15,762 results on '"greenland"'
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2. 'Uumasuusivissuaq': Spirit and Indigenous Writing
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Williamson, Karla Jessen
- Abstract
The scholarship on Indigenous peoples is deeply steeped in colonization and often assumes a Western perspective. I start this article with my poetry as a female "kalaaleq" (Inuk from Greenland) poet. I contextualize my writing through discussions on praxis and new knowledge creation through poetry. In this article, I argue for a process of decolonization of written, academic knowledge on Indigenous peoples by inviting Indigenous writers to consider writing in poetry form, which comes from giftedness of inner soul-namely the spirit.
- Published
- 2014
3. Greenland Camp: Mentorship as a Disciplined Practice in Preparedness
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Lee, Jocelyn Lok-Yee
- Abstract
Sea kayaking may be best understood through the insights and knowledge of people whose ancestors kayaked for survival. Greenland Camp, held over several days in late summer, is a kayaking event that draws paddlers from around the world to reconnect with one another and learn age-old and advanced skills of the Arctic's Inuit. Greenland Camp is a gathering for paddlers that preserves and passes on to future generations the traditional paddling/rolling skills of Greenland's experienced seal catchers. Rooted in the need for responsive skill development and observant awareness as well as the indispensable skills needed to hunt and survive in Arctic waters, the Inuit point to a traditional practice that challenges the depth, scope, and limitation of experience of all kayakers. Facilitating mentorship of the disciplined practice of sea kayaking is thus explored to discern how the cultivated practice of hunter-gatherer Inuit communities may positively affect youth resilience to adversity.
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- 2019
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4. Knowing When to Step Forward, Back, or Out: An Autoethnography of a White Researcher in Two Post-Colonial Educational Contexts
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Wyatt, Tasha R.
- Abstract
This autoethnography makes use of 10 years of field notes that the author collected while living and working as an educational researcher in Greenland and Hawaii. Using Kaomea's framework for thinking about when non-Native people should step forward, step back, or step out, the author's analysis of these field notes indicates that she struggled around knowing her role in these post-colonial communities. The author was hesitant in moving into leadership positions in Greenland because it was only recently decolonized and she feared being perceived as someone interested in usurping qualified Greenlanders to fill important leadership positions. However, in Hawaii, which has had more time to consider its colonial past, the author felt less threatened, which gave her greater freedom to explore opportunities for where she could step forward. The study provides another dimension on white researchers working in post-colonial educational settings, and demonstrates the complexity of navigating post-colonial settings even in circumstances where researchers have personal experience with these power dynamics.
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- 2018
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5. News from the International Clearinghouse on Children and Violence on the Screen (ICCVOS), 2000.
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United Nations Educational, Scientific, and Cultural Organization, Goteborg (Sweden). International Clearinghouse on Children and Violence on the Screen., Nordic Documentation Center for Mass Communication Research, Aarhus (Denmark)., and von Feilitzen, Cecilia
- Abstract
This document is comprised of the year 2000 reports from the UNESCO International Clearinghouse on Children and Violence on the Screen. The two issues describe research findings concerning children and media violence, children's media use, and activities aimed at limiting gratuitous media violence. The first issue includes articles addressing children's media use in India, Chile, the United States, and Sweden, and adolescents' media use in Greenland. This issue also contains a section on children's TV programs on the global market. The second issue contains several articles on the media and children in Russia, along with sections on media violence, children and advertising, media for children, media literacy and children's participation, and regulation and self-regulation. Both issues contain a listing of relevant coming events. (EV)
- Published
- 2000
6. Self-Sufficiency in Northern Justice Issues. Proceedings of the Northern Justice Society Meeting (5th, Sitka, Alaska, April 1991).
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Simon Fraser Univ., Burnaby (British Columbia)., Northern Justice Society, Burnaby (British Columbia)., Griffiths, Curt Taylor, Griffiths, Curt Taylor, Simon Fraser Univ., Burnaby (British Columbia)., and Northern Justice Society, Burnaby (British Columbia).
- Abstract
As indigenous peoples in the Arctic move closer to sovereignty, self-sufficiency in the realm of criminal justice assumes paramount importance. This book outlines initiatives and strategies to improve the delivery of justice services to aboriginal peoples in Canada, Alaska, and Greenland. Topics include: social and spiritual causes of alcoholism and alcohol abuse among Alaska Natives; the indigenous understanding of self-government, based on traditional values; evolution of self-government among the Carrier tribe of British Columbia, and comparisons with tribal government structures in Alaska Native villages; the Dene Justice Project and traditional Dene methods of social control; a community-based system of justice on the Sandy Lake Reserve, Ontario (Canada); the struggle of the Metis people for recognition; history and practices of the Greenland justice system; Native policing programs in Alberta (Canada) and Greenland; community centers for legal services and legal education; the role of Native courtworkers; the province and tribal courts; a spirituality-based model for mediation and conflict resolution; maximizing community involvement in the juvenile justice system; a Junior Achievement program for community youth or young offenders; specialized foster family care; interpersonal violence and youth suicide among Greenland Inuit; family violence; the Sitka (Alaska) Alliance for Health; and writing skills for community-based justice administrators. (SV)
- Published
- 1992
7. Is an Inuit Literary History Possible?
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Martin, Keavy
- Abstract
In 1921, the Greenlandic anthropologist Knud Rasmussen set out to travel twenty thousand miles by dog team across Inuit Nunaat--the Inuit homeland. During this three-year journey--the famous Fifth Thule Expedition--Rasmussen was struck by the similarities in the language and culture of Inuit communities across the entire Arctic. Considering the geographical and historical distance between groups of Inuit, Rasmussen observed that "it would be natural for the language and traditions of the various tribes to have lost all homogeneity." The Inuit people may have been composed of widespread regional groups, but their language and literary traditions told a different story. They spoke of a connection that surpassed geographical and historical distance. As one might expect, the literature of this territory is likewise varied and complex. The texts that make up the Inuit literary corpus span thousands of years and a number of genres: they include the classic stories and songs of the oral tradition, more recent memoirs and life writing, elders' oral histories, and contemporary fiction, poetry, and film. Local contexts are highly important to these works, as the literature of each region takes on the particular flavors of its geography and political history. However, Inuit continue to suffer from underrepresentation in southern university classrooms. Even in Native literature classes, Inuit writers and storytellers have a marginal presence, if they are present at all. This article asks whether the strategic concept of an Inuit circumpolar literature is justifiable, even as a temporary measure. Is an Inuit literary history possible? The author concludes that in view of the Arctic's current role as an international political chesspiece, an Inuit literary history is possible; and not only that--it is necessary. (Contains 66 notes.)
- Published
- 2010
8. A Record of Climate Change
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Smith, Zach
- Abstract
The hydrologic cycle is a very basic scientific principle. In this article, background information is presented on how the hydrologic cycle provides scientists with clues to understanding the history of Earth's climate. Also detailed is a web-based activity that allows students to learn about how scientists are able to piece together a record of Earth's climate thanks to a unique ice core drilling program in Greenland. (Contains 4 figures and 11 resources.)
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- 2007
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9. The Divergent Meanings of Life Satisfaction: Item Response Modeling of the Satisfaction with Life Scale in Greenland and Norway
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Vitterso, Joar, Biswas-Diener, Robert, and Diener,
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Cultural differences in response to the Satisfaction With Life Scale (SWLS) items is investigated. Data were fit to a mixed Rasch model in order to identify latent classes of participants in a combined sample of Norwegians (N = 461) and Greenlanders (N = 180). Initial analyses showed no mean difference in life satisfaction between the two subsamples. After transforming the ordinal raw scores into interval scales while simultaneously controlling for response bias, different results appeared. First, approximately 80% of the participants in the Greenlandic subsample fit a latent class with a large degree of random responding to the SWLS. Second, relative to the Norwegians, more Greenlanders were using extreme categories in responding to the SWLS. After statistically controlling for this tendency, Norwegians were in general more satisfied with their lives than Greenlanders. Third, Greenlanders who belonged to one specific latent class were more satisfied than their Norwegian counterparts. A salient feature of this class was the relative unwillingness of respondents to change the circumstances of their lives if they were given such an opportunity. The above results are a reminder of the care that must be used in analyzing survey data across cultures. The analytical strategy applied in the article offers an improved approach to handling such data.
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- 2005
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10. The Federal Cylinder Project: A Guide to Field Cylinder Collections in Federal Agencies. Volume 3, Great Basin/Plateau Indian Catalog, Northwest Coast/Arctic Indian Catalog.
- Author
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Library of Congress, Washington, DC. American Folklife Center. and Gray, Judith A.
- Abstract
Two catalogs inventory wax cylinder collections, field recorded among Native American groups, 1890-1942. The catalog for Great Basin and Plateau Indian tribes contains entries for 174 cylinders in 7 collections from the Flathead, Nez Perce, Thompson/Okanagon, Northern Ute, and Yakima tribes. The catalog for Northwest Coast and Arctic Indian tribes contains entries for 498 cylinders in 20 collections from the Carrier, Clackamas Chinook, Clayoquot, Mainland Comox, Polar Eskimos, Halkomelem, Ingalik, Kalapuya, Kwakiutl, Makah, Nitinat, Nootka, Quileute, Shasta, Squamish, Tlingit, Tsimshian, Tututni, and Upper Umpqua. Collectors include Frances Densmore, Leo Joachim Frachtenberg, and 10 others. Catalog introductions provide information about the collectors and their aims, the circumstances of recording expeditions, and aspects of classification. Collection introductions summarize basic information about scope, organization, recording locations and dates, institutional affiliations, and collectors. Individual entries include cylinder number, Archive of Folk Culture number, number assigned by collector, duration and quality of recording, collector's description of contents, performer, location and date of recording, and technical notes. Selected bibliographies contain published and unpublished materials: 34 references for the first catalog; 70 references for the second catalog. Maps show sites of field recordings. (SV)
- Published
- 1988
11. Indigenous Peoples and Education in the Circumpolar North.
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Demmert, William G.
