on humans and wildlife. It is of special concern in the Arctic due to accumulation in the food web and exposure of the Arctic population through a rich marine diet. Climate change may alter the exposure of the Arctic population to Hg. We have investigated the effect of climate change on the atmospheric Hg transport to and deposition within the Arctic by making a sensitivity study of how the atmospheric chemistry-transport model Danish Eulerian Hemispheric Model (DEHM) reacts to climate change forcing. The total deposition of Hg to the Arctic is 18% lower in the 2090s compared to the 1990s under the applied Special Report on Emissions Scenarios (SRES-A1B) climate scenario. Asia is the major anthropogenic source area (25% of the deposition to the Arctic) followed by Europe (6%) and North America (5%), with the rest arising from the background concentration, and this is independent of the climate. DEHM predicts between a 6% increase (Status Quo scenario) and a 37% decrease (zero anthropogenic emissions scenario) in Hg deposition to the Arctic depending on the applied emission scenario, while the combined effect of future climate and emission changes results in up to 47% lower Hg deposition. PMID:26378551

The Arctic-Subarctic Sea Ice System is Entering a Seasonal Regime: Implications for Future Arctic Amplication

Science.gov (United States)

Haine, T. W. N.; Martin, T.

2017-12-01

The loss of Arctic sea ice is a conspicuous example of climate change. Climate models project ice-free conditions during summer this century under realistic emission scenarios, reflecting the increase in seasonality in ice cover. To quantify the increased seasonality in the Arctic-Subarctic sea ice system, we define a non-dimensional seasonality number for sea ice extent, area, and volume from satellite data and realistic coupled climate models. We show that the Arctic-Subarctic, i.e. the northern hemisphere, sea ice now exhibits similar levels of seasonality to the Antarctic, which is in a seasonal regime without significant change since satellite observations began in 1979. Realistic climate models suggest that this transition to the seasonal regime is being accompanied by a maximum in Arctic amplification, which is the faster warming of Arctic latitudes compared to the global mean, in the 2010s. The strong link points to a peak in sea-ice-related feedbacks that occurs long before the Arctic becomes ice-free in summer.

An energy efficient building for the Arctic climate

DEFF Research Database (Denmark)

Vladyková, Petra

through the building envelope in the winter due to the pressure difference, strong winds and low water ratio in the outdoor air. The Arctic is also defined by different conditions such as building techniques and availability of the materials and energy supply. The passive house uses the basic idea......The Arctic is climatically very different from a temperate climate. In the Arctic regions, the ambient temperature reaches extreme values and it has a direct large impact on the heat loss through the building envelope and it creates problems with the foundation due to the permafrost. The solar...... influence the infiltration heat loss through the building envelope. The wind patterns have large influences on the local microclimate around the building and create the snowdrift and problems with thawing, icing and possible condensation in the building envelope. The humidity in the interior is driven out...

Population dynamics in the high Arctic: Climate variations in time and space

DEFF Research Database (Denmark)

Hendrichsen, Ditte Katrine

Climatic factors profoundly influence the population dynamics, species interactions and demography of Arctic species. Analyses of the spatio-temporal dynamics within and across species are therefore necessary to understand and predict the responses of Arctic ecosystems to climatic variability...

Development of wind power production in arctic climate

Energy Technology Data Exchange (ETDEWEB)

Peltola, E.; Kaas, J.; Aarnio, E. [Kemijoki Oy (Finland)

1998-10-01

The project Development of wind power production in arctic climate is a direct continuation of Arctic wind energy research project, which started in 1989. The main topics in 1996-97 have been production development and commercialising the blade heating systems, development of operation and maintenance practices of arctic wind power plants, preparations for new wind farms and various network connection and energy system studies. Practical operations have taken place in Pyhaetunturi test power plant and in Paljasselkae and Lammashovi power plants, which are in commercial operation

The 7 Aarhus Statements on Climate Change

DEFF Research Database (Denmark)

Basse, Ellen Margrethe; Svenning, J.-C.; Olesen, Jørgen E

2009-01-01

; Nanotechnology solutions for a sustainable future; Citizens and society, and The Arctic. The main responsible scientists for the seven conference themes and representatives from the think-tank CONCITO delivered 'The 7 Aarhus Statements on Climate Change' as part of the closing session of the conference...... interest for understanding the effects of the projected future climate change and how the foreseen negative impacts can be counteracted by mitigation and adaptation measures. The themes were: Climate policy: the role of law and economics; Biodiversity and ecosystems; Agriculture and climate change...

Amplified Arctic warming by phytoplankton under greenhouse warming.

Science.gov (United States)

Park, Jong-Yeon; Kug, Jong-Seong; Bader, Jürgen; Rolph, Rebecca; Kwon, Minho

2015-05-12

Phytoplankton have attracted increasing attention in climate science due to their impacts on climate systems. A new generation of climate models can now provide estimates of future climate change, considering the biological feedbacks through the development of the coupled physical-ecosystem model. Here we present the geophysical impact of phytoplankton, which is often overlooked in future climate projections. A suite of future warming experiments using a fully coupled ocean-atmosphere model that interacts with a marine ecosystem model reveals that the future phytoplankton change influenced by greenhouse warming can amplify Arctic surface warming considerably. The warming-induced sea ice melting and the corresponding increase in shortwave radiation penetrating into the ocean both result in a longer phytoplankton growing season in the Arctic. In turn, the increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating, triggering additional positive feedbacks in the Arctic, and consequently intensifying the Arctic warming further. Our results establish the presence of marine phytoplankton as an important potential driver of the future Arctic climate changes.

Effect of recent climate change on Arctic Pb pollution: a comparative study of historical records in lake and peat sediments.

Science.gov (United States)

Liu, Xiaodong; Jiang, Shan; Zhang, Pengfei; Xu, Liqiang

2012-01-01

Historical changes of anthropogenic Pb pollution were reconstructed based on Pb concentrations and isotope ratios in lake and peat sediment profiles from Ny-Ålesund of Arctic. The calculated excess Pb isotope ratios showed that Pb pollution largely came from west Europe and Russia. The peat profile clearly reflected the historical changes of atmospheric deposition of anthropogenic Pb into Ny-Ålesund, and the result showed that anthropogenic Pb peaked at 1960s-1970s, and thereafter a significant recovery was observed by a rapid increase of (206)Pb/(207)Pb ratios and a remarkable decrease in anthropogenic Pb contents. In contrast to the peat record, the longer lake record showed relatively high anthropogenic Pb contents and a persistent decrease of (206)Pb/(207)Pb ratios within the uppermost samples, suggesting that climate-sensitive processes such as catchment erosion and meltwater runoff might have influenced the recent change of Pb pollution record in the High Arctic lake sediments. Copyright © 2011 Elsevier Ltd. All rights reserved.

Historical and contemporary imagery to assess ecosystem change on the Arctic coastal plain of northern Alaska

Science.gov (United States)

Tape, Ken D.; Pearce, John M.; Walworth, Dennis; Meixell, Brandt W.; Fondell, Tom F.; Gustine, David D.; Flint, Paul L.; Hupp, Jerry W.; Schmutz, Joel A.; Ward, David H.

2014-01-01

The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low-relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades leading to thawing of on-shore permafrost and the disappearance of sea ice at unprecedented rates. The U.S. Geological Survey’s (USGS) Changing Arctic Ecosystems (CAE) research initiative was developed to investigate and forecast these rapid changes in the physical environment of the Arctic, and the associated changes to wildlife populations, in order to inform key management decisions by the U.S. Department of the Interior and other agencies. Forecasting future wildlife responses to changes in the Arctic can benefit greatly from historical records that inform what changes have already occurred. Several Arctic wildlife and plant species have already responded to climatic and physical changes to the Arctic Coastal Plain of northern Alaska. Thus, we located historical aerial imagery to improve our understanding of recent habitat changes and the associated response to such changes by wildlife populations.

Evaluating climate variables, indexes and thresholds governing Arctic urban sustainability: case study of Russian permafrost regions

Science.gov (United States)

Anisimov, O. A.; Kokorev, V.

2013-12-01

Addressing Arctic urban sustainability today forces planners to deal with the complex interplay of multiple factors, including governance and economic development, demography and migration, environmental changes and land use, changes in the ecosystems and their services, and climate change. While the latter can be seen as a factor that exacerbates the existing vulnerabilities to other stressors, changes in temperature, precipitation, snow, river and lake ice, and the hydrological regime also have direct implications for the cities in the North. Climate change leads to reduced demand for heating energy, on one hand, and heightened concerns about the fate of the infrastructure built upon thawing permafrost, on the other. Changes in snowfall are particularly important and have direct implications for the urban economy, as together with heating costs, expenses for snow removal from streets, airport runways, roofs and ventilation corridors underneath buildings erected on pile foundations on permafrost constitute the bulk of the city's maintenance budget. Many cities are located in river valleys and are prone to flooding that leads to enormous economic losses and casualties, including human deaths. The severity of the northern climate has direct implications for demographic changes governed by regional migration and labor flows. Climate could thus be viewed as an inexhaustible public resource that creates opportunities for sustainable urban development. Long-term trends show that climate as a resource is becoming more readily available in the Russian North, notwithstanding the general perception that globally climate change is one of the challenges facing humanity in the 21st century. In this study we explore the sustainability of the Arctic urban environment under changing climatic conditions. We identify key governing variables and indexes and study the thresholds beyond which changes in the governing climatic parameters have significant impact on the economy

Trends in historical mercury deposition inferred from lake sediment cores across a climate gradient in the Canadian High Arctic.

Science.gov (United States)

Korosi, Jennifer B; Griffiths, Katherine; Smol, John P; Blais, Jules M

2018-06-02

Recent climate change may be enhancing mercury fluxes to Arctic lake sediments, confounding the use of sediment cores to reconstruct histories of atmospheric deposition. Assessing the independent effects of climate warming on mercury sequestration is challenging due to temporal overlap between warming temperatures and increased long-range transport of atmospheric mercury following the Industrial Revolution. We address this challenge by examining mercury trends in short cores (the last several hundred years) from eight lakes centered on Cape Herschel (Canadian High Arctic) that span a gradient in microclimates, including two lakes that have not yet been significantly altered by climate warming due to continued ice cover. Previous research on subfossil diatoms and inferred primary production indicated the timing of limnological responses to climate warming, which, due to prevailing ice cover conditions, varied from ∼1850 to ∼1990 for lakes that have undergone changes. We show that climate warming may have enhanced mercury deposition to lake sediments in one lake (Moraine Pond), while another (West Lake) showed a strong signal of post-industrial mercury enrichment without any corresponding limnological changes associated with warming. Our results provide insights into the role of climate warming and organic carbon cycling as drivers of mercury deposition to Arctic lake sediments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changing seasonality of Arctic hydrology disrupts key biotic linkages in Arctic aquatic ecosystems.

Science.gov (United States)

Deegan, L.; MacKenzie, C.; Peterson, B. J.; Fishscape Project

2011-12-01

Arctic grayling (Thymallus arcticus) is an important circumpolar species that provide a model system for understanding the impacts of changing seasonality on arctic ecosystem function. Grayling serve as food for other biota, including lake trout, birds and humans, and act as top-down controls in stream ecosystems. In Arctic tundra streams, grayling spend their summers in streams but are obligated to move back into deep overwintering lakes in the fall. Climatic change that affects the seasonality of river hydrology could have a significant impact on grayling populations: grayling may leave overwintering lakes sooner in the spring and return later in the fall due to a longer open water season, but the migration could be disrupted by drought due to increased variability in discharge. In turn, a shorter overwintering season may impact lake trout dynamics in the lakes, which may rely on the seasonal inputs of stream nutrients in the form of migrating grayling into these oligotrophic lakes. To assess how shifting seasonality of Arctic river hydrology may disrupt key trophic linkages within and between lake and stream components of watersheds on the North Slope of the Brooks Mountain Range, Alaska, we have undertaken new work on grayling and lake trout population and food web dynamics. We use Passive Integrated Transponder (PIT) tags coupled with stream-width antenna units to monitor grayling movement across Arctic tundra watersheds during the summer, and into overwintering habitat in the fall. Results indicate that day length may prime grayling migration readiness, but that flooding events are likely the cue grayling use to initiate migration in to overwintering lakes. Many fish used high discharge events in the stream as an opportunity to move into lakes. Stream and lake derived stable isotopes also indicate that lake trout rely on these seasonally transported inputs of stream nutrients for growth. Thus, changes in the seasonality of river hydrology may have broader

Understanding how lake populations of arctic char are structured and function with special consideration of the potential effects of climate change: a multi-faceted approach.

Science.gov (United States)

Budy, Phaedra; Luecke, Chris

2014-09-01

Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40-96%; SGR range 0.03-1.5%) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28-34%) under climate change scenarios led to much greater growth rates (23-34%). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a "resource pulse," allowing a sub-set of small char to "break through," thus setting the cycle in population structure.

The role of climate change in regulating Arctic permafrost peatland hydrological and vegetation change over the last millennium

Science.gov (United States)

Zhang, Hui; Piilo, Sanna R.; Amesbury, Matthew J.; Charman, Dan J.; Gallego-Sala, Angela V.; Väliranta, Minna M.

2018-02-01

Climate warming has inevitable impacts on the vegetation and hydrological dynamics of high-latitude permafrost peatlands. These impacts in turn determine the role of these peatlands in the global biogeochemical cycle. Here, we used six active layer peat cores from four permafrost peatlands in Northeast European Russia and Finnish Lapland to investigate permafrost peatland dynamics over the last millennium. Testate amoeba and plant macrofossils were used as proxies for hydrological and vegetation changes. Our results show that during the Medieval Climate Anomaly (MCA), Russian sites experienced short-term permafrost thawing and this induced alternating dry-wet habitat changes eventually followed by desiccation. During the Little Ice Age (LIA) both sites generally supported dry-hummock habitats, at least partly driven by permafrost aggradation. However, proxy data suggest that occasionally, MCA habitat conditions were drier than during the LIA, implying that evapotranspiration may create important additional eco-hydrological feedback mechanisms under warm conditions. All sites showed a tendency towards dry conditions as inferred from both proxies starting either from ca. 100 years ago or in the past few decades after slight permafrost thawing, suggesting that recent warming has stimulated surface desiccation rather than deeper permafrost thawing. This study shows links between two important controls over hydrology and vegetation changes in high-latitude peatlands: direct temperature-induced surface layer response and deeper permafrost layer-related dynamics. These data provide important backgrounds for predictions of Arctic permafrost peatlands and related feedback mechanisms. Our results highlight the importance of increased evapotranspiration and thus provide an additional perspective to understanding of peatland-climate feedback mechanisms.

Projected changes in atmospheric heating due to changes in fire disturbance and the snow season in the western Arctic, 2003-2100

Science.gov (United States)

E.S. Euskirchen; A.D. McGuire; T.S. Rupp; F.S. Chapin; J.E. Walsh

2009-01-01

In high latitudes, changes in climate impact fire regimes and snow cover duration, altering the surface albedo and the heating of the regional atmosphere. In the western Arctic, under four scenarios of future climate change and future fire regimes (2003-2100), we examined changes in surface albedo and the related changes in regional atmospheric heating due to: (1)...

Collaborative Research: Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic

Energy Technology Data Exchange (ETDEWEB)

Melillo, Jerry [Marine Biological Lab., Woods Hole, MA (United States)

2017-12-12

Our overall goal in this research was to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically-forced climate warming, and the conditions under which these emissions provide a strong feedback mechanism to global climate warming. This goal was motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes to the landscape of wetlands and lakes, especially thermokarst (thaw) lakes, across the Arctic. Through a suite of numerical experiments that encapsulate the fundamental processes governing methane emissions and carbon exchanges – as well as their coupling to the global climate system - we tested the following hypothesis in the proposed research: There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases in methane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in a strong, positive feedback to global climate warming. In collaboration with our Purdue and MIT colleagues, we have attempted to quantify global climate warming effects on land-atmosphere interactions, land-river network interactions, permafrost degradation, vegetation shifts, and land use influence water, carbon, and nitrogen fluxes to and from terrestrial ecosystems in the pan-arctic along with their

The Siberian High and Arctic Sea Ice: Long-term Climate Change and Impacts on Air Pollution during Wintertime in China

Science.gov (United States)

Long, X.; Zhao, S.; Feng, T.; Tie, X.; Li, G.

2017-12-01

China has undergone severe air pollution during wintertime as national industrialization and urbanization have been increasingly developed in the past three decades. It has been suggested that high emission and adverse weather patterns contribute to wintertime air pollution. Recent studies propose that climate change and Arctic sea ice loss likely lead to extreme haze events in winter. Here we use two reanalysis and observational datasets to present the trends of Siberian High (SH) intensity over Eurasia, and Arctic temperature and sea ice. The results show the Arctic region of Asia is becoming warming accompanied by a rapid decline of sea ice while Eurasia is cooling and SH intensity is gradually enhancing. Wind patterns induced by these changes cause straight westerly prevailing over Eurasia at the year of weak SH while strengthened northerly winds at the year of strong SH. Therefore, we utilize regional dynamical and chemical WRF-Chem model to determine the impact of SH intensity difference on wintertime air pollution in China. As a result, enhancing northerly winds at the year of strong SH rapidly dilute and transport air pollution, causing a decline of 50 - 400 µg m-3 PM2.5 concentrations relative to that at the year of weak SH. We also assess the impact of emission reduction to half the current level on air pollution. The results show that emission reduction by 50% has an equivalent impact as the variability of SH intensity. This suggests that climate change over Eurasia has largely offset the negative impact of emission on air pollution and it is urgently needed to take measures to mitigate air pollution. In view of current high emission scenario in China, it will be a long way to effectively mitigate, or ultimately prevent wintertime air pollution.

Indicators of Arctic Sea Ice Bistability in Climate Model Simulations and Observations

Science.gov (United States)

2014-09-30

associated with the ice - albedo feedback and the seasonal melt and growth of sea ice , as well as horizontal climate variations on a global domain. (2...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Indicators of Arctic Sea Ice Bistability in Climate...possibility that the climate system supports multiple Arctic sea ice states that are relevant for the evolution of sea ice during the next several

McCall Glacier record of Arctic climate change: Interpreting a northern Alaska ice core with regional water isotopes

Science.gov (United States)

Klein, E. S.; Nolan, M.; McConnell, J.; Sigl, M.; Cherry, J.; Young, J.; Welker, J. M.

2016-01-01

We explored modern precipitation and ice core isotope ratios to better understand both modern and paleo climate in the Arctic. Paleoclimate reconstructions require an understanding of how modern synoptic climate influences proxies used in those reconstructions, such as water isotopes. Therefore we measured periodic precipitation samples at Toolik Lake Field Station (Toolik) in the northern foothills of the Brooks Range in the Alaskan Arctic to determine δ18O and δ2H. We applied this multi-decadal local precipitation δ18O/temperature regression to ∼65 years of McCall Glacier (also in the Brooks Range) ice core isotope measurements and found an increase in reconstructed temperatures over the late-20th and early-21st centuries. We also show that the McCall Glacier δ18O isotope record is negatively correlated with the winter bidecadal North Pacific Index (NPI) climate oscillation. McCall Glacier deuterium excess (d-excess, δ2H - 8*δ18O) values display a bidecadal periodicity coherent with the NPI and suggest shifts from more southwestern Bering Sea moisture sources with less sea ice (lower d-excess values) to more northern Arctic Ocean moisture sources with more sea ice (higher d-excess values). Northern ice covered Arctic Ocean McCall Glacier moisture sources are associated with weak Aleutian Low (AL) circulation patterns and the southern moisture sources with strong AL patterns. Ice core d-excess values significantly decrease over the record, coincident with warmer temperatures and a significant reduction in Alaska sea ice concentration, which suggests that ice free northern ocean waters are increasingly serving as terrestrial precipitation moisture sources; a concept recently proposed by modeling studies and also present in Greenland ice core d-excess values during previous transitions to warm periods. This study also shows the efficacy and importance of using ice cores from Arctic valley glaciers in paleoclimate reconstructions.

Geopolitics of climate change: A review

Directory of Open Access Journals (Sweden)

Bošnjaković Branko

2012-01-01

Full Text Available The paper reviews the geopolitical elements of the emerging discourse on how to control, and cope with climate change. Two complementary approaches may be distinguished: the actor-related approach analyses the positioning of states and interest groups, which develop strategies on coping with climate change; the other approach addresses processes and problem areas (physical, economic, demographic… emerging in the geographic space as a consequence of, or linked to climate change. With failing mitigation policies and instruments, the urgency of adaptation to climate change is increasing. Assessment of regional consequences of climate change includes the perceptions and motivations of presumed losers or winners. New security implications related to climate change are emerging in the Arctic, South-East Asia, Africa and the Pacific. Energy supply security is a dominant factor in geopolitical considerations. The geopolitics of climate change is inextricably linked to many other issues of globalization. Significant shift of global power raises the discussion of ethical responsibility. Climate change is evolving as a testing ground for competitiveness and innovation potential of political and economic models in achieving sustainability.

Simulation of the modern arctic climate by the NCAR CCM1

Science.gov (United States)

Bromwich, David H.; Tzeng, Ren-Yow; Parish, Thomas, R.

1994-01-01

result from the advection term. The contribution by the moisture fixer is as large as from advection. By contrast, the semi-Lagrangian transport scheme used in the CCM2 significantly improves the moisture simulation for this region; however, globally the error is as serious as for the positive moisture fixer scheme. Finally, because the model has such serious problems in simulating the present arctic climate, its simulations of past and future climate change for this region are questionable.

Understanding how lake populations of arctic char are structured and function with special consideration of the potential effects of climate change: A multi-faceted approach.

Science.gov (United States)

Budy, Phaedra; Luecke, Chris

2014-01-01

Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40–96 %; SGR range 0.03–1.5 %) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28–34 %) under climate change scenarios led to much greater growth rates (23–34 %). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a “resource pulse,” allowing a sub-set of small char to “break through,” thus setting the cycle in population structure.

Association of climatic factors with infectious diseases in the Arctic and subarctic region--a systematic review.

Science.gov (United States)

Hedlund, Christina; Blomstedt, Yulia; Schumann, Barbara

2014-01-01

The Arctic and subarctic area are likely to be highly affected by climate change, with possible impacts on human health due to effects on food security and infectious diseases. To investigate the evidence for an association between climatic factors and infectious diseases, and to identify the most climate-sensitive diseases and vulnerable populations in the Arctic and subarctic region. A systematic review was conducted. A search was made in PubMed, with the last update in May 2013. Inclusion criteria included human cases of infectious disease as outcome, climate or weather factor as exposure, and Arctic or subarctic areas as study origin. Narrative reviews, case reports, and projection studies were excluded. Abstracts and selected full texts were read and evaluated by two independent readers. A data collection sheet and an adjusted version of the SIGN methodology checklist were used to assess the quality grade of each article. In total, 1953 abstracts were initially found, of which finally 29 articles were included. Almost half of the studies were carried out in Canada (n=14), the rest from Sweden (n=6), Finland (n=4), Norway (n=2), Russia (n=2), and Alaska, US (n=1). Articles were analyzed by disease group: food- and waterborne diseases, vector-borne diseases, airborne viral- and airborne bacterial diseases. Strong evidence was found in our review for an association between climatic factors and food- and waterborne diseases. The scientific evidence for a link between climate and specific vector- and rodent-borne diseases was weak due to that only a few diseases being addressed in more than one publication, although several articles were of very high quality. Air temperature and humidity seem to be important climatic factors to investigate further for viral- and bacterial airborne diseases, but from our results no conclusion about a causal relationship could be drawn. More studies of high quality are needed to investigate the adverse health impacts of weather and

Climate change freezing caused by overheating

International Nuclear Information System (INIS)

Ferrara, Vincenzo

2006-01-01

Based on the principal findings from an extensive study of the Arctic, the subject of an international symposium held in Reykjavik, Iceland, in November of 2004, the Arctic Region is heating up twice as fast as the average for the rest of the world. If warming continues at this pace, or even faster, the most significant effects of future climate changes will occur in the polar regions, and the greatest threat seems to be the collapse of the Gulf Stream [it

Evaluation of CORDEX-Arctic daily precipitation and temperature-based climate indices over Canadian Arctic land areas

Science.gov (United States)

Diaconescu, Emilia Paula; Mailhot, Alain; Brown, Ross; Chaumont, Diane

2018-03-01

This study focuses on the evaluation of daily precipitation and temperature climate indices and extremes simulated by an ensemble of 12 Regional Climate Model (RCM) simulations from the ARCTIC-CORDEX experiment with surface observations in the Canadian Arctic from the Adjusted Historical Canadian Climate Dataset. Five global reanalyses products (ERA-Interim, JRA55, MERRA, CFSR and GMFD) are also included in the evaluation to assess their potential for RCM evaluation in data sparse regions. The study evaluated the means and annual anomaly distributions of indices over the 1980-2004 dataset overlap period. The results showed that RCM and reanalysis performance varied with the climate variables being evaluated. Most RCMs and reanalyses were able to simulate well climate indices related to mean air temperature and hot extremes over most of the Canadian Arctic, with the exception of the Yukon region where models displayed the largest biases related to topographic effects. Overall performance was generally poor for indices related to cold extremes. Likewise, only a few RCM simulations and reanalyses were able to provide realistic simulations of precipitation extreme indicators. The multi-reanalysis ensemble provided superior results to individual datasets for climate indicators related to mean air temperature and hot extremes, but not for other indicators. These results support the use of reanalyses as reference datasets for the evaluation of RCM mean air temperature and hot extremes over northern Canada, but not for cold extremes and precipitation indices.

