Now showing items 21-40 of 12900

    • Centering community and joy through co-production: tracking the seasonal changes of Utqiaġvik’s spring whaling

      Pikok, Kimberly Kivvaq; Carothers, Courtney; Hauser, Donna; Adams, Billy; Black, Jessica; Brinkman, Todd (2024)
      Using mixed methods and multimedia approaches, I investigated the multigenerational perspectives and seasonal changes in Utqiaġvik’s spring whaling. As an Iñupiaq living in my home community of Utqiaġvik, it was important to me to center my community’s knowledge and Iñupiaq-led entities. I used various tools and resources such as conducting semi-directed interviews, hiring a local Iñupiaq videographer to take photos and videos of spring whaling preparations, and using observational data from the Alaska Arctic Observatory and Knowledge Hub. The interviews, conversations with local Iñupiat-led entities and whalers, and the observational data guided my research goals and objectives and, more importantly, determined what key whaling events to research and analyze. Here, I am combining these techniques and resources to address the seasonal changes of our spring whaling key events (e.g., breaking trail) in the context of coastal Iñupiaq communities of northern Alaska and how we can use observations from our Indigenous Knowledge holders to inform scientists and managers of what is happening during spring whaling. In my research, science communication and community engagement occurred concurrently. Therefore, my thesis presents two chapters and a video project, all using excerpts from the interviews and footage and photos from museum archives and the videographer. The two main objectives of this research were communicating the observations of seasonal changes of Utqiaġvik’s spring whaling and centering Inupiat voices and resources. This research embodies significant Indigenous Knowledge and centers hunter and whaler experiences. As an Iñupiaq resident of Utqiaġvik, I hope the research will uplift Indigenous Knowledge and center it in decision-making. Indigenous Knowledge is critical for understanding change in the Arctic.
    • Fine-scale spatial patterns of gelatinous zooplankton in the Northern Gulf of Alaska

      Kepner, Hannah E.; Hopcroft, Russell R.; Kelly, Thomas B.; Questel, Jennifer M. (2024-12)
      The Northern Gulf of Alaska (NGA) is characterized by high variability across spatial and temporal scales. In the NGA, zooplankton are a crucial link between primary production and higher trophic levels. Understanding the mechanisms that structure zooplankton assemblages is important to our overall understanding of ecosystem functioning. Nonetheless, thorough description of zooplankton abundance and distribution patterns is challenging due to the inherent variability and complexity of the marine environment. The study of gelatinous zooplankton is further complicated by the limitations of traditional plankton net sampling methods that are inefficient for the collection of high-resolution spatiotemporal data and often inflict damage on these fragile bodied organisms. In the NGA, and many other ocean systems, this has historically left gelatinous zooplankton under sampled and poorly studied in comparison to cooccurring crustacean zooplankton. To address these challenges, recent advances in imaging technology and computing power were leveraged by deploying an In Situ Ichthyoplankton Imaging System Deep-Focus Particle Imager (ISIIS-DPI) in the NGA from 2022-2023. The ISIIS-DPI is a towed vehicle capable of collecting vast amounts of high-resolution imaging and oceanographic data. An analysis pipeline with convolutional neural network (CNN) architecture was employed to automate the identification of zooplankton images and expedite processing time, allowing for description of fine-scale distributional patterns of gelatinous zooplankton and their associations with surrounding biophysical drivers. Evidence is presented that ctenophore, hydromedusae, and siphonophore aggregations are concentrated around frontal features and track with the surrounding variability in their ocean environment. Several first records in the NGA of previously undetected species are also presented. These novel datasets demonstrate the previously underestimated prominence of gelatinous zooplankton in the NGA and improve our understanding of ctenophore, hydromedusae, and siphonophore abundance and distribution patterns in the context of their oceanographic environment. This work is the first adaptation of in situ imaging and machine learning technologies in the NGA and presents the opportunity to more accurately describe the role of gelatinous zooplankton in marine ecosystem function.
    • Spatial and temporal variability of carbohydrate compositions in cultivated Alaria marginata, Nereocystis luekteana, and Saccharina latissima