- Abstract
This collection of papers represents an attempt to define better the purposes and content of education among the indigenous peoples of the circumpolar north. All the papers, except one on the Soviet Union, were written by members of indigenous groups in the far north. They are professionally involved in the field of Native education in their respective countries. (The exception was prepared by a scholar from England whose special field of expertise derives from his study of the indigenous minority peoples of the Soviet north.) In his paper, "Education and the Native Saamis," Jan Henry Keskitalo expresses the need to have a realistic relationship among the school, the local Saami society, and the majority society of Scandinavia. Ingmar Egede, in his paper "Education in Greenland, 1985," offers a general review of the Greenland educational situation from the early 18th century to 1985. In "Educational Opportunities for the Native Canadian," Mary Cousins deals specifically with education of the Inuit people of the Northwest Territories. Terence Armstrong reviewed available documents to synthesize a comprehensive description: "Education of Minority Peoples in Northern USSR." William Demmert's "Native Education: The Alaskan Perspective" is an historical review of education for Alaska Natives which also provides the background for a description of current programs and activities for Native Alaskan students. (TES)
- Published
- 1987
12. Faces of the Circumpolar World.
- Author
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Zuk, Bill and Dalton, Robert
- Abstract
Presents a lesson that asks students to compare a culture's traditional and innovative artwork in order to encourage an appreciation of artistic heritage. Gives the historical and cultural contexts of two artworks from Greenland and two from Alaska, along with a collection of activities, as the means for investigation. (CMK)
- Published
- 1998
13. The Pedagogical Situation in Greenland.
- Author
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Alaska Univ., Fairbanks., Arctic Inst. of North America, Montreal (Quebec)., and Gunther, Bent
- Abstract
The history of Greenland's educational activities began in 1721 with the work of a missionary who encouraged the people to learn to read and write. A century later, higher education became available. In 1905, legislation was enacted that served as a milestone of progress for the growth of education. Separation from Denmark, which was leading Greenland in its programs, was a problem, particularly with respect to language differences. Reforms instigated in 1950 were designed to link the 2 countries more closely, and efforts were made to overcome the difficulties of having 2 languages. Problems today include population increase, a lack of Greenlandic-speaking teachers and tutors, and a lack of suitable textbooks. Also of major concern are administration of the growing educational system, curriculum design, vocational training needs, and an increased demand for higher education. Much progress can be cited, but there is much yet to be done. [Not available in hard copy due to marginal legibility of original document.] (BD)
- Published
- 1969
14. CLARITY: A Call for Transparency in Marine Diamond Mining
- Author
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Burger, Morgan
- Subjects
Marine Diamond Mining ,Seafloor Mining ,Seabed Mining ,Namibia ,Greenland ,Orange River ,Maniitsoq ,Economic Development ,Ecosystem Preservation ,Fisheries ,Climate Change ,Seafloor Extraction ,Arctic Ecosystems ,Sociopolitical Conflict ,Environmental Ethics ,Marine Conservation ,Inuit Communities ,Sustainability ,Marine Science ,Deep-Sea Mining ,Economic Trade-offs ,Environmental Justice ,Documentary Film ,Science Communication - Abstract
This capstone project tells the untold story of marine diamond mining, tracing its origins from the shores of Namibia to the fjords of Greenland. Despite the stark differences between these two locales, they share striking similarities in diamond potential. In Namibia, marine diamond mining flourished prior to the country's independence and the establishment of international mining laws, setting a precedent for potential challenges in Greenland's current political landscape. Through in-depth research, stakeholder interviews, and media production, this project fosters an informed storyline for a full-length documentary film. The capstone deliverables encompass a film treatment, budget, film plan, concise trailer, and transcribed interviews, strategically crafted towards securing future support of the project. The outcome of such seeking to advocate for greater transparency in the diamond industry and policies that prioritize both economic development and environmental integrity. The final film will engage audiences worldwide in considering the implications of marine diamond mining for Greenland's evolving climate and economy.CLARITY film treatment can be found here: https://tinyurl.com/ClarityTreatment CLARITY interview transcriptions can be found here: https://tinyurl.com/ClarityTranscriptions
- Published
- 2024
15. Prevalence of cardiovascular and other selected diseases among Greenlanders with and without type 2 diabetes.
- Author
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Klockmann, Lise Lyngbak, Tøttenborg, Emma Marie Kragh, Backe, Marie Balslev, Jørgensen, Marit Eika, and Pedersen, Michael Lynge
- Abstract
This study aims to estimate the prevalence of cardiovascular disease, kidney disease, and other selected diseases including hypertension, atrial fibrillation, asthma, chronic obstructive lung disease, osteoarthritis, osteoporosis, psoriasis and depression among Greenlanders living in Nuuk with and without type 2 diabetes (T2D). The study was designed as a cross-sectional case-control study based on data from the electronic medical record (EMR) in Greenland. Persons with a registered T2D diagnosis in EMR and residence in Nuuk (N = 435) were included. The prevalence of cardiovascular disease was 17.9% among persons with T2D and significantly higher compared to the control group (10.1%). In addition, our results showed a significantly higher prevalence of ischaemic heart disease, hypertension, heart failure, atrial fibrillation, osteoarthritis and psoriasis among persons with T2D compared to the control group.Our study found a higher prevalence in five out of 10 selected diseases in regularly followed persons with T2D in Nuuk compared to unselected controls. This enlightens the importance of a broad multifaceted approach in combination of changing primary health care to focus on early detection of controllable risk factors and chronic conditions care in Artic Greenland. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Substance use and lifestyle risk factors for somatic disorders among psychiatric patients in Greenland.
- Author
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Nielsen, Ida Margrethe, Sørensen, Lisbeth Uhrskov, Wichmand, Søren, Heilmann, Parnûna, and Pedersen, Michael Lynge
- Abstract
Patients with psychotic disorders exhibit elevated mortality and morbidity rates compared to the general population primarily due to comorbid somatic diseases. This study aims to describe the prevalence of selected risk factors and somatic disorders among psychiatric patients with a diagnosis of psychotic disorder. Material and methods: Data were retrieved from Greenland's nationwide electronic medical record. The study population consists of 104 patients diagnosed with a psychotic disorder, encompassing schizophrenia or schizotypal and delusional disorders, residing in Nuuk. The study population comprised 104 patients (68 males and 36 females) with a mean age of 40 years. More than 80% were daily smokers, and 68% had harmful use of cannabis. More than half had dyslipidemia (any imbalance in lipids), while over a quarter were classified as obese with body mass index of 30 kg/m2 or higher. Eighteen percent had hypertension, and six percent suffered from diabetes. This study revealed a notable prevalence of risk factors for somatic diseases, particularly smoking and cannabis use among patients with schizophrenia in Nuuk, indicating that a high prevalence of somatic diseases might be expected as the population gets older and the risk of developing somatic diseases becomes greater. Increased focus on monitoring and preventing those as part of the health care is recommended. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Important intergenerational transmission of knowledge in promotion of well-being and cultural identity in Greenland.
- Author
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Rubin, Sofie Emma, Mørch, Inunnguaq, Olsen, Nuka, and Nørtoft, Kamilla
- Abstract
The "Kinguaariit Inuunerissut" (KI) camps, meaning "generations in well-being" in Greenlandic, was a pilot initiative designed to enhance cultural identity and intergenerational connections through culturally relevant activities. The outcomes of the KI-camps have informed the development of a broader KI-concept aiming at tailoring and implementing elements from KI-camps into early childhood education services, after-school programmes, and schools. In this paper we present the results from three workshop held in January 2024 in Sisimiut, Greenland where 28 older participants and 28 professionals were asked about essential knowledge and skills to be passed down to younger generations. The focus was on songs, storytelling/myths, the spiritual world, animals, plants, skills in nature/home, and handicrafts. Results shows that older people and professionals agree on the importance of passing down cultural knowledge through all the different categories and support the need to integrate these elements into educational programmes to preserve cultural heritage and strengthen community cohesion. The findings will guide the integration of intergenerational activities into municipal institutions and contribute to culturally relevant health promotion strategies in Greenland. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. Skin diseases among adults in Tasiilaq, East Greenland.
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Haulrig, Morten B., Andersson, Anna M., Maul, Julia-Tatjana, Xu, Jingyuan, Lwin, Su M., Flohr, Carsten, Hove, Lone S., Agner, Tove, Koch, Anders, Griffiths, Christopher E. M., Zachariae, Claus, and Thyssen, Jacob P.
- Abstract
Cold climate and unique genetic and environmental factors may influence the prevalence of skin diseases in Greenland. However, there is a lack of epidemiological studies on skin diseases in the adult Greenlandic population. To address this unmet need a cross-sectional study, run by dermatologists from Denmark, the UK, and Switzerland estimated the prevalence and clinical manifestations of skin diseases among adults in East Greenland in May 2022. All adults ≥18 years in the town of Tasiilaq were invited, and 295 individuals aged 18–78 years participated (22.5% of the overall adult population in Tasiilaq). Two-hundred and three participants (69%) had visible signs of current skin disease, and among these, 242 cases of dermatoses were identified. The most common skin diseases were hand eczema (22.4%), lichen simplex (9.5%), discoid eczema (7.1%), psoriasis, atopic dermatitis and acne vulgaris (5.8% each). Scabies was the most frequent infectious skin disease (4.4%). No cases of skin cancer were identified. Atopic dermatitis and psoriasis presented with disease that was of limited extent and different from the classical presentations. Skin diseases showed a high prevalence among adults in East Greenland, and some of them were severe. This indicates a noteworthy public health problem that warrants better access to dermatologist support. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Feasibility of a 12 weeks supervised exercise training intervention among people with Maturity Onset Diabetes of the Young (MODY) or type 2 diabetes in Greenland.
- Author
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Motzfeldt, Laila, Ried-Larsen, Mathias, Hovden, Freya Jørgensen, Eika-Jørgensen, Marit, Pedersen, Michael Lynge, and Nielsen, Maja Hykkelbjerg
- Abstract
Preventing and managing Type 2 diabetes (T2D) involves adopting healthy lifestyle habits such as balanced nutrition and regular exercise. Maturity Onset Diabetes of The Young (MODY) shares diagnostic characteristics with T2D, but exercise responses in MODY remain unclear. In Greenland, MODY is 4–5 times more common than in other countries. No established exercise regimen exists for either T2D or MODY in Greenland. This study assessed the feasibility of a 12-week supervised exercise programme for MODY and T2D in Greenland, focusing on attendance, satisfaction, and effects on cardiovascular disease (CVD) risk factors and quality of life (QoL). Conducted as an experimental, two-armed, controlled trial, nine participants (4 with MODY) engaged in prescribed training sessions twice weekly for 45–60 minutes, while another nine (4 with MODY) formed the control group. Key outcomes included adherence rates, satisfaction levels, changes in HbA1c, body composition, aerobic fitness, blood pressure, CVD risk factors, and SF-12 scores. Although training adherence was modest at 56%, participant satisfaction remained high. Notable findings included a slight decrease of −0.3 mmol/l in HDL-cholesterol and a 5.7-point increase in the mental component (MCS) of SF-12 within the intervention group. However, the study underscores the need to refine the study design before supervised exercise programmes can be widely implemented in clinical settings in Greenland. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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20. Vision screening of school children in greenland 2017-2022: coverage and low vision prevalence.