Arctic melt ponds and energy balance in the climate system

Science.gov (United States)

Sudakov, Ivan

2017-02-01

Elements of Earth's cryosphere, such as the summer Arctic sea ice pack, are melting at precipitous rates that have far outpaced the projections of large scale climate models. Understanding key processes, such as the evolution of melt ponds that form atop Arctic sea ice and control its optical properties, is crucial to improving climate projections. These types of critical phenomena in the cryosphere are of increasing interest as the climate system warms, and are crucial for predicting its stability. In this paper, we consider how geometrical properties of melt ponds can influence ice-albedo feedback and how it can influence the equilibria in the energy balance of the planet.

A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska experiencing climate and land-use changes

Science.gov (United States)

Jones, Benjamin M.; Arp, Christopher D.; Whitman, Matthew S.; Nigro, Debora A.; Nitze, Ingmar; Beaver, John; Gadeke, Anne; Zuck, Callie; Liljedahl, Anna K.; Daanen, Ronald; Torvinen, Eric; Fritz, Stacey; Grosse, Guido

2017-01-01

Lakes are dominant and diverse landscape features in the Arctic, but conventional land cover classification schemes typically map them as a single uniform class. Here, we present a detailed lake-centric geospatial database for an Arctic watershed in northern Alaska. We developed a GIS dataset consisting of 4362 lakes that provides information on lake morphometry, hydrologic connectivity, surface area dynamics, surrounding terrestrial ecotypes, and other important conditions describing Arctic lakes. Analyzing the geospatial database relative to fish and bird survey data shows relations to lake depth and hydrologic connectivity, which are being used to guide research and aid in the management of aquatic resources in the National Petroleum Reserve in Alaska. Further development of similar geospatial databases is needed to better understand and plan for the impacts of ongoing climate and land-use changes occurring across lake-rich landscapes in the Arctic.

Geospatial Analysis of Climate-Related Changes in North American Arctic Ecosystems and Implications for Terrestrial Flora and Fauna

Science.gov (United States)

Amirazodi, S.; Griffin, R.

2016-12-01

Climate change induces range shifts among many terrestrial species in Arctic regions. At best, warming often forces poleward migration if a stable environment is to be maintained. At worst, marginal ecosystems may disappear entirely without a contiguous shift allowing migratory escape to similar environs. These changing migration patterns and poleward range expansion push species into higher latitudes where ecosystems are less stable and more sensitive to change. This project focuses on ecosystem geography and interspecies relationships and interactions by analyzing seasonality and changes over time in variables including the following: temperature, precipitation, vegetation, physical boundaries, population demographics, permafrost, sea ice, and food and water availability. Publicly available data from remote sensing platforms are used throughout, and processed with both commercially available and open sourced GIS tools. This analysis describes observed range changes for selected North American species, and attempts to provide insight into the causes and effects of these phenomena. As the responses to climate change are complex and varied, the goal is to produce the aforementioned results in an easily understood set of geospatial representations to better support decision making regarding conservation prioritization and enable adaptive responses and mitigation strategies.

What we know, do not know, and need to know about climate change vulnerability in the western Canadian Arctic: a systematic literature review

International Nuclear Information System (INIS)

Ford, James D; Pearce, Tristan

2010-01-01

This letter systematically reviews and synthesizes scientific and gray literature publications (n = 420) to identify and characterize the nature of climate change vulnerability in the Inuvialuit Settlement Region of the western Canadian Arctic and identify gaps in understanding. The literature documents widespread evidence of climate change, with implications for human and biophysical systems. Adaptations are being employed to manage changing conditions and are indicative of a high adaptive capacity. However, barriers to adaptation are evident and are expected to constrain adaptive capacity to future climate change. Continued climate change is predicted for the region, with differential exposure sensitivity for communities, groups and sectors: a function of social-economic-biophysical characteristics and projected future climatic conditions. Existing climate risks are expected to increase in magnitude and frequency, although the interaction between projected changes and socio-economic-demographic trends has not been assessed. The capacity for adapting to future climate change has also not been studied. The review identifies the importance of targeted vulnerability research that works closely with community members and other stakeholders to address research needs. Importantly, the fully categorized list of reviewed references accompanying this letter will be a valuable resource for those working or planning to work in the region, capturing climate change research published since 1990. At a broader level, the systematic review methodology offers a promising tool for climate/environmental change studies in general where there is a large and emerging body of research but limited understanding of research gaps and needs.

Understanding Pan-Arctic Tundra Vegetation Change Through Long-term Remotely Sensed Data

Science.gov (United States)

Bhatt, U.; Walker, D. A.; Bieniek, P.; Raynolds, M. K.; Epstein, H. E.; Comiso, J. C.; Pinzon, J. E.; Tucker, C. J.

2012-12-01

The goal of this paper is to present an analysis of the seasonality of tundra vegetation variability and change using long-term remotely sensed data as well as ground based measurements and reanalyses. An increase of Pan-Arctic tundra vegetation greenness has been documented using the remotely sensed Normalized Difference Vegetation Index (NDVI). Coherent variability between NDVI, springtime coastal sea ice (passive microwave) and land surface temperatures (AVHRR) has also been established. Satellite based snow and cloud cover data sets are being incorporated into this analysis. The Arctic tundra is divided into domains based on Treshnikov divisions that are modified based on floristic provinces. There is notable heterogeneity in Pan-Arctic vegetation and climate trends, which necessitates a regional analysis. This study uses remotely sensed weekly 25-km sea ice concentration, weekly surface temperature, and bi-weekly NDVI from 1982 to 2010. The GIMMS NDVI3g data has been corrected for biases during the spring and fall, with special focus on the Arctic. Trends of Maximum NDVI (MaxNDVI), Time Integrated NDVI (TI-NDVI), Summer Warmth Index (SWI, sum of degree months above freezing during May-August), and open water area are calculated for the Pan Arctic. Remotely sensed snow data trends suggest varying patterns throughout the Arctic and may in part explain the heterogeneous MaxNDVI trends. Standard climate data (station, reanalysis, and model data) and ground observations are used in the analysis to provide additional support for hypothesized mechanisms. Overall, we find that trends over the 30-year record are changing as evidenced by the following examples from recent years. The sea ice decline has increased in Eurasia and slowed in North America. The weekly AVHRR landsurface temperatures reveal that there has been summer cooling over Eurasia and that the warming over North America has slowed. The MaxNDVI rates of change have diverged between N. America and Eurasia

Climate variability and temporal trends of persistent organic pollutants in the arctic: a study of glaucous gulls.

Science.gov (United States)

Bustnes, Jan O; Gabrielsen, Geir W; Verreault, Jonathan

2010-04-15

The impact of climate variability on temporal trends (1997-2006) of persistent organic pollutants (POPs; polychlorinated biphenyls [PCB], hexachlorobenzene [HCB], and oxychlordane) was assessed in glaucous gulls (Larus hyperboreus) breeding in the Norwegian Arctic (n = 240). The Arctic Oscillation (AO: an index of sea-level pressure variability in the Northern Hemisphere above 20 degrees N) with different time lags was used as a climate proxy. The estimated concentrations of POPs in glaucous gull blood/plasma declined substantially (16-60%) over the time period. Multiple regression analyses showed that the rates of decline for POPs were correlated to climate variation when controlling for potential confounding variables (sex and body condition). More specifically AO in the current winter showed negative associations with POP concentrations, whereas the relationships with AO measurements from the year preceding POP measurements (AO preceding summer and AO preceding winter) were positive. Hence, gulls had relatively higher POP concentrations in breeding seasons following years with high air transport toward the Arctic. Furthermore, the impact of AO appeared to be stronger for HCB, a relatively volatile compound with high transport potential, compared to heavy chlorinated PCB congeners. This study thus suggests that predicted climate change should be considered in assessments of future temporal trends of POPs in Arctic wildlife.

Integrating Access to Arctic Environmental Change and Human Health Research for the International Polar Year and Beyond

Science.gov (United States)

Garrett, C. L.

2006-12-01

Each day, people in the communities of the Arctic face challenges to their health and well-being from changing climatic and environmental conditions and increasing levels of pollution to emerging infectious diseases. For this reason, it is critical that Arctic researchers and residents have access to timely, accurate, and relevant information addressing their unique concerns. To meet this need, the National Library of Medicine (NLM) and the University of Alaska Anchorage (UAA) have developed the Arctic Health website, www.arctichealth.org. The website provides an easy-to-use one-stop shop for information on the diverse health-related aspects of the Arctic region. It is organized around relevant topics, including climate change and environmental health, traditional healing and telehealth/telemedicine. The Arctic Health website provides links to the most reliable resources available from local, state, and international agencies, universities, and professional organizations. Two major goals of the site are to create a comprehensive, accessible repository for various media and a listing of research projects, past and present that relate to climate change and human health in the Arctic. To increase the site's relevance, the project has established and continues to create collaborations with researchers, communities, and other organizations to supply publications not available elsewhere, including gray literature, streaming video of traditional healers, and oral histories. These collaborations will also help ensure a database with a comprehensive list of research projects being done in the Arctic, from the international to the local level. Finding ways to negotiate the legal, cultural and national concerns of data sharing are a continuing job for the management team. All of this helps to create a system that will eventually track and ensure that data and reports from the research database translate to the publications database. As part of these efforts, the site is

Seasonal changes in the optical properties of dissolved organic matter (DOM) in large Arctic rivers

DEFF Research Database (Denmark)

Walker, S.A.; Amon, R.M.; Stedmon, Colin

Arctic rivers deliver over 10% of the annual global river discharge yet little is known about the seasonal fluctuations in the quantity and quality of terrigenous dissolved organic matter (tDOM). A good constraint on such fluctuations is paramount to understand the role that climate change may have...... on tDOM input to the Arctic Ocean. To understand such changes the optical properties of colored tDOM (tCDOM) were studied. Samples were collected over several seasonal cycles from the six largest Arctic Rivers as part of the PARTNERS project. This unique dataset is the first of its kind capturing...

Additive impacts of experimental climate change increase risk to an ectotherm at the Arctic's edge

Science.gov (United States)

Davenport, Jon M.; Hossack, Blake R.; Fishback, LeeAnn

2017-01-01

Globally, Arctic and Subarctic regions have experienced the greatest temperature increases during the last 30 years. These extreme changes have amplified threats to the freshwater ecosystems that dominate the landscape in many areas by altering water budgets. Several studies in temperate environments have examined the adaptive capacity of organisms to enhance our understanding of the potential repercussions of warming and associated accelerated drying for freshwater ecosystems. However, few experiments have examined these impacts in Arctic or Subarctic freshwater ecosystems, where the climate is changing most rapidly. To evaluate the capacity of a widespread ectotherm to anticipated environmental changes, we conducted a mesocosm experiment with wood frogs (Rana sylvatica) in the Canadian Subarctic. Three warming treatments were fully crossed with three drying treatments to simulate a range of predicted changes in wetland environments. We predicted wetland warming and drying would act synergistically, with water temperature partially compensating for some of the negative effects of accelerated drying. Across all drying regimes, a 1 °C increase in water temperature increased the odds of survival by 1.79, and tadpoles in 52-day and 64-day hydroperiod mesocosms were 4.1–4.3 times more likely to survive to metamorphosis than tadpoles in 45-day mesocosms. For individuals who survived to metamorphosis, there was only a weak negative effect of temperature on size. As expected, increased temperatures accelerated tadpole growth through day 30 of the experiment. Our results reveal that one of the dominant herbivores in Subarctic wetlands, wood frog tadpoles, are capable of increasing their developmental rates in response to increased temperature and accelerated drying, but only in an additive manner. The strong negative effects of drying on survival, combined with lack of compensation between these two environmental drivers, suggest changes in the aquatic environment

The Opening of the Arctic-Atlantic Gateway: Tectonic, Oceanographic and Climatic Dynamics - an IODP Initiative

Science.gov (United States)

Geissler, Wolfram; Knies, Jochen

2016-04-01

The modern polar cryosphere reflects an extreme climate state with profound temperature gradients towards high-latitudes. It developed in association with stepwise Cenozoic cooling, beginning with ephemeral glaciations and the appearance of sea ice in the late middle Eocene. The polar ocean gateways played a pivotal role in changing the polar and global climate, along with declining greenhouse gas levels. The opening of the Drake Passage finalized the oceanographic isolation of Antarctica, some 40 Ma ago. The Arctic Ocean was an isolated basin until the early Miocene when rifting and subsequent sea-floor spreading started between Greenland and Svalbard, initiating the opening of the Fram Strait / Arctic-Atlantic Gateway (AAG). Although this gateway is known to be important in Earth's past and modern climate, little is known about its Cenozoic development. However, the opening history and AAG's consecutive widening and deepening must have had a strong impact on circulation and water mass exchange between the Arctic Ocean and the North Atlantic. To study the AAG's complete history, ocean drilling at two primary sites and one alternate site located between 73°N and 78°N in the Boreas Basin and along the East Greenland continental margin are proposed. These sites will provide unprecedented sedimentary records that will unveil (1) the history of shallow-water exchange between the Arctic Ocean and the North Atlantic, and (2) the development of the AAG to a deep-water connection and its influence on the global climate system. The specific overarching goals of our proposal are to study: (1) the influence of distinct tectonic events in the development of the AAG and the formation of deep water passage on the North Atlantic and Arctic paleoceanography, and (2) the role of the AAG in the climate transition from the Paleogene greenhouse to the Neogene icehouse for the long-term (~50 Ma) climate history of the northern North Atlantic. Getting a continuous record of the

The 7 Aarhus Statements on Climate Change

DEFF Research Database (Denmark)

Basse, Ellen Margrethe; Svenning, Jens-Christian; Olesen, Jørgen E

2009-01-01

; Nanotechnology solutions for a sustainable future; Citizens and society, and The Arctic. The main responsible scientists for the seven conference themes and representatives from the think-tank CONCITO delivered 'The 7 Aarhus Statements on Climate Change' as part of the closing session of the conference......More than 1000 prominent representatives from science, industry, politics and NGOs were gathered in Aarhus on 5–7 March 2009 for the international climate conference 'Beyond Kyoto: Addressing the Challenges of Climate Change'. Thematically, Beyond Kyoto was divided into seven areas of particular...

Arctic Climate Change: A Tale of Two Cod Species

Science.gov (United States)

Arctic cod play an important role in the Arctic trophic hierarchy as the consumer of primary productivity and a food source for many marine fish and mammals. Shifts in their distribution and abundance could have cascading affects in the marine environment. This paper investigates...

A history of climate change

DEFF Research Database (Denmark)

Hastrup, Kirsten Blinkenberg

2016-01-01

This article presents a small community of High Arctic hunters (the Inughuit in North West Greenland) who have always had to negotiate climatic changes with great impact on their living conditions. This points us toward the natural-social entanglements implied in the notion of the Anthropocene......, and to the new intellectual challenges that both natural and social scientists are facing in relation to the current climatic changes. These challenges are discussed through the case of the Inughuit with whom the author has worked over many years. Departing from their dire situation in the 19th century, when...

Arctic air pollution: New insights from POLARCAT-IPY

International Nuclear Information System (INIS)

Law, Katharine S.; Ancellet, Gerard; Pelon, Jacques; Thomas, Jennie L.; Stohl, Andreas; Quinn, Patricia K.; Brock, Charles A.; Burkhart, John F.

2014-01-01

Given the rapid nature of climate change occurring in the Arctic and the difficulty climate models have in quantitatively reproducing observed changes such as sea ice loss, it is important to improve understanding of the processes leading to climate change in this region, including the role of short-lived climate pollutants such as aerosols and ozone. It has long been known that pollution produced from emissions at mid latitudes can be transported to the Arctic, resulting in a winter/spring aerosol maximum known as Arctic haze. However, many uncertainties remain about the composition and origin of Arctic pollution throughout the troposphere; for example, many climate-chemistry models fail to reproduce the strong seasonality of aerosol abundance observed at Arctic surface sites, the origin and deposition mechanisms of black carbon (soot) particles that darken the snow and ice surface in the Arctic is poorly understood, and chemical processes controlling the abundance of tropospheric ozone are not well quantified. The International Polar Year (IPY) Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, Climate, Chemistry, Aerosols and Transport (POLARCAT) core project had the goal to improve understanding about the origins of pollutants transported to the Arctic; to detail the chemical composition, optical properties, and climate forcing potential of Arctic aerosols; to evaluate the processes governing tropospheric ozone; and to quantify the role of boreal forest fires. This article provides a review of the many results now available based on analysis of data collected during the POLARCAT aircraft-, ship-, and ground-based field campaigns in spring and summer 2008. Major findings are highlighted and areas requiring further investigation are discussed. (authors)

An atmosphere-ocean GCM modelling study of the climate response to changing Arctic seaways in the early Cenozoic.

Science.gov (United States)

Roberts, C. D.; Legrande, A. N.; Tripati, A. K.

2008-12-01

previous findings on the potential influence of Arctic gateways on ocean overturning and also suggests that Northern Hemisphere climate, particularly in the North Atlantic, was very sensitive to changes in Arctic seaways. This result is of particular significance when considered in the context of the Paleocene Eocene Thermal Maximum (PETM). Volcanic activity prior to the PETM may have been responsible for the formation of a sub-aerial barrier in the North Atlantic, and consequently may have driven warming of intermediate waters sufficient to destabilize methane clathrates. Evidence for freshening of Arctic ocean waters prior to the PETM would support this hypothesis.

Energy Design Guidelines for High Performance Schools: Arctic and Subarctic Climates

Energy Technology Data Exchange (ETDEWEB)

2004-11-01

The Energy Design Guidelines for High Performance Schools--Arctic and Subarctic Climates provides school boards, administrators, and design staff with guidance to help them make informed decisions about energy and environmental issues important to school systems and communities. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school in arctic and subarctic climates. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs.

Factors affecting projected Arctic surface shortwave heating and albedo change in coupled climate models.

Science.gov (United States)

Holland, Marika M; Landrum, Laura

2015-07-13

We use a large ensemble of simulations from the Community Earth System Model to quantify simulated changes in the twentieth and twenty-first century Arctic surface shortwave heating associated with changing incoming solar radiation and changing ice conditions. For increases in shortwave absorption associated with albedo reductions, the relative influence of changing sea ice surface properties and changing sea ice areal coverage is assessed. Changes in the surface sea ice properties are associated with an earlier melt season onset, a longer snow-free season and enhanced surface ponding. Because many of these changes occur during peak solar insolation, they have a considerable influence on Arctic surface shortwave heating that is comparable to the influence of ice area loss in the early twenty-first century. As ice area loss continues through the twenty-first century, it overwhelms the influence of changes in the sea ice surface state, and is responsible for a majority of the net shortwave increases by the mid-twenty-first century. A comparison with the Arctic surface albedo and shortwave heating in CMIP5 models indicates a large spread in projected twenty-first century change. This is in part related to different ice loss rates among the models and different representations of the late twentieth century ice albedo and associated sea ice surface state. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Arctic Research Plan: FY2017-2021

Science.gov (United States)

Starkweather, Sandy; Jeffries, Martin O; Stephenson, Simon; Anderson, Rebecca D.; Jones, Benjamin M.; Loehman, Rachel A.; von Biela, Vanessa R.

2016-01-01

The United States is an Arctic nation—Americans depend on the Arctic for biodiversity and climate regulation and for natural resources. America’s Arctic—Alaska—is at the forefront of rapid climate, environmental, and socio-economic changes that are testing the resilience and sustainability of communities and ecosystems. Research to increase fundamental understanding of these changes is needed to inform sound, science-based decision- and policy-making and to develop appropriate solutions for Alaska and the Arctic region as a whole. Created by an Act of Congress in 1984, and since 2010 a subcommittee of the National Science and Technology Council (NSTC) in the Executive Office of the President, the Interagency Arctic Research Policy Committee (IARPC) plays a critical role in advancing scientific knowledge and understanding of the changing Arctic and its impacts far beyond the boundaries of the Arctic. Comprising 14 Federal agencies, offices, and departments, IARPC is responsible for the implementation of a 5-year Arctic Research Plan in consultation with the U.S. Arctic Research Commission, the Governor of the State of Alaska, residents of the Arctic, the private sector, and public interest groups.

Climate change influence on the internal structure of talus slopes in the Arctic - A case study from the southern Spitsbergen, Norway

Science.gov (United States)

Senderak, K.; Kondracka, M.; Gądek, B.

2017-12-01

Talus slopes are present in all geographical altitudes, but the most active and dynamic slopes occur in high-mountain and polar areas. Spitsbergen, Norwegian archipelago in the Arctic, combines these two environments, therefore, the talus slopes develop in specific environmental conditions that have changed since the beginning of deglaciation. On Spitsbergen, which is 60% glaciated, talus slope evolution depends frequently on the interaction with glaciers, as well as the size of sediment supply area, the lithology, and the intensive of rock weathering. The warming of climate in the Arctic cause the identifiable changes in the internal structures of talus slopes associated with i.e. the melting of glaciers and the high activity of many morphogenetic processes on slope surface. The identification of these changes is a key to understanding of climate change influence (direct and indirect influence) on talus slope evolution. Our work presents the results of research, mainly based on the measurements using electrical resistivity tomography method (ERT) and ground-penetrating radar method (GPR), which were made on the talus slopes of southern Spitsbergen in the vicinity of Polish Polar Station in Hornsund. The geophysical surveys and geomorphological observations show that the climatic factor plays the significant role in the development of slopes, what is clearly visible when analyzing the whole slope systems in the selected glacial valleys (partly glaciated). The differences in the internal structure can depend on distance from the glacier and age of form. This mainly concerns the volume of buried glacial ice in slope material, the thickness of talus slopes, the depth of permafrost and active layer, the stored sedimentological structures including e.g. the traces of fresh material supply. New data on the internal structure of talus slopes developing in the present glaciated area allow for discussions on the talus slope evolution, which, according to the authors, needs

Collaborative Research. Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Qianlai [Purdue Univ., West Lafayette, IN (United States); Schlosser, Courtney [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Melillo, Jerry [Marine Biological Lab. (MBL), Woods Hole, MA (United States); Walter, Katey [Univ. of Alaska, Fairbanks, AK (United States)

2015-09-15

Our overall goal is to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically-forced climate warming, and the conditions under which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes to the landscape of wetlands and lakes, especially thermokarst (thaw) lakes, across the Arctic. Through a suite of numerical experiments that encapsulate the fundamental processes governing methane emissions and carbon exchanges – as well as their coupling to the global climate system - we intend to test the following hypothesis in the proposed research: There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases in methane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in a strong, positive feedback to global climate warming.

