• Control of internal transport barriers in magnetically confined tokamak fusion plasmas

      Panta, Soma Raj; Newman, David; Wackerbauer, Renate; Ng, Chung Sang; Sanchez, Raul (2020-07)
      In the Tokamak plasma, for fusion to be possible, we have to maintain a very high temperature and density at the core at the same time keeping them low at the edge to protect the machine. Nature does not favor gradients. Gradients are source of free energy that causes instability. But we require a large gradient to get energy from plasma fusion. We therefore, apply a huge magnetic field on the order of few Tesla (1 T-10 T) that confines the plasma in the core, maintaining gradients. Due to gradients in density of charged particles (ions and electrons), there is an electric field in the plasma. Heat and particle transport takes place from core to edge mainly through anomalous transport while the E x B velocity sheer acts to reduce the transport of heat and particles. The regime at which the E x B velocity shear exceeds the maximum linear instability growth rate, as a result, the transport of particles and heat gets locally reduced is termed as the formation of a transport barrier. This regime can be identified by calculating the transport coefficients in the local region. Sometimes it can be observed in the edge where it is called an edge barrier while if it is near the core it is an internal transport barrier. There is a positive feedback loop between gradients and transport barrier formation. External heating and current drives play an important role to control such barriers. Auxiliary heating like neutral beam injection (NBI) and radio frequency (RF) heating can be used at a proper location (near the core of the plasma) to trigger or (far outside from the core) to destroy those barriers. Barrier control mechanism in the burning plasmas in international thermonuclear test reactor (ITER) parameter scenarios employing fusion power along with auxiliary heating source and pellets are studied. Continuous bombardment with pellets in the interval of a fraction of a second near the core of the burning plasma results in a stronger barrier. Frozen pellets along with auxiliary heating are found to be helpful to control the barriers in the tokamak plasmas. Active control mechanism for transport barriers using pellets and auxiliary heating in one of tokamaks in United States (DIII-D) parameter scenarios are presented in which intrinsic hysteresis is used as a novel control tool. During this process, a small background NBI power near the core assists in maintaining the profile. Finally, a self-sustained control mechanism in the presence of core heating is also explored in Japanese tokamak (JT-60SA) parameter scenarios. Centrally peaked narrow NBI power is mainly absorbed by ions with a smaller fraction by the electrons. Heat exchange between the electron and ion channels and heat conduction in the electron channel are found to be the main processes that govern this self control effect. A strong barrier which is formed in the ion channel is found to play the main role during the profile steepening while the burst after the peaked core density is found to have key role in the profile relaxation.
    • Community composition and biogeography of beetles and spiders across an elevational gradient in Denali National Park, Alaska

      Haberski, Adam; Sikes, Derek S.; Hollingsworth, Teresa; Armbruster, W. Scott (2020-08)
      Anthropogenic climate change is rapidly altering alpine ecosystems in Alaska. Trees and woody shrubs are expanding upslope and displacing alpine tundra. As alpine tundra habitats shrink and fragment, arthropods and other animals face an increased risk of extirpation due to smaller population sizes and reduced geneflow. Arthropods--insects, spiders, and their relatives--are the most speciose component of the alpine fauna and perform key ecosystem services, such as pollination and nutrient cycling, and are food for vertebrates. Many species have responded by shifting their distribution to higher elevations, but species respond to change idiosyncratically, which could alter species interactions and disrupt communities. I compared beetle and spider communities along an elevational gradient in Denali National Park and Preserve, Alaska, an area with a complex biogeographic history and a poorly known arthropod fauna, in order to 1) examine differences in diversity, abundance, and community composition among forest, shrub, and alpine tundra habitats; 2) link the observed differences to abiotic factors relevant to climate change; and 3) test if shared habitat preferences lead to community-level patterns in geographic distribution. After three consecutive summers of sampling, I found that alpine tundra supports an unexpectedly diverse arthropod community with a high proportion of unique species and that vegetation cover and mean air temperature are strongly correlated with community composition. I therefore expect species losses among alpine tundra communities as shrubification continues. Community-level distribution patterns were not observed, but trends in the data point to a reduction of Holarctic distributions among forest-dwelling arthropods and an increased proportion of Beringian endemics among tundra species. This was the first systematic survey of Denali's terrestrial arthropods and added over 450 new park records.
    • Impacts of climate change on juvenile broad whitefish Coregonus nasus in Arctic Alaska: bioenergetics model development and application

      Green, Duncan G.; Sutton, Trent M.; Norcross, Brenda L.; Cunningham, Curry J. (2020-08)
      Anthropogenic climate change is contributing to rising temperatures worldwide, yet the increase is particularly rapid in the Arctic. Despite their position on the front of global temperature warming, the responses of Arctic ecosystems and the individual species within them are poorly understood. Broad whitefish Coregonus nasus in the Alaska nearshore Beaufort Sea not only inhabit a rapidly changing ecosystem, but are also a key component of subsistence harvest in the region and a relatively understudied fish. I parameterized and corroborated a bioenergetics model through species-specific physiological investigation and laboratory rearing trials, and used the resulting model to simulate potential responses in growth and consumption under climate change scenarios projected with global climate models. Simulations at current estimated prey energy densities projected increases in future consumption rates of up to 4% required to maintain historically observed summer growth, while simulations in which prey energy density was reduced by 50% resulted in projected consumption increases of up to 107% necessary to maintain historic growth. Simulations in which prey energy density was increased by 50% indicated the ability for juvenile broad whitefish to reduce consumption rates by up to 32% and maintain current growth rates. These results suggest that, although the physiological effects of rising water temperatures have the potential to increase growth rates of juvenile broad whitefish, climate-induced shifts in prey availability or prey quality are likely to be regulating factors that determine the magnitude and direction of changes in growth rates.
    • Beyond trending: using risking connection as a framework for moving agency culture toward trauma-informed care