- Author
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Duelund, Nick, Nisted, Ivan, Frederiksen, Ivalu, Eika Jørgensen, Marit, Heegaard, Steffen, and Jensen, Hanne
- Abstract
Vision screening during childhood is vital for the early detection and treatment of visual impairment that may significantly impact a child's development and quality of life. This nationwide cross-sectional study used data from Greenland's national electronic medical records, including 2,493 six-year-old children from July 2017 to July 2023, to evaluate the coverage rate of vision screening and the prevalence of low vision in Greenlandic schoolchildren. The participation rate in vision screening increased from 43% in 2017 to 61% in 2022, while referral rates to ophthalmologists decreased from 14% to 5%, despite a consistent prevalence of low vision. The mean prevalence of impaired vision (0.3 logMAR / ≤0.50 Snellen decimal) in the better-seeing eye at the vision screening throughout the study period was 3%. At the same time, it was 8% for the worse-seeing eyes, indicating a continuous need for ophthalmological evaluation of the Greenlandic children. This study highlights healthcare delivery challenges in Greenland's sparsely populated areas and emphasises the need for new national guidelines to optimise referral processes. Utilising other healthcare professionals, such as optometrists, for vision screenings and ensuring follow-ups are critical for improving the visual health outcomes of Greenlandic children. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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21. Childhood conditions and mental health among youth and young adults in Greenland: a latent class analysis.
- Author
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Ottendahl, Charlotte Brandstrup, Bjerregaard, Peter, Svartá, Durita Lyngsø, Seidler, Ivalu Katajavaara, Olesen, Ingelise, Nielsen, Martine Stecher, and Larsen, Christina Viskum Lytken
- Abstract
Poor mental health among youth in Greenland is a major challenge, childhood conditions are critical for mental health later in life. The study aimed to examine the clustering of childhood conditions by considering risk and protective factors for mental health among youth and young adults in Greenland and to explore the relationship between these clusters and mental health outcomes in youth. The study included 565 participants aged 15–34 living in Greenland. Seven indicators including childhood adversities (ACEs), childhood residence, language, and cultural indicators (protective factors) were used to define clusters via latent class analysis (LCA). The associations between clusters and mental health outcomes (satisfaction with life (Cantrill's ladder), self-esteem, self-efficacy, loneliness, psychological distress (General Health Questionnaire) and mental illness (Kessler 6)) were assessed by logistic regression. Four clusters were identified through LCA. While most participants reported positive childhoods, 40% (in two clusters) experienced ACEs. The two clusters differed as more participants in one cluster had experienced protective factors than the other. ACEs were associated with increased odds of negative aspects of mental health in youth. However, participants who faced high levels of adversity and few protective factors also had reduced odds of positive aspects of mental health in youth. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Inuit population have shorter gastric emptying, higher duodenal motility and altered pan-enteric micromilieu: a comparative study between Greenlandic and Danish populations with and without type 2 diabetes.
- Author
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Jensen, Mads Mose, Albertsen, Nadja, Wegeberg, Anne-Marie, Pedersen, Michael Lynge, Andersen, Stig, and Brock, Christina
- Abstract
Gastrointestinal function plays a pivotal role in nutrient absorption and overall digestive health. Abnormal gastric emptying is closely linked to type 2 diabetes, impacting blood glucose regulation and causing gastrointestinal symptoms. This study aims to investigate and compare segmental transit times, motility indices, and micromilieu between Greenlandic Inuit and Danish individuals with and without type 2 diabetes. We included forty-four Greenlandic Inuit, twenty-three of whom had type 2 diabetes, and age and gender-matched Danish individuals. Segmental transit time, motility, and luminal environment were measured using the SmartPill®. Greenlandic controls displayed shorter gastric emptying time (GET) (163 min), higher gastric median pH (2.0 pH) and duodenal median contractions (18.2 mm Hg) compared to Greenlanders with type 2 diabetes (GET: 235 min, pH:1.9, median duodenal contraction 18.4 mm Hg) and Danish controls (GET: 190, pH:1.2 median duodenal contraction 17.5 mmHg). Despite similar anti-diabetic management efforts, variations in gastrointestinal physiology were evident, highlighting the complexity of diabetes and its interaction with ethnicity, suggesting potential dietary or even genetic influences, emphasising the necessity for personalised diabetes management approaches. Finally, the study opens possibilities for future research, encouraging investigations into the underlying mechanisms linking genetics, diet, and gastric physiology, as an understanding of factors can lead to more effective, tailored strategies for diabetes care and improved digestive health in diverse populations. [ABSTRACT FROM AUTHOR]
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- 2024
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23. Personal experiences of living with sucrose intolerance and attitudes towards genetic research in Greenland - a user study.
- Author
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Isidor, Silvia, Senftleber, Ninna, Schnoor, Cecilie, Pedersen, Kristine Skoett, Seibæk, Lene, Jørgensen, Marit Eika, and Marcussen, Jette
- Abstract
There is high prevalence of the genetic SI variant c.273_274delAG in the sucrase-isomaltase-encoding gene in Greenland, resulting in congenital sucrase-isomaltase deficiency and thereby an inability to digest sucrose, the most common dietary sugar. There are no studies of Greenlanders' everyday experiences of sucrose intolerance related to this genetic variant. This study therefore explored, how Greenlandic people experience sucrose intolerance influences life and their attitudes towards research in health and genetics. The study is qualitative, using semi-structured focus groups and/or individual telephone interviews. The analysis was based on the phenomenological-hermeneutic approach of Paul Ricoeur, consisting naïve reading, structural analysis, interpretation and discussion. We identified two themes; "Sucrose intolerance impacts daily living", dealt with physical and emotional reactions and coping with social adaption to activities. And "openness to participate in genetic and health research" were caused by participants wanting more knowledge to improve their people and family's life. The study concluded that most of the participants with symptoms of sucrose intolerance experienced the impact in their daily life, both physically, emotionally, and socially. Further, they expressed openness to participate in health and genetic research. There is a need for more accessible health knowledge and support from health care to manage sucrose intolerance. [ABSTRACT FROM AUTHOR]
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- 2024
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24. Subarachnoid haemorrhage and intracranial aneurysms in Greenland in the period 2018–2021: incidence, outcome and familial disposition.
- Author
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Svendsen, Joo Roerholm, Pedersen, Michael Lynge, Hauerberg, John, and Gredal, Ole
- Abstract
Subarachnoid haemorrhages (SAH) caused by rupture of intracranial aneurysms (IA) are a severe condition. Earlier studies found a higher incidence of SAH in Greenlandic patients compared to Danish patients, with familial aggregation also higher in Greenland. However, updated data is lacking. To investigate the contemporary incidence, outcome, and familial disposition of SAH/IA in Greenlandic patients in 2018–2021. Greenlandic patients diagnosed with ruptured or unruptured IA (UIA) during 2018–2021 were included. Data was obtained from patient files, x-ray department, and discharge registry. Incidence rates were estimated as cases/100,000/year. Direct age-standardised incidence rates were calculated using WHO 2000–2025 as standards. Of 30 SAH patients, 20 (66.7%) were females, 10 (33.3%) males. Of 36 UIA patients, 27 (75.0%) were females, 9 (25.0%) males. For SAH, crude incidence was 13.4/100,000/year, age-standardised incidence was 10.8/100,000/year. Familial history was observed in 30.0% of SAH patients. 5 patients (16.7%) died before treatment, 28-day case-fatality rate (CFR) for all patients was 23.3%. Overall and age-standardised incidence rates were similar to previous studies but higher among females and compared to neighbouring countries. A high occurrence of familial history was reported. SAH remains a serious condition in Greenland, as evidenced by five fatalities before treatment was administered. [ABSTRACT FROM AUTHOR]
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- 2024
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25. The social and organisational factors shaping acceptability of a self-management education and exercise intervention for people with hip or knee osteoarthritis in Greenland.
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Nielsen, Marie Tolver, Nielsen, Maja Hykkelbjerg, Sørensen, Sonja, and Skovdal, Morten
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This study aimed to explore the experiences and perspectives of people with osteoarthritis attending the "Osteoarthritis School" (OA School) in Nuuk, Greenland to generate insights and lessons that can inform the development of self-management education and exercise interventions for people with other lifestyle conditions in a Greenland context. We conducted a qualitative interpretive description (ID) study based on ten semi-structured interviews with people with hip or knee osteoarthritis. Interviews were audio-recorded, transcribed, and coded. Using ID, we identified three themes: 1) perceptions and experiences of how the OA School intervention was organised (time and place); 2) perspectives and experiences of the education and exercise components (social factors, motivation, and education); and 3) significant change stories (physical and mental improvements and increased knowledge of OA). Social and organisational factors, such as working out with peers and the time and place of the intervention, influenced the participants' acceptance of the OA School intervention. Knowledge from this study will help us gain insight into what to address when developing future self-management education and exercise interventions in the Greenlandic healthcare system. [ABSTRACT FROM AUTHOR]
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- 2024
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26. The 1919–21 influenza pandemic in Greenland.