ARCTOX: a pan-Arctic sampling network to track mercury contamination across Arctic marine food webs

DEFF Research Database (Denmark)

Fort, Jerome; Helgason, Halfdan; Amelineau, Francoise

and is still a source of major environmental concerns. In that context, providing a large-scale and comprehensive understanding of the Arctic marine food-web contamination is essential to better apprehend impacts of anthropogenic activities and climate change on the exposure of Arctic species and humans to Hg....... In 2015, an international sampling network (ARCTOX) has been established, allowing the collection seabird samples all around the Arctic. Seabirds are indeed good indicators of Hg contamination of marine food webs at large spatial scale. Gathering researchers from 10 countries, ARCTOX allowed......Arctic marine ecosystems are threatened by new risks of Hg contamination under the combined effects of climate change and human activities. Rapid change of the cryosphere might for instance release large amounts of Hg trapped in sea-ice, permafrost and terrestrial glaciers over the last decades...

Polar Voices: Relaying the Science and Story of Polar Climate Change through Podcast

Science.gov (United States)

Moloney, M.; Quinney, A.; Murray, M. S.

2016-12-01

The resurgence of audio programming with the advent of podcasting in the early 2000's spawned a new medium for communicating advances in science, research, and technology. To capitalize on this informal educational outlet, the Arctic Institute of North America (AINA) partnered with the International Arctic Research Center, the University of Alaska Fairbanks, and the UA Museum of the North to develop a podcast series called PoLAR Voices for the Polar Learning and Responding (PoLAR) Climate Change Education Partnership. Now entering its third season of production, PoLAR Voices has facilitated the communication of scientific knowledge regarding the impact of climate change on the Arctic and Antarctic from the perspectives of both scientific researchers and Arctic indigenous peoples. We present a holistic program detailing both data and research related to climate change in addition to personal stories from those people and communities most affected. An evaluation of the program has been conducted by the Goodman Research Group to assess the effectiveness of the program for relaying the whole story of climate change to the public. The results of this assessment will be used to further develop the program to effectively reach larger and more diverse audiences. The series is currently available on thepolarhub.org and iTunes, and we are exploring opportunities to air the program on radio to reach as many people as possible.

Propaganda, News, or Education: Reporting Changing Arctic Sea Ice Conditions

Science.gov (United States)

Leitzell, K.; Meier, W.

2010-12-01

The National Snow and Ice Data Center provides information on Arctic sea ice conditions via the Arctic Sea Ice News & Analysis (ASINA) website. As a result of this effort to explain climatic data to the general public, we have attracted a huge amount of attention from our readers. Sometimes, people write to thank us for the information and the explanation. But people also write to accuse us of bias, slant, or outright lies in our posts. The topic of climate change is a minefield full of political animosity, and even the most carefully written verbiage can appear incomplete or biased to some audiences. Our strategy has been to report the data and stick to the areas in which our scientists are experts. The ASINA team carefully edits our posts to make sure that all statements are based on the science and not on opinion. Often this means using some technical language that may be difficult for a layperson to understand. However, we provide concise definitions for technical terms where appropriate. The hope is that by communicating the data clearly, without an agenda, we can let the science speak for itself. Is this an effective strategy to communicate clearly about the changing climate? Or does it downplay the seriousness of climate change? By writing at a more advanced level and avoiding oversimplification, we require our readers to work harder. But we may also maintain the attention of skeptics, convincing them to read further and become more knowledgeable about the topic.

China and the Arctic: An Opportunity for the U.S.

Science.gov (United States)

2017-04-06

of the lack of China’s sovereignty in the Arctic.15 Most academic writings focus on China’s need to voice an opinion concerning sea routes...effects that climate change in the Arctic will have on food production and extreme weather; (b) to ensure access at a reasonable cost to Arctic...21 Studying climate change and the Arctic will enable scholars to predict consequences to the environment, and potential effects on Chinese food

Arctic security and Norway

Energy Technology Data Exchange (ETDEWEB)

Tamnes, Rolf

2013-03-01

Global warming is one of the most serious threats facing mankind. Many regions and countries will be affected, and there will be many losers. The earliest and most intense climatic changes are being experienced in the Arctic region. Arctic average temperature has risen at twice the rate of the global average in the past half century. These changes provide an early indication for the world of the environmental and societal significance of global warming. For that reason, the Arctic presents itself as an important scientific laboratory for improving our understanding of the causes and patterns of climate changes. The rapidly rising temperature threatens the Arctic ecosystem, but the human consequences seem to be far less dramatic there than in many other places in the world. According to the U.S. National Intelligence Council, Russia has the potential to gain the most from increasingly temperate weather, because its petroleum reserves become more accessible and because the opening of an Arctic waterway could provide economic and commercial advantages. Norway might also be fortunate. Some years ago, the Financial Times asked: #Left Double Quotation Mark#What should Norway do about the fact that global warming will make their climate more hospitable and enhance their financial situation, even as it inflicts damage on other parts of the world?#Right Double Quotation Mark#(Author)

Recent changes in seasonal variations of climate within the range of northern caribou populations

Directory of Open Access Journals (Sweden)

Paul H. Whitfield

2005-05-01

Full Text Available The Arctic is one region where it is expected that the impacts of a globally changing climate will be readily observed. We present results that indicate that climate derivatives of potential significance to caribou changed during the past 50 years. Many temperature derivatives reflect the increasing overall temperature in the Arctic such as decreases in the number of days with low temperatures, increases in the number of days with thaw, and days with extremely warm temperatures. Other derivatives reflect changes in the precipitation regime such as days with heavy precipitation and number of days when rain fell on snow. Our results indicate that specific caribou herds from across the Arctic were subjected to different variations of these derivatives in different seasons in the recent past. Examination of temperature and precipitation at finer time-steps than annual or monthly means, shows that climatic variations in the region are neither consistent through the seasons nor across space. Decadal changes in seasonal patterns of temperature and precipitation are shown for selected herds. A process for assessing caribou-focused climate derivatives is proposed.

Pan-Arctic distributions of continental runoff in the Arctic Ocean.

Science.gov (United States)

Fichot, Cédric G; Kaiser, Karl; Hooker, Stanford B; Amon, Rainer M W; Babin, Marcel; Bélanger, Simon; Walker, Sally A; Benner, Ronald

2013-01-01

Continental runoff is a major source of freshwater, nutrients and terrigenous material to the Arctic Ocean. As such, it influences water column stratification, light attenuation, surface heating, gas exchange, biological productivity and carbon sequestration. Increasing river discharge and thawing permafrost suggest that the impacts of continental runoff on these processes are changing. Here, a new optical proxy was developed and implemented with remote sensing to determine the first pan-Arctic distribution of terrigenous dissolved organic matter (tDOM) and continental runoff in the surface Arctic Ocean. Retrospective analyses revealed connections between the routing of North American runoff and the recent freshening of the Canada Basin, and indicated a correspondence between climate-driven changes in river discharge and tDOM inventories in the Kara Sea. By facilitating the real-time, synoptic monitoring of tDOM and freshwater runoff in surface polar waters, this novel approach will help understand the manifestations of climate change in this remote region.

Signs of the Land: Reaching Arctic Communities Facing Climate Change

Science.gov (United States)

Sparrow, E. B.; Chase, M. J.; Demientieff, S.; Pfirman, S. L.; Brunacini, J.

2014-12-01

In July 2014, a diverse and intergenerational group of Alaskan Natives came together on Howard Luke's Galee'ya Camp by the Tanana River in Fairbanks, Alaska to talk about climate change and it's impacts on local communities. Over a period of four days, the Signs of the Land Climate Change Camp wove together traditional knowledge, local observations, Native language, and climate science through a mix of storytelling, presentations, dialogue, and hands-on, community-building activities. This camp adapted the model developed several years ago under the Association for Interior Native Educators (AINE)'s Elder Academy. Part of the Polar Learning and Responding Climate Change Education Partnership, the Signs of the Land Climate Change Camp was developed and conducted collaboratively with multiple partners to test a model for engaging indigenous communities in the co-production of climate change knowledge, communication tools, and solutions-building. Native Alaskans have strong subsistence and cultural connections to the land and its resources, and, in addition to being keen observers of their environment, have a long history of adapting to changing conditions. Participants in the camp included Elders, classroom teachers, local resource managers and planners, community members, and climate scientists. Based on their experiences during the camp, participants designed individualized outreach plans for bringing culturally-responsive climate learning to their communities and classrooms throughout the upcoming year. Plans included small group discussions, student projects, teacher training, and conference presentations.

Changing Conditions in the Arctic: An Analysis of 45 years of Tropospheric Ozone Measurements at Barrow Observatory

Science.gov (United States)

McClure-Begley, A.; Petropavlovskikh, I. V.; Crepinsek, S.; Jefferson, A.; Emmons, L. K.; Oltmans, S. J.

2017-12-01

In order to understand the impact of climate on local bio-systems, understanding the changes to the atmospheric composition and processes in the Arctic boundary layer and free troposphere is imperative. In the Arctic, many conditions influence tropospheric ozone variability such as: seasonal halogen caused depletion events, long range transport of pollutants from mid-northern latitudes, compounds released from wildfires, and different meteorological conditions. The Barrow station in Utqiagvik, Alaska has collected continuous measurements of ground-level ozone since 1973. This unique long-term time series allows for analysis of the influence of a rapidly changing climate on ozone conditions in this region. Specifically, this study analyzes the frequency of enhanced ozone episodes over time and provides in depth analysis of periods of positive deviations from the expected conditions. To discern the contribution of different pollutant sources to observed ozone variability, co-located measurements of aerosols, carbon monoxide, and meteorological conditions are used. In addition, the NCAR Mozart-4/MOPITT Chemical Forecast model and NOAA Hysplit back-trajectory analysis provide information on transport patterns to the Arctic and confirmation of the emission sources that influenced the observed conditions. These anthropogenic influences on ozone variability in and below the boundary layer are essential for developing an understanding of the interaction of climate change and the bio-systems in the Arctic.

Does Reality Matter? Social and Science Bases of Public Beliefs about Arctic Change

Science.gov (United States)

Walker, D. A.; Schaefer, K. M.; Schaeffer, K. P.; Schaefer, K. M.; Hamilton, L.

2015-12-01

Surveys of public perceptions about trends in Arctic sea ice find that over two-thirds are aware of the multi-decade decrease. This awareness differs sharply across ideological and educational subgroups, however. It does not appear to shift in response to scientific and media discussion following a September with unusually low (2012) or somewhat higher (2013) sea ice extent. Other perceptions about Arctic change, such as impacts on mid-latitude weather, follow similar patterns with sharp ideological difference and limited response to external events, including science reports. On the other hand, public accuracy on basic factual questions that do not by themselves imply directional change (such as location of the North Pole) may be very low, and among some subgroups accurate knowledge shows an oddly negative correlation with self-confidence about understanding of climate change. These results from 13 surveys over 2011-2015 suggest that biased assimilation filters the acceptance of information about Arctic change, with implications for science communication.

Eocene climate and Arctic paleobathymetry: A tectonic sensitivity study using GISS ModelE-R

Science.gov (United States)

Roberts, C. D.; Legrande, A. N.; Tripati, A. K.

2009-12-01

The early Paleogene (65-45 million years ago, Ma) was a ‘greenhouse’ interval with global temperatures warmer than any other time in the last 65 Ma. This period was characterized by high levels of CO2, warm high-latitudes, warm surface-and-deep oceans, and an intensified hydrological cycle. Sediments from the Arctic suggest that the Eocene surface Arctic Ocean was warm, brackish, and episodically enabled the freshwater fern Azolla to bloom. The precise mechanisms responsible for the development of these conditions remain uncertain. We present equilibrium climate conditions derived from a fully-coupled, water-isotope enabled, general circulation model (GISS ModelE-R) configured for the early Eocene. We also present model-data comparison plots for key climatic variables (SST and δ18O) and analyses of the leading modes of variability in the tropical Pacific and North Atlantic regions. Our tectonic sensitivity study indicates that Northern Hemisphere climate would have been very sensitive to the degree of oceanic exchange through the seaways connecting the Arctic to the Atlantic and Tethys. By restricting these seaways, we simulate freshening of the surface Arctic Ocean to ~6 psu and warming of sea-surface temperatures by 2°C in the North Atlantic and 5-10°C in the Labrador Sea. Our results may help explain the occurrence of low-salinity tolerant taxa in the Arctic Ocean during the Eocene and provide a mechanism for enhanced warmth in the north western Atlantic. We also suggest that the formation of a volcanic land-bridge between Greenland and Europe could have caused increased ocean convection and warming of intermediate waters in the Atlantic. If true, this result is consistent with the theory that bathymetry changes may have caused thermal destabilisation of methane clathrates in the Atlantic.

The Arctic Climate Modeling Program: K-12 Geoscience Professional Development for Rural Educators

Science.gov (United States)

Bertram, K. B.

2009-12-01

Helping teachers and students connect with scientists is the heart of the Arctic Climate Modeling Program (ACMP), funded from 2005-09 by the National Science Foundation’s Innovative Technology Experience for Students and Teachers. ACMP offered progressive yearlong science, technology and math (STM) professional development that prepared teachers to train youth in workforce technologies used in Arctic research. ACMP was created for the Bering Strait School District, a geographically isolated area with low standardized test scores, high dropout rates, and poverty. Scientists from around the globe have converged in this region and other areas of the Arctic to observe and measure changes in climate that are significant, accelerating, and unlike any in recorded history. Climate literacy (the ability to understand Earth system science and to make scientifically informed decisions about climate changes) has become essential for this population. Program resources were designed in collaboration with scientists to mimic the processes used to study Arctic climate. Because the Bering Strait School District serves a 98 percent Alaska Native student population, ACMP focused on best practices shown to increase the success of minority students. Significant research indicates that Alaska Native students succeed academically at higher rates when instruction addresses topics of local interest, links education to the students’ physical and cultural environment, uses local knowledge and culture in the curriculum, and incorporates hands-on, inquiry-based lessons in the classroom. A seven-partner consortium of research institutes and Alaska Native corporations created ACMP to help teachers understand their role in nurturing STM talent and motivating students to explore geoscience careers. Research underscores the importance of increasing school emphasis in content areas, such as climate, that facilitate global awareness and civic responsibility, and that foster critical thinking and

Beyond Thin Ice: Co-Communicating the Many Arctics

Science.gov (United States)

Druckenmiller, M. L.; Francis, J. A.; Huntington, H.

2015-12-01

Science communication, typically defined as informing non-expert communities of societally relevant science, is persuaded by the magnitude and pace of scientific discoveries, as well as the urgency of societal issues wherein science may inform decisions. Perhaps nowhere is the connection between these facets stronger than in the marine and coastal Arctic where environmental change is driving advancements in our understanding of natural and socio-ecological systems while paving the way for a new assortment of arctic stakeholders, who generally lack adequate operational knowledge. As such, the Arctic provides opportunity to advance the role of science communication into a collaborative process of engagement and co-communication. To date, the communication of arctic change falls within four primary genres, each with particular audiences in mind. The New Arctic communicates an arctic of new stakeholders scampering to take advantage of unprecedented access. The Global Arctic conveys the Arctic's importance to the rest of the world, primarily as a regulator of lower-latitude climate and weather. The Intra-connected Arctic emphasizes the increasing awareness of the interplay between system components, such as between sea ice loss and marine food webs. The Transforming Arctic communicates the region's trajectory relative to the historical Arctic, acknowledging the impacts on indigenous peoples. The broad societal consensus on climate change in the Arctic as compared to other regions in the world underscores the opportunity for co-communication. Seizing this opportunity requires the science community's engagement with stakeholders and indigenous peoples to construct environmental change narratives that are meaningful to climate responses relative to non-ecological priorities (e.g., infrastructure, food availability, employment, or language). Co-communication fosters opportunities for new methods of and audiences for communication, the co-production of new interdisciplinary

Arctic Storms and Their Influence on Surface Climate in the Chukchi-Beaufort Seas

Science.gov (United States)

Yang, Y.; Zhang, X.; Rinke, A.; Zhang, J.

2017-12-01

Increases in the frequency and intensity of Arctic storms and resulting weather hazards may endanger the offshore environment, coastal community, and energy infrastructure in the Arctic as sea ice retreats. Advancing ability to identify fine-scale variations in surface climate produced by progressively stronger storm would be extremely helpful to resources management and sustainable development for coastal community. In this study, we analyzed the storms and their impacts on surface climate over the Beaufort-Chukchi seas by employing the date sets from both the hindcast simulations of the coupled Arctic regional climate model HIRHAM-NAOSIM and the recently developed Chukchi-Beaufort High-resolution Atmospheric Reanalysis (CBHAR). Based on the characteristics of spatial pattern and temporal variability of the Arctic storm activity, we categorized storms to three groups with their different origins: the East Siberia Sea, Alaska and the central Arctic Ocean. The storms originating from the central Arctic Ocean have the strongest intensity in winter with relatively less storm number. Storms traveling from Alaska to the Beaufort Sea most frequently occurred in autumn with weaker intensity. A large portion of storms originated from the East Siberia Sea region in summer. Further statistical analysis suggests that increase in surface air temperature and wind speed could be attributed to the increased frequency of storm occurrence in autumn (September to November) along the continental shelf in the Beaufort Sea.

The great challenges in Arctic Ocean paleoceanography

International Nuclear Information System (INIS)

Stein, Ruediger

2011-01-01

Despite the importance of the Arctic in the climate system, the data base we have from this area is still very weak, and large parts of the climate history have not been recovered at all in sedimentary sections. In order to fill this gap in knowledge, international, multidisciplinary expeditions and projects for scientific drilling/coring in the Arctic Ocean are needed. Key areas and approaches for drilling and recovering undisturbed and complete sedimentary sequences are depth transects across the major ocean ridge systems, i.e., the Lomonosov Ridge, the Alpha-Mendeleev Ridge, and the Chukchi Plateau/Northwind Ridge, the Beaufort, Kara and Laptev sea continental margins, as well as the major Arctic gateways towards the Atlantic and Pacific oceans. The new detailed climate records from the Arctic Ocean spanning time intervals from the Late Cretaceous/Paleogene Greenhouse world to the Neogene-Quaternary Icehouse world and representing short- and long-term climate variability on scales from 10 to 10 6 years, will give new insights into our understanding of the Arctic Ocean within the global climate system and provide an opportunity to test the performance of climate models used to predict future climate change. With this, studying the Arctic Ocean is certainly one of the major challenges in climate research for the coming decades.

Additive impacts of experimental climate change increase risk to an ectotherm at the Arctic's edge.

Science.gov (United States)

Davenport, Jon M; Hossack, Blake R; Fishback, LeeAnn

2017-06-01

Globally, Arctic and Subarctic regions have experienced the greatest temperature increases during the last 30 years. These extreme changes have amplified threats to the freshwater ecosystems that dominate the landscape in many areas by altering water budgets. Several studies in temperate environments have examined the adaptive capacity of organisms to enhance our understanding of the potential repercussions of warming and associated accelerated drying for freshwater ecosystems. However, few experiments have examined these impacts in Arctic or Subarctic freshwater ecosystems, where the climate is changing most rapidly. To evaluate the capacity of a widespread ectotherm to anticipated environmental changes, we conducted a mesocosm experiment with wood frogs (Rana sylvatica) in the Canadian Subarctic. Three warming treatments were fully crossed with three drying treatments to simulate a range of predicted changes in wetland environments. We predicted wetland warming and drying would act synergistically, with water temperature partially compensating for some of the negative effects of accelerated drying. Across all drying regimes, a 1 °C increase in water temperature increased the odds of survival by 1.79, and tadpoles in 52-day and 64-day hydroperiod mesocosms were 4.1-4.3 times more likely to survive to metamorphosis than tadpoles in 45-day mesocosms. For individuals who survived to metamorphosis, there was only a weak negative effect of temperature on size. As expected, increased temperatures accelerated tadpole growth through day 30 of the experiment. Our results reveal that one of the dominant herbivores in Subarctic wetlands, wood frog tadpoles, are capable of increasing their developmental rates in response to increased temperature and accelerated drying, but only in an additive manner. The strong negative effects of drying on survival, combined with lack of compensation between these two environmental drivers, suggest changes in the aquatic environment that

Sex- and habitat-specific responses of a high arctic willow, Salix arctica, to experimental climate change

Energy Technology Data Exchange (ETDEWEB)

Jones, M.H.; Macdonald, S.E. [Univ. of Alberta, Dept. of Renewable Resources, Edmonton, AB (Canada); Henry, G.H.R. [Univ. of British Columbia, Dept. of Geography, Vancouver, BC (Canada)

1999-10-01

Dioecious plant species and those occupying diverse habitats may present special analytical problems to researchers examining effects of climate change. Here we report the results from two complementary studies designed to determine the importance of sex and habitat on gas exchange and growth of male and female individuals of a dioecious, circumpolar willow, Salix arctica, in the Canadian High Arctic. In field studies, male and female willows from dry and wet habitats were subjected to passively enhanced summer temperature ({approx} to 1.3 deg C) using small open-top chambers over three years. Peak season gas exchange varied significantly by willow sex and habitat. Overall net assimilation was higher in the dry habitat than in the wet, and higher in females than in males. In the dry habitat, net assimilation of females was enhanced by experimental warming, but decreased in males. In the wet habitat, net assimilation of females was substantially depressed by experimental warming, while males showed an inconsistent response. Development and growth of male and female catkins were enhanced by elevated temperature more than leaf fascicles, but leaf fascicle development and growth varied more between the two habitats, particularly in males. In a controlled environment study, male and female willows from these same wet and dry habitats were grown in a 2x2 factorial experiment including 1 x or 2 x ambient [CO{sub 2}] and 5 or 12 deg. C. The sexes responded very differently to the experimental treatments, but we found no effect of original habitat. Net assimilation in males was affected by the interaction of temperature and CO{sub 2}, but in females by CO{sub 2} only. Our results demonstrate (a) significant intraspecific and intersexual differences in arctic willow physiology and growth, (b) that these differences are affected by environmental conditions expected to accompany global climate change, and (c) that sex- and habitat-specific responses should be explicitly

Fisheries: climate change impacts and adaptation

International Nuclear Information System (INIS)

2003-01-01

The report entitled Climate Change Impacts and Adaptation : A Canadian Perspective, presents a summary of research regarding the impacts of climate change on key sectors over the past five years as it relates to Canada. This chapter on fisheries focuses on the impact of climate change on Canada's marine and freshwater fisheries, and the role of adaptation in reducing the vulnerability of the sector. Canadian fisheries encompass the Atlantic, Pacific and Arctic oceans as well as freshwater systems. Fish health, productivity and distribution is strongly influenced by climatic factors such as air and water temperature, precipitation and wind. Most fish species have a distinct set of environmental conditions for optimal growth and survival. If the conditions change in response to changing climate, the fish may be affected. Some of the impacts include reduced growth, increased competition, a shift in species distribution, greater susceptibility to disease, and altered ecosystem function. Studies show that in some areas, fisheries may already be experiencing the effect of climate change. Recommendations were suggested on how to deal with the impacts associated with climate change in sensitive environments. It was noted that actions taken in the fisheries sector will have implications for the water resources, transportation, tourism and human health sectors. 103 refs., 2 tabs., 6 figs

Expanding research capabilities with sea ice climate records for analysis of long-term climate change and short-term variability

Science.gov (United States)

Scott, D. J.; Meier, W. N.

2008-12-01

Recent sea ice analysis is leading to predictions of a sea ice-free summertime in the Arctic within 20 years, or even sooner. Sea ice topics, such as concentration, extent, motion, and age, are predominately studied using satellite data. At the National Snow and Ice Data Center (NSIDC), passive microwave sea ice data sets provide timely assessments of seasonal-scale variability as well as consistent long-term climate data records. Such data sets are crucial to understanding changes and assessing their impacts. Noticeable impacts of changing sea ice conditions on native cultures and wildlife in the Arctic region are now being documented. With continued deterioration in Arctic sea ice, global economic impacts will be seen as new shipping routes open. NSIDC is at the forefront of making climate data records available to address the changes in sea ice and its global impacts. By focusing on integrated data sets, NSIDC leads the way by broadening the studies of sea ice beyond the traditional cryospheric community.