      Jardell, Cameron; Umanzor, Schery; Iken, Katrin; Stekoll, Michael (2024-12)
      Carbohydrates derived from Laminariales (kelp), including polysaccharides and sugar alcohols, present significant market opportunities for nascent mariculture industries. These carbohydrates can enhance crop biomass value through extractive processing, with applications in medicine, manufacturing, health supplements, and bio-plastics. The relative abundance and composition of carbohydrates in kelp can vary depending on species, life history, tissue type, season, and environmental conditions. In Alaska, mariculture of kelp focuses on three species: Alaria marginata, Nereocystis luetkeana, and Saccharina latissima. This study assessed the relative abundance of carbohydrates (glucan, mannitol, alginate, and fucoidan) in these species, as well as the sulfate content of fucoidan and the ratio of mannuronic to guluronic acids in alginate (M:G ratio) as proxies of chemical attributes for these carbohydrates. Samples were collected from commercial farm sites in the Kodiak Archipelago, Prince William Sound, and Southeast Alaska between April and June of 2023. Carbohydrate composition was analyzed using high- performance anion-exchange chromatography with pulsed amperometric detection. Composition varied among species, where on a dry mass basis, A. marginata had the highest average contents of fucoidan and alginate, while S. latissima had the highest average glucan content. Fucoidan was the only measured component to have consistent trends over time across sites for all species. Inconsistency in trends over time across sites for biochemical components was most notable in A. marginata. Seawater temperature was the most consistent environmental predictor across species, having a moderate, negative correlation the M:G ratio in all species and a moderate, positive correlation with fucoidan in A. marginata and S. latissima. Of the species studied, S. latissima harvested in June may have the highest potential for extractive processing in Alaska. This species had a balanced composition of valuable carbohydrates, high consistency across sites, and high potential yield from a relatively large fraction of solids in wet biomass combined with generally high wet mass growth. This study highlights the complex variability of carbohydrate compositions in kelp and provides the first detailed assessment of A. marginata, N. luetkeana, and S. latissima in Alaska.
    • Teaching Dena'ina language through Dena'ina culturally based reading practices

      Yes, Joel Isaak Łiq'a; Peter, Hishinlai'; Tuttle, Siri; Dunstan, Adam; Koskey, Michael (2024-12)
      The Dena'ina language is a well-documented Northern Dene Alaska Native language in south-central Alaska. The Dena'ina language is on the brink of going to sleep. The Dena'ina community strongly desires for the Dena'ina language to once again thrive in the community. Language-use within the community is a contributing factor to the health of the community. As Dena'ina tribes work towards bringing back the Dena'ina language, the community grapples with the role of reading and writing, both potentially harmful and aiding community language work. A Classroom-Based Action Research qualitative study was conducted to determine if reading instruction in the Dena'ina language can be culturally based and if the culturally based teaching method produces student growth. A Dene language instructor talking circle evaluated the cultural basis and considerations of the proposed teaching approach based on a sample demonstration. The Dena'ina cultural approach was defined as tying together an individual responsibility to meaningfully give back and contribute to the community, learning to listen while demonstrating understanding through action, and individual and collective response through a relationship to place. The Dene language instructor talking circle included nine participants who identified the presented Dena'ina language teaching approach as having a high degree of Dena'ina cultural basis. The significant cultural indicators are producing Dena'ina language speaking skills as student outcomes, utilizing Dena'ina songs, and utilizing color and visualizations that connect the teaching to the Dena'ina story Unhtsah Ninya Niteh Hja'idatl' When The Animals Divided Into Pairs. Student growth data was provided by a single college student enrolled in the Dena'ina Orthography course taught at the Kenai Peninsula College. The student participant displayed meaningful growth in vowel pronunciation. Bringing back the Dena'ina language was noted as being healing for the participants, their families, and the community.
    • Effects of juvenile mass on reproduction and calf survival in a low-density moose population

      Henslee, Sara R.; Crimmins, Shawn; Muehlbauer, Jeff; Kielland, Knut; Parrett, Lincoln (2024-12)
      Moose (Alces alces) are a valuable big game species in Alaska and serve as a critical food source for residents. Near Nome, Alaska, the local moose population has remained at low densities for decades, and there is strong public interest in investigating the cause behind the population's failure to increase in abundance. Compared to other moose populations in Alaska, the population of moose near Nome does not appear to be nutritionally limited or close to carrying capacity. I sought to explore how juvenile mass, a widely used metric to assess moose nutritional status in Alaska, influences reproductive output and subsequent calf survival rates in the moose population in Game Management Units 22C and 22D near Nome by estimating calving rates of collared known-age and known-mass female moose and then monitoring their calves. I found that female moose that were heavier as juveniles had a higher probability of calving for the first time at age 2 or 3 and a higher probability of twinning. I found low calf survival rates (18%) through the first year of life and did not find a significant relationship between any maternal or calf characteristics and calf survival. Overall, it appears that this moose population is defined by low calf survival rates but high reproductive rates and high survival after the first year of life. Additionally, the metric of juvenile mass and primiparity as indicators of nutritional status appears to be variable within populations among years and may not be a reliable management tool. Additional research is warranted to further explore the effect of environmental factors on driving variation in primiparity probability.
    • Climate variability, trends, and impacts on the Yukon-Kuskokwim Delta with insights into relationship-building to enhance climate science