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Ingholt, Mathias Mølbak, Simonsen, Lone, Mamelund, Svenn-Erik, Noahsen, Paneeraq, and van Wijhe, Maarten
- Abstract
In Alaska, the 1918–20 influenza pandemic was devastating, with mortality rates up to 90% of the population, while in other arctic regions in northern Sweden and Norway mortality was considerably lower. We investigated the timing and age-patterns in excess mortality in Greenland during the period 1918–21 and compare these to other epidemics and the 1889–92 pandemic. We accessed the Greenlandic National Archives and transcribed all deaths from 1880 to 1921 by age, geography, and cause of death. We estimated monthly excess mortality and studied the spatial-temporal patterns of the pandemics and compared them to other mortality crises in the 40-year period. The 1918–21 influenza pandemic arrived in Greenland in the summer of 1919, one year delayed due to ship traffic interruptions during the winter months. We found that 5.2% of the Greenland population died of the pandemic with substantial variability between counties (range, 0.1% to 11%). We did not see the typical pandemic age-pattern of high young-adult mortality, possibly due to high baseline mortality in this age-group or remoteness. However, despite substantial mortality, the mortality impact was not standing out relative to other mortality crises, or of similar devastation reported in Alaskan populations. [ABSTRACT FROM AUTHOR]
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- 2024
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27. Reproducibility and validity of a 45 item food-frequency questionnaire for inuit in Greenland.
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Bjerregaard, Peter and Olesen, Ingelise
- Abstract
Since 1993, dietary assessment has been carried out in Greenland as part of recurrent population health surveys. In preparation for the next survey in 2024, 91 participants from the survey in 2018 were selected for a validation study of the Food Frequency Questionnaire (FFQ). The 91 participants were reinterviewed 38–50 months after the first FFQ and invited to complete a food diary. As part of the 2018 survey, blood was analysed for mercury. The food diary was completed by 65 participants. The agreement between the two FFQ interviews was very good for macronutrients and fatty acids (p > 0.20), whereas the calculated intake of mercury was 22% higher in the second FFQ (p = 0.04) due to a higher intake of whale meat and muktuk (whale skin). The agreement between the second FFQ and the food diary was good for local food, imported meat and cakes/sweets/snacks but fruit and vegetables, dairy products, beverages and added sugar were significantly underreported in the food diary. Food items not included in the FFQ were identified from the food diaries. The correlation between the intake of marine mammals and blood mercury was moderate (Spearman's rho = 0.41–0.50; p < 0.0001). The results will inspire future dietary studies in the circumpolar North. [ABSTRACT FROM AUTHOR]
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- 2024
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28. The prevalence and disease course of autoimmune liver diseases in Greenland.
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Gantzel, Rasmus Hvidbjerg, Bagge, Carina Nørskov, Villadsen, Gerda Elisabeth, Rex, Karsten Fleischer, Grønbæk, Henning, and Pedersen, Michael Lynge
- Abstract
Autoimmune liver diseases are rare serious diseases causing chronic inflammation and fibrosis in the liver parenchyma and bile ducts. Yet, the prevalence and burden of autoimmune liver diseases are largely unexplored in Arctic native populations. We investigated the prevalence and management of autoimmune liver diseases in Greenland using nationwide cross-sectional register data and subsequent medical chart reviews validating diagnoses and extracting liver histology examinations and medical treatments. The overall prevalence of autoimmune liver diseases in Greenland was 24.6 per 100,000 (95% CI: 14.7–41.3). This was based on 7 patients with autoimmune hepatitis (AIH) (12.3 per 100,000), 3 patients with primary biliary cholangitis (PBC) (5.3 per 100,000), 4 patients with AIH/PBC overlap disease (7.0 per 100,000), and no patients with primary sclerosing cholangitis. All diagnoses were confirmed by liver histology examinations. Medical treatments adhered to internal recommendations and induced complete remission in most patients with AIH, and complete or partial remission in 1 patient with PBC and 3 patients with AIH/PBC overlap disease. One patient had established cirrhosis at the time of diagnosis, while 2 patients progressed to cirrhosis. In conclusion, the prevalence of autoimmune liver diseases was lower in Greenland than in Scandinavia and among Alaska Inuit. [ABSTRACT FROM AUTHOR]
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- 2024
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29. Quality of care among patients diagnosed with atrial fibrillation in Greenland.
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Nielsen, Marie Tolver, Hykkelbjerg Nielsen, Maja, Andersen, Stig, Riahi, Sam, Geisler, Uka Wilhjelm, Lynge Pedersen, Michael, and Albertsen, Nadja
- Abstract
This cross-sectional study sought to assess the prevalence of atrial fibrillation (AF) diagnosis in Greenland among various age groups and examine the corresponding quality of care. We collected data from Greenland's electronic medical records and evaluated the quality of care using six internationally recommended indicators, which are: percentage of AF patients with an assessment of smoking status within the previous year, an assessment of body mass index within the previous year, assessment of blood pressure within the previous year, measurement of thyroid stimulating hormone (TSH), treatment with an anticoagulant and percentage of patients with a measurement of serum-creatinine. We found the prevalence of AF among patients aged 20 years or older in Greenland to be 1.75% (95% CI 1.62–1.88). We found an increasing prevalence of AF with age and a greater proportion of men than women until the age of 74 years. Our study suggests that the associated quality of care could be higher as the requirement of only one of the six quality indicators was met. A lack of registration may partly explain this, and initiatives to improve the quality of care are recommended. [ABSTRACT FROM AUTHOR]
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- 2024
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30. A Factor Two Difference in 21st‐Century Greenland Ice Sheet Surface Mass Balance Projections From Three Regional Climate Models Under a Strong Warming Scenario (SSP5‐8.5).
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Glaude, Q., Noel, B., Olesen, M., Van den Broeke, M., van de Berg, W. J., Mottram, R., Hansen, N., Delhasse, A., Amory, C., Kittel, C., Goelzer, H., and Fettweis, X.
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GREENLAND ice , *GLOBAL warming , *ATMOSPHERIC models , *ICE sheets , *POLAR climate - Abstract
The Arctic is warming rapidly, significantly reducing the Greenland ice sheet (GrIS) surface mass balance (SMB) and raising its contribution to global sea‐level rise. Since these trends are expected to continue, it is essential to explore the GrIS SMB response to projected climate warming. We compare projections from three polar regional climate models, RACMO, MAR, and HIRHAM, forced by the Community Earth System Model CESM2 under a high‐end warming scenario (SSP5‐8.5, 1970–2099). We reveal different modeled SMB by 2100, including a twofold larger annual surface mass loss in MAR (−1735 Gt/yr) and HIRHAM (−1698 Gt/yr) relative to RACMO (−964 Gt/yr). Discrepancies primarily stem from differences in projected runoff, triggering melt‐albedo positive feedback and subsequent modeled ablation zone expansion. In addition, we find different responses of modeled meltwater production to similar atmospheric warming. Our analysis suggests clear avenues for model developments to further improve SMB projections and contribution to sea‐level rise. Plain Language Summary: We explore how three different polar climate models predict the future surface mass balance (SMB) of the Greenland ice sheet (GrIS), a major contributor to global sea‐level rise. Our results show that SMB projections among these models differ significantly by the end of the century. Differences primarily stem from how models convert meltwater into surface runoff toward the ocean, a crucial SMB component that directly contributes to sea‐level rise. Another key factor is the response of these models to climate warming, substantially affecting future melting rates. Our research highlights the need for further improvements of these climate models. By identifying and understanding the drivers behind model differences, we can improve SMB predictions and better estimate future global sea‐level rise. Key Points: With identical forcing, Greenland Ice Sheet surface mass balance from 3 regional climate models shows a two‐fold difference by 2100Different runoff projections stem from substantial discrepancies in projected ablation zone expansion, and reciprocallyThe response of meltwater production to similar atmospheric warming differs significantly among regional climate models [ABSTRACT FROM AUTHOR]
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- 2024
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31. Greenland Ice Sheet's Distinct Calving Styles Are Identified in Terminus Change Timeseries.
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Bézu, Chris and Bartholomaus, Timothy C.
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ICE calving , *GREENLAND ice , *ICE sheets , *ICEBERGS , *ALPINE glaciers - Abstract
At least three primary iceberg calving styles have been identified in Greenland: serac collapse, which produces falling icebergs tens of meters in length; slab capsize, which produces rotating icebergs hundreds of meters in length; and tabular rifting, which produces kilometer‐scale icebergs. However, calving styles are mostly undocumented across Greenland. Here, we develop a method to disentangle the sizes of individual calving events and map the dominant calving style at glaciers, using the characteristic properties of step retreats in satellite‐derived terminus positions. At glaciers known to frequently produce calving teleseisms, step retreats greater than 200 m account for >80% ${ >} 80\%$ of net calved length since 2018. In contrast, at glaciers known to calve by serac failure, 200 m step retreats account <20% ${< } 20\%$ of net calving. Thus, terminus change timeseries can offer promising insight into the dominant calving styles at marine‐terminating glaciers. Plain Language Summary: Iceberg calving is ubiquitous at the ocean‐bounded edges of ice sheets. However, not all iceberg calving is the same: at least three distinct mechanisms govern the discharge of solid ice from the Greenland Ice Sheet. We show these are associated with a characteristic range of iceberg sizes. Because calving constitutes a major component of Greenland's continued mass loss, it is important that these distinct mechanisms be understood. We develop a method to identify which calving mechanisms are important at various glaciers. We do so by using satellite observations to estimate the lengths of terminus retreats producing icebergs at individual glaciers. Key Points: Greenland outlet glaciers with different calving styles have different characteristic retreat magnitudes in consecutive satellite imagesAt glaciers which frequently produce calving teleseisms, step retreats in terminus position are dominated by retreats >200 mThe distinct processes underlying different calving styles will likely necessitate several distinct calving laws [ABSTRACT FROM AUTHOR]
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- 2024
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32. Extreme wind events responsible for an outsized role in shelf-basin exchange around the southern tip of Greenland.
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Coquereau, Arthur, Foukal, Nicholas P., and Våge, Kjetil
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GREENLAND ice , *FRESH water , *ICE sheets , *WATER masses - Abstract
The coastal circulation around Southern Greenland transports fresh, buoyant water masses from the Arctic and Greenland Ice Sheet near regions of convection, sinking, and deep-water formation in the Irminger and Labrador Seas. Here, we track the pathways and fate of these fresh water masses by initializing synthetic particles in the East Greenland Coastal Current on the Southeast Greenland shelf and running them through altimetry-derived surface currents from 1993 to 2021. We report that the majority of waters (83%) remain on the shelf around the southern tip of Greenland. Variability in the shelf-basin exchange of the remaining particles closely follows the number of tip jet wind events on seasonal and interannual timescales. The probability of a particle exiting the shelf increases almost fivefold during a tip jet event. These results indicate that the number of tip jets is a close proxy of the shelf-basin exchange around Southern Greenland. [ABSTRACT FROM AUTHOR]
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- 2024
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33. The Nonlinear and Distinct Responses of Ocean Heat Content and Anthropogenic Carbon to Ice Sheet Freshwater Discharge in a Warming Climate.