Arctic Aerosols and Sources

DEFF Research Database (Denmark)

Nielsen, Ingeborg Elbæk

2017-01-01

Since the Industrial Revolution, the anthropogenic emission of greenhouse gases has been increasing, leading to a rise in the global temperature. Particularly in the Arctic, climate change is having serious impact where the average temperature has increased almost twice as much as the global during......, ammonium, black carbon, and trace metals. This PhD dissertation studies Arctic aerosols and their sources, with special focus on black carbon, attempting to increase the knowledge about aerosols’ effect on the climate in an Arctic content. The first part of the dissertation examines the diversity...... of aerosol emissions from an important anthropogenic aerosol source: residential wood combustion. The second part, characterizes the chemical and physical composition of aerosols while investigating sources of aerosols in the Arctic. The main instrument used in this research has been the state...

The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

DEFF Research Database (Denmark)

Stewart, L.; Alsos, Inger G.; Bay, Christian

2016-01-01

Aim The Arctic has experienced marked climatic differences between glacial and interglacial periods and is now subject to a rapidly warming climate. Knowledge of the effects of historical processes on current patterns of diversity may aid predictions of the responses of vegetation to future climate...... species richness of the vascular plant flora of 21 floristic provinces and examined local species richness in 6215 vegetation plots distributed across the Arctic. We assessed levels of genetic diversity inferred from amplified fragment length polymorphism variation across populations of 23 common Arctic...... size compared to the models of bryophyte and lichen richness. Main conclusion Our study suggests that imprints of past glaciations in Arctic vegetation diversity patterns at the regional scale are still detectable today. Since Arctic vegetation is still limited by post-glacial migration lag...

Impacts of climate change on resource management of the north: Symposium summary

International Nuclear Information System (INIS)

Goos, T.; Wall, G.

1994-01-01

A Canada/USA symposium was held to address critical issues related to the impacts of climatic changes on Arctic regions. A review of the papers presented at the symposium and the symposium findings and recommendations is presented. Highlights of the proceedings are as follows. An improved understanding of Arctic processes, such as the hydrological cycle, ocean circulation, and permafrost is required. This information should be incorporated as it becomes available into global climate models at scales which will allow representation and assessment of regional consequences. Improved mechanisms are needed to facilitate the use of the results of scientific work in the formulation of resource management options and decisions. If climate change occurs as expected, the presence of ice and permafrost will be reduced throughout much of the north, with profound implications for such aspects of northern living as life styles, transport, land use, and resource development. Improved knowledge is required regarding the sensitivities of Arctic species and ecosystems and their responses when thresholds are exceeded. There is also a need to assess the relative importance of climate in the context of other factors which have implications for resource management decisions

Recent dynamics of arctic and sub-arctic vegetation

International Nuclear Information System (INIS)

Epstein, Howard E; Myers-Smith, Isla; Walker, Donald A

2013-01-01

We present a focus issue of Environmental Research Letters on the ‘Recent dynamics of arctic and sub-arctic vegetation’. The focus issue includes three perspective articles (Verbyla 2011 Environ. Res. Lett. 6 041003, Williams et al 2011 Environ. Res. Lett. 6 041004, Loranty and Goetz 2012 Environ. Res. Lett. 7 011005) and 22 research articles. The focus issue arose as a result of heightened interest in the response of high-latitude vegetation to natural and anthropogenic changes in climate and disturbance regimes, and the consequences that these vegetation changes might have for northern ecosystems. A special session at the December 2010 American Geophysical Union Meeting on the ‘Greening of the Arctic’ spurred the call for papers. Many of the resulting articles stem from intensive research efforts stimulated by International Polar Year projects and the growing acknowledgment of ongoing climate change impacts in northern terrestrial ecosystems. (synthesis and review)

Temporal constraints on future accumulation-area loss of a major Arctic ice cap due to climate change (Vestfonna, Svalbard).

Science.gov (United States)

Möller, Marco; Schneider, Christoph

2015-01-28

Arctic glaciers and ice caps are major contributors to past, present and future sea-level fluctuations. Continued global warming may eventually lead to the equilibrium line altitudes of these ice masses rising above their highest points, triggering unstoppable downwasting. This may feed future sea-level rise considerably. We here present projections for the timing of equilibrium-line loss at the major Arctic ice cap Vestfonna, Svalbard. The projections are based on spatially distributed climatic mass balance modelling driven by the outputs of multiple climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) forced by the Representative Concentration Pathways (RCPs) 2.6, 4.5, 6.0 and 8.5. Results indicate strongly decreasing climatic mass balances over the 21(st) century for all RCPs considered. Glacier-wide mass-balance rates will drop down to -4 m a(-1) w.e. (water equivalent) at a maximum. The date at which the equilibrium line rises above the summit of Vestfonna (630 m above sea level) is calculated to range between 2040 and 2150, depending on scenario.

Seasonal climate change patterns due to cumulative CO2 emissions

Science.gov (United States)

Partanen, Antti-Ilari; Leduc, Martin; Damon Matthews, H.

2017-07-01

Cumulative CO2 emissions are near linearly related to both global and regional changes in annual-mean surface temperature. These relationships are known as the transient climate response to cumulative CO2 emissions (TCRE) and the regional TCRE (RTCRE), and have been shown to remain approximately constant over a wide range of cumulative emissions. Here, we assessed how well this relationship holds for seasonal patterns of temperature change, as well as for annual-mean and seasonal precipitation patterns. We analyzed an idealized scenario with CO2 concentration growing at an annual rate of 1% using data from 12 Earth system models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Seasonal RTCRE values for temperature varied considerably, with the highest seasonal variation evident in the Arctic, where RTCRE was about 5.5 °C per Tt C for boreal winter and about 2.0 °C per Tt C for boreal summer. Also the precipitation response in the Arctic during boreal winter was stronger than during other seasons. We found that emission-normalized seasonal patterns of temperature change were relatively robust with respect to time, though they were sub-linear with respect to emissions particularly near the Arctic. Moreover, RTCRE patterns for precipitation could not be quantified robustly due to the large internal variability of precipitation. Our results suggest that cumulative CO2 emissions are a useful metric to predict regional and seasonal changes in precipitation and temperature. This extension of the TCRE framework to seasonal and regional climate change is helpful for communicating the link between emissions and climate change to policy-makers and the general public, and is well-suited for impact studies that could make use of estimated regional-scale climate changes that are consistent with the carbon budgets associated with global temperature targets.

AMAP Assessment 2013: Arctic Ocean acidification

Science.gov (United States)

2013-01-01

This assessment report presents the results of the 2013 AMAP Assessment of Arctic Ocean Acidification (AOA). This is the first such assessment dealing with AOA from an Arctic-wide perspective, and complements several assessments that AMAP has delivered over the past ten years concerning the effects of climate change on Arctic ecosystems and people. The Arctic Monitoring and Assessment Programme (AMAP) is a group working under the Arctic Council. The Arctic Council Ministers have requested AMAP to: - produce integrated assessment reports on the status and trends of the conditions of the Arctic ecosystems;

A Recommended Set of Key Arctic Indicators

Science.gov (United States)

Stanitski, D.; Druckenmiller, M.; Fetterer, F. M.; Gerst, M.; Intrieri, J. M.; Kenney, M. A.; Meier, W.; Overland, J. E.; Stroeve, J.; Trainor, S.

2017-12-01

The Arctic is an interconnected and environmentally sensitive system of ice, ocean, land, atmosphere, ecosystems, and people. From local to pan-Arctic scales, the area has already undergone major changes in physical and societal systems and will continue at a pace that is greater than twice the global average. Key Arctic indicators can quantify these changes. Indicators serve as the bridge between complex information and policy makers, stakeholders, and the general public, revealing trends and information people need to make important socioeconomic decisions. This presentation evaluates and compiles more than 70 physical, biological, societal and economic indicators into an approachable summary that defines the changing Arctic. We divided indicators into "existing," "in development," "possible," and "aspirational". In preparing a paper on Arctic Indicators for a special issue of the journal Climatic Change, our group established a set of selection criteria to identify indicators to specifically guide decision-makers in their responses to climate change. A goal of the analysis is to select a manageable composite list of recommended indicators based on sustained, reliable data sources with known user communities. The selected list is also based on the development of a conceptual model that identifies components and processes critical to our understanding of the Arctic region. This list of key indicators is designed to inform the plans and priorities of multiple groups such as the U.S. Global Change Research Program (USGCRP), Interagency Arctic Research Policy Committee (IARPC), and the Arctic Council.

Polar cloud observatory at Ny-Ålesund in GRENE Arctic Climate Change Research Project

Science.gov (United States)

Yamanouchi, Takashi; Takano, Toshiaki; Shiobara, Masataka; Okamoto, Hajime; Koike, Makoto; Ukita, Jinro

2016-04-01

Cloud is one of the main processes in the climate system and especially a large feed back agent for Arctic warming amplification (Yoshimori et al., 2014). From this reason, observation of polar cloud has been emphasized and 95 GHz cloud profiling radar in high precision was established at Ny-Ålesund, Svalbard in 2013 as one of the basic infrastructure in the GRENE (Green Network of Excellence Program) Arctic Climate Change Research Project. The radar, "FALCON-A", is a FM-CW (frequency modulated continuous wave) Doppler radar, developed for Arctic use by Chiba University (PI: T. Takano) in 2012, following its prototype, "FALCON-1" which was developed in 2006 (Takano et al., 2010). The specifications of the radar are, central frequency: 94.84 GHz; antenna power: 1 W; observation height: up to 15 km; range resolution: 48 m; beam width: 0.2 degree (15 m at 5 km); Doppler width: 3.2 m/s; time interval: 10 sec, and capable of archiving high sensitivity and high spatial and time resolution. An FM-CW type radar realizes similar sensitivity with much smaller parabolic antennas separated 1.4 m from each other used for transmitting and receiving the wave. Polarized Micro-Pulse Lidar (PMPL, Sigma Space MPL-4B-IDS), which is capable to measure the backscatter and depolarization ratio, has also been deployed to Ny-Ålesund in March 2012, and now operated to perform collocated measurements with FALCON-A. Simultaneous measurement data from collocated PMPL and FALCON-A are available for synergetic analyses of cloud microphysics. Cloud mycrophysics, such as effective radius of ice particles and ice water content, are obtained from the analysis based on algorithm, which is modified for ground-based measurements from Okamoto's retrieval algorithm for satellite based cloud profiling radar and lidar (CloudSat and CALIPSO; Okamoto et al., 2010). Results of two years will be shown in the presentation. Calibration is a point to derive radar reflectivity (dBZ) from original intensity data

Connecting Alaskan Youth, Elders, and Scientists in Climate Change Research and Community Resilience

Science.gov (United States)

Spellman, K.; Sparrow, E.

2017-12-01

Integrated science, technology, engineering and math (STEM) solutions and effective, relevant learning processes are required to address the challenges that a changing climate presents to many Arctic communities. Learning that can both enhance a community's understanding and generate new knowledge about climate change impacts at both local and continental scales are needed to efficiently build the capacity to navigate these changes. The Arctic and Earth STEM Integrating GLOBE and NASA (SIGNs) program is developing a learning model to engage Alaskan rural and indigenous communities in climate change learning, research and action. Youth, elders, educators, community leaders and scientists collaborate to address a pressing local climate change concern. The program trains teams of educators and long-time community members on climate change concepts and environmental observing protocols in face-to-face or online workshops together with Arctic and NASA subject matter experts. Community teams return to their community to identify local data or information needs that align with their student's interests and the observations of local elders. They deepen their understanding of the subject through culturally responsive curriculum materials, and collaborate with a scientist to develop an investigation with their students to address the identified need. Youth make observations using GLOBE (Global Learning and Observations to Benefit the Environment) protocols that best fit the issue, analyze the data they have collected, and utilize indigenous or knowledge, and NASA data to address the issue. The use of GLOBE protocols allow for communities to engage in climate change research at both local and global scales, as over 110 nations worldwide are using these standardized protocols. Teams work to communicate their investigation results back to their community and other scientists, and apply their results to local stewardship action or climate adaptation projects. In this

Environmental marine geology of the Arctic Ocean

International Nuclear Information System (INIS)

Mudie, P.J.

1991-01-01

The Arctic Ocean and its ice cover are major regulators of Northern Hemisphere climate, ocean circulation and marine productivity. The Arctic is also very sensitive to changes in the global environment because sea ice magnifies small changes in temperature, and because polar regions are sinks for air pollutants. Marine geology studies are being carried out to determine the nature and rate of these environmental changes by study of modem ice and sea-bed environments, and by interpretation of geological records imprinted in the sea-floor sediments. Sea ice camps, an ice island, and polar icebreakers have been used to study both western and eastern Arctic Ocean basins. Possible early warning signals of environmental changes in the Canadian Arctic are die-back in Arctic sponge reefs, outbreaks of toxic dinoflagellates, and pesticides in the marine food chain. Eastern Arctic ice and surface waters are contaminated by freon and radioactive fallout from Chernobyl. At present, different sedimentary processes operate in the pack ice-covered Canadian polar margin than in summer open waters off Alaska and Eurasia. The geological records, however, suggest that a temperature increase of 1-4 degree C would result in summer open water throughout the Arctic, with major changes in ocean circulation and productivity of waters off Eastern North America, and more widespread transport of pollutants from eastern to western Arctic basins. More studies of longer sediment cores are needed to confirm these interpretations, but is is now clear that the Arctic Ocean has been the pacemaker of climate change during the past 1 million years

Selected physical, biological and biogeochemical implications of a rapidly changing Arctic Marginal Ice Zone

Science.gov (United States)

Barber, David G.; Hop, Haakon; Mundy, Christopher J.; Else, Brent; Dmitrenko, Igor A.; Tremblay, Jean-Eric; Ehn, Jens K.; Assmy, Philipp; Daase, Malin; Candlish, Lauren M.; Rysgaard, Søren

2015-12-01

The Marginal Ice Zone (MIZ) of the Arctic Ocean is changing rapidly due to a warming Arctic climate with commensurate reductions in sea ice extent and thickness. This Pan-Arctic review summarizes the main changes in the Arctic ocean-sea ice-atmosphere (OSA) interface, with implications for primary- and secondary producers in the ice and the underlying water column. Changes in the Arctic MIZ were interpreted for the period 1979-2010, based on best-fit regressions for each month. Trends of increasingly open water were statistically significant for each month, with quadratic fit for August-November, illustrating particularly strong seasonal feedbacks in sea-ice formation and decay. Geographic interpretations of physical and biological changes were based on comparison of regions with significant changes in sea ice: (1) The Pacific Sector of the Arctic Ocean including the Canada Basin and the Beaufort, Chukchi and East Siberian seas; (2) The Canadian Arctic Archipelago; (3) Baffin Bay and Hudson Bay; and (4) the Barents and Kara seas. Changes in ice conditions in the Barents sea/Kara sea region appear to be primarily forced by ocean heat fluxes during winter, whereas changes in the other sectors appear to be more summer-autumn related and primarily atmospherically forced. Effects of seasonal and regional changes in OSA-system with regard to increased open water were summarized for photosynthetically available radiation, nutrient delivery to the euphotic zone, primary production of ice algae and phytoplankton, ice-associated fauna and zooplankton, and gas exchange of CO2. Changes in the physical factors varied amongst regions, and showed direct effects on organisms linked to sea ice. Zooplankton species appear to be more flexible and likely able to adapt to variability in the onset of primary production. The major changes identified for the ice-associated ecosystem are with regard to production timing and abundance or biomass of ice flora and fauna, which are related to

Radiative Impacts of Further Arctic Sea Ice Melt: Using past Observations to Inform Future Climate Impacts

Science.gov (United States)

Pistone, K.; Eisenman, I.; Ramanathan, V.

2017-01-01

The Arctic region has seen dramatic changes over the past several decades, from polar amplification of global temperature rise to ecosystem changes to the decline of the sea ice. While there has been much speculation as to when the world will see an ice-free Arctic, the radiative impacts of an eventual disappearance of the Arctic sea ice are likely to be significant regardless of the timing. Using CERES radiation and microwave satellite sea ice data, Pistone et al (2014) estimated the radiative forcing due to albedo changes associated with the Arctic sea ice retreat over the 30 years of the satellite data record. In this study, we found that the Arctic Ocean saw a decrease in all-sky albedo of 4% (from 52% to 48%), for an estimated increase in solar heating of 6.4 W/m(exp 2) between 1979 and 2011, or 0.21 W/m(exp 2) when averaged over the globe. This value is substantial--approximately 25% as large as the forcing due to the change in CO2 during the same period. Here we update and expand upon this previous work and use the CERES broadband shortwave observations to explore the radiative impacts of a transition to completely ice-free Arctic Ocean. We estimate the annually-averaged Arctic Ocean planetary albedo under ice-free and cloud-free conditions to be 14% over the region, or approximately 25% lower in absolute terms than the Arctic Ocean cloud-free albedo in 1979. However, the question of all-sky conditions (i.e. including the effects of clouds) introduces a new level of complexity. We explore several cloud scenarios and the resultant impact on albedo. In each of these cases, the estimated forcing is not uniformly distributed throughout the year. We describe the relative contributions of ice loss by month as well as the spatial distributions of the resulting changes in absorbed solar energy. The seasonal timing and location—in addition to magnitude—of the altered solar absorption may have significant implications for atmospheric and ocean dynamics in the

Changing Permafrost in the Arctic and its Global Effects in the 21st Century (PAGE21): A very large international and integrated project to measure the impact of permafrost degradation on the climate system

Science.gov (United States)

Lantuit, Hugues; Boike, Julia; Dahms, Melanie; Hubberten, Hans-Wolfgang

2013-04-01

The northern permafrost region contains approximately 50% of the estimated global below-ground organic carbon pool and more than twice as much as is contained in the current atmos-pheric carbon pool. The sheer size of this carbon pool, together with the large amplitude of predicted arctic climate change im-plies that there is a high potential for global-scale feedbacks from arctic climate change if these carbon reservoirs are desta-bilized. Nonetheless, significant gaps exist in our current state of knowledge that prevent us from producing accurate assess-ments of the vulnerability of the arctic permafrost to climate change, or of the implications of future climate change for global greenhouse gas (GHG) emissions. Specifically: • Our understanding of the physical and biogeochemical processes at play in permafrost areas is still insuffi-cient in some key aspects • Size estimates for the high latitude continental carbon and nitrogen stocks vary widely between regions and research groups. • The representation of permafrost-related processes in global climate models still tends to be rudimentary, and is one reason for the frequently poor perform-ances of climate models at high latitudes. The key objectives of PAGE21 are: • to improve our understanding of the processes affect-ing the size of the arctic permafrost carbon and nitro-gen pools through detailed field studies and monitor-ing, in order to quantify their size and their vulnerability to climate change, • to produce, assemble and assess high-quality datasets in order to develop and evaluate representations of permafrost and related processes in global models, • to improve these models accordingly, • to use these models to reduce the uncertainties in feed-backs from arctic permafrost to global change, thereby providing the means to assess the feasibility of stabili-zation scenarios, and • to ensure widespread dissemination of our results in order to provide direct input into the ongoing debate on

Arctic summer school onboard an icebreaker

Science.gov (United States)

Alexeev, Vladimir A.; Repina, Irina A.

2014-05-01

The International Arctic Research Center (IARC) of the University of Alaska Fairbanks conducted a summer school for PhD students, post-docs and early career scientists in August-September 2013, jointly with an arctic expedition as a part of NABOS project (Nansen and Amundsen Basin Observational System) onboard the Russian research vessel "Akademik Fedorov". Both the summer school and NABOS expedition were funded by the National Science Foundation. The one-month long summer school brought together graduate students and young scientists with specialists in arctic oceanography and climate to convey to a new generation of scientists the opportunities and challenges of arctic climate observations and modeling. Young scientists gained hands-on experience during the field campaign and learned about key issues in arctic climate from observational, diagnostic, and modeling perspectives. The summer school consisted of background lectures, participation in fieldwork and mini-projects. The mini-projects were performed in collaboration with summer school instructors and members of the expedition. Key topics covered in the lectures included: - arctic climate: key characteristics and processes; - physical processes in the Arctic Ocean; - sea ice and the Arctic Ocean; - trace gases, aerosols, and chemistry: importance for climate changes; - feedbacks in the arctic system (e.g., surface albedo, clouds, water vapor, circulation); - arctic climate variations: past, ongoing, and projected; - global climate models: an overview. An outreach specialist from the Miami Science Museum was writing a blog from the icebreaker with some very impressive statistics (results as of January 1, 2014): Total number of blog posts: 176 Blog posts written/contributed by scientists: 42 Blog views: 22,684 Comments: 1,215 Number of countries who viewed the blog: 89 (on 6 continents) The 33-day long NABOS expedition started on August 22, 2013 from Kirkenes, Norway. The vessel ("Akademik Fedorov") returned to

Arctic Climate and Atmospheric Planetary Waves

Science.gov (United States)

Cavalieri, D. J.; Haekkinen, S.; Zukor, Dorothy J. (Technical Monitor)

2001-01-01

Analysis of a fifty-year record (1946-1995) of monthly-averaged sea level pressure data provides a link between the phases of planetary-scale sea level pressure waves and Arctic Ocean and ice variability. Results of this analysis show: (1) a breakdown of the dominant wave 1 pattern in the late 1960's, (2) shifts in the mean phase of waves 1 and 2 since this breakdown, (3) an eastward shift in the phases of both waves 1 and 2 during the years of simulated cyclonic Arctic Ocean circulation relative to their phases during the years of anticyclonic circulation, (4) a strong decadal variability of wave phase associated with simulated Arctic Ocean circulation changes. Finally, the Arctic atmospheric circulation patterns that emerge when waves 1 and 2 are in their extreme eastern and western positions suggest an alternative approach for determining significant forcing patterns of sea ice and high-latitude variability.

Wave climate and trends along the eastern Chukchi Arctic Alaska coast

Science.gov (United States)

Erikson, L.H.; Storlazzi, C.D.; Jensen, R.E.

2011-01-01

Due in large part to the difficulty of obtaining measurements in the Arctic, little is known about the wave climate along the coast of Arctic Alaska. In this study, numerical model simulations encompassing 40 years of wave hind-casts were used to assess mean and extreme wave conditions. Results indicate that the wave climate was strongly modulated by large-scale atmospheric circulation patterns and that mean and extreme wave heights and periods exhibited increasing trends in both the sea and swell frequency bands over the time-period studied (1954-2004). Model simulations also indicate that the upward trend was not due to a decrease in the minimum icepack extent. ?? 2011 ASCE.

The 7 Aarhus Statements on Climate Change

Science.gov (United States)

Margrethe Basse, Ellen; Svenning, Jens-Christian; Olesen, Jørgen E.; Besenbacher, Flemming; Læssøe, Jeppe; Seidenkrantz, Marit-Solveig; Lange, Lene

2009-03-01

More than 1000 prominent representatives from science, industry, politics and NGOs were gathered in Aarhus on 5-7 March 2009 for the international climate conference 'Beyond Kyoto: Addressing the Challenges of Climate Change'. Thematically, Beyond Kyoto was divided into seven areas of particular interest for understanding the effects of the projected future climate change and how the foreseen negative impacts can be counteracted by mitigation and adaptation measures. The themes were: Climate policy: the role of law and economics; Biodiversity and ecosystems; Agriculture and climate change; Nanotechnology solutions for a sustainable future; Citizens and society, and The Arctic. The main responsible scientists for the seven conference themes and representatives from the think-tank CONCITO delivered 'The 7 Aarhus Statements on Climate Change' as part of the closing session of the conference. The statements were also communicated to the Danish Government as well as to the press. This article is the product of the collective subsequent work of the seven theme responsibles and is a presentation of each theme statement in detail, emphasizing the current state of knowledge and how it may be used to minimize the expected negative impacts of future climate change.