      Hendricks, Amy Sakura; Bhatt, Uma; Polyakov, Igor; Frost, Gerald; Kettle, Nathan; Trainor, Sarah (2024-12)
      Climate change impacts in the Arctic and Alaska vary widely, providing opportunities to study regional complexities. This thesis, guided by insights from Yup'ik Elders from the Yukon-Kuskokwim Delta, explores the significant impacts of climate change and examines four key topics: climate-vegetation connections, shifting hydroclimate regimes, the role of large-scale climate patterns in tundra wildfires, and fostering community relationships. The first paper investigates tundra vegetation productivity trends which have decreased in the Yukon-Kuskokwim Delta despite increasing temperatures during the growing season, contrasting with other Arctic tundra regions. Using available long-term climate datasets, a coherent multi-decadal pattern involving spring sea-ice concentration in the East Bering Sea, growing season temperatures, and tundra productivity is revealed. This finding highlights that low-frequency variability can obscure long-term climate relationships. The second paper examines moisture dynamics in the Yukon-Kuskokwim Delta, revealing significant variability in moisture-related climatic factors. A comprehensive analysis of atmospheric data indicates a shifting hydroclimate regime in the Yukon-Kuskokwim Delta, with decreasing large-scale precipitation, increasing convective precipitation and evaporation, and fewer synoptic storms. The study underscores that warmer conditions and changing precipitation patterns can alter vegetation and overall landscape vulnerability to climatic changes. The third paper delves into early-season climate drivers of tundra wildland fires in the Yukon-Kuskokwim Delta. It establishes a baseline climatology for early fire seasons, connecting warmer temperatures and earlier snow-off dates with increased fire activity. It identifies May and June temperatures exceeding 15°C and snow-off dates before May 8 as key indicators for large fire seasons, emphasizing that lightning stroke counts crucially influence the area burned. Contrary to previous research, this study finds that May and June precipitation and spring sea-ice concentration are not primary drivers of tundra fires in the region. The findings suggest a future increase in fire frequency due to projected climate conditions. The fourth topic synthesizes perspectives on regional climate research, relationshipbuilding, and community engagement in Alaska. It discusses the importance of focusing on smaller regions for climate studies to build relevant, credible, and legitimate scientific endeavors with local communities. It emphasizes the value of cultural humility, self-reflection, and active community participation for effective climate science communication and relationship-building. This piece also addresses the systemic challenges of community work within academia and highlights the significance of volunteerism to enhance community-based climate research. Collectively, these papers underscore the intricate relationships between climate variables, tundra landscapes, and wildfire dynamics in Alaskan tundra regions, and the need for region-specific research approaches. The research concludes that community collaboration and culturally sensitive approaches are essential for impactful climate science.
    • Identification and future susceptibility of permafrost degradation near Red Dog Mine

      Hanna, Caitlynn Tautuk; Ahn, Il-Sang; Nicolsky, Dmitry; Iwahana, Go; Bray, Matthew; Zwieback, Simon (2024-12)
      Permafrost degradation is a major concern in the Arctic region, and its impacts on infrastructure, ecosystems, and global climate are significant. Within recent years, 2018 to present, the level of Total Dissolved Solids (TDS) has been elevated in Ikalukrok Creek in Northwest Alaska, made evident by creek discolorations known as river rusting. The current analyses indicate that changes in permafrost regimes can trigger the observed rise in TDS. Data visualization, remote sensing, and permafrost modeling were used to understand the physical mechanisms involved in the increase of TDS and to identify regions susceptible to permafrost degradation. This comprehensive approach integrates various datasets to capture the spatiotemporal characteristics of talik formation near Ikalukrok Creek. The permafrost models incorporate a variety of data such as soil temperature, soil type, vegetation, snow cover, and topography. Spatially distributed 1-D models utilize vegetation as a proxy to parameterize ground thermal properties. All models are validated using ground temperature measurements. The study aims to investigate the correlation between changes in TDS and climatic factors, particularly how variations in air temperature influence TDS concentrations in river water. Additionally, it seeks to understand the mechanisms driving river rusting, monitor hydrological and permafrost changes using remote sensing and modeling. By utilizing remote sensing images, it is possible to identify and map the visual extent of river rusting and to investigate the relationship between river rusting concentration, climatic events, and talik formation. This study presents a better understanding of the factors driving talik formation and the increase of TDS. Understanding talik formation and increases in TDS is critical for the mitigation of pollution in the environment. This research provides a foundation for other researchers to build upon, as we learn more about river rusting, it is hoped that policymakers will be able to utilize this information or similar insights.
    • Modeling rate of penetration in a south Texas oil field with aggregated well data in a supercomputing framework