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Gorte, Tessa, Lovenduski, Nicole S., Nissen, Cara, Lenaerts, Jan T. M., and Weiss, Jeffrey B.
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CLIMATE change models ,ICE sheet thawing ,EFFECT of human beings on climate change ,ICE sheets ,HEAT storage - Abstract
Anthropogenic climate change will drive extensive mass loss across both the Antarctic (AIS) and Greenland Ice Sheets (GrIS), with the potential for global climate system feedbacks, especially in polar regions. Historically, the high‐latitude North Atlantic and Southern Ocean have been critical regions for anthropogenic heat and carbon uptake, but our understanding of how this uptake will be altered by future freshwater discharge is incomplete. We assess each ice sheet's impact on global ocean anthropogenic heat and carbon storage for a high‐emission scenario over the 21st ${21}^{\text{st}}$‐century using a coupled Earth system model. We explore the impact of contemporaneous mass loss from both ice sheets on anthropogenic heat and carbon storage and quantify their linear and nonlinear contributions. Notably, added freshwater reduces ocean heat and carbon storage by 2,100, and the sum of individual freshwater effects differ from those induced by simultaneous freshwater discharge from both ice sheets. Combined AIS and GrIS freshwater engenders distinct anthropogenic storage anomalies—particularly in the high‐latitude Southern Ocean and North Atlantic. From 2080 to 2100, GrIS freshwater exerts primary control on the temporal evolution of global ocean heat storage, while global ocean carbon storage is modulated by the linear AIS and GrIS freshwater impacts. Nonlinear impacts of simultaneous ice sheet discharge have a non‐negligible contribution to the evolution of global ocean heat storage. Further, anthropogenic heat changes are realized more quickly in response to ice sheet discharge than anthropogenic carbon. Our results highlight the need to incorporate both ice sheets actively in climate models to accurately project future global climate. Plain Language Summary: As the globe continues to warm in the next 100 years, the Antarctic and Greenland Ice sheets will continue to melt, adding freshwater to the surrounding ocean regions. This process is often poorly (if at all) represented in global climate models used to make projections about future climate change. Here, we simulate the climate response to melting ice sheets in a global climate model by adding freshwater to the model ocean near the edges of ice sheets. We focus our analysis on the impact of this freshwater addition on the future evolution of heat and carbon in the ocean, because both heat and carbon have the potential to feed back on the climate system (less heat/carbon in the ocean means more heat/carbon in the atmosphere and a warmer climate). By the end of the century, we find that the ocean stores less heat and carbon because of the melting ice sheets. We also find that summing the effects from melt on Antarctica and Greenland separately is not equal to the effect of melting both ice sheets simultaneously. Finally, we show that ocean heat and carbon respond differently to the same amount of ice sheet melt. Key Points: We disentangle the linear and nonlinear effects of Greenland and Antarctic Ice Sheet melt on ocean heat content and anthropogenic carbonFuture anthropogenic carbon storage and ocean heat content have disparate responses to separate and combined ice sheet melt in polar regionsGreenland freshwater is more influential than Antarctic freshwater in driving future changes in anthropogenic carbon and ocean heat content [ABSTRACT FROM AUTHOR]
- Published
- 2024
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34. Impact of Summer Air Temperature on Water and Solute Transport on a Permafrost‐Affected Slope in West Greenland.
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Zastruzny, Sebastian F., Sjöberg, Ylva, Jensen, Karsten H., Liu, Yijing, and Elberling, Bo
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CLIMATE change models ,ARCTIC climate ,CLIMATE change ,ATMOSPHERIC temperature ,FROZEN ground - Abstract
In Arctic landscapes, the active layer forms a near‐surface aquifer on top of the permafrost where water and nutrients are available for plants or subject to downslope transport. Warmer summer air temperatures can increase the thickness of the active layer and alter the partitioning of water into evapotranspiration and discharge by increasing the potential evapotranspiration, the depth to the water table, and changing the flow paths but the interacting processes are poorly understood. In this study, a numerical model for surface‐ and subsurface cryo‐hydrology is calibrated based on field observations from a discontinue permafrost area in West Greenland considered sensitive to future climate changes. The validated model is used to simulate the effect of three summers with contrasting temperature regimes to quantify the variations in the active layer thickness, the resulting changes in the water balance, and the implications on solute transport. We find that an increase of summer air temperature by1.6°C, under similar precipitation can increase the active layer thickness by 0.25 m, increase evapotranspiration by 5%, and reduce the total discharge compared to a colder summer by 9%. Differences in soil moisture and evapotranspiration between upslope and downslope were amplified in a warm summer. These hydrological differences impact solute transport which is 1.6 times faster in a cold summer. Surprisingly, we note that future warmer summer with increase in permafrost thaw may not necessary lead to an increase in discharge along a hill slope with underlying permafrost. Plain Language Summary: Precipitation that falls in the Arctic can be restricted from moving deeper into the subsurface by the permanently frozen soil that constraints water movement close to the surface in a layer that thaws every year during the summer. Warmer summers make this layer thaw deeper and water moves to deeper soil. In the deeper soil water moves more slowly as the material is more difficult to flow through, and thus also solute move slower. Moreover, the amount of water that returns to the atmosphere becomes higher with warmer temperatures. We measure soil conditions, and the velocity of solutes in the field along a hillslope in Greenland. Based on warm, average and cold years, we build a model capable of simulating storage and movement of water and the temperature in the soil. We use the model to test a warm, a normal, and a cold summer, and analyze the effects on the amount of water that reaches the end of the hillslope. We show that less water will move across the slope in warmer summers, but solutes travel at a higher velocity, and that cold summers have only a small effects on the movement of this solute. Key Points: Warmer summers reduce discharge from hillslope by 35%Solute movement is non‐uniform and controlled by precipitation eventsWarmer summers amplify differences between up‐ and downslope [ABSTRACT FROM AUTHOR]
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- 2024
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35. Structure of the crust and upper mantle in Greenland and northeastern Canada: insights from anisotropic Rayleigh-wave tomography.
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Ajourlou, Parviz, Darbyshire, Fiona, Audet, Pascal, and Milne, Glenn A
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SEISMIC wave velocity , *SEISMIC anisotropy , *PHASE velocity , *OROGENIC belts , *LITHOSPHERE , *SEISMOGRAMS - Abstract
Seismic velocity models provide important constraints on Greenland's deep structure, which, in turn, has profound implications for our understanding of the tectonic history of this region. However, the resolution of seismic models has been limited by a sparse network, particularly in northern and central Greenland. We address these limitations by generating new high-resolution Rayleigh-wave phase velocity maps encompassing Greenland and northeastern Canada by processing over three decades of teleseismic earthquake records and incorporating recently added stations in Greenland and Arctic Canada. These phase velocity maps are sensitive to structure from the lower crust down to the sub-lithospheric mantle (25–185 s period). We find significant heterogeneity and a strong correlation between isotropic and anisotropic seismic velocities with inferred geological structure. High seismic velocities associated with cratonic lithosphere are broadly divided into two regions, with a belt of reduced velocity spanning central Greenland, which we interpret as lithospheric erosion resulting from interaction between the Greenland continental keel and the Iceland plume. Within each region, we identify tectonic subdivisions that suggest fundamental differences between the blocks that make up Precambrian Greenland. In the south, the North Atlantic craton (NAC) has a high-velocity keel exhibiting anisotropic stratification. Between the NAC and the cratonic lithosphere further north, the Proterozoic Nagssugtoqidian orogenic belt shows a distinct signature of reduced seismic velocity to |$\sim$| 75 s period, but then appears to pinch out at depth. The northern Greenland lithosphere exhibits significant isotropic heterogeneity, with a distinct core of high velocities in the northwest (|$\sim$| 55–75 s period) giving way to a set of distinct east-west trending high-velocity belts at longer periods. At all periods sensitive to the lithospheric mantle in this region, anisotropic fast orientations are E–W, consistent with a north–south Precambrian assembly of the Greenland shield. In contrast to the NAC, there is no evidence of anisotropic stratification in the northern part of the cratonic keel. Based on both isotropic and anisotropic phase-velocity anomalies, we suggest that the Phanerozoic Caledonian and Ellesmerian-Franklinian fold belts are relatively thin-skinned features onshore Greenland, though the Caledonian belt may have a stronger signature off the east coast. At the longest periods, a prominent low-velocity anomaly initially centred on Iceland migrates northwards and spreads beneath central-eastern Greenland. Coupled with NW–SE trending anisotropy, this feature is interpreted as the effect of mantle flow radiating outward from the Iceland plume and interacting with the eroded Greenland lithosphere. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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36. The Pivotal Role of Evaporation in Lake Water Isotopic Variability Across Space and Time in a High Arctic Periglacial Landscape.
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Akers, Pete D., Kopec, Ben G., Klein, Eric S., Bailey, Hannah, and Welker, Jeffrey M.