Arctic melt ponds and bifurcations in the climate system

Science.gov (United States)

Sudakov, I.; Vakulenko, S. A.; Golden, K. M.

2015-05-01

Understanding how sea ice melts is critical to climate projections. In the Arctic, melt ponds that develop on the surface of sea ice floes during the late spring and summer largely determine their albedo - a key parameter in climate modeling. Here we explore the possibility of a conceptual sea ice climate model passing through a bifurcation point - an irreversible critical threshold as the system warms, by incorporating geometric information about melt pond evolution. This study is based on a bifurcation analysis of the energy balance climate model with ice-albedo feedback as the key mechanism driving the system to bifurcation points.

Drivers of inter-annual variation and long-term change in High-Arctic spider species abundances

DEFF Research Database (Denmark)

Bowden, Joseph J.; Hansen, Oskar L. P.; Olsen, Kent

2018-01-01

Understanding how species abundances vary in space and time is a central theme in ecology, yet there are few long-term field studies of terrestrial invertebrate abundances and the determinants of their dynamics. This is particularly relevant in the context of rapid climate change occurring...... in the Arctic. Arthropods can serve as strong indicators of ecosystem change due to their sensitivity to increasing temperatures and other environmental variables. We used spider samples collected by pitfall trapping from three different habitats (fen, mesic and arid heath) in High-Arctic Greenland to assess...... interpretation of long-term trends. We used model selection to determine which climatic variables and/or previous years’ abundance best explained annual variation in species abundances over this period. We identified and used 28 566 adult spiders that comprised eight species. Most notably, the abundances of some...

Little auks buffer the impact of current Arctic climate change

DEFF Research Database (Denmark)

Grémillet, David; Welcker, Jorg; Karnovsky, Nina J.

2012-01-01

Climate models predict a multi-degree warming of the North Atlantic in the 21st century. A research priority is to understand the impact of such changes upon marine organisms. With 40-80 million individuals, planktivorous little auks (Alle alle) are an essential component of pelagic food webs...... in this region that are potentially highly susceptible to climatic effects. Using an integrative study of their behaviour, physiology and fitness at three study sites, we evaluated the impact of ocean warming on little auks across the Greenland Sea in 2005-2007. Contrary to our hypothesis, the birds responded...... to a wide range of sea surface temperatures via plasticity of their foraging behaviour, allowing them to maintain their fitness levels unchanged. Predicted effects of climate change are significantly attenuated by such plasticity, confounding attempts to forecast future impacts of climate change by envelope...

Atmospheric HCH concentrations over the Marine Boundary Layer from Shanghai, China to the Arctic Ocean: role of human activity and climate change.

Science.gov (United States)

Wu, Xiaoguo; Lam, James C W; Xia, Chonghuan; Kang, Hui; Sun, Liguang; Xie, Zhouqing; Lam, Paul K S

2010-11-15

From July to September 2008, air samples were collected aboard the research expedition icebreaker XueLong (Snow Dragon) as part of the 2008 Chinese Arctic Research Expedition Program. Hexachlorocyclohexane (HCH) concentrations were analyzed in all of the samples. The average concentrations (± standard deviation) over the entire period were 33 ± 16, 5.4 ± 3.0, and 13 ± 7.5 pg m⁻³ for α-, β- and γ-HCH, respectively. Compared to previous studies in the same areas, total HCH (ΣHCH, the sum of α-, β-, and γ-HCH) levels declined by more than 10 × compared to those observed in the 1990s, but were approximately 4 × higher than those measured by the 2003 China Arctic Research Expedition, suggesting the increase of atmospheric ΣHCH recently. Because of the continuing use of lindane, ratios of α/γ-HCH showed an obvious decrease in North Pacific and Arctic region compared with those for 2003 Chinese Arctic Research Expedition. In Arctic, the level of α-HCH was found to be linked to sea ice distribution. Geographically, the average concentration of α-HCH in air samples from the Chukchi and Beaufort Seas, neither of which contain sea ice, was 23 ± 4.4 pg m⁻³, while samples from the area covered by seasonal ice (∼75°N to ∼83°N), the so-called "floating sea ice region", contained the highest average levels of α-HCH at 48 ± 12 pg m⁻³, likely due to emission from sea ice and strong air-sea exchange. The lowest concentrations of α-HCH were observed in the pack ice region in the high Arctic covered by multiyear sea ice (∼83°N to ∼86°N). This phenomenon implies that the re-emission of HCH trapped in ice sheets and Arctic Ocean may accelerate during the summer as ice coverage in the Arctic Ocean decreases in response to global climate change.

Potential Arctic tundra vegetation shifts in response to changing temperature, precipitation and permafrost thaw

NARCIS (Netherlands)

Kolk, van der Henk-Jan; Heijmans, M.M.P.D.; Huissteden, van J.; Pullens, J.W.M.; Berendse, F.

2016-01-01

Over the past decades, vegetation and climate have changed significantly in the Arctic. Deciduous shrub cover is often assumed to expand in tundra landscapes, but more frequent abrupt permafrost thaw resulting in formation of thaw ponds could lead to vegetation shifts towards graminoid-dominated

Greenland and the international politics of a changing arctic

DEFF Research Database (Denmark)

Greenland and the International Politics of a Changing Arctic examines the international politics of semi-independent Greenland in a changing and increasingly globalised Arctic. Without sovereign statehood, but with increased geopolitical importance, independent foreign policy ambitions......, and a solidified self-image as a trailblazer for Arctic indigenous peoples’ rights, Greenland is making its mark on the Arctic and is in turn affected – and empowered – by Arctic developments. The chapters in this collection analyse how a distinct Greenlandic foreign policy identity shapes political ends and means...... for regional change in the Arctic. This is the first comprehensive and interdisciplinary examination of Greenland’s international relations and how they are connected to wider Arctic politics. It will be essential reading for students and scholars interested in Arctic governance and security, international...

Changing geo-political realities in the Arctic region

DEFF Research Database (Denmark)

Sørensen, Camilla T. N.

2014-01-01

This article analyzes and discusses how Denmark seeks to manage the changing geopolitical realities in the Arctic region specifically focusing on how Denmark seeks to manage its relations with China in the Arctic region.......This article analyzes and discusses how Denmark seeks to manage the changing geopolitical realities in the Arctic region specifically focusing on how Denmark seeks to manage its relations with China in the Arctic region....

Between Earth and Sky - Climate Change on the Last Frontier

Science.gov (United States)

Weindorf, David; Hunton, Paul

2017-04-01

Globally, Gelisols comprise 11.26 million km2; 8.6% of earth's surface. These soils effectively sequester 25% of global soil organic carbon. Global climate change has disproportionately affected arctic regions of the world, accelerating warming, erosion events, and altering soils and ecosystems. While many documentary films have touched on global climate change, this film is the first to consider the critical role soils play in the biogeochemical carbon cycle. Between Earth and Sky is a feature length documentary filmed in 4K which presents both the science of soil/climate dynamics whilst integrating the perspective of native Alaskans and respected elders of the community who provide personal accounts of changes observed over the past decades in Alaska. More than 40 scientists from universities, governmental research units, and consultancies deconstruct this complex topic to explain how soils form an integral part of the carbon cycle in arctic environments. This presentation will cover the development of the film from initial concepts, writing, fundraising, and project development, through filming on-site, post-production, marketing, and outreach plans.

Inuit Perspectives on Arctic Environmental Change': A Traveling Exhibition

Science.gov (United States)

Sheffield, E. M.; Hakala, J. S.; Gearheard, S.

2006-12-01

The Inuit of Nunavut, Canada, have an intimate relationship with their surroundings. As a culture that relies on knowledge of sea ice, snow, and weather conditions for success in hunting, fishing, and healthy wellbeing, Inuit have observed and studied environmental patterns for generations. An ongoing study into their traditional knowledge and their observations of environmental change is being conducted by researcher Dr. Shari Gearheard, who has worked with Inuit communities in Nunavut for over a decade. The results of the research have been published in scientific journals, and to communicate the results to a broader audience, Dr. Gearheard designed an interactive CD-ROM displaying photographs, maps, and interview videos of Inuit Elders' perspectives on the changes they have witnessed. Receiving immediate popularity since its release in 2004, copies of `When the Weather is Uggianaqtuq: Inuit Observations of Environmental Change' have been distributed worldwide, to indigenous peoples, social science and climate change researchers, teachers, students, and the general public. To further disseminate the information contained on the CD-ROM, the National Snow and Ice Data Center and the Museum of Natural History, both of the University of Colorado, are partnering to create an exhibition which will open at the Museum during the International Polar Year in April 2008. The exhibit, tentatively titled `Inuit Perspectives on Arctic Environmental Change,' will feature photographs, graphics, and text in both English and Inuktitut describing environmental change in the North. The goals are to make the information and interpretation contained on the CD-ROM available and more accessible to a broad audience and to raise awareness about Arctic climate change and the important contribution of Inuit knowledge. Following exhibition at the Museum, the exhibit will travel throughout the United States, Alaska, and Nunavut, through a network of museums, schools, libraries, tribal

Tundra shrubification and tree-line advance amplify arctic climate warming: results from an individual-based dynamic vegetation model

Science.gov (United States)

Zhang, Wenxin; Miller, Paul A.; Smith, Benjamin; Wania, Rita; Koenigk, Torben; Döscher, Ralf

2013-09-01

One major challenge to the improvement of regional climate scenarios for the northern high latitudes is to understand land surface feedbacks associated with vegetation shifts and ecosystem biogeochemical cycling. We employed a customized, Arctic version of the individual-based dynamic vegetation model LPJ-GUESS to simulate the dynamics of upland and wetland ecosystems under a regional climate model-downscaled future climate projection for the Arctic and Subarctic. The simulated vegetation distribution (1961-1990) agreed well with a composite map of actual arctic vegetation. In the future (2051-2080), a poleward advance of the forest-tundra boundary, an expansion of tall shrub tundra, and a dominance shift from deciduous to evergreen boreal conifer forest over northern Eurasia were simulated. Ecosystems continued to sink carbon for the next few decades, although the size of these sinks diminished by the late 21st century. Hot spots of increased CH4 emission were identified in the peatlands near Hudson Bay and western Siberia. In terms of their net impact on regional climate forcing, positive feedbacks associated with the negative effects of tree-line, shrub cover and forest phenology changes on snow-season albedo, as well as the larger sources of CH4, may potentially dominate over negative feedbacks due to increased carbon sequestration and increased latent heat flux.

Does temporal variation of mercury levels in Arctic seabirds reflect changes in global environmental contamination, or a modification of Arctic marine food web functioning?

International Nuclear Information System (INIS)

Fort, Jérôme; Grémillet, David; Traisnel, Gwendoline; Amélineau, Françoise; Bustamante, Paco

2016-01-01

Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts of anthropogenic activities and climate change on the exposure of sensitive species and marine ecosystems. We concurrently measured temporal changes (2006–2014) in mercury (Hg) contamination of little auks (Alle alle; the most abundant Arctic seabird) and in their major zooplankton prey species (Calanoid copepods, Themisto libellula, Gammarus spp.). We found an increasing contamination of the food-chain in East Greenland during summer over the last decade. More specifically, bird contamination (determined by body feather analyses) has increased at a rate of 3.4% per year. Conversely, bird exposure to Hg during winter in the northwest Atlantic (determined by head feather analyses) decreased over the study period (at a rate of 1.5% per year), although winter concentrations remained consistently higher than during summer. By combining mercury levels measured in birds and zooplankton to isotopic analyses, our results demonstrate that inter-annual variations of Hg levels in little auks reflect changes in food-chain contamination, rather than a reorganization of the food web and a modification of seabird trophic ecology. They therefore underline the value of little auks, and Arctic seabirds in general, as bio-indicators of long-term changes in environmental contamination. - Highlights: • We examined temporal trends of Hg in Arctic seabirds and major zooplankton species. • We investigated the role of underlying ecological drivers in seabird contamination. • Hg contamination of the East Greenland marine food web increased over the last decade. • Hg levels in Arctic seabirds reflect changes in the food-chain contamination. • Little auks are bio-indicators of long-term changes in environmental contamination. - Temporal increase of seabird exposure to Hg reflects changes in Arctic environmental contamination.

Climate change science compendium 2009

Energy Technology Data Exchange (ETDEWEB)

McMullen, C.P.; Jabbour, J.

2009-09-15

In a matter of a few weeks' time, governments will gather in Copenhagen, Denmark, for a crucial UN climate convention meeting. Many governments and stakeholders have requested an annual snapshot of how the science has been evolving since the publication of the IPCC's landmark fourth assessment in advance of the panel's next one in 2014. This Climate Change Science Compendium, based on the wealth of peerreviewed research published by researchers and institutions since 2006, has been compiled by UNEP in response to that request. The findings indicate that ever more rapid environmental change is underway with the pace and the scale of climate change accelerating, along with the confidence among researchers in their forecasts. The Arctic, with implications for the globe, is emerging as an area of major concern. There is growing evidence that the ice there is melting far faster than had been previously supposed. Mountains glaciers also appear to be retreating faster. Scientists now suggest that the Arctic could be virtually ice free in September of 2037 and that a nearly ice-free September by 2028 is well within the realms of possibility. Recent findings also show that significant warming extends well beyond the Antarctic Peninsula to cover most of West Antarctica, an area of warming much larger than previously reported. The impact on the Earth's multi-trillion dollar ecosystems is also a key area of concern. Under a high emission scenario-the one that most closely matches current trends-12-39 per cent of the planet's terrestrial surface could experience novel climate conditions and 10-48 per cent could suffer disappearing climates by 2100. Rising levels of aridity are also concentrating scientific minds. New research indicates that by the end of the 21st century the Mediterranean region will also experience much more severe increases in aridity than previously estimated rendering the entire region, but particularly the southern Mediterranean

Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies

Directory of Open Access Journals (Sweden)

S. Menon

2008-03-01

Full Text Available Several short-lived pollutants known to impact Arctic climate may be contributing to the accelerated rates of warming observed in this region relative to the global annually averaged temperature increase. Here, we present a summary of the short-lived pollutants that impact Arctic climate including methane, tropospheric ozone, and tropospheric aerosols. For each pollutant, we provide a description of the major sources and the mechanism of forcing. We also provide the first seasonally averaged forcing and corresponding temperature response estimates focused specifically on the Arctic. The calculations indicate that the forcings due to black carbon, methane, and tropospheric ozone lead to a positive surface temperature response indicating the need to reduce emissions of these species within and outside the Arctic. Additional aerosol species may also lead to surface warming if the aerosol is coincident with thin, low lying clouds. We suggest strategies for reducing the warming based on current knowledge and discuss directions for future research to address the large remaining uncertainties.

Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies

Energy Technology Data Exchange (ETDEWEB)

Menon, Surabi; Quinn, P.K.; Bates, T.S.; Baum, E.; Doubleday, N.; Fiore, A.M.; Flanner, M.; Fridlind, A.; Garrett, T.J.; Koch, D.; Menon, S.; Shindell, D.; Stohl, A.; Warren, S.G.

2007-09-24

Several short-lived pollutants known to impact Arctic climate may be contributing to the accelerated rates of warming observed in this region relative to the global annually averaged temperature increase. Here, we present a summary of the short-lived pollutants that impact Arctic climate including methane, tropospheric ozone, and tropospheric aerosols. For each pollutant, we provide a description of the major sources and the mechanism of forcing. We also provide the first seasonally averaged forcing and corresponding temperature response estimates focused specifically on the Arctic. The calculations indicate that the forcings due to black carbon, methane, and tropospheric ozone lead to a positive surface temperature response indicating the need to reduce emissions of these species within and outside the Arctic. Additional aerosol species may also lead to surface warming if the aerosol is coincident with thin, low lying clouds. We suggest strategies for reducing the warming based on current knowledge and discuss directions for future research to address the large remaining uncertainties.

Western Arctic Temperature Sensitivity Varies under Different Mean States

Science.gov (United States)

Daniels, W.; Russell, J. M.; Morrill, C.; Longo, W. M.; Giblin, A. E.; Holland-Stergar, P.; Hu, A.; Huang, Y.

2017-12-01

The Arctic is warming faster than anywhere on earth. Predictions of future change, however, are hindered by uncertainty in the mechanisms that underpin Arctic amplification. Data from Beringia (Alaska and Eastern Siberia) are particularly inconclusive with regards to both glacial-interglacial climate change as well as the presence or absence of abrupt climate change events such as the Younger Dryas. Here we investigate temperature change in Beringia from the last glacial maximum (LGM) to present using a unique 30 kyr lacustrine record of leaf wax hydrogen isotope ratios (δDwax) from Northern Alaska. We evaluate our results in the context of PMIP3 climate simulations as well as sensitivity tests of the effects of sea level and Bering Strait closure on Arctic Alaskan climate. The amplitude of LGM cooling in Alaska (-3.2 °C relative to pre-industrial) is smaller than other parts of North America and areas proximal to LGM ice sheets, but similar to Arctic Asia and Europe. This suggests that the local feedbacks (vegetation, etc.) had limited impacts on regional temperatures during the last ice-age, and suggests most of the Arctic exhibited similar responses to global climate boundary conditions. Deglacial warming was superimposed by a series of rapid warming events that encompass most of the temperature increase. These events are largely synchronous with abrupt events in the North Atlantic, but are amplified, muted, or even reversed in comparison depending on the mean climate state. For example, we observe warming during Heinrich 1 and during the submergence of the Bering Land Bridge, which are associated with cooling in the North Atlantic. Climate modeling suggests that opening of the Bering Strait controlled the amplitude and sign of millennial-scale temperature changes across the glacial termination.

Arctic climatechange and its impacts on the ecology of the North Atlantic.

Science.gov (United States)

Greene, Charles H; Pershing, Andrew J; Cronin, Thomas M; Ceci, Nicole

2008-11-01

Arctic climate change from the Paleocene epoch to the present is reconstructed with the objective of assessing its recent and future impacts on the ecology of the North Atlantic. A recurring theme in Earth's paleoclimate record is the importance of the Arctic atmosphere, ocean, and cryosphere in regulating global climate on a variety of spatial and temporal scales. A second recurring theme in this record is the importance of freshwater export from the Arctic in regulating global- to basin-scale ocean circulation patterns and climate. Since the 1970s, historically unprecedented changes have been observed in the Arctic as climate warming has increased precipitation, river discharge, and glacial as well as sea-ice melting. In addition, modal shifts in the atmosphere have altered Arctic Ocean circulation patterns and the export of freshwater into the North Atlantic. The combination of these processes has resulted in variable patterns of freshwater export from the Arctic Ocean and the emergence of salinity anomalies that have periodically freshened waters in the North Atlantic. Since the early 1990s, changes in Arctic Ocean circulation patterns and freshwater export have been associated with two types of ecological responses in the North Atlantic. The first of these responses has been an ongoing series of biogeographic range expansions by boreal plankton, including renewal of the trans-Arctic exchanges of Pacific species with the Atlantic. The second response was a dramatic regime shift in the shelf ecosystems of the Northwest Atlantic that occurred during the early 1990s. This regime shift resulted from freshening and stratification of the shelf waters, which in turn could be linked to changes in the abundances and seasonal cycles of phytoplankton, zooplankton, and higher trophic-level consumer populations. It is predicted that the recently observed ecological responses to Arctic climate change in the North Atlantic will continue into the near future if current trends

What is happening in the International Polar Year? Latest news about the climate changes

International Nuclear Information System (INIS)

Orheim, Olav

2008-01-01

The International Polar (IPY) Year 2007-2008 is a large scientific programme focused on the Arctic and the Antarctic. Scientists from over 60 nations participates. The IPY have two primary objectives: to improve weather forecasts especially regarding extreme weather and to improve climatic models for better understanding of possible instabilities, especially regarding ocean currents. The presentation includes data on natural climate change, temperature anomaly, the ice in the Arctic Ocean and Northern and Southern Hemisphere sea ice area, current in Southern and Northern hemisphere sea ice area and variations of the surface temperature ice arctic regions antarctic regions. The presentation was held at the MNT-Forum, 29. January 2008

Predicting Changes in Arctic Tundra Vegetation: Towards an Understanding of Plant Trait Uncertainty

Science.gov (United States)

Euskirchen, E. S.; Serbin, S.; Carman, T.; Iversen, C. M.; Salmon, V.; Helene, G.; McGuire, A. D.

2017-12-01

Arctic tundra plant communities are currently undergoing unprecedented changes in both composition and distribution under a warming climate. Predicting how these dynamics may play out in the future is important since these vegetation shifts impact both biogeochemical and biogeophysical processes. More precise estimates of these future vegetation shifts is a key challenge due to both a scarcity of data with which to parameterize vegetation models, particularly in the Arctic, as well as a limited understanding of the importance of each of the model parameters and how they may vary over space and time. Here, we incorporate newly available field data from arctic Alaska into a dynamic vegetation model specifically developed to take into account a particularly wide array of plant species as well as the permafrost soils of the arctic tundra (the Terrestrial Ecosystem Model with Dynamic Vegetation and Dynamic Organic Soil, Terrestrial Ecosystem Model; DVM-DOS-TEM). We integrate the model within the Predicative Ecosystem Analyzer (PEcAn), an open-source integrated ecological bioinformatics toolbox that facilitates the flows of information into and out of process models and model-data integration. We use PEcAn to evaluate the plant functional traits that contribute most to model variability based on a sensitivity analysis. We perform this analysis for the dominant types of tundra in arctic Alaska, including heath, shrub, tussock and wet sedge tundra. The results from this analysis will help inform future data collection in arctic tundra and reduce model uncertainty, thereby improving our ability to simulate Arctic vegetation structure and function in response to global change.

Vulnerability and adaptation to climate change in the arctic (VACCA): Implementing recommendations

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

This report provides recommendations for how Norway's government could move forward with the results from the Arctic Council supported VACCA project, suggesting how concrete activities may be implemented and applied to policy and practice. Based on the results of interviews with Arctic peoples and people involved in Arctic work, combined with desk studies of relevant literature, four Arctic contexts are defined within the dividing lines coastal/non-coastal and urban/non-urban. This report provides up to five concrete recommendations within each context, recommendations for cross-contextual action, and specific projects for further research and action.(auth)

Arctic Ocean Paleoceanography and Future IODP Drilling

Science.gov (United States)

Stein, Ruediger

2015-04-01

Although the Arctic Ocean is a major player in the global climate/earth system, this region is one of the last major physiographic provinces on Earth where the short- and long-term geological history is still poorly known. This lack in knowledge is mainly due to the major technological/logistical problems in operating within the permanently ice-covered Arctic region which makes it difficult to retrieve long and undisturbed sediment cores. Prior to 2004, in the central Arctic Ocean piston and gravity coring was mainly restricted to obtaining near-surface sediments, i.e., only the upper 15 m could be sampled. Thus, all studies were restricted to the late Pliocene/Quaternary time interval, with a few exceptions. These include the four short cores obtained by gravity coring from drifting ice floes over the Alpha Ridge, where older pre-Neogene organic-carbon-rich muds and laminated biosiliceous oozes were sampled. Continuous central Arctic Ocean sedimentary records, allowing a development of chronologic sequences of climate and environmental change through Cenozoic times and a comparison with global climate records, however, were missing prior to the IODP Expedition 302 (Arctic Ocean Coring Expedition - ACEX), the first scientific drilling in the central Arctic Ocean. By studying the unique ACEX sequence, a large number of scientific discoveries that describe previously unknown Arctic paleoenvironments, were obtained during the last decade (for most recent review and references see Stein et al., 2014). While these results from ACEX were unprecedented, key questions related to the climate history of the Arctic Ocean remain unanswered, in part because of poor core recovery, and in part because of the possible presence of a major mid-Cenozoic hiatus or interval of starved sedimentation within the ACEX record. In order to fill this gap in knowledge, international, multidisciplinary expeditions and projects for scientific drilling/coring in the Arctic Ocean are needed. Key

Dynamics of a recovering Arctic bird population: the importance of climate, density dependence, and site quality

Science.gov (United States)

Bruggeman, Jason E.; Swem, Ted; Andersen, David E.; Kennedy, Patricia L.; Nigro, Debora A.