      Golden, Timothy B.; Awoleke, Obadare; Das, Arghya; Goddard, Scott; Mattiolli, Brandon (2024-12)
      The objective of this work is to develop an accurate and practical tool for drilling engineers supporting operations to predict rate of penetration (ROP) in the tangent section of the wellbore using easily obtainable data. Historically, tacit knowledge has been used to predict both ROP and the ideal parameters. Such a tool is valuable for planners seeking to adjust rig schedules. Further, this tool could easily be modified to also optimize parameters. This work was comprised of two major efforts: data acquisition and wrangling, and modeling. Data was obtained from three distinct sources: well files, drilling logs, and survey logs. Data on bit geometry or formation was not available. This data was manually downloaded and imported into Python. Due to the size of the data, a university-owned high-performance computer (HPC) was required to process the data. Special care was given to optimizing for memory efficiencies that allowed the HPC to perform these operations. A test data set of 5 wells was used to pilot the data wrangling process and initial linear regression models. Four different model types were produced and evaluated: linear regression, polynomial regression, nonlinear regression, and neural networks. Neural networks provided the best prediction with a R2 of 0.85. The most important variables affecting ROP in the tangent section in descending order are: total pump output, rotary speed, hook load, differential pressure, and bit type. To the best of our knowledge, this is the largest dataset of ROP data found in literature; containing over 350 wells and 30 million rows of data. This workflow can be adopted to create other field-specific models or adapted to evaluate other sections of the wellbore. More immediately, this work creates a large database ready to be utilized for developing other models undergirded by different computational methodologies.
    • Early considerations and estimates for the performance of an Alaska-based earthquake early warning system

      Fozkos, Alexander; West, Michael; Grapenthin, Ronni; Tape, Carl (2024-12)
      The complexity of Alaska presents several challenges for earthquake early warning systems. These include the presence of offshore earthquakes, transform boundaries and crustal faults extending hundreds of kilometers, deep earthquakes, and a complicated coastline. This variety, combined with population centers spread far apart, makes it challenging to anticipate an earthquake early warning system's performance and to design a network accordingly. As Alaska begins to plan for earthquake early warning, our objective is to envision how and how well it might function in Alaska. We present here sets of scenarios with warning time and ground motion estimates for a variety of communities. These scenarios are designed to be meaningful test cases for Alaska earthquake early warning while also exploring how changes in source characteristics--such as magnitude, depth, location, and fault system--impact the timeliness of warnings. We combine travel time estimates, source time models, and the current seismic network to model hypothetical detection and alert times. We compare warning times to peak ground motions to determine the warning effectiveness. Our results suggest the potential for timely warnings up to Modified Mercalli Intensity 6 in the case of shallow earthquakes. More ideal scenarios, including deep earthquakes, could receive advanced warning for shaking up to intensity 8. Informed by these results, we discuss where we expect an Alaska earthquake early warning system to excel and what challenges should be tackled to improve other areas. Finally, we offer ways in which our results and insights can inform future works related to earthquake early warning in Alaska.
    • Salmon, stewardship, and indigenous livelihoods: bridging knowledge systems and reshaping research relationality in the Kuskokwim Region of southwestern Alaska