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WATER quality monitoring ,STABLE isotopes ,WATER sampling ,HYDROLOGY ,ISOTOPES - Abstract
Rapidly changing climate is disrupting the High Arctic's water systems. As tracers of hydrological processes, stable water isotopes can be used for high quality monitoring of Arctic waters to better reconstruct past changes and assess future environmental threats. However, logistical challenges typically limit the length and scope of isotopic monitoring in High Arctic landscapes. Here, we present a comprehensive isotopic survey of 535 water samples taken in 2018 and 2019 of the lakes and other surface waters of the periglacial Pituffik Peninsula in far northwest Greenland. The δ18O, δ2H, and deuterium‐excess values of these samples, representing 196 unique sites, grant unprecedented insight into the environmental drivers of the regional hydrology and water isotopic variability. We find that the spatial variability of lake water isotopes can best be explained through evaporation and the hydrological ability of a lake to replace evaporative water losses with precipitation and snowmelt. Temporally, summer‐long evaporation can drive lake water isotopes beyond the isotopic range observed in precipitation, and wide interannual changes in lake water isotopes reflect annual weather differences that influenced evaporation. Following this, water isotope samples taken at individual times or sites in similar periglacial landscapes may have limited regional representativeness, and increasing the spatiotemporal extent of isotopic sampling is critical to producing accurate and informative High Arctic paleoclimate reconstructions. Overall, our survey highlights the diversity of isotopic compositions in Pituffik surface waters, and our complete isotopic and geospatial database provides a strong foundation for future researchers to study hydrological changes at Pituffik and across the Arctic. Plain Language Summary: Water isotopes can help us track how rapidly changing climate is disrupting High Arctic water systems, but the challenging Arctic environment has limited the monitoring required to understand these isotopes. To address this, we collected 535 water isotope samples from lakes and other waters on the Pituffik Peninsula in northwest Greenland in 2018 and 2019. We found that differences in lake water isotopes are mainly due to water evaporation and how connected a lake is to sources of precipitation and snowmelt that can replace evaporated water in the summer. The information we collected about isotopes is a good starting point for other scientists who want to study how water is changing, not just in Pituffik, but also in the whole Arctic. Our findings tell us that if we only collect water samples once or twice, or only in one place, we might not get the full picture of what is happening with the isotopes across the whole region. To get a better understanding of how the climate is changing in the High Arctic, water isotopic samples should be collected from a wide range of locations over long periods of time. Key Points: Five hundred and thirty five water isotope samples taken over 2 years in Pituffik, Greenland, provide insight into High Arctic isotope hydrologySpatially, lake water isotopic composition reflects the degree that evaporation losses are offset by precipitation and snowmelt rechargeEvaporation drives summer‐long lake water isotopic evolution and best explains interannual isotopic differences [ABSTRACT FROM AUTHOR]
- Published
- 2024
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37. Narwhal (Monodon monoceros) associations with Greenland summer meltwater release.
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Laidre, Kristin L., Zahn, Marie J., Simon, Malene, Ladegaard, Michael, Stafford, Kathleen M., Phillips, Elizabeth, Moon, Twila, Stern, Harry L., and Cohen, Benjamin
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GREENLAND ice ,HEAT waves (Meteorology) ,NARWHAL ,SEA ice ,ICE sheets ,MELTWATER - Abstract
Climate change is rapidly transforming the coastal margins of Greenland. At the same time, there is increasing recognition that marine‐terminating glaciers provide unique and critical habitats to ice‐associated top predators. We investigated the connection between a top predator occupying glacial fjord systems in Northwest Greenland and the properties of Atlantic‐origin water and marine‐terminating glaciers through a multiyear interdisciplinary project. Using passive acoustic monitoring, we quantified the summer presence and autumn departure of narwhals (Monodon monoceros) at glacier fronts in Melville Bay and modeled what glacier fjord physical attributes are associated with narwhal occurrence. We found that narwhals are present at glacier fronts after Greenland Ice Sheet peak summer runoff and they remain there during the period when the water column is becoming colder and fresher. Narwhals occupied glacier fronts when ocean temperatures ranged from −0.6 to 0.8°C and salinities between 33.2 and 34.0 psu at around 200 m depth and they departed on their southbound migration between October and November. Narwhals' departure was approximately 4 weeks later in 2019 than in 2018, after an extreme 2019 summer heatwave event that also delayed sea ice formation by 2 months. Our study provides further support for the niche conservative narwhal's preference for cold ocean temperatures. These results may inform projections about how future changes will impact narwhal subpopulations, especially those occupying Greenland glacial fjords. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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38. Anomaly Detection Using Graph Deviation Networks Within Spatiotemporal Neighborhoods: A Case Study in Greenland
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Chhaya Kulkarni, Bayu Adhi Tama, Nicole-Jeanne Schlegel, and Vandana P. Janeja
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Anomaly detection ,graph neural network ,Greenland ,neighborhood ,spatiotemporal data ,Ocean engineering ,TC1501-1800 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Polar ice melt contributes to sea level rise. To understand this contribution, we need to examine the anomalous behaviors leading to significant snowmelts in polar regions, including the Greenland ice sheet. These regions are complex systems where various phenomena are represented by different sets of spatiotemporal data. Such data possess unique characteristics like spatial autocorrelation, heterogeneity, temporal nonstationarity, and multiple scales and resolutions. In this article, we provide a framework to analyze disparate datasets by forming spatial neighborhoods to capture local behaviors. We then perform graph deviation network-based anomaly detection for multivariate datasets within these neighborhoods. Although this study focuses on spatiotemporal data from Greenland as an example, the methodology is intended to be adaptable and relevant to other regions with similar data properties. Specifically, using spatiotemporal data from Greenland, we, first, integrate all subdomain data, including both spatial and temporal data. Second, create neighborhoods to preserve the spatial autocorrelation and heterogeneity present in the data. Third, apply graph deviation networks, a variant of graph neural networks, to locate anomalous regions with respect to snowmelt. We outline our findings in the Greenland region, evaluating anomalous patterns and validating them with ground truth findings from polar science domain experts. Our methodology allows for performing localized analysis on a Greenland-wide scale.
- Published
- 2025
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39. Burden of selected chronic non-communicable diseases in a primary healthcare setting in Nuuk, Greenland, compared to a Danish suburb
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Marie Balslev Backe, Per Kallestrup, Kurt Rasmussen, Marit Eika Jørgensen, and Michael Lynge Pedersen
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Non-communicable diseases ,prevalence ,primary healthcare ,Greenland ,Denmark ,Public aspects of medicine ,RA1-1270 - Abstract
Introduction Noncommunicable diseases (NCDs) constitute a massive global burden and are the leading cause of death and disability worldwide. In Greenland, the prevalence of NCDs has historically been low. However, during the past approximately 70 years, life circumstances have changed dramatically resulting in increased life expectancy. Today, the proportion of inhabitants in Greenland ≥65 years has nearly tripled since the 1980s, and the prevalence of obesity and diabetes has increased rapidly within the past decades. The aim of this study was to describe the burden of selected NCDs in a primary care setting in Nuuk and compare it to a modern westernized suburban general practice in Denmark.Methods The study was performed as a cross sectional register-based study using data extracted from the electronic medical records (EMR) based on diagnosis codes from inhabitants living in Nuuk, Greenland, and a suburb in Denmark. Estimates of prevalence were age-standardized to the WHO world standard population.Results In both Nuuk and the Danish suburb, the highest prevalence was observed for hypertension (13.2% for both populations), followed by asthma (4.4 and 9.5%, respectively) and diabetes (4.3 and 2.9%, respectively). The age-standardized prevalences of diabetes, COPD, atrial fibrillation, and heart failure, were significantly higher in Nuuk, while seven NCDs including asthma, ischemic heart disease, arthritis urica, psoriasis, hyperthyreosis, hypothyreosis and osteoporosis were significantly higher in the Danish suburb.Conclusion In contrast to the disease pattern observed in Greenland in the last century, the prevalence of diagnosed NCDs in Nuuk is no longer rare. Thus, the overall prevalence of NCDs in the population of Nuuk is now comparable to or even higher than in the suburb in Denmark. This calls for increased focus on all NCDs in the primary healthcare system in Greenland and adaption of the primary healthcare services to a changed disease spectrum.
- Published
- 2024
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40. Inland Summer Speedup at Zachariæ Isstrøm, Northeast Greenland, Driven by Subglacial Hydrology.
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Khan, Shfaqat A., Morlighem, Mathieu, Ehrenfeucht, Shivani, Seroussi, Helene, Choi, Youngmin, Rignot, Eric, Humbert, Angelika, Pickell, Derek, and Hassan, Javed
- Subjects
- *
GREENLAND ice , *RUNOFF , *CLIMATE change , *HYDROLOGIC models , *GLACIERS ,GLACIER speed - Abstract
The Northeast Greenland Ice Stream (NEGIS) has experienced substantial dynamic thinning in recent years. Here, we examine the evolving behavior of NEGIS, with focus on summer speedup at Zachariae Isstrøm, one of the NEGIS outlet glaciers, which has exhibited rapid retreat and acceleration, indicative of its vulnerability to changing climate conditions. Through a combination of Sentinel‐1 data, in‐situ GPS observations, and numerical ice flow modeling from 2007, we investigate the mechanisms driving short‐term changes. Our analysis reveals a summer speedup in ice flow both near the terminus and inland, with satellite data detecting changes up to 60 km inland, while GPS data capture changes up to 190 km inland along the glacier center line. We attribute this summer speedup to variations in subglacial hydrology, where surface meltwater runoff influences basal friction over the melt season. Incorporating subglacial hydrology into numerical models makes it possible to replicate observed ice velocity patterns. Plain Language Summary: The Northeast Greenland Ice Stream (NEGIS), a crucial part of the Greenland Ice Sheet, has been experiencing significant dynamic thinning recently. This study focuses on the summer speedup of Zachariae Isstrøm (ZI), one of NEGIS's outlet glaciers, which is rapidly retreating and accelerating, highlighting its sensitivity to climate change. Utilizing Sentinel‐1 satellite data, in‐situ GPS observations, and numerical ice flow modeling, we explore the mechanisms behind short‐term dynamic changes. We find that satellite data reveals short‐term summer (June to August) fluctuations in ice flow speed near the glacier terminus and up to 50–70 km inland. However, GPS data shows that this speedup extends further inland, up to at least 190 km along the main flow line. Only GPS data can detect the smaller‐scale summer speedups in these inland regions, providing critical observations for validating ice flow models. We determine that the seasonal acceleration of ice velocity at Zachariae Isstrøm is due to variations in subglacial hydrology, where surface meltwater runoff reduces basal friction by altering the subglacial hydrologic system during the melt season. Additionally, our study highlights that these findings are applicable beyond NEGIS, with similar speedup patterns observed in other Greenland glaciers. Key Points: GPS data reveal summer speed up at least 190 km inland along the main flowline of Zachariae IsstrømSubglacial hydrology is the main driver of the summer speedup near the terminus and deep inlandRecord high warming in 2019 led to a more intense and longer duration of the summer speedup [ABSTRACT FROM AUTHOR]
- Published
- 2024
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41. The palaeobiological significance of clustering in acritarchs: a case study from the early Cambrian of North Greenland.