2015-01-01

indicative of higher-quality habitat), are a priority for continued protection from potential nearby development and disturbance to minimize population-level impacts. Climate change may affect Arctic peregrines in multiple ways, including through access to more snow-free nest sites and a lengthened breeding season that may increase likelihood of nest success. Our work provides insight into factors affecting a population during and after recovery, and demonstrates how the Dail-Madsen model can be used for any unmarked population with multiple years of abundance data collected through repeated surveys.

Planning in a climate of change: Choices under uncertainty

International Nuclear Information System (INIS)

Etkin, D.

1993-01-01

As part of a plan to ensure that potential changes in the Canadian environment as a result of climate change are considered in major projects, the Canadian Climate Centre has developed a set of interim guidelines for consideration of climate change concerns in environmental assessments. One such guideline is to identify the sensitivity of the project to climate variability and change, including increased risks of extreme events. This guideline is discussed in a consideration of different methodologies of assessing possible future impacts, and in an examination of ways to assemble a climate data base. Climatological data sets may be obtained from climate normals, historical or paleoclimate data, global climate models, or spatial analogues. Methodological approaches include selecting the most likely future, selecting a range of scenarios, bounding the problem, or using a probability distribution function. A case study is used for illustration, in which the effects of climate change on a permafrost dyke of a tailings pond at an Arctic mining operation are assessed. 18 refs., 3 figs

Quantification of physical and economic impacts of climate change on public infrastructure in Alaska and benefits of global greenhouse gas mitigation

Science.gov (United States)

Melvin, A. M.; Larsen, P.; Boehlert, B.; Martinich, J.; Neumann, J.; Chinowsky, P.; Schweikert, A.; Strzepek, K.

2015-12-01

Climate change poses many risks and challenges for the Arctic and sub-Arctic, including threats to infrastructure. The safety and stability of infrastructure in this region can be impacted by many factors including increased thawing of permafrost soils, reduced coastline protection due to declining arctic sea ice, and changes in inland flooding. The U.S. Environmental Protection Agency (EPA) is coordinating an effort to quantify physical and economic impacts of climate change on public infrastructure across the state of Alaska and estimate how global greenhouse gas (GHG) mitigation may avoid or reduce these impacts. This research builds on the Climate Change Impacts and Risk Analysis (CIRA) project developed for the contiguous U.S., which is described in an EPA report released in June 2015. We are using a multi-model analysis focused primarily on the impacts of changing permafrost, coastal erosion, and inland flooding on a range of infrastructure types, including transportation (e.g. roads, airports), buildings and harbors, energy sources and transmission, sewer and water systems, and others. This analysis considers multiple global GHG emission scenarios ranging from a business as usual future to significant global action. These scenarios drive climate projections through 2100 spanning a range of outcomes to capture variability amongst climate models. Projections are being combined with a recently developed public infrastructure database and integrated into a version of the Infrastructure Planning Support System (IPSS) we are modifying for use in the Arctic and sub-Arctic region. The IPSS tool allows for consideration of both adaptation and reactive responses to climate change. Results of this work will address a gap in our understanding of climate change impacts in Alaska, provide estimates of the physical and economic damages we may expect with and without global GHG mitigation, and produce important insights about infrastructure vulnerabilities in response to

Graduate training in Earth science across borders and disciplines: ArcTrain -"Processes and impacts of climate change in the North Atlantic Ocean and the Canadian Arctic"

Science.gov (United States)

Stein, Rüdiger; Kucera, Michal; Walter, Maren; de Vernal, Anne

2015-04-01

Due to a complex set of feedback processes collectively known as "polar amplification", the Arctic realm is expected to experience a greater-than-average response to global climate forcing. The cascades of feedback processes that connect the Arctic cryosphere, ocean and atmosphere remain incompletely constrained by observations and theory and are difficult to simulate in climate models. Our capacity to predict the future of the region and assess the impacts of Arctic change processes on global and regional environments hinges on the availability of interdisciplinary experts with strong international experience and understanding of the science/society interface. This is the basis of the International Research Training Group "Processes and impacts of climate change in the North Atlantic Ocean and the Canadian Arctic - ArcTrain", which was initiated in 2013. ArcTrain aims to educate PhD students in an interdisciplinary environment that combines paleoclimatology, physical oceanography, remote sensing and glaciology with comprehensive Earth system modelling, including sea-ice and ice-sheet components. The qualification program for the PhD students includes joint supervision, mandatory research residences at partner institutions, field courses on land and on sea (Floating University), annual meetings and training workshops and a challenging structured training in expert skills and transferrable skills. Its aim is to enhance the career prospects and employability of the graduates in a challenging international job market across academic and applied sectors. ArcTrain is a collaborative project at the University of Bremen and the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven. The German part of the project is designed to continue for nine years and educate three cohorts of twelve PhD students each. The Canadian partners comprise a consortium of eight universities led by the GEOTOP cluster at the Université du Québec à Montréal and including

Arctic species resilience

DEFF Research Database (Denmark)

Mortensen, Lars O.; Forchhammer, Mads C.; Jeppesen, Erik

The peak of biological activities in Arctic ecosystems is characterized by a relative short and intense period between the start of snowmelt until the onset of frost. Recent climate changes have induced larger seasonal variation in both timing of snowmelt as well as changes mean temperatures......, an extensive monitoring program has been conducted in the North Eastern Greenland National Park, the Zackenberg Basic. The objective of the program is to provide long time series of data on the natural innate oscillations and plasticity of a High Arctic ecosystem. With offset in the data provided through...

Northern Peatland Shifts Under Changing Climate and Their Impact on Permafrost

Science.gov (United States)

Shur, Y.; Jorgenson, T.; Kanevskiy, M. Z.

2014-12-01

Formation of peatlands depends primarily on climate and its interactions with hydrology, soil thermal regimes, plant composition, and nutrients. A water balance with precipitation exceeding evaporation is necessary for their formation. The rate of peat accumulation also greatly depends on thermal resources. The prominent impact of the water balance and temperature on peatland formation is evident in the West Siberia Lowland. The rate of peat accumulation steadily increases from arctic tundra to moss tundra, to forest tundra, to northern taiga, and to southern taiga. This increase is a result in increase in air temperature and length of the growing season because all of these zones have water balance favorable for peat formation. Further to south, evaporation prevails over precipitation and peat formation occurs only in isolated areas. Climate change will redefine geographical distribution of climatic and vegetation zones. It is predicted that in arctic and subarctic regions the difference between precipitation and evaporation will increase and as a result these regions will remain favorable to peat accumulation. With increase of thermal resources, the rate of peat accumulation will also increase. The Alaska Arctic Coastal Plain is of a special interest because it has thousands of shallow lakes, which due to warming climate would shift from open waterbodies to peatlands through shoreline paludification and infilling. The accumulation of organic matter will likely turn open water into shore fens and bogs, and eventually to peat plateaus, as is occurring in many boreal landscapes. Expected impact on permafrost in arctic and subarctic regions will include rise of the permafrost table, thickening of the ice-rich intermediate layer with ataxitic (suspended) cryostructure, and replacement of frost boils with earth hummocks. In the contemporary continuous permafrost zone, permafrost formed as climate-driven will be transformed into climate-driven ecosystem protected

DOE Final Report on Collaborative Research. Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Qianlai [Purdue Univ., West Lafayette, IN (United States); Schlosser, C. Adam [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Melillo, Jerry M. [Marine Biological Lab. (MBL), Woods Hole, MA (United States); Anthony, Katey Walter [Univ. of Alaska, Fairbanks, AK (United States); Kicklighter, David [Marine Biological Lab. (MBL), Woods Hole, MA (United States); Gao, Xiang [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2015-11-03

Our overall goal is to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically-forced climate warming, and the conditions under which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes to the landscape of wetlands and lakes, especially thermokarst (thaw) lakes, across the Arctic. Through a suite of numerical experiments that encapsulate the fundamental processes governing methane emissions and carbon exchanges – as well as their coupling to the global climate system - we intend to test the following hypothesis in the proposed research: There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases in methane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in a strong, positive feedback to global climate warming.

Indigenous observations of climate change in the Lower Yukon River Basin, Alaska

Science.gov (United States)

Herman-Mercer, Nicole M.; Schuster, Paul F.; Maracle, Karonhiakt'tie

2011-01-01

Natural science climate change studies have led to an overwhelming amount of evidence that the Arctic and Subarctic are among the world's first locations to begin experiencing climate change. Indigenous knowledge of northern regions is a valuable resource to assess the effects of climate change on the people and the landscape. Most studies, however, have focused on coastal Arctic and Subarctic communities with relatively little focus on inland communities. This paper relates the findings from fieldwork conducted in the Lower Yukon River Basin of Alaska in the spring of 2009. Semi-structured interviews were conducted with hunters and elders in the villages of St. Mary's and Pitka's Point, Alaska to document observations of climate change. This study assumes that scientific findings and indigenous knowledge are complementary and seeks to overcome the false dichotomy that these two ways of knowing are in opposition. The observed changes in the climate communicated by the hunters and elders of St. Mary's and Pitka's Point, Alaska are impacting the community in ways ranging from subsistence (shifting flora and fauna patterns), concerns about safety (unpredictable weather patterns and dangerous ice conditions), and a changing resource base (increased reliance on fossil fuels). Here we attempt to address the challenges of integrating these two ways of knowing while relating indigenous observations as described by elders and hunters of the study area to those described by scientific literature.

Climate-induced behavioral changes influence exposure of an Arctic apex predator to pathogens and contaminants

Science.gov (United States)

Polar bears (Ursus maritimus) may serve as sentinels for pathogens and contaminants, providing insight into changing Arctic ecosystems and health risks to wildlife and humans. Recent changes in the availability of sea ice habitat have coincided with increased use of land by polar bears from the sout...

Arctic Warming as News - Perils and Possibilities

Science.gov (United States)

Revkin, A. C.

2015-12-01

A science journalist in his 30th year covering human-driven climate change, including on three Arctic reporting trips, reflects on successes and setbacks as news media, environmentalists and Arctic communities have tried to convey the significance of polar change to a public for which the ends of the Earth will always largely be a place of the imagination.Novel challenges are arising in the 24/7 online media environment, as when a paper by a veteran climate scientist proposing a mechanism for abrupt sea-level rise became a big news story before it was accepted by the open-review journal to which it had been submitted. New science is digging in on possible connections between changing Arctic sea ice and snow conditions and disruptive winter weather in more temperate northern latitudes, offering a potential link between this distant region and the lives of ordinary citizens. As cutting-edge research, such work gets substantial media attention. But, as with all new areas of inquiry, uncertainty dominates - creating the potential for distracting the public and policymakers from the many aspects of anthropogenic climate change that are firmly established - but, in a way, boring because of that.With the challenges, there are unprecedented opportunities for conveying Arctic science. In some cases, researchers on expeditions are partnering with media, offering both scientists and news outlets fresh ways to convey the story of Arctic change in an era of resource constraints.Innovative uses of crittercams, webcams, and satellite observations offer educators and interested citizens a way to track and appreciate Arctic change. But more can be done to engage the public directly without the news media as an intermediary, particularly if polar scientists or their institutions test some of the established practices honed by more experienced communicators at NASA.

Tundra shrubification and tree-line advance amplify arctic climate warming: results from an individual-based dynamic vegetation model

International Nuclear Information System (INIS)

Zhang Wenxin; Miller, Paul A; Smith, Benjamin; Wania, Rita; Koenigk, Torben; Döscher, Ralf

2013-01-01

One major challenge to the improvement of regional climate scenarios for the northern high latitudes is to understand land surface feedbacks associated with vegetation shifts and ecosystem biogeochemical cycling. We employed a customized, Arctic version of the individual-based dynamic vegetation model LPJ-GUESS to simulate the dynamics of upland and wetland ecosystems under a regional climate model–downscaled future climate projection for the Arctic and Subarctic. The simulated vegetation distribution (1961–1990) agreed well with a composite map of actual arctic vegetation. In the future (2051–2080), a poleward advance of the forest–tundra boundary, an expansion of tall shrub tundra, and a dominance shift from deciduous to evergreen boreal conifer forest over northern Eurasia were simulated. Ecosystems continued to sink carbon for the next few decades, although the size of these sinks diminished by the late 21st century. Hot spots of increased CH 4 emission were identified in the peatlands near Hudson Bay and western Siberia. In terms of their net impact on regional climate forcing, positive feedbacks associated with the negative effects of tree-line, shrub cover and forest phenology changes on snow-season albedo, as well as the larger sources of CH 4 , may potentially dominate over negative feedbacks due to increased carbon sequestration and increased latent heat flux. (letter)

Lessons learned in managing crowdsourced data in the Alaskan Arctic.

Science.gov (United States)

Mastracci, Diana

2017-04-01

There is perhaps no place in which the consequences of global climate change can be felt more acutely than the Arctic. However, due to lack of measurements at the high latitudes, validation processes are often problematic. Citizen science projects, co-designed together with Native communities at the interface of traditional knowledge and scientific research, could play a major role in climate change adaptation strategies by advancing knowledge of the Arctic system, strengthening inter-generational bonds and facilitating improved knowledge transfer. This presentation will present lessons learned from a pilot project in the Alaskan Arctic, in which innovative approaches were used to design climate change adaptation strategies to support young subsistence hunters in taking in-situ measurements whilst out on the sea-ice. Both the socio-cultural and hardware/software challenges presented in this presentation, could provide useful guidance for future programs that aim to integrate citizens' with scientific data in Arctic communities.

Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic

Science.gov (United States)

Gustine, David D.; Brinkman, Todd J.; Lindgren, Michael A.; Schmidt, Jennifer I.; Rupp, T. Scott; Adams, Layne G.

2014-01-01

Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (−21%) than the Central Arctic herd that wintered primarily in the arctic tundra (−11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

Directory of Open Access Journals (Sweden)

David D Gustine

Full Text Available Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs, and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21% than the Central Arctic herd that wintered primarily in the arctic tundra (-11%. Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

Science.gov (United States)

Gustine, David D; Brinkman, Todd J; Lindgren, Michael A; Schmidt, Jennifer I; Rupp, T Scott; Adams, Layne G

2014-01-01

Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21%) than the Central Arctic herd that wintered primarily in the arctic tundra (-11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

Physiological and ecological effects of increasing temperature on fish production in lakes of Arctic Alaska

Science.gov (United States)

Carey, Michael P.; Zimmerman, Christian E.

2014-01-01

Lake ecosystems in the Arctic are changing rapidly due to climate warming. Lakes are sensitive integrators of climate-induced changes and prominent features across the Arctic landscape, especially in lowland permafrost regions such as the Arctic Coastal Plain of Alaska. Despite many studies on the implications of climate warming, how fish populations will respond to lake changes is uncertain for Arctic ecosystems. Least Cisco (Coregonus sardinella) is a bellwether for Arctic lakes as an important consumer and prey resource. To explore the consequences of climate warming, we used a bioenergetics model to simulate changes in Least Cisco production under future climate scenarios for lakes on the Arctic Coastal Plain. First, we used current temperatures to fit Least Cisco consumption to observed annual growth. We then estimated growth, holding food availability, and then feeding rate constant, for future projections of temperature. Projected warmer water temperatures resulted in reduced Least Cisco production, especially for larger size classes, when food availability was held constant. While holding feeding rate constant, production of Least Cisco increased under all future scenarios with progressively more growth in warmer temperatures. Higher variability occurred with longer projections of time mirroring the expanding uncertainty in climate predictions further into the future. In addition to direct temperature effects on Least Cisco growth, we also considered changes in lake ice phenology and prey resources for Least Cisco. A shorter period of ice cover resulted in increased production, similar to warming temperatures. Altering prey quality had a larger effect on fish production in summer than winter and increased relative growth of younger rather than older age classes of Least Cisco. Overall, we predicted increased production of Least Cisco due to climate warming in lakes of Arctic Alaska. Understanding the implications of increased production of Least Cisco to

The Arctic Turn

DEFF Research Database (Denmark)

Rahbek-Clemmensen, Jon

2018-01-01

In October 2006, representatives of the Arctic governments met in Salekhard in northern Siberia for the biennial Arctic Council ministerial meeting to discuss how the council could combat regional climate change, among other issues. While most capitals were represented by their foreign minister......, a few states – Canada, Denmark, and the United States – sent other representatives. There was nothing unusual about the absence of Per Stig Møller, the Danish foreign minister – a Danish foreign minister had only once attended an Arctic Council ministerial meeting (Arctic Council 2016). Møller......’s nonappearance did, however, betray the low status that Arctic affairs had in the halls of government in Copenhagen. Since the end of the Cold War, where Greenland had helped tie Denmark and the US closer together due to its geostrategically important position between North America and the Soviet Union, Arctic...

Building Resilience and Adaptation to Manage Arctic Change

Energy Technology Data Exchange (ETDEWEB)

Chapin, F. Stuart III [Univ. of Alaska, Fairbanks (United States). Inst. of Arctic Biology; Hoel, Michael [Oslo Univ. (Norway). Dept. of Economics; Carpenter, Steven R. [Wisconsin Univ., Madison, WI, (US). Center for Limnology] (and others)

2006-06-15

Unprecedented global changes caused by human actions challenge society's ability to sustain the desirable features of our planet. This requires proactive management of change to foster both resilience (sustaining those attributes that are important to society in the face of change) and adaptation (developing new socio- ecological configurations that function effectively under new conditions). The Arctic may be one of the last remaining opportunities to plan for change in a spatially extensive region where many of the ancestral ecological and social processes and feedbacks are still intact. If the feasibility of this strategy can be demonstrated in the Arctic, our improved understanding of the dynamics of change can be applied to regions with greater human modification. Conditions may now be ideal to implement policies to manage Arctic change because recent studies provide the essential scientific understanding, appropriate international institutions are in place, and Arctic nations have the wealth to institute necessary changes, if they choose to do so.

Calcareous microfossil-based orbital cyclostratigraphy in the Arctic Ocean

Science.gov (United States)

Marzen, Rachel; DeNinno, Lauren H.; Cronin, Thomas M.

2016-01-01

Microfaunal and geochemical proxies from marine sediment records from central Arctic Ocean (CAO) submarine ridges suggest a close relationship over the last 550 thousand years (kyr) between orbital-scale climatic oscillations, sea-ice cover, marine biological productivity and other parameters. Multiple paleoclimate proxies record glacial to interglacial cycles. To understand the climate-cryosphere-productivity relationship, we examined the cyclostratigraphy of calcareous microfossils and constructed a composite Arctic Paleoclimate Index (API) "stack" from benthic foraminiferal and ostracode density from 14 sediment cores. Following the hypothesis that API is driven mainly by changes in sea-ice related productivity, the API stack shows the Arctic experienced a series of highly productive interglacials and interstadials every ∼20 kyr. These periods signify minimal ice shelf and sea-ice cover and maximum marine productivity. Rapid transitions in productivity are seen during shifts from interglacial to glacial climate states. Discrepancies between the Arctic API curves and various global climatic, sea-level and ice-volume curves suggest abrupt growth and decay of Arctic ice shelves related to climatic and sea level oscillations.

The sea ice mass budget of the Arctic and its future change as simulated by coupled climate models

Energy Technology Data Exchange (ETDEWEB)

Holland, Marika M. [National Center for Atmospheric Research, Boulder, CO (United States); Serreze, Mark C.; Stroeve, Julienne [University of Colorado, National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, Boulder, CO (United States)

2010-02-15

Arctic sea ice mass budgets for the twentieth century and projected changes through the twenty-first century are assessed from 14 coupled global climate models. Large inter-model scatter in contemporary mass budgets is strongly related to variations in absorbed solar radiation, due in large part to differences in the surface albedo simulation. Over the twenty-first century, all models simulate a decrease in ice volume resulting from increased annual net melt (melt minus growth), partially compensated by reduced transport to lower latitudes. Despite this general agreement, the models vary considerably regarding the magnitude of ice volume loss and the relative roles of changing melt and growth in driving it. Projected changes in sea ice mass budgets depend in part on the initial (mid twentieth century) ice conditions; models with thicker initial ice generally exhibit larger volume losses. Pointing to the importance of evolving surface albedo and cloud properties, inter-model scatter in changing net ice melt is significantly related to changes in downwelling longwave and absorbed shortwave radiation. These factors, along with the simulated mean and spatial distribution of ice thickness, contribute to a large inter-model scatter in the projected onset of seasonally ice-free conditions. (orig.)

The Svalbard REU Program: Undergraduates Pursuing Arctic Climate Change Research on Svalbard, Norway

Science.gov (United States)

Roof, S.; Werner, A.

2007-12-01

The Svalbard Research Experiences for Undergraduates (REU) program sponsored by the Arctic Natural Sciences Program of the National Science Foundation has been successfully providing international field research experiences since 2004. Each year, 7-9 undergraduate students have participated in 4-5 weeks of glacial geology and climate change fieldwork on Spitsbergen in the Svalbard archipelago in the North Atlantic (76- 80° N lat.). While we continue to learn new and better ways to run our program, we have learned specific management and pedagogical strategies that allow us to streamline our logistics and to provide genuine, meaningful research opportunities to undergraduate students. We select student participants after extensive nationwide advertising and recruiting. Even before applying to the program, students understand that they will be doing meaningful climate change science, will take charge of their own project, and will be expected to continue their research at their home institution. We look for a strong commitment of support from a student's advisor at their home institution before accepting students into our program. We present clear information, including participant responsibilities, potential risks and hazards, application procedures, equipment needed, etc on our program website. The website also provides relevant research papers and data and results from previous years, so potential participants can see how their efforts will contribute to growing body of knowledge. New participants meet with the previous years' participants at a professional meeting (our "REUnion") before they start their field experience. During fieldwork, students are expected to develop research questions and test their own hypotheses while providing and responding to peer feedback. Professional assessment by an independent expert provides us with feedback that helps us improve logistical procedures and shape our educational strategies. The assessment also shows us how

Climate Change and Risks to National Security

Science.gov (United States)

Titley, D.

2017-12-01

Climate change impacts national security in three ways: through changes in the operating environments of the military; by increasing risks to security infrastructure, specifically bases and training ranges; and by exacerbating and accelerating the risks of state collapse and conflict in regions that are already fragile and unstable. Additionally there will be unique security challenges in the Arctic as sea-ice melts out and human activities increase across multiple dimensions. Military forces will also likely see increased demand for Humanitarian Assistance and Disaster Relief resulting from a combination of increased human population, rising sea-level, and potentially stronger and wetter storms. The talk will explore some of the lesser known aspects of these changes, examine selected climate-driven 'wild cards' that have the potential to disrupt regional and global security, and explore how migration in the face of a changing climate may heighten security issues. I will assess the positions U.S. executive and legislative branches with respect to climate & security, and how those positions have evolved since the November 2016 election, sometimes in counter-intuitive ways. The talk will close with some recommended courses of action the security enterprise can take to manage this climate risk.

Coordinating for Arctic Conservation: Implementing Integrated Arctic Biodiversity Monitoring, Data Management and Reporting

Science.gov (United States)

Gill, M.; Svoboda, M.