      Esquible, Janessa; Carothers, Courtney; Black, Jessica; Cunningham, Curry; Williams, Mike (2024-12)
      This dissertation research is situated in southwestern Alaska, in the communities of Kongiganak, Quinhagak, Bethel, Aniak, and McGrath, spanning the Kuskokwim Bay and Kuskokwim River, and with Alaska Native Peoples (primarily Yup'ik and Athabascan fishing families) who have been salmon peoples and stewards of their ancestral homelands since time immemorial. This Indigenous-led project documented historical and current ways in which Yup'ik and Athabascan Peoples have served as salmon stewards, and the values and governance mechanisms pertaining to salmon stewardship. We utilized a participatory approach by involving Tribal governments, communities, and Indigenous local youth in all aspects of our research. We carried out multiple methods including: participant observation, circle dialogues, and individual and multigenerational fishing family interviews with Kuskokwim fishers in the coastal, lower, middle, and headwater communities of the Kuskokwim Region. We used a grounded theory approach to qualitative data analysis that generated five key themes that form the first chapter of this dissertation including: traditional Indigenous ways of life, Indigenous stewardship, self-determination, food and livelihood sovereignty, and ecosystem changes. This chapter identified equitable and sustainable paths forward for salmon and people in Alaska. Chapter two of this dissertation bridged perspectives and experiences around the state of salmon management and research, with a focus on Alaska Native inclusion in these processes and organizations, equity, equality, and relationships. Lastly, the third chapter of this dissertation research highlights the methodologies utilized in this research process, with an emphasis on circle dialogues as a core methodology for building initial relationships and partnerships between Tribes and universities, and as a mechanism to shape the research in a way that is aligned with Tribal priorities and respecting Tribal sovereignty. This chapter highlights the importance of including local Alaska Native youth in research, spending time in community and building relationships, because it is these relationships that serve as a core foundation for carrying out research in a 'good way'.
    • Cultivation protocols for the red seaweeds, Devaleraea mollis and Palmaria hecatensis from Alaska

      Dittrich, Muriel; Umanzor, Schery; Kelly, Amanda; Stekoll, Michael (2024-12)
      Species diversification is crucial for the long-term viability, competitiveness, and sustainability of the seaweed farming industry in the United States. This study investigated the effects of temperature (4, 8 and 12 °C), photoperiod (8L:16D, 12L:12D and 16L:8D), and irradiance (20, 40, 100 ± 10 μmol photons m-2 s-1) on the specific growth rate (SGR) of Devaleraea mollis and Palmaria hecatensis from Alaska. Outputs were used to adjust indoor cultivation protocols for D. mollis and develop the first protocols for Palmaria hecatensis. This study also explored the use of two relatively low-cost commercial nutrient products (F/2 and Jack's Special 25-5-15) as potential alternatives to the recommended nutrient medium, von Stoch Enrichment medium. Assessments focused on determining whether their use resulted in similar SGRs without compromising biomass quality or raising production costs. Quality was assessed as a function of protein and pigment content in the tissue, with higher content considered higher tissue quality. Both species showed significant differences in SGR for all factors tested. Results showed that both species responded differently to each factor, indicating distinct ecological and physiological adaptations. D. mollis exhibited higher growth rates in warmer temperatures and responded to higher irradiance levels with spore release but showed no clear preference between neutral and long-day photoperiods. In contrast, P. hecatensis demonstrated higher growth rates in cooler environments with a long-day photoperiod promoting the most growth without spore release. Nutrient supplementation revealed that growth in D. mollis was affected by nutrient formulation, while P. hecatensis showed no significant growth variation. Outcomes also revealed that protein and pigment content could be increased depending on the formulation used. These findings underscore the importance of species and geographic-specific protocols for seaweed farming. Further research is needed to optimize the potential cultivation protocols provided here. Cultivation protocols would also benefit from exploring the ecological and physiological nuances of both species.
    • Unveiling soil microbial communities and resistomes in northern Alaska National Wildlife Refuges

      Cover, Bevyn Amber Lee; Drown, Devin M.; Kade, Anja; López, Andrés (2024-12)
      Microbial communities residing in pristine high-latitude soils play a critical role in ecosystem function, but also harbor potential threats such as acting as reservoirs of antimicrobial resistance (AMR) genes. Current knowledge about these microbial communities and the resistance genes they carry presents limits to the ability to predict how these ecosystems will respond to climate change. This knowledge gap is particularly concerning in light of the potential public health threat posed by antimicrobial resistance harbored within these communities as antibiotic-resistant human infections continue to increase. This study investigated the microbial communities and details the antimicrobial resistance gene reservoirs in previously unsurveyed soils of three northern Alaska National Wildlife Refuges representing three distinct high-latitude biomes. I used a combination of 16S rRNA gene sequencing and metagenomic sequencing to characterize microbial community diversity and composition, as well as the AMR gene resistome. Also, I analyzed soil chemical components to evaluate their potential role in shaping these communities. My findings reveal significant geographic structure in microbial communities likely driven by differences in soil properties and dispersal limitation. Additionally, I found variation in pH significantly explained differences in alpha diversity, with slightly acidic soils harboring the highest diversity. The pattern of resistome structure matched the pattern of community structure, with microbial communities within the same refuge showing less variation than communities between refuges. Additionally, the data revealed significantly fewer AMR genes in the Selawik National Wildlife Refuge than in the other refuges. I found that variation in pH and in phosphorus concentrations significantly explained variation in AMR gene abundance with higher pH and higher phosphorus resulting in more AMR genes detected. My analysis identified that over 60% of AMR genes encoded resistance to lastresort glycopeptide antibiotics. My findings reveal that soil chemistry, particularly pH, plays a key role in shaping both microbial communities and AMR gene reservoirs in these pristine high-latitude soils. This study's characterization provides a crucial foundation for understanding how climate change and human activities might impact these ecosystems. Understanding the presence and distribution of AMR genes within microbial communities of pristine soils is essential for conserving these ecosystems and mitigating public health risks, including those associated with the spread of antibiotic resistance genes, especially those encoding resistance to last-resort antibiotics.
    • An investigation of solar induced phenomena at magnetically conjugate points