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Wallet, Elise, Slater, Ben J., and Willman, Sebastian
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ACRITARCHS , *CELL anatomy , *HABIT , *PLANKTON , *CYSTS (Pathology) , *FOSSIL microorganisms - Abstract
Aggregated clusters of acritarchs are relatively common among assemblages of organic‐walled microfossils, yet such associations have received relatively little attention. Here we report a new diversity of acritarch clusters from the early Cambrian Buen Formation of North Greenland. The aggregation patterns of four genera (Skiagia, Comasphaeridium, Asteridium and Synsphaeridium) are described together with their background population characteristics (presence of openings, inner bodies and overall disparity) in order to better understand the palaeobiology of these acritarchs. The majority of Skiagia clusters were found to be monospecific despite significant intraspecific variability, a pattern that is suggestive of a strong environmental influence on Skiagia morphologies and aggregation habits. Abundant small (<20 μm) Comasphaeridium vesicles were recovered in a broad range of chiefly monospecific clusters that are likely to have been formed under bloom conditions. A colonial habit is tentatively inferred from the tightly packed appearance of monogeneric Asteridium aggregates, and clearly evidenced by the highly conserved cellular structure of recovered Synsphaeridium clusters. A lack of excystment structures in Comasphaeridium and Asteridium vesicles suggest these taxa represent actively growing cells rather than resting cysts. Altogether, these findings shed new light on the diversity of cellular structures and lifestyles represented among Cambrian acritarchs, and illustrate a range of reproduction and defence strategies adopted by plankton in the face of novel environmental pressures. [ABSTRACT FROM AUTHOR]
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- 2024
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42. Burden of selected chronic non-communicable diseases in a primary healthcare setting in Nuuk, Greenland, compared to a Danish suburb.
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Backe, Marie Balslev, Kallestrup, Per, Rasmussen, Kurt, Jørgensen, Marit Eika, and Pedersen, Michael Lynge
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HYPERTENSION epidemiology , *CROSS-sectional method , *RESEARCH funding , *PRIMARY health care , *GLOBAL burden of disease , *SYMPTOMS , *NON-communicable diseases , *ELECTRONIC health records , *CONFIDENCE intervals , *COMPARATIVE studies , *MEDICAL care costs , *OBESITY , *DIABETES , *ASTHMA - Abstract
Introduction: Noncommunicable diseases (NCDs) constitute a massive global burden and are the leading cause of death and disability worldwide. In Greenland, the prevalence of NCDs has historically been low. However, during the past approximately 70 years, life circumstances have changed dramatically resulting in increased life expectancy. Today, the proportion of inhabitants in Greenland ≥65 years has nearly tripled since the 1980s, and the prevalence of obesity and diabetes has increased rapidly within the past decades. The aim of this study was to describe the burden of selected NCDs in a primary care setting in Nuuk and compare it to a modern westernized suburban general practice in Denmark. Methods: The study was performed as a cross sectional register-based study using data extracted from the electronic medical records (EMR) based on diagnosis codes from inhabitants living in Nuuk, Greenland, and a suburb in Denmark. Estimates of prevalence were age-standardized to the WHO world standard population. Results: In both Nuuk and the Danish suburb, the highest prevalence was observed for hypertension (13.2% for both populations), followed by asthma (4.4 and 9.5%, respectively) and diabetes (4.3 and 2.9%, respectively). The age-standardized prevalences of diabetes, COPD, atrial fibrillation, and heart failure, were significantly higher in Nuuk, while seven NCDs including asthma, ischemic heart disease, arthritis urica, psoriasis, hyperthyreosis, hypothyreosis and osteoporosis were significantly higher in the Danish suburb. Conclusion: In contrast to the disease pattern observed in Greenland in the last century, the prevalence of diagnosed NCDs in Nuuk is no longer rare. Thus, the overall prevalence of NCDs in the population of Nuuk is now comparable to or even higher than in the suburb in Denmark. This calls for increased focus on all NCDs in the primary healthcare system in Greenland and adaption of the primary healthcare services to a changed disease spectrum. [ABSTRACT FROM AUTHOR]
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- 2024
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43. The distribution and generation of carbonatites.
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Gibson, Sally, McKenzie, Dan, and Lebedev, Sergei
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CARBONATITES , *RARE earth metals , *NATIVE Americans , *IGNEOUS provinces , *LITHOSPHERE , *MANTLE plumes , *HEAT conduction , *GEOTHERMAL ecology - Abstract
The physio-chemical framework that generates carbonatites and, ultimately, the associated rare earth element deposits remains contentious. This primarily reflects the diverse tectonic settings in which carbonatites occur: large igneous provinces, continental rifts and major extensional terranes, syn- to post-collisional settings, or ocean islands. There is, however, a broad consensus that carbonatites (or their parental melts) originate in the mantle. These exotic melts have small volumes that make them ideal probes of conditions in their underlying source regions. We combine the carbonatite locations with global maps of lithospheric thickness, derived from seismic tomography, and show that post-Neoproterozoic carbonatites occur preferentially above the margins of thick cratonic lithosphere (e.g., adjacent to the South Atlantic and Indian Oceans or in North America, Greenland, and Asia) and where once thick lithosphere has undergone stretching (e.g., eastern Asia). Our thermal modeling reveals that lateral and vertical heat conduction on rifted craton margins, or rapid stretching of cratonic lithosphere, can mobilize carbonated peridotite at the temperatures (950–1250 °C) and pressures (2–3 GPa) required to form primary carbonatites or their parental alkali silicate melts. Importantly, our models show that heat conduction from upwelling mantle plumes or ambient mantle on rifted cratonic margins may sufficiently modify the temperature of the lithospheric mantle to cause melting of carbonated peridotite, settling the long-standing debate on the role of rifting and heating in the generation of carbonatites. [ABSTRACT FROM AUTHOR]
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- 2024
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44. An assessment of global land susceptibility to wind erosion based on deep-active learning modelling and interpretation techniques.
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Gholami, Hamid, Mohammadifar, Aliakbar, Song, Yougui, Li, Yue, Rahmani, Paria, Kaskaoutis, Dimitris G., Panagos, Panos, and Borrelli, Pasquale
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- *
WIND erosion , *CARBON in soils , *EROSION , *LANDSLIDES , *RECURRENT neural networks , *RECEIVER operating characteristic curves , *LANDSLIDE hazard analysis , *SOIL moisture , *SAND dunes - Abstract
Spatial accurate mapping of land susceptibility to wind erosion is necessary to mitigate its destructive consequences. In this research, for the first time, we developed a novel methodology based on deep learning (DL) and active learning (AL) models, their combination (e.g., recurrent neural network (RNN), RNN-AL, gated recurrent units (GRU), and GRU-AL) and three interpretation techniques (e.g., synergy matrix, SHapley Additive exPlanations (SHAP) decision plot, and accumulated local effects (ALE) plot) to map global land susceptibility to wind erosion. In this respect, 13 variables were explored as controlling factors to wind erosion, and eight of them (e.g., wind speed, topsoil carbon content, topsoil clay content, elevation, topsoil gravel fragment, precipitation, topsoil sand content and soil moisture) were selected as important factors via the Harris Hawk Optimization (HHO) feature selection algorithm. The four models were applied to map land susceptibility to wind erosion, and their performance was assessed by three measures consisting of area under of receiver operating characteristic (AUROC) curve, cumulative gain and Kolmogorov Smirnov (KS) statistic plots. The results revealed that GRU-AL model was considered as the most accurate, revealing that 38.5%, 12.6%, 10.3%, 12.5% and 26.1% of the global lands are grouped at very low, low, moderate, high and very high susceptibility classes to wind erosion hazard, respectively. Interpretation techniques were applied to interpret the contribution and impact of the eight input variables on the model's output. Synergy plot revealed that the soil carbon content exhibited high synergy with DEM and soil moisture on the model's predictions. ALE plot showed that soil carbon content and precipitation had negative feedback on the prediction of land susceptibility to wind erosion. Based on SHAP decision plot, soil moisture and DEM presented the highest contribution on the model's output. Results highlighted new regions at high latitudes (southern Greenland coast, hotspots in Alaska and Siberia), which exhibited high and very high land susceptibility to wind erosion. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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45. Velocity of Greenland's Helheim Glacier Controlled Both by Terminus Effects and Subglacial Hydrology With Distinct Realms of Influence.
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Sommers, A. N., Meyer, C. R., Poinar, K., Mejia, J., Morlighem, M., Rajaram, H., Warburton, K. L. P., and Chu, W.
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GREENLAND ice , *ICE , *ICE sheets , *HYDROLOGIC models , *HYDROLOGY , *MELTWATER , *SUBGLACIAL lakes - Abstract
Two outstanding questions for the future of the Greenland Ice Sheet are (a) how enhanced meltwater draining beneath the ice will impact the behavior of large tidewater glaciers, and (b) to what extent tidewater glacier velocity is driven by changes at the terminus versus changes in sliding velocity due to meltwater. We present a two‐way coupled framework to simulate the nonlinear feedbacks of evolving subglacial hydrology and ice dynamics using the Subglacial Hydrology And Kinetic, Transient Interactions (SHAKTI) model within the Ice‐sheet and Sea‐level System Model (ISSM). Through coupled simulations of Helheim Glacier, we find that terminus effects dominate the seasonal velocity pattern up to 15 km from the terminus, while hydrology drives the velocity response upstream. With increased melt, the hydrology influence yields seasonal acceleration of several hundred meters per year in the interior, suggesting that hydrology will play an important role in future mass balance of tidewater glaciers. Plain Language Summary: Water draining under glaciers and ice sheets affects the friction between the ice and the bed, and controls how fast the ice can slide into the ocean, contributing to sea‐level rise. We present a framework for simulating the feedbacks between hydrology and ice flow. We investigate the relative influence of changes at the terminus of the glacier where it meets the ocean, versus changes in meltwater drainage, in determining how fast the glacier moves. Our modeling of Helheim Glacier in southeast Greenland highlights the importance of terminus effects up to 15 km from the terminus, and hydrology farther upstream, with increased melt yielding higher inland acceleration. These results suggest that meltwater will play an increasingly important role in the future behavior of glaciers. Key Points: We couple a subglacial hydrology model with an ice flow model to simulate the relationship between sliding velocity and effective pressureTerminus effects at Helheim Glacier drive velocity up to 15 km upstream, but seasonal hydrology controls velocity patterns further inlandIncreased melt accelerates ice inland of the main trunk, implying importance of hydrology in tidewater glacier future mass balance [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Glacier Terminus Morphology Informs Calving Style.
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Goliber, S. A. and Catania, G. A.