2012-12-01

Arctic ecosystems and the biodiversity they support are experiencing growing pressure from various stressors (e.g. development, climate change, contaminants, etc.) while established research and monitoring programs remain largely uncoordinated, lacking the ability to effectively monitor, understand and report on biodiversity trends at the circumpolar scale. The maintenance of healthy arctic ecosystems is a global imperative as the Arctic plays a critical role in the Earth's physical, chemical and biological balance. A coordinated and comprehensive effort for monitoring arctic ecosystems is needed to facilitate effective and timely conservation and adaptation actions. The Arctic's size and complexity represents a significant challenge towards detecting and attributing important biodiversity trends. This demands a scaled, pan-arctic, ecosystem-based approach that not only identifies trends in biodiversity, but also identifies underlying causes. It is critical that this information be made available to generate effective strategies for adapting to changes now taking place in the Arctic—a process that ultimately depends on rigorous, integrated, and efficient monitoring programs that have the power to detect change within a "management" time frame. To meet these challenges and in response to the Arctic Climate Impact Assessment's recommendation to expand and enhance arctic biodiversity monitoring, the Conservation of Arctic Flora and Fauna (CAFF) Working Group of the Arctic Council launched the Circumpolar Biodiversity Monitoring Program (CBMP). The CBMP is led by Environment Canada on behalf of Canada and the Arctic Council. The CBMP is working with over 60 global partners to expand, integrate and enhance existing arctic biodiversity research and monitoring efforts to facilitate more rapid detection, communication and response to significant trends and pressures. Towards this end, the CBMP has established three Expert Monitoring Groups representing major Arctic

Climate change and infectious diseases in the Arctic

DEFF Research Database (Denmark)

Parkinson, Alan J; Evengard, Birgitta; Semenza, Jan C

2014-01-01

The Arctic, even more so than other parts of the world, has warmed substantially over the past few decades. Temperature and humidity influence the rate of development, survival and reproduction of pathogens and thus the incidence and prevalence of many infectious diseases. Higher temperatures may......., Coxiella burnetti, rabies virus, West Nile virus, Hantaviruses, and tick-borne encephalitis viruses....

High-Arctic Plant-Herbivore Interactions under Climate Influence

DEFF Research Database (Denmark)

Berg, Thomas B.; Schmidt, Niels M.; Høye, Toke Thomas

This chapter focuses on a 10-year data series from Zackenberg on the trophic interactions between two characteristic arctic plant species, arctic willow Salix arctica and mountain avens Dryas octopetala, and three herbivore species covering the very scale of size present at Zackenberg, namely......, the moth Sympistis zetterstedtii, the collared lemming Dicrostonyx groenlandicus and the musk ox Ovibos moschatus. Data from Zackenberg show that timing of snowmelt, the length of the growing season and summer temperature are the basic variables that determine the phenology of flowering and primary...... production upon which the herbivores depend, and snow may be the most important climatic factor affecting the different trophic levels and the interactions between them. Hence, the spatio-temporal distribution of snow, as well as thawing events during winter, may have considerable effects on the herbivores...

Will climate change capitalism? The major change of the X XI century

International Nuclear Information System (INIS)

Mistral, Jacques; Tirole, Jean; Rocard, Michel; Artus, Patrick; Benhamou, Francoise; Betbeze, Jean-Paul; Brender, Anton; Charpin, Jean-Michel; Chevalier, Jean-Marie; Contamin, Raphael; Fulda, Bruno; Geoffron, Patrice; Giraud, Pierre-Noel; Gonand, Frederic; Hassan, Fabien; Jacquet, Pierre; Jouvet, Pierre-Andre; Parker, Geoffrey; Perthuis, Christian de; Schubert, Katheline; Suwa-Eisenmann, Akiko

2015-01-01

After an introduction and an interview with an historian on the Little Ice Age of the 17. century, this collective book gathers several contributions. A first set discusses the possible change of capitalism under the influence of the carbon market. The authors discuss the political economy of global warming, the relationship between climate negotiation and carbon price, the ways companies take the carbon price into account in their decisions, and the energy and economic transitions. The second set of contributions discusses the influence of climate on the logics of political choices. The authors address the relationship between natural resources and growth, the macro-economic consequences of climate disruption, how to finance the climate, the virtuous relationships between finance and climate, and why it seems so difficult to act for the climate when considering political ambition and economic lucidity. The third and last set of contributions addresses the possible influence of climate change on geopolitics. The authors address and comment the situation of southern countries with respect to climate change, the American leadership challenged by climate issues, the threat China could be for climate more than for anything else, and the European energy strategy with respect to the COP21. A last article discusses the relationship between global warming and the evolution of the Arctic area

Quality Climate Change Professional Development Translates into Quality Climate Change Education (Invited)

Science.gov (United States)

Holzer, M. A.

2013-12-01

Perhaps one of the reasons we have so many climate change deniers in the United States is that to them climate change is not occurring. This is a valid claim about climate change deniers considering that the effects of climate change in the mid-latitudes are quite subtle as compared to those found in low-latitude and high-latitude regions. A mid-latitude classroom teacher is saddled with the challenge of enlightening students about our changing climate and empowering students to assist in making necessary lifestyle changes, all the while the students don't understand the urgency in doing so. Quality climate change data and resources from the Polar Regions and low latitudes, as well as connections to researchers from these regions help to bridge the understanding of our changing climate from the extreme latitudes to the mid-latitudes. Connecting science teachers with data, resources, and researchers is one way of ensuring our mid-latitude students understand the urgency in taking appropriate actions to adapt, mitigate, and show resilience. This presentation will highlight a few of the many impacts of an authentic research experience for teachers that not only provides teachers with data, resources, and researchers, but changes the way a science teacher teaches where the methods they use mirror the methods used by scientists. National projects like PolarTREC connect educators with the science of climate change as well as the reality of impacts of climate change. For example, research expeditions in the Arctic and in Antarctica connect teachers with the content and practices of climate change science preparing them to replicate their experiences with their students. A PolarTREC experience does not end with the close of the expedition. Teachers continue their connections with the program through their educator network, the integration of PolarTREC resources into their curriculums, and communications with their principal investigators either virtually or with school

Progress report for project modeling Arctic barrier island-lagoon system response to projected Arctic warming

Science.gov (United States)

Erikson, Li H.; Gibbs, Ann E.; Richmond, Bruce M.; Storlazzi, Curt; B.M. Jones,

2012-01-01

Changes in Arctic coastal ecosystems in response to global warming may be some of the most severe on the planet. A better understanding and analysis of the rates at which these changes are expected to occur over the coming decades is crucial in order to delineate high-priority areas that are likely to be affected by climate changes. In this study we investigate the likelihood of changes to habitat-supporting barrier island – lagoon systems in response to projected changes in atmospheric and oceanographic forcing associated with Arctic warming. To better understand the relative importance of processes responsible for the current and future coastal landscape, key parameters related to increasing arctic temperatures are investigated and used to establish boundary conditions for models that simulate barrier island migration and inundation of deltaic deposits and low-lying tundra. The modeling effort investigates the dominance and relative importance of physical processes shaping the modern Arctic coastline as well as decadal responses due to projected conditions out to the year 2100.

International Regulation of Central Arctic Ocean Fisheries

NARCIS (Netherlands)

Molenaar, E.J.

Due in particular to the impacts of climate change, the adequacy of the international regulation of Central Arctic Ocean fisheries has come under increasing scrutiny in recent years. As shown in this article, however, international regulation of Central Arctic Ocean fisheries is by no means entirely

Correlated declines in Pacific arctic snow and sea ice cover

Science.gov (United States)

Stone, Robert P.; Douglas, David C.; Belchansky, Gennady I.; Drobot, Sheldon

2005-01-01

Simulations of future climate suggest that global warming will reduce Arctic snow and ice cover, resulting in decreased surface albedo (reflectivity). Lowering of the surface albedo leads to further warming by increasing solar absorption at the surface. This phenomenon is referred to as “temperature–albedo feedback.” Anticipation of such a feedback is one reason why scientists look to the Arctic for early indications of global warming. Much of the Arctic has warmed significantly. Northern Hemisphere snow cover has decreased, and sea ice has diminished in area and thickness. As reported in the Arctic Climate Impact Assessment in 2004, the trends are considered to be outside the range of natural variability, implicating global warming as an underlying cause. Changing climatic conditions in the high northern latitudes have influenced biogeochemical cycles on a broad scale. Warming has already affected the sea ice, the tundra, the plants, the animals, and the indigenous populations that depend on them. Changing annual cycles of snow and sea ice also affect sources and sinks of important greenhouse gases (such as carbon dioxide and methane), further complicating feedbacks involving the global budgets of these important constituents. For instance, thawing permafrost increases the extent of tundra wetlands and lakes, releasing greater amounts of methane into the atmosphere. Variable sea ice cover may affect the hemispheric carbon budget by altering the ocean–atmosphere exchange of carbon dioxide. There is growing concern that amplification of global warming in the Arctic will have far-reaching effects on lower latitude climate through these feedback mechanisms. Despite the diverse and convincing observational evidence that the Arctic environment is changing, it remains unclear whether these changes are anthropogenically forced or result from natural variations of the climate system. A better understanding of what controls the seasonal distributions of snow and ice

Arctic marine climate of the early nineteenth century

Directory of Open Access Journals (Sweden)

P. Brohan

2010-05-01

Full Text Available The climate of the early nineteenth century is likely to have been significantly cooler than that of today, as it was a period of low solar activity (the Dalton minimum and followed a series of large volcanic eruptions. Proxy reconstructions of the temperature of the period do not agree well on the size of the temperature change, so other observational records from the period are particularly valuable. Weather observations have been extracted from the reports of the noted whaling captain William Scoresby Jr., and from the records of a series of Royal Navy expeditions to the Arctic, preserved in the UK National Archives. They demonstrate that marine climate in 1810–1825 was marked by consistently cold summers, with abundant sea-ice. But although the period was significantly colder than the modern average, there was considerable variability: in the Greenland Sea the summers following the Tambora eruption (1816 and 1817 were noticeably warmer, and had less sea-ice coverage, than the years immediately preceding them; and the sea-ice coverage in Lancaster Sound in 1819 and 1820 was low even by modern standards.

Climate change and ice hazards in the Beaufort Sea

DEFF Research Database (Denmark)

Barber, D. G.; McCullough, G.; Babb, D.

2014-01-01

Recent reductions in the summer extent of sea ice have focused the world’s attention on the effects of climate change. Increased CO2-derived global warming is rapidly shrinking the Arctic multi-year ice pack. This shift in ice regimes allows for increasing development opportunities for large oil...... will be a much more complex task than modeling average ice circulation. Given the observed reduction in sea ice extent and thickness this rather counterintuitive situation, associated with a warming climate, poses significant hazards to Arctic marine oil and gas development and marine transportation. Accurate...... forecasting of hazardous ice motion will require improved real-time surface wind and ocean current forecast models capable of ingesting local satellite-derived wind data and/or local, closely-spaced networks of anemometers and improved methods of determining high-frequency components of surface ocean current...

Technical Report 14-11 Overview of Danish Contributions to Monitoring of SLCPs in the Arctic

DEFF Research Database (Denmark)

Korsholm, Ulrik Smith; Krogh Andersen, Katrine; Christensen, Tina

2014-01-01

In the Tromsø Declaration (2009) the Arctic Council noted the role that shorter-lived climate forcers such as black carbon, methane and tropospheric ozone precursors may play in Arctic climate change, and recognized that reductions of emissions have the potential to slow the rate of Arctic snow...

Net Ecosystem Exchange of CO2 with Rapidly Changing High Arctic Landscapes

Science.gov (United States)

Emmerton, C. A.

2015-12-01

High Arctic landscapes are expansive and changing rapidly. However our understanding of their functional responses and potential to mitigate or enhance anthropogenic climate change is limited by few measurements. We collected eddy covariance measurements to quantify the net ecosystem exchange (NEE) of CO2 with polar semidesert and meadow wetland landscapes at the highest-latitude location measured to date (82°N). We coupled these rare data with ground and satellite vegetation production measurements (Normalized Difference Vegetation Index; NDVI) to evaluate the effectiveness of upscaling local to regional NEE. During the growing season, the dry polar semidesert landscape was a near zero sink of atmospheric CO2 (NEE: -0.3±13.5 g C m-2). A nearby meadow wetland accumulated over two magnitudes more carbon (NEE: -79.3±20.0 g C m-2) than the polar semidesert landscape, and was similar to meadow wetland NEE at much more southern latitudes. Polar semidesert NEE was most influenced by moisture, with wetter surface soils resulting in greater soil respiration and CO2 emissions. At the meadow wetland, soil heating enhanced plant growth, which in turn increased CO2 uptake. Our upscaling assessment found that polar semidesert NDVI measured on site was low (mean: 0.120-0.157) and similar to satellite measurements (mean: 0.155-0.163). However, weak plant growth resulted in poor satellite NDVI-NEE relationships and created challenges for remotely-detecting changes in the cycling of carbon on the polar semidesert landscape. The meadow wetland appeared more suitable to assess plant production and NEE via remote-sensing, however high Arctic wetland extent is constrained by topography to small areas that may be difficult to resolve with large satellite pixels. We predict that until summer precipitation and humidity increases substantially, climate-related changes of dry high Arctic landscapes may be restricted by poor soil moisture retention, and therefore have some inertia against

A multiple-proxy approach to understanding rapid Holocene climate change in Southeast Greenland

Science.gov (United States)

Davin, S. H.; Bradley, R. S.; Balascio, N. L.; de Wet, G.

2012-12-01

The susceptibility of the Arctic to climate change has made it an excellent workshop for paleoclimatological research. Although there have been previous studies concerning climate variability carried out in the Arctic, there remains a critical dearth of knowledge due the limited number of high-resolution Holocene climate-proxy records available from this region. This gap skews our understanding of observed and predicted climate change, and fuels uncertainty both in the realms of science and policy. This study takes a comprehensive approach to tracking Holocene climate variability in the vicinity of Tasiilaq, Southeast Greenland using a ~5.6 m sediment core from Lower Sermilik Lake. An age-depth model for the core has been established using 8 radiocarbon dates, the oldest of which was taken at 4 m down core and has been been dated to approximately 6.2 kyr BP. The bottom meter of the core below the final radiocarbon date contains a transition from cobbles and coarse sand to organic-rich laminations, indicating the termination of direct glacial influence and therefore likely marking the end of the last glacial period in this region. The remainder of the core is similarly organic-rich, with light-to-dark brown laminations ranging from 0.5 -1 cm in thickness and riddled with turbidites. Using this core in tandem with findings from an on-site assessment of the geomorphic history of the locale we attempt to assess and infer the rapid climatic shifts associated with the Holocene on a sub-centennial scale. Such changes include the termination of the last glacial period, the Mid-Holocene Climatic Optimum, the Neoglacial Period, the Medieval Climatic Optimum, and the Little Ice Age. A multiple proxy approach including magnetic susceptibility, bulk organic geochemistry, elemental profiles acquired by XRF scanning, grain-size, and spectral data will be used to characterize the sediment and infer paleoclimate conditions. Additionally, percent biogenic silica by weight has been

Strengthening Sovereignty: Security and Sustainability in an Era of Climate Change

Directory of Open Access Journals (Sweden)

Rymn J. Parsons

2011-08-01

Full Text Available Using Pakistan and the Arctic as examples, this article examines security challenges arising from climate change. Pakistan is in crisis, and climate change, a transnational phenomenon perhaps better characterized as radical enviro-transformation, is an important reason. Its survival as a state may depend to great extent on how it responds to 2010’s devastating floods. In the Arctic, the ice cap is melting faster than predicted, as temperatures there rise faster than in almost any other region. Unmanaged, a complex interplay of climate-related conditions, including large-scale “ecomigration”, may turn resource competition into resource conflict. Radical enviro-transformation has repeatedly overborne the resilience of societies. War is not an inevitable by-product of such transformation, but in the 21st Century climate-related instability, from resource scarcity and “ecomigration”, will likely create increasingly undesirable conditions of insecurity. Weak and failing states are one of today’s greatest security challenges. The pace of radical enviro-transformation, unprecedented in human history, is accelerating, especially in the Arctic, where a new, open, rich, and accessible maritime environment is coming into being. The international community must work together to enhance security and stability, promote sustainability, and strengthen sovereignty. Radical enviro-transformation provides ample reason and plentiful opportunity for preventative, collaborative solutions focused broadly on adaptation to climate change, most particularly the effects of “ecomigration”. Nations must work together across the whole of government and with all instruments of national power to create conditions for human transformation—social, political, and economic—to occur stably and sustainably, so as to avoid or lessen the prospects for and consequences of conflict. Collaborative international solutions to environmental issues, i.e., solutions that

International student Arctic Field School on Permafrost and urban areas study

Science.gov (United States)

Suter, L.; Tolmanov, V. A.; Grebenets, V. I.; Streletskiy, D. A.; Shiklomanov, N. I.

2017-12-01

Arctic regions are experiencing drastic climatic and environmental changes. These changes are exacerbated in the Russian Arctic, where active resource development resulted in further land cover transformations, especially near large settlements. There is a growing need in multidisciplinary studies of climate and human- induced changes in the Arctic cities. In order to fill this gap, International Arctic Field Course on Permafrostand Northern Studies was organized in July 2017 to the Russian Arctic. The course was organized under the umbrella of the Arctic PIRE project in cooperation between the George Washington University, Moscow State University, and the Russian Center for Arctic Development. The course attracted twenty undergraduate and graduate students from Russia, USA, and EU countries and involved instructors specializing in Arctic system science, geocryology, permafrost engineering, and urban sustainability. The field course was focused on studying typical natural Arctic landscapes of tundra and forest tundra; transformations of natural landscapes in urban and industrial areas around Vorkuta and Salekhard; construction and planning on permafrost and field methods and techniques, including permafrost and soil temperature monitoring, active layer thickness (ALT) measurements, studying of cryogenic processes, stratigraphic and soil investigations, vegetation and microclimate studies. The students were also engaged in a discussion of climatic change and historical development of urban areas on permafrost,and were exposed to examples of both active and passive construction principles while conducting a field survey of permafrost related building deformations. During the course, students collected more than 800 ALT and soil temperature measurements in typical landscapes around Vorkuta and Salekhard to determine effects of soil and vegetation factors on ground thermal regime; surveyed several hundreds of buildings to determine locations with most deformation

Towards improved estimation of the dynamic topography and ocean circulation in the high latitude and arctic ocean: The importance of GOCE

DEFF Research Database (Denmark)

Johannessen, J. A.; Raj, R. P.; Nilsen, J. E. Ø.

2013-01-01

The Arctic plays a fundamental role in the climate system and shows significant sensitivity to anthropogenic climate forcing and the ongoing climate change. Evidently changes in the Arctic and surrounding seas have far reaching influences on regional and global environment and climate variability...

The Island of Amsterdamøya: A key site for studying past climate in the Arctic Archipelago of Svalbard

Science.gov (United States)

Bakke, Jostein; Balascio, Nicholas; van der Bilt, Willem G. M.; Bradley, Raymond; D'Andrea, William J.; Gjerde, Marthe; Ólafsdóttir, Sædís; Røthe, Torgeir; De Wet, Greg

2018-03-01

This paper introduces a series of articles assembled in a special issue that explore Holocene climate evolution, as recorded in lakes on the Island of Amsterdamøya on the westernmost fringe of the Arctic Svalbard archipelago. Due to its location near the interface of oceanic and atmospheric systems sourced from Arctic and Atlantic regions, Amsterdamøya is a key site for recording the terrestrial response to marine and atmospheric changes. We employed multi-proxy approaches on lake sediments, integrating physical, biogeochemical, and isotopic analyses to infer past changes in temperature, precipitation, and glacier activity. The results comprise a series of quantitative Holocene-length paleoclimate reconstructions that reveal different aspects of past climate change. Each of the four papers addresses various facets of the Holocene climate history of north-western Svalbard, including a reconstruction of the Annabreen glacier based on the sedimentology of the distal glacier-fed lake Gjøavatnet, a reconstruction of changing hydrologic conditions based on sedimentology and stratigraphy in Lake Hakluytvatnet, reconstruction of summer temperature based on alkenone paleothermometry from lakes Hakluytvatnet and Hajeren, and a hydrogen isotope-based hydrological reconstruction from lake Hakluytvatnet. We also present high-resolution paleomagnetic secular variation data from the same lake, which document important regional magnetic field variations and demonstrate the potential for use in synchronizing Holocene sedimentary records in the Arctic. The paleoclimate picture that emerges is one of early Holocene warmth from ca. 10.5 ka BP interrupted by transient cooling ca. 10-8ka BP, and followed by cooling that mostly manifested as two stepwise events ca. 7 and 4 ka BP. The past 4ka were characterized by dynamic glaciers and summer temperature fluctuations decoupled from the declining summer insolation.

Arctic climate change and decadal variability

NARCIS (Netherlands)

Linden, van der Eveline C.

2016-01-01

High northern latitudes exhibit enhanced near-surface warming in a climate with increasing greenhouse gases compared to other parts of the globe, indicating an amplified climate response to external forcing. Decadal to multidecadal variability sometimes enhances and at other times reduces the

Remarkable separability of the circulation response to Arctic sea ice loss and greenhouse gas forcing

Science.gov (United States)

McCusker, K. E.; Kushner, P. J.; Fyfe, J. C.; Sigmond, M.; Kharin, V. V.; Bitz, C. M.

2017-12-01

Arctic sea ice loss has an important effect on local climate through increases in ocean to atmosphere heat flux and associated feedbacks, and may influence midlatitude climate by changing large-scale circulation that can enhance or counter changes that are due to greenhouse gases. The extent to which climate change in a warming world can be understood as greenhouse gas-induced changes that are modulated by Arctic sea ice loss depends on how additive the responses to the separate influences are. Here we use a novel sea ice nudging methodology in the Canadian Earth System Model, which has a fully coupled ocean, to isolate the effects of Arctic sea ice loss and doubled atmospheric carbon dioxide (CO2) to determine their additivity and sensitivity to mean state. We find that the separate effects of Arctic sea ice loss and doubled CO2 are remarkably additive and relatively insensitive to mean climate state. This separability is evident in several thermodynamic and dynamic fields throughout most of the year, from hemispheric to synoptic scales. The extent to which the regional response to sea ice loss sometimes agrees with and sometimes cancels the response to CO2 is quantified. In this model, Arctic sea ice loss enhances the CO2-induced surface air temperature changes nearly everywhere and zonal wind changes over the Pacific sector, whereas sea ice loss counters CO2-induced sea level pressure changes nearly everywhere over land and zonal wind changes over the Atlantic sector. This separability of the response to Arctic sea ice loss from the response to CO2 doubling gives credence to the body of work in which Arctic sea ice loss is isolated from the forcing that modified it, and might provide a means to better interpret the diverse array of modeling and observational studies of Arctic change and influence.

Scenarios use to engage scientists and decision-makers in a changing Arctic

Science.gov (United States)

Lee, O. A.; Eicken, H.; Payne, J. F.

2015-12-01

Scenarios provide a framework to develop more adaptive Arctic policies that allow decision makers to consider the best available science to address complex relationships and key uncertainties in drivers of change. These drivers may encompass biophysical factors such as climate change, socioeconomic drivers, and wild-cards that represent low likelihood but influential events such as major environmental disasters. We outline some of the lessons learned from the North Slope Science Initiative (NSSI) scenarios project that could help in the development of adaptive science-based policies. Three spatially explicit development scenarios were identified corresponding to low, medium and high resource extraction activities on the North Slope and adjacent seas. In the case of the high energy development scenario science needs were focused on new technology, oil spill response, and the effects of offshore activities on marine mammals important for subsistence. Science needs related to community culture, erosion, permafrost degradation and hunting and trapping on land were also identified for all three scenarios. The NSSI science needs will guide recommendations for future observing efforts, and data from these observing activities could subsequently improve policy guidance for emergency response, subsistence management and other issues. Scenarios at pan-Arctic scales may help improve the development of international policies for resilient northern communities and encourage the use of science to reduce uncertainties in plans for adapting to change in the Arctic.

Transitions in Arctic ecosystems: Ecological implications of a changing hydrological regime

Science.gov (United States)

Wrona, Frederick J.; Johansson, Margareta; Culp, Joseph M.; Jenkins, Alan; Mârd, Johanna; Myers-Smith, Isla H.; Prowse, Terry D.; Vincent, Warwick F.; Wookey, Philip A.