      Wescott, Eugene M.; Mather, Keith Benson (1964-05)
      The results of a comprehensive study of solar induced geophysical phenomena at pairs of stations linked by a magnetic field line are presented. Studies have established that magnetic variations (except Sq), telluric currents, ionospheric absorption, visual auroras, VLF and ELF emissions and auroral X-rays occur in similar manner in conjugate areas—in time, form and amplitude. The variations of the magnetic field were the most thoroughly studied phenomena. It was found that auroral zone electrojets occur in conjugate patterns, and that a conjugate area, elongated in geomagnetic latitude, can be defined by comparisons of magnetic records. This conjugate area appears to move in time, as the electrojets depart somewhat from conjugate patterns. The magnetic variations at mid and low latitude due to the return current paths of the electrojets are conjugate to approximately the same degree as the ‘primary’ auroral zone activity. At very high latitudes there is a diurnal variation in the degree of correlation at conjugate points—probably due to the distortion of the magnetic field by the solar wind. Some evidence is presented for two kinds of very high latitude magnetic disturbance. One occurring on the night side is probably due to the poleward expansion of auroral electrojet systems. The other occurs on the day side, even on very quiet days, and is possibly due to hydromagnetic waves, produced by the interaction of the magnetosphere surface and the solar wind. This dayside agitation shows inferior correlation. The Sq variation was investigated and found to be a non-conjugate phenomenon. The theoretical effects of field line linkage are found to skew rather than to equalize the variations from a conjugate pattern. The close relationship of telluric currents to magnetic variations, and the effects of local conductivity are considered. Comparison of records from paired stations confirm that telluric currents are conjugate. The mechanism of short period (~ 1 minute) oscillations may be found in modes of oscillation of the magnetosphere, as apart from ionospheric current systems. A pronounced diurnal variation was found in the power spectra and the polarization of short period oscillations at a mid-latitude pair. Comparisons of all-sky camera data from several conjugate pairs confirm that auroras occur in similar, simultaneous displays in conjugate areas. Occasional differences between the northern and southern displays were observed, similar to the anomalies in the magnetic variations. An attempt was made to study the conjugacy of radio auroras at 50-55 Mc/s but the results were inconclusive. Ionospheric absorption of cosmic radio noise—a phenomenon closely related to influx of charged particles and X-rays—has been shown in several studies to occur as a conjugate phenomenon. A conjugate area, similar in shape to that defined by correlation of magnetic variations was found for absorption events. Although no new work was carried out, the published results of conjugate studies of VLF (whistlers, etc.), ELF (micropulsations) and auroral zone balloon flights (auroral zone X-rays) are presented and discussed.
    • Creating a digital house of knowledge: ensuring the continuation and integrity of Indigenous knowledge transfers in the digital era