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GREENLAND ice , *ICE sheets , *ICE calving , *GLACIAL melting , *OCEAN temperature , *MELTWATER , *GLACIERS - Abstract
Terminus change is a complex outcome of ice‐ocean boundary processes and poses challenges for ice sheet models due to inadequate calving laws, creating uncertainty in sea level change projections. To address this, we quantify glacier termini sinuosity and convexity, testing the hypothesis that terminus morphology reflects dominant calving processes. Using 10 glaciers with diverse calving styles in Greenland over the period from 1985 to 2021, we establish a supervised classification of calving style by comparing morphology and literature‐derived calving observations. Validation with four of these glaciers and flotation conditions and subglacial discharge routing observations confirms concave, smooth termini indicate buoyant flexure dominated‐calving, while convex, sinuous termini suggest serac failure dominated‐calving. We also identify a mixed style where both calving types may occur. We use these classes to label calving style from 1985 to 2021 for all 10 glaciers and explore how this changes over time as glaciers retreat. Plain Language Summary: The ice‐ocean boundary (terminus) of the Greenland ice sheet changes over space and time due to the melt and calving of ice. There is a range of calving behaviors due to many environmental and geometric factors, including changing ocean temperatures, glacier melting, and the geometry of the glacier. This makes representing how these boundary changes in ice sheet models are difficult, leading to uncertainties in predicting sea level rise from retreating glaciers. The study focuses on the shape (morphology) of 10 glaciers from 1985 to 2021, finding that smooth, concave termini indicate a type of calving related to the flotation of the glacier, while sinuous, convex termini indicate melt‐dominated calving. The research helps classify calving styles and understand how they change over time as glaciers retreat. Key Points: Two calving styles are linked to distinct terminus morphologies but both can exist for a single glacier (over time or space)Mixed styles of calving are more difficult to classifyClassifying terminus morphology over time can aid in identifying how terminus calving mechanisms change over time [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Nature of Hydrocarbons in Bottom Sediments of the European Arctic Seas.
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Nemirovskaya, I. A., Khramtsova, A. V., and Gulev, S. K.
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SEDIMENTS , *SEDIMENTATION & deposition , *FLUID flow , *HYDROCARBONS , *POLYCYCLIC aromatic hydrocarbons , *CONTINENTAL shelf - Abstract
The concentrations and composition of hydrocarbons (aliphatic, AHCs, and polycyclic aromatic, PAHs) are determined using molecular markers in bottom sediments of the Greenland–Norwegian basin and the Barents Sea (during the 84th cruise of the R/V Akademik Mstislav Keldysh in 2021). The research covered the deep-sea part of the Greenland Basin, the northern part of the East Greenland Ridge, the near-fault zone in the area of the junction of the Mohns and Knipovich ridges, the Western and Northwestern extremities of the Svalbard continental shelf (the Vestnes Ridge, the Ermak Plateau, the Sofia Basin, and the Hinlopen Trough), the Fram Strait, the Orly trough area with the intersection of the Erik-Eriksen trough, and the central part of the Barents Sea. The surface bottom sediments are found to contain a wide range of concentrations of Corg (0.25%–2.71%), AHCs (7–182 μg/g), and PAHs (23–1918 ng/g). The distribution of HCs is determined by the processes occurring in the sedimentary stratum (changes in Eh and fluid flows), and, to a lesser extent, by the lithotype of sediments. Therefore, in the sedimentary stratum, autochthonous components form in the composition of alkanes and naphthalenes form in the composition of PAHs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. U-Pb calcite ages date oblique rifting of the Arctic–North Atlantic gateway.
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Haaland, L. C., Slagstad, T., Osmundsen, P. T., and Redfield, T.
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CALCITE , *URANIUM-lead dating , *CONTINENTAL crust , *CLIMATE change , *VEINS (Geology) - Abstract
Miocene breakup of Svalbard from Greenland formed a deep oceanic gateway that enabled circulation between the Arctic and Atlantic Oceans, significantly changing the global climate. However, the timing of events remains unclear. An excellent opportunity to constrain this timing is found onshore western Svalbard, where the Sarsbukta fault forms the eastern margin of the Eocene–Oligocene Forlandsundet basin. Here, we present new results from U-Pb dating of calcite precipitated in fault-related veins to constrain the timing of Sarsbukta fault deformation and the evolution of the basin. Our oldest calcite age is Permo-Triassic, suggesting long-lived deformation along the fault. A cluster of ages between 41 and 33 Ma overlaps with fossil-based depositional ages from parts of the Forlandsundet basin. These data indicate that onshore transtension partly pre-dated the well-established Chron 13 (magnetic polarity time scale; 35.5–33.7 Ma) reorganization of spreading ridges in the North Atlantic. Our youngest age of 13 Ma indicates that faulting persisted long after the preserved basin fill was deposited. If seafloor spreading marked the end of extension of continental crust, Molloy Ridge spreading during Chron 5 (19.6–9.8 Ma) may have initiated after 13 Ma. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Flow‐Dependence of Ensemble Spread of Subseasonal Forecasts Explored via North Atlantic‐European Weather Regimes.
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Spaeth, J., Rupp, P., Osman, M., Grams, C. M., and Birner, T.
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WEATHER , *GEOPOTENTIAL height , *FORECASTING , *AIR pressure , *LEAD time (Supply chain management) , *WEATHER forecasting , *POLAR vortex - Abstract
Atmospheric prediction at 2–6 weeks lead time (so‐called subseasonal‐to‐seasonal timescales) entails large forecast uncertainty. Here we investigate the flow‐dependence of this uncertainty during Boreal winter. We categorize the large‐scale flow using North Atlantic‐European weather regimes. First, we show that forecast uncertainty of near‐surface geopotential height (Z1000) and temperature (T2m) are strongly sensitive to the prevailing regime. Specifically, forecast uncertainty of Z1000 reduces over northern Europe following Greenland Blocking (enhanced predictability) due to a southward shifting eddy‐driven jet. However, due to strong temperature gradients and variable flow patterns, Greenland blocking is linked to increased forecast uncertainty of T2m over Europe (reduced predictability). Second, we show that forecast uncertainty of weather regimes is modulated via the stratospheric polar vortex. Weak polar vortex states tend to reduce regime‐uncertainty, for example, due to more frequent predicted occurrence of Greenland blocking. These regime changes are associated with increased T2m uncertainty over Europe. Plain Language Summary: Weather is chaotic, and forecasts several weeks ahead are quite uncertain. Nevertheless, the degree of uncertainty varies, which can be relevant for long‐term planning in various sectors, including agriculture, energy supply, and public health. Here we show that the degree of uncertainty depends on the weather at the time of forecast start, which we categorize using eight characteristic weather patterns for the North Atlantic and Europe. We analyze a large set of forecasts during winter, with lead times up to 6 weeks. For example, persistent high‐pressure systems over Greenland are known to favor low temperatures over northern Europe. Our results indicate that, in addition, temperatures are highly variable in these cases, leading to unusually high forecast uncertainty. In contrast, uncertainty of near‐surface air pressure tends to decrease due to less frequent storms over the North Atlantic. Furthermore, we show that forecast uncertainty of the weather patterns themselves varies, which is useful when large‐scale flow conditions are more critical than local weather. We analyze forecasts under different circulation conditions in the Arctic stratosphere, as these can have long‐lasting impacts on surface weather. We find forecasts of weather patterns become less uncertain when the circumpolar winds in the Arctic stratosphere are weak. Key Points: Ensemble spread of near‐surface weather in subseasonal forecasts is sensitive to the prevailing North Atlantic‐European weather regimeGreenland blocking is linked to the smallest ensemble spread of geopotential but to the largest spread of temperature over northern EuropeWeak polar vortex states are followed by reduced forecast uncertainty of weather regimes but increased uncertainty of European temperature [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. The Impact of CO2 and Climate State on Whether Dansgaard–Oeschger Type Oscillations Occur in Climate Models.
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Malmierca‐Vallet, Irene, Sime, Louise C., Valdes, Paul J., Klockmann, Marlene, Vettoretti, Guido, and Slattery, John
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- *
ATMOSPHERIC models , *ATLANTIC meridional overturning circulation , *OSCILLATIONS , *GLACIAL Epoch , *ATMOSPHERIC carbon dioxide , *GREENLAND ice , *NORTH Atlantic oscillation - Abstract
Greenland ice core records feature Dansgaard–Oeschger (D‐O) events, which are abrupt warming episodes followed by gradual cooling during ice age climate. The three climate models used in this study (CCSM4, MPI‐ESM, and HadCM3) show spontaneous self‐sustained D‐O‐like oscillations (albeit with differences in amplitude, duration, and shape) in a remarkably similar, narrow window of carbon dioxide (CO2) concentration, roughly 185–230 ppm. This range matches atmospheric CO2 during Marine Isotopic Stage 3 (MIS 3: between 27.8 and 59.4 thousand of years BP, hereafter ka), a period when D‐O events were most frequent. Insights from the three climate models point to North Atlantic (NA) sea‐ice coverage as a key ingredient behind D‐O type oscillations, which acts as a "tipping element." Other climate state properties such as Mean Atlantic Meridional Overturning Circulation strength, global mean temperature and salinity gradient in the Atlantic Ocean do not determine whether D‐O type behavior can occur in all three models. Plain Language Summary: Dansgaard‐Oeschger (D‐O) events are sudden periods of warming followed by slow cooling during ice ages, as observed in Greenland's ice core records. The study used three different climate models to analyze these events, and all models showed similar behavior within a specific range of atmospheric carbon dioxide (CO2) concentrations. This range of CO2 concentrations aligns well with the levels found during the latter half of the last ice age when D‐O events were most frequent. The study found that when CO2 levels are outside this specific range, the climate models settle into one of two stable states, either warm with high CO2 levels or cold with low CO2 levels. These states are stable until CO2 levels reach a certain "tipping point"‐ below around 185–195 ppm for the cold state and above around 217–230 ppm for the warm state. This study suggests that North Atlantic sea ice coverage is a crucial property essential for D‐O like behavior to develop in complex climate models. Key Points: Three complex climate models show internal unforced oscillations at glacial levels of atmospheric carbon dioxide concentrationNorth Atlantic (NA) sea‐ice coverage plays a crucial role behind Dansgaard–Oeschger type behavior in all three modelsThe three models reproduce oscillations in a similar range of NA sea ice coverage [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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