2016-03-01

Numerous international scientific assessments and related articles have, during the last decade, described the observed and potential impacts of climate change as well as other related environmental stressors on Arctic ecosystems. There is increasing recognition that observed and projected changes in freshwater sources, fluxes, and storage will have profound implications for the physical, biogeochemical, biological, and ecological processes and properties of Arctic terrestrial and freshwater ecosystems. However, a significant level of uncertainty remains in relation to forecasting the impacts of an intensified hydrological regime and related cryospheric change on ecosystem structure and function. As the terrestrial and freshwater ecology component of the Arctic Freshwater Synthesis, we review these uncertainties and recommend enhanced coordinated circumpolar research and monitoring efforts to improve quantification and prediction of how an altered hydrological regime influences local, regional, and circumpolar-level responses in terrestrial and freshwater systems. Specifically, we evaluate (i) changes in ecosystem productivity; (ii) alterations in ecosystem-level biogeochemical cycling and chemical transport; (iii) altered landscapes, successional trajectories, and creation of new habitats; (iv) altered seasonality and phenological mismatches; and (v) gains or losses of species and associated trophic interactions. We emphasize the need for developing a process-based understanding of interecosystem interactions, along with improved predictive models. We recommend enhanced use of the catchment scale as an integrated unit of study, thereby more explicitly considering the physical, chemical, and ecological processes and fluxes across a full freshwater continuum in a geographic region and spatial range of hydroecological units (e.g., stream-pond-lake-river-near shore marine environments).

Invited review: climate change impacts in polar regions: lessons from Antarctic moss bank archives.

Science.gov (United States)

Royles, Jessica; Griffiths, Howard

2015-03-01

Mosses are the dominant plants in polar and boreal regions, areas which are experiencing rapid impacts of regional warming. Long-term monitoring programmes provide some records of the rate of recent climate change, but moss peat banks contain an unrivalled temporal record of past climate change on terrestrial plant Antarctic systems. We summarise the current understanding of climatic proxies and determinants of moss growth for contrasting continental and maritime Antarctic regions, as informed by 13C and 18O signals in organic material. Rates of moss accumulation are more than three times higher in the maritime Antarctic than continental Antarctica with growing season length being a critical determinant of growth rate, and high carbon isotope discrimination values reflecting optimal hydration conditions. Correlation plots of 13C and 18O values show that species (Chorisodontium aciphyllum / Polytrichum strictum) and growth form (hummock / bank) are the major determinants of measured isotope ratios. The interplay between moss growth form, photosynthetic physiology, water status and isotope composition are compared with developments of secondary proxies, such as chlorophyll fluorescence. These approaches provide a framework to consider the potential impact of climate change on terrestrial Antarctic habitats as well as having implications for future studies of temperate, boreal and Arctic peatlands. There are many urgent ecological and environmental problems in the Arctic related to mosses in a changing climate, but the geographical ranges of species and life-forms are difficult to track individually. Our goal was to translate what we have learned from the more simple systems in Antarctica, for application to Arctic habitats. © 2014 John Wiley & Sons Ltd.

Effect of Warm Atlantic Waters on the Climate Anomalies in the West Arctic

Directory of Open Access Journals (Sweden)

A. N. Zolotokrylin

2015-01-01

Full Text Available Significant climatic changes of oceanic and atmospheric elements and a relation of them to the ocean surface winter anomalies in North Atlantic are analyzed in the paper. Periods of «warm» ocean (2002–2012 and «cold» ocean (1960–1970 were determined. Positive anomalies of the ocean surface temperature increase the ice-free water area and, correspondingly, decrease the ice-field area. As a result of such changes in a state of the ocean surface (open water and ice, surface air temperature rises, and, consequently, atmospheric pressure in central part of a given Arctic sector drops.

Changing Arctic Ocean freshwater pathways.

Science.gov (United States)

Morison, James; Kwok, Ron; Peralta-Ferriz, Cecilia; Alkire, Matt; Rigor, Ignatius; Andersen, Roger; Steele, Mike

2012-01-04

Freshening in the Canada basin of the Arctic Ocean began in the 1990s and continued to at least the end of 2008. By then, the Arctic Ocean might have gained four times as much fresh water as comprised the Great Salinity Anomaly of the 1970s, raising the spectre of slowing global ocean circulation. Freshening has been attributed to increased sea ice melting and contributions from runoff, but a leading explanation has been a strengthening of the Beaufort High--a characteristic peak in sea level atmospheric pressure--which tends to accelerate an anticyclonic (clockwise) wind pattern causing convergence of fresh surface water. Limited observations have made this explanation difficult to verify, and observations of increasing freshwater content under a weakened Beaufort High suggest that other factors must be affecting freshwater content. Here we use observations to show that during a time of record reductions in ice extent from 2005 to 2008, the dominant freshwater content changes were an increase in the Canada basin balanced by a decrease in the Eurasian basin. Observations are drawn from satellite data (sea surface height and ocean-bottom pressure) and in situ data. The freshwater changes were due to a cyclonic (anticlockwise) shift in the ocean pathway of Eurasian runoff forced by strengthening of the west-to-east Northern Hemisphere atmospheric circulation characterized by an increased Arctic Oscillation index. Our results confirm that runoff is an important influence on the Arctic Ocean and establish that the spatial and temporal manifestations of the runoff pathways are modulated by the Arctic Oscillation, rather than the strength of the wind-driven Beaufort Gyre circulation.

Evidence of Climate Change (Global Warming) and Temperature Increases in Arctic Areas

OpenAIRE

Eric Kojo Wu Aikins

2012-01-01

This paper contributes to the debate on the proximate causes of climate change. Also, it discusses the impact of the global temperature increases since the beginning of the twentieth century and the effectiveness of climate change models in isolating the primary cause (anthropogenic influences or natural variability in temperature) of the observed temperature increases that occurred within this period. The paper argues that if climate scientist and policymakers ignore the...

The scramble for the Arctic? A discourse analysis of Norway and the EU's strategies towards the European Arctic

Energy Technology Data Exchange (ETDEWEB)

Grindheim, Astrid

2009-11-15

This report examines the discourses on engagement in the European Arctic. Since 2006, both Norway and the EU have launched strategies directed toward engagement in the North. By means of discourse analysis, the report will investigate how the two actors have portrayed and discussed the European Arctic. Taking a social constructivist approach, it is assumed that regions are what we make them to be, and that discourse analysis can indicate the area of action for the region. Special attention will be paid to climate change, environmental issues and energy, as these issues play a prominent role in the Arctic. The region shows evident signs of climate change - but it also contains perhaps 25% of the world's untapped energy resources. This creates tension between the wish to preserve the environment and the climate, and the business potential of the energy reservoirs. The European Arctic was of high geostrategic importance during the Cold War, and there is now talk of a possible renewal of that role. The report applies the theoretical approach developed by Buzan, Waever and de Wilde (1998) about the widened security concept in examining whether the two actors' discourses are framed within security terms and within a security framework. (Author)

Centennial-scale climate change from decadally-paced explosive volcanism: a coupled sea ice-ocean mechanism

Energy Technology Data Exchange (ETDEWEB)

Zhong, Y. [University of Colorado, INSTAAR, Boulder, CO (United States); Miller, G.H. [University of Colorado, INSTAAR, Boulder, CO (United States); University of Colorado, Department of Geological Sciences, Boulder, CO (United States); Otto-Bliesner, B.L.; Holland, M.M.; Bailey, D.A. [NCAR, Boulder, CO (United States); Schneider, D.P. [NCAR, Boulder, CO (United States); University of Colorado, CIRES, Boulder, CO (United States); Geirsdottir, A. [University of Iceland, Department of Earth Sciences and Institute of Earth Sciences, Reykjavik (Iceland)

2011-12-15

Northern Hemisphere summer cooling through the Holocene is largely driven by the steady decrease in summer insolation tied to the precession of the equinoxes. However, centennial-scale climate departures, such as the Little Ice Age, must be caused by other forcings, most likely explosive volcanism and changes in solar irradiance. Stratospheric volcanic aerosols have the stronger forcing, but their short residence time likely precludes a lasting climate impact from a single eruption. Decadally paced explosive volcanism may produce a greater climate impact because the long response time of ocean surface waters allows for a cumulative decrease in sea-surface temperatures that exceeds that of any single eruption. Here we use a global climate model to evaluate the potential long-term climate impacts from four decadally paced large tropical eruptions. Direct forcing results in a rapid expansion of Arctic Ocean sea ice that persists throughout the eruption period. The expanded sea ice increases the flux of sea ice exported to the northern North Atlantic long enough that it reduces the convective warming of surface waters in the subpolar North Atlantic. In two of our four simulations the cooler surface waters being advected into the Arctic Ocean reduced the rate of basal sea-ice melt in the Atlantic sector of the Arctic Ocean, allowing sea ice to remain in an expanded state for > 100 model years after volcanic aerosols were removed from the stratosphere. In these simulations the coupled sea ice-ocean mechanism maintains the strong positive feedbacks of an expanded Arctic Ocean sea ice cover, allowing the initial cooling related to the direct effect of volcanic aerosols to be perpetuated, potentially resulting in a centennial-scale or longer change of state in Arctic climate. The fact that the sea ice-ocean mechanism was not established in two of our four simulations suggests that a long-term sea ice response to volcanic forcing is sensitive to the stability of the seawater

Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

Science.gov (United States)

Isaksen, Ivar S.A.; Gauss, Michael; Myhre, Gunnar; Walter Anthony, Katey M.; Ruppel, Carolyn

2011-01-01

The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the large potential for future methane releases calls for improved understanding of the interaction of a changing climate with processes in the Arctic and chemical feedbacks in the atmosphere. Here we apply a “state of the art” atmospheric chemistry transport model to show that large emissions of CH4 would likely have an unexpectedly large impact on the chemical composition of the atmosphere and on radiative forcing (RF). The indirect contribution to RF of additional methane emission is particularly important. It is shown that if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. Assuming several hypothetical scenarios of CH4 release associated with permafrost thaw, shallow marine hydrate degassing, and submarine landslides, we find a strong positive feedback on RF through atmospheric chemistry. In particular, the impact of CH4 is enhanced through increase of its lifetime, and of atmospheric abundances of ozone, stratospheric water vapor, and CO2 as a result of atmospheric chemical processes. Despite uncertainties in emission scenarios, our results provide a better understanding of the feedbacks in the atmospheric chemistry that would amplify climate warming.

Multinational Experiment 7. Maritime Security Region: The Arctic

Science.gov (United States)

2013-07-08

increasingly affect human communities , natural systems, and infrastructure. Resources and Trade Routes in the Arctic Climate change in the Far...capelin, herring, navaga, and wolffishes. Some areas of the Arctic and sub-Arctic suffer from high levels of illegal fishing and overfishing , and...maneuvering, joint air defense drills, communications and search and rescue operations. The exercise is normally held every second year. 8 In

Arctic Ocean Scientific Drilling: The Next Frontier

Directory of Open Access Journals (Sweden)

Ruediger Stein

2010-04-01

Full Text Available The modern Arctic Ocean appears to be changing faster than any other region on Earth. To understand the potential extent of high latitude climate change, it is necessary to sample the history stored in the sediments filling the basins and covering the ridges of the Arctic Ocean. These sediments have been imaged with seismic reflection data, but except for the superficial record, which has been piston cored, they have been sampled only on the Lomonosov Ridge in 2004 during the Arctic Coring Expedition (ACEX-IODP Leg 302; Backman et al., 2006 and in 1993 in the ice-free waters in the Fram Strait/Yermak Plateau area (ODP Leg 151; Thiede et al., 1996.Although major progress in Arctic Ocean research has been made during the last few decades, the short- and long-term paleoceanographic and paleoclimatic history as well as its plate-tectonic evolution are poorly known compared to the other oceans. Despite the importance of the Arctic in the climate system, the database we have from this area is still very weak. Large segments of geologic time have not been sampled in sedimentary sections. The question of regional variations cannot be addressed.

The relative importance of impacts from climate change vs. emissions change on air pollution levels in the 21st century

Directory of Open Access Journals (Sweden)

G. B. Hedegaard

2013-04-01

Full Text Available So far several studies have analysed the impacts of climate change on future air pollution levels. Significant changes due to impacts of climate change have been made clear. Nevertheless, these changes are not yet included in national, regional or global air pollution reduction strategies. The changes in future air pollution levels are caused by both impacts from climate change and anthropogenic emission changes, the importance of which needs to be quantified and compared. In this study we use the Danish Eulerian Hemispheric Model (DEHM driven by meteorological input data from the coupled Atmosphere-Ocean General Circulation Model ECHAM5/MPI-OM and forced with the newly developed RCP4.5 emissions. The relative importance of the climate signal and the signal from changes in anthropogenic emissions on the future ozone, black carbon (BC, total particulate matter with a diameter below 2.5 μm (total PM2.5 including BC, primary organic carbon (OC, mineral dust and secondary inorganic aerosols (SIA and total nitrogen (including NHx + NOy has been determined. For ozone, the impacts of anthropogenic emissions dominate, though a climate penalty is found in the Arctic region and northwestern Europe, where the signal from climate change dampens the effect from the projected emission reductions of anthropogenic ozone precursors. The investigated particles are even more dominated by the impacts from emission changes. For black carbon the emission signal dominates slightly at high latitudes, with an increase up to an order of magnitude larger, close to the emission sources in temperate and subtropical areas. Including all particulate matter with a diameter below 2.5 μm (total PM2.5 enhances the dominance from emissions change. In contrast, total nitrogen (NHx + NOy in parts of the Arctic and at low latitudes is dominated by impacts of climate change.

Organic Carbon Delivery from a High-Arctic North American Watershed: Implications for Beaufort Sea Carbon Cycling in a Changing Climate

Science.gov (United States)

Schreiner, K. M.; Bruner, V. J.; Kessler, J. D.

2016-12-01

Riverine delivery of terrestrial organic carbon (OC) and subsequent burial in coastal margins is a significant sink for OC on Earth. The amount of fresh OC compared to old OC buried in coastal margins affects the long-term ratio of O2 to CO2 in the atmosphere. And yet, the fate of OC on marine shelves is not well known. Analysis of the fate of terrestrial OC from Arctic rivers are especially important, as half of the global soil carbon pool resides in the top few meters of Arctic permafrost soils, and much of this OC, more than twice the amount of carbon currently residing in the atmospheric CO2 pool, is thousands of years old and under threat of disturbance from a warming Arctic climate. Flux of this old, deeply-buried permafrost OC to coastal sediments has already been noted in both the Russian and Alaskan Arctic. This study focuses on OC delivered by the Colville River, a medium-sized North American Arctic river that drains the North Slope of Alaska, and has been previously shown to be an important source of extremely old OC to coastal Beaufort Sea sediments. Here we report stable carbon isotopes and radiocarbon ages of particulate OC (POC), dissolved OC (DOC), and surface sediments from the Beaufort Sea near the Colville River outflow and nearby Simpson Lagoon from samples collected in August 2015. In general, DOC ages are younger than POC ages, and both have stable isotope signatures indicative of terrestrial C3 sources. Waters with higher concentrations of DOC tend to have younger radiocarbon ages and more enriched stable isotope signatures, indicating the presence of aquatic primary production. These data represent some of the first water column radiocarbon signatures to be reported from an Arctic river the size of the Colville; while the six largest Arctic rivers have been well studied over the past few decades, much less data is available for small and medium sized Arctic rivers.

Changes in Arctic and Boreal ecosystems of North America: Integrating Recent Results from the Field, Remote Sensing and Ecosystem Models

Science.gov (United States)

Goetz, S. J.; Rogers, B. M.; Mack, M. C.; Goulden, M.; Pastick, N. J.; Berner, L. T.; Fisher, J.

2017-12-01

The Arctic and boreal forest biomes have global significance in terms of climate feedbacks associated with land surface interactions with the atmosphere. Changes in Arctic tundra and boreal forest ecosystem productivity and fire disturbance feedbacks have been well documented in recent years, but findings are often only locally relevant and are sometimes inconsistent among research teams. Part of these inconsistencies lie in utilization of different data sets and time periods considered. Integrated approaches are thus needed to adequately address changes in these ecosystems in order to assess consistency and variability of change, as well as ecosystem vulnerability and resiliency across spatial and temporal scales. Ultimately this can best be accomplished via multiple lines of evidence including remote sensing, field measurements and various types of data-constrained models. We will discuss some recent results integrating multiple lines of evidence for directional ecosystem change in the Arctic and boreal forest biomes of North America. There is increasing evidence for widespread spatial and temporal variability in Arctic and boreal ecosystem productivity changes that are strongly influenced by cycles of changing fire disturbance severity and its longer-term implications (i.e legacy effects). Integrated, multi-approach research, like that currently underway as part of the NASA-led Arctic Boreal Vulnerability Experiment (above.nasa.gov), is an effective way to capture the complex mechanisms that drive patterns and directionality of ecosystem structure and function, and ultimately determine feedbacks to environmental change, particularly in the context of global climate change. Additional ongoing ABoVE research will improve our understanding of the consequences of environmental changes underway, as well as increase our confidence in making projections of the ecosystem responses, vulnerability and resilience to change. ABoVE will also build a lasting legacy of

Low-energy house in Arctic climate - 5 years of experience

DEFF Research Database (Denmark)

Vladyková, Petra; Rode, Carsten; Kragh, J.

2011-01-01

The aim of this article is to present and disseminate the experience gained from a low‐energy house in Sisimiut, Greenland, over the 5 years of operation since its inauguration in April 2005. The house was designed to test and present new low‐energy technologies in the Arctic climate and to impro...

The Sinuosity of Atmospheric Circulation over North America and its Relationship to Arctic Climate Change and Extreme Events

Science.gov (United States)

Vavrus, S. J.; Wang, F.; Martin, J. E.; Francis, J. A.

2015-12-01

Recent research has suggested a relationship between mid-latitude weather and Arctic amplification (AA) of global climate change via a slower and wavier extratropical circulation inducing more extreme events. To test this hypothesis and to quantify the waviness of the extratropical flow, we apply a novel application of the geomorphological concept of sinuosity (SIN) over greater North America. SIN is defined as the ratio of the curvilinear length of a geopotential height contour to the perimeter of its equivalent latitude, where the contour and the equivalent latitude enclose the same area. We use 500 hPa daily heights from reanalysis and model simulations to calculate past and future SIN. The circulation exhibits a distinct annual cycle of maximum SIN (waviness) in summer and a minimum in winter, inversely related to the annual cycle of zonal wind speed. Positive trends in SIN have emerged in recent decades during winter and summer at several latitude bands, generally collocated with negative trends in zonal wind speeds. High values of SIN coincide with many prominent extreme-weather events, including Superstorm Sandy. RCP8.5 simulations (2006-2100) project a dipole pattern of zonal wind changes that varies seasonally. In winter, AA causes inflated heights over the Arctic relative to mid-latitudes and an associated weakening (strengthening) of the westerlies north (south) of 40N. The AA signal in summer is strongest over upper-latitude land, promoting localized atmospheric ridging aloft with lighter westerlies to the south and stronger zonal winds to the north. The changes in wind speeds in both seasons are inversely correlated with SIN, indicating a wavier circulation where the flow weakens. In summer the lighter winds over much of the U. S. resemble circulation anomalies observed during extreme summer heat and drought. Such changes may be linked to enhanced heating of upper-latitude land surfaces caused by earlier snow melt during spring-summer.

Arctic research vessel design would expand science prospects

Science.gov (United States)

Elsner, Robert; Kristensen, Dirk

The U.S. polar marine science community has long declared the need for an arctic research vessel dedicated to advancing the study of northern ice-dominated seas. Planning for such a vessel began 2 decades ago, but competition for funding has prevented construction. A new design program is underway, and it shows promise of opening up exciting possibilities for new research initiatives in arctic marine science.With its latest design, the Arctic Research Vessel (ARV) has grown to a size and capability that will make it the first U.S. academic research vessel able to provide access to the Arctic Ocean. This ship would open a vast arena for new studies in the least known of the world's seas. These studies promise to rank high in national priority because of the importance of the Arctic Ocean as a source of data relating to global climate change. Other issues that demand attention in the Arctic include its contributions to the world's heat budget, the climate history buried in its sediments, pollution monitoring, and the influence of arctic conditions on marine renewable resources.

Carbon dioxide exchange in the Arctic

DEFF Research Database (Denmark)

Ravn, Nynne Marie Rand

in further warming. This PhD thesis addresses different aspects of climate change effects on C dynamics in the Arctic. The focus has been on i) changes in ER, age of the C sources, GEP and the net ecosystem exchange (NEE) in response to long- and short-term climate manipulations and ii) comparisons of CO2...... warming indications of emission of old C were observed, though most pronounced in the spring. I found no short-term response of summer warming on GEP at the low arctic heath and the measurements of NEE showed an increased emission of CO2 to the atmosphere during two snow free seasons. Increased winter......-term warming can cause GEP to increase and leave NEE unaltered. Hence, the risk of warming induced long-term positive feedback on climate change might be reduced. The new balance in the C cycling might though be sensitive to limitations of GEP due to for instance late snowmelt or herbivory....

Novel Tools for Climate Change Learning and Responding in Earth Science Education

Science.gov (United States)

Sparrow, Elena; Brunacini, Jessica; Pfirman, Stephanie

2015-04-01

Several innovative, polar focused activities and tools including a polar hub website (http://thepolarhub.org) have been developed for use in formal and informal earth science or STEM education by the Polar Learning and Responding (PoLAR) Climate Change Education Partnership (consisting of climate scientists, experts in the learning sciences and education practitioners). In seeking to inform understanding of and response to climate change, these tools and activities range from increasing awareness to informing decisions about climate change, from being used in classrooms (by undergraduate students as well as by pre-college students or by teachers taking online climate graduate courses) to being used in the public arena (by stakeholders, community members and the general public), and from using low technology (card games such as EcoChains- Arctic Crisis, a food web game or SMARTIC - Strategic Management of Resources in Times of Change, an Arctic marine spatial planning game) to high technology (Greenify Network - a mobile real world action game that fosters sustainability and allows players to meaningfully address climate change in their daily lives, or the Polar Explorer Data Visualization Tablet App that allows individuals to explore data collected by scientists and presented for the everyday user through interactive maps and visualizations, to ask questions and go on an individualized tour of polar regions and their connections to the rest of the world). Games are useful tools in integrative and applied learning, in gaining practical and intellectual skills, and in systems thinking. Also, as part of the PoLAR Partnership, a Signs of the Land Climate Change Camp was collaboratively developed and conducted, that can be used as a model for engaging and representing indigenous communities in the co-production of climate change knowledge, communication tools and solutions building. Future camps are planned with Alaska Native Elders, educators including classroom

Source Characterization and Temporal Variation of Methane Seepage from Thermokarst Lakes on the Alaska North Slope in Response to Arctic Climate Change

Energy Technology Data Exchange (ETDEWEB)

None, None

2012-09-30

The goals of this research were to characterize the source, magnitude and temporal variability of methane seepage from thermokarst lakes (TKL) within the Alaska North Slope gas hydrate province, assess the vulnerability of these areas to ongoing and future arctic climate change and determine if gas hydrate dissociation resulting from permafrost melting is contributing to the current lake emissions. Analyses were focused on four main lake locations referred to in this report: Lake Qalluuraq (referred to as Lake Q) and Lake Teshekpuk (both on Alaska's North Slope) and Lake Killarney and Goldstream Bill Lake (both in Alaska's interior). From analyses of gases coming from lakes in Alaska, we showed that ecological seeps are common in Alaska and they account for a larger source of atmospheric methane today than geologic subcap seeps. Emissions from the geologic source could increase with potential implications for climate warming feedbacks. Our analyses of TKL sites showing gas ebullition were complemented with geophysical surveys, providing important insight about the distribution of shallow gas in the sediments and the lake bottom manifestation of seepage (e.g., pockmarks). In Lake Q, Chirp data were limited in their capacity to image deeper sediments and did not capture the thaw bulb. The failure to capture the thaw bulb at Lake Q may in part be related to the fact that the present day lake is a remnant of an older, larger, and now-partially drained lake. These suggestions are consistent with our analyses of a dated core of sediment from the lake that shows that a wetland has been present at the site of Lake Q since approximately 12,000 thousand years ago. Chemical analyses of the core indicate that the availability of methane at the site has changed during the past and is correlated with past environmental changes (i.e. temperature and hydrology) in the Arctic. Discovery of methane seeps in Lake Teshekpuk in the northernmost part of the lake during 2009