      Cordova, Jacquelyn C.; Koskey, Michael; Collin, Yvette Running Horse; Afraid of Bear-Cook, Loretta (2024-12)
      Traditional Indigenous knowledge transfer systems have contributed to the sustainability of highly advanced Indigenous societies since time immemorial. These systems have been purposefully targeted since European arrival to the Americas in the late 1400s and early 1500s, consequently creating barriers for Indigenous Peoples as they strive to conduct their traditional knowledge transfer processes within their communities. These barriers, paired with the continual rise and use of global technologies, have created circumstances where many Native Elders and Knowledge Keepers experience difficulty reaching their youth and community members to ensure the successful transfer of Indigenous data and knowledge to current and future generations. This research applies Critical Indigenous Research Methodologies (CIRM), Participant Action Research (PAR), and Grounded Theory (GT), along with data generated from twenty-five project participants, to create a model of an Indigenous-made "Digital House of Knowledge" for those who seek to ensure the continuation and integrity of their distinct Indigenous knowledge transfer systems now and into the future. By discussing critical topics such as the security, privacy, and protection of data, processes for gathering, storing, sharing, accessing, and maintaining data, the design and structural components of digital platforms, and the importance and urgency of the application of traditional Indigenous protocols within the digital realm, this research provides a comprehensive overview of critical key points for the successful gathering, storage, protection, and dissemination of Indigenous data and knowledge within the digital realm.
    • Addressing non-stationary fishery dynamics and demographic complexity in integrated stock assessment models

      Cheng, Matthew L. H.; Cunningham, Curry J.; Mueter, Franz J.; Goethel, Daniel R.; Hulson, Peter-John F. (2024-12)
      Integrated stock assessment models are complex non-linear statistical models that fit a variety of fishery-dependent and independent data sources to estimate the status and trends of fish populations, providing recommendations for sustainable harvest levels. Given their complexity, simplifying assumptions are necessary in stock assessment models to balance model parsimony versus complexity, while also considering data limitations. In this dissertation, I investigated considerations for addressing non-stationary fishery dynamics and evaluated the consequences of oversimplified assumptions of fishery dynamics and sex-specific demography in stock assessment models. Using Alaska sablefish (Anoplopoma fimbria) as a case-study, I developed a generalized framework to standardize fishery-dependent abundance indices, while incorporating various data sources and catch records from multiple gear types to address rapid shifts in fishery fleet structure (Chapter 2). Building on this foundation, I then explored the implications of accounting for, or ignoring, complex temporal changes in fishery fleet structure in stock assessment models by comparing multi-fleet and single-fleet models (Chapter 3). Here, I found that the treatment of fleet structure generally had minimal impacts on quantities of management interest, but selectivity assumptions had large impacts on recommended harvest levels. I then employed a generalized simulation-estimation framework to evaluate the performance of different stock assessment approaches for addressing changes in fleet structure (Chapter 4), which suggested that single-fleet models with time-varying selectivity are adequate for accounting for changes in fleet structure. To understand the consequences of oversimplified assumptions of sex-specific demography in stock assessment models, I developed a simulation­ estimation framework (Chapter 5), which revealed that such simplifications led to suboptimal management advice. Collectively, this dissertation underscores the various approaches available for addressing non-stationary fishery dynamics, the importance of biologically motivated models that adequately reflect a population's demographic characteristics, and the necessity of expert judgment in stock assessment models given the constraints of data limitations.
    • Russian use of smart power to achieve Northern Sea Route objectives

      Bouffard, Troy; Carlson, Cameron; Castellini, Michael; Morton, James; Grau, Lester (2024-12)
      This dissertation examines Russia's use of smart power in pursuing its strategic objectives for the Northern Sea Route (NSR) in the Arctic. Through three interconnected articles, it analyzes how Russia combines soft and hard power approaches to assert control over the NSR and legitimize its claims. The first article challenges Russia's legal justification for NSR control by presenting new data on sea ice conditions and navigational risks. The second article explores how Russia's military posture in the Arctic has evolved in response to geopolitical shifts, particularly NATO expansion. The third article investigates Russia's strategic communication efforts to shape international perceptions of the NSR. Drawing on smart power theory, the dissertation demonstrates how Russia integrates legal, military, and informational tactics to advance its interests. It argues that Russia's smart power strategy aims to establish customary law status for its NSR policies, secure a maritime defensive buffer, and maintain regional dominance. The research contributes to broader understandings of smart power dynamics in international relations, offering insights for policymakers and scholars on the interplay of hard and soft power in achieving geopolitical objectives. By examining Russia's multifaceted approach to the NSR, this dissertation reveals the complex strategies employed by states in navigating the changing global landscape and evolving nature of power in the 21st century.
    • Inverse problems for shallow water equations and applications to tsunami modelling

      Bobrovnikov, Oleksandr; Rybkin, Alexei; Bueler, Ed; Maxwell, David (2024-12)
      The problem of tsunami run-up has been extensively studied in the framework of the shallow water equations. Typically one assumes that the initial water displacement and the initial velocity are known, and then the run-up is computed using the Carrier-Greenspan transformation. The inverse problem consists of recovering the initial displacement and/or velocity from the shoreline oscillations. It has been previously demonstrated that the initial displacement can be recovered from shoreline oscillations under the assumption of zero initial velocity for the sloping plane beach. We show that this result can be generalised to arbitrary power-shaped bathymetries. Moreover, we show that for non-breaking waves, the contributions of velocity and displacement can be separated at the shoreline. This separation allows for the recovery of both the initial displacement and velocity from the shoreline oscillations.
    • Stable isotope analyses of eye lenses and stomach-content analysis reveal ontogenetic variation in arctic whitefish trophic dynamics

      Bacon, Jonah A.; Sutton, Trent M.; Glass, Jessica R.; Wooller, Matthew J. (2024-12)
      Determining the ontogenetic trophic ecology of sympatric, morphologically similar fishes is critical for increasing our understanding of life history. We combined bulk and amino acid compound-specific stable isotope analysis of eye lenses with stomach-content analysis to examine ontogenetic trophic dynamics of four amphidromous whitefishes (Arctic Cisco Coregonus autumnalis, Least Cisco C. sardinella, Broad Whitefish C. nasus, Humpback Whitefish C. pidschian) from the central Beaufort Sea, Alaska. Compound-specific stable nitrogen isotope results showed slight increases in trophic position across ontogeny for each species and indicated the feasibility of this method for comparing the trophic ontogenetic development of closely related, mobile predator species. Bulk δ15N and δ13C ontogenetic timelines were reflective of an amphidromous geographic life-history strategy, where foraging occurs primarily in freshwater habitats early in life and nearshore marine habitats at larger sizes. Stomach-content analysis revealed that diet was dominated by a single prey item (amphipods) in all four species, but that short-term diets differed for five of six pairwise species interactions (only Arctic and Least Cisco had diet compositions that overlapped). This was the first study to compare trophic ontogenies of multiple fish species through eye lens compound-specific stable nitrogen isotope analysis. Trophic dynamics were similar among whitefishes from the central Beaufort Sea, highlighting the vulnerability of this ecologically and culturally important clade.
    • Beaver, Alaska: The story of a multi-ethnic community

      Schneider, William (1976-03)
      This work addresses itself to the role that ethno-historical research can play in understanding the present day life of Indians and Eskimos living in a multi-ethnic community in the interior of Alaska. To do this, an attempt has been made to write and analyze the history of the community in a manner that reflects the separate tribal, ethnic, and individual differences of the various people who settled there. Documentation of cultural patterning by different groups enables the researcher to understand the dynamics of cultural persistence and change throughout time in land use, social relations, economic pursuits, attitudes and values. This research does not presuppose that individuals and groups who are influenced by outside intrusions will necessarily respond by changing their ways of life. Instead, the problem has been to investigate the nature of the outside influences and the manner in which these intrusions are perceived by members of the community and the nature of the responses made to them. Written documentation is employed to set an order to the events, but my main reliance is on personal recollections of past events to discern the feelings and associations that people today hold for those forces that have affected their lives in the past and that are now operating
    • Seasonal patterns in riverine carbon form and export from a temperate forested watershed in Southeast Alaska

      Delbecq, Claire; Fellman, Jason; Bellmore, Ryan; Whitney, Emily J.; Hood, Eran; Fitzgerald, Kevin; Falke, Jeffery A. (Springer Nature, 2024-08-23)
      Riverine export of carbon (C) is an important part of the global C cycle; however, most riverine C budgets focus on individual forms of C and fail to comprehensively measure both organic and inorganic C species in concert. To address this knowledge gap, we conducted high frequency sampling of multiple C forms, including dissolved organic C (DOC), inorganic carbon (as alkalinity), particulate organic C (POC), coarse particulate organic C (CPOC), and invertebrate biomass C across the main run-off season in a predominantly rain-fed watershed in Southeast Alaska. Streamwater concentrations were used to model daily watershed C export from May through October. Concentration and modeled yield data indicated that DOC was the primary form of riverine C export (8708 kg C/km2), except during low flow periods when alkalinity (3125 kg C/km2) was the dominant form of C export. Relative to DOC and alkalinity, export of particulate organic C (POC: 992 kg C/km2; CPOC: 313 kg C/km2) and invertebrates (40 kg C/km2) was small, but these forms of organic matter could disproportionately impact downstream food webs because of their higher quality, assessed via C to nitrogen ratios. These seasonal and flow driven changes to C form and export likely provide subsidies to downstream and nearshore ecosystems such that predicted shifts in regional hydroclimate could substantially impact C transfer and incorporation into aquatic food webs.