      Healey, Michael J.; Renes, Susan L.; Strange, Anthony; Baker, Courtney; Anahita, Sine (2020-08)
      The prevalence and pervasive impact of adverse childhood experiences (ACEs), and more broadly, trauma, are well supported in the extant literature. Despite this evidence, there remains a significant dearth of formal training and educational programs that prepare staff who work with trauma survivors within complex behavioral health systems. Trauma-informed care (TIC) has moved beyond a trend in the mental health field and is gaining momentum as a leading philosophical paradigm that is being infused as an operational framework for agencies that work with survivors. Risking Connection (RC) is a curriculum-based training program that works with agencies interested in becoming trauma-informed. The current study examined the impact of RC on trainee outcomes for knowledge gain, attitude change, and vicarious trauma (VT) on 119 participants who all work for a therapeutic group home system being operated by a provincial government in Atlantic Canada. The findings in this study suggest that RC is effective in improving knowledge gain and attitude change in a favorable direction toward TIC. The study also supported previous findings associated with the improvement of VT.
    • The effect of Siberian alder on the activities of three extracellular enzymes and their implications for soil decomposition in Arctic and boreal Alaska

      Heslop, Calvin; Ruess, Roger; Bret-Harte, Syndonia; Kielland, Knut (2020-08)
      As tall shrubs increase in extent and abundance in response to a changing climate, they have the potential to substantially alter ecosystem nutrient availability and carbon (C) balance. Siberian alder (Alnus viridis ssp. fruticosa), a nitrogen (N) fixing shrub, is among the species responding to climate warming in both the Arctic and boreal forests. Alder-fixed N has the potential to increase decomposition of labile C, by relieving N limitation on microbial activity. Simultaneously, it has the potential to decrease decomposition of recalcitrant C by downregulating microbial N mining. The net effect of N additions is influenced by the relative quality of the soil C and could determine whether alder N additions result in a net sink or source of C to the atmosphere. We measured the activities of three extracellular enzymes in bulk organic soils under and away from alder canopies, in stands differing in soil organic matter quality, in both arctic and boreal forest regions of Alaska, USA. In the Alaskan arctic, the proximity of alder increased the activities of both recalcitrant and labile C-degrading enzymes regardless of soil C quality, potentially resulting in increased C losses. In the boreal forest, enzyme activities did not differ with alder proximity nor stand soil C quality, possibly due to long legacies of alder N inputs relieving microbial N limitation in these stands. As arctic and boreal forest ecosystems experience shifts in the distribution and abundance of this N fixing shrub, alders' influence on soil decomposition could have significant consequences for high latitude soil C budgets.
    • UAF's light-duty vehicle fleet lifecyle, maintenance costs and composition: ordinary least square regression and panel data analysis

      Hix, Edward R.; Wright, Christopher; Baek, Jungho; Little, Joe; Goering, Greg; Platt, Nathan (2020-08)
      The University of Alaska Fairbanks maintains a vehicle fleet for use by its staff, faculty, and students. Given the multifaceted needs of the campus and the impact that the harsh subarctic climate can have on vehicles, management of the fleet to meet the needs of its users is a complex task. One method UAF uses to manage the cost of the fleet is to extract the depreciation expense from each fleet vehicle into a non-interest bearing recharge account to eventually purchase its replacement. While several reviews have been conducted regarding the management of this fleet, a gap in research involves analysis of cost of this fleet over its lifecycle. This study examined the effects of fleet vehicle lifecycle extension beyond the predetermined 10-year useful life at UAF. Three novel datasets were created from UAF Facilities Services' archival maintenance work order data: a vehicle dataset, work order dataset, and a panel dataset. Ordinary least squares regression methods were used to examine the impact of model year on a vehicle's nominal purchase price and the impact of vehicle specification on real purchase price. Fixed and random effects panel methods were used to examine the impact of vehicle specification and vehicle age on maintenance costs. The effects of extending the fleet lifecycle from ten to twenty-years on maintenance and operational cost were estimated. Population dynamics models estimated the impact of the ten year lifecycle extension on the replacement fund. The results of this study suggested increasing vehicle lifecycles by ten years increased operating, maintenance, and replacement costs and effectively reduced the replacement fund purchasing power. The extension of vehicle lifecycles resulted in continually increasing rental rates and ultimately to the insolvency of the replacement fund.
    • Cultural adaptations of evidence based practices in supporting children diagnosed with autism spectrum disorder

      James, Krista P.; Barnhardt, Raymond; Leonard, Beth; Wells, Cassie; Healy, Joanne (2020-08)
      Research shows that early identification and intervention result in a higher quality of life and contribution to society for individuals with Autism Spectrum Disorder (ASD). As society sees an ever-increasing percentage of individuals diagnosed with ASD, identification of culturally responsive, evidence-based practices is of critical importance. While the National Autism Center has provided a guide to evidence-based practices, minimal research has been done to determine if these practices are culturally relevant. This is a community-based formative research project. The purpose of this project was to evaluate the cultural appropriateness of the practices identified as "evidence-based practices" by the National Autism Center in the 2015 standards report, specifically a token economy system which is a positive behavioral support that utilizes the principles of applied behavior analysis to decrease challenging behaviors and increase positive behaviors. The study utilized qualitative research strategies, including surveys and interviews within the American Samoan community, to accomplish this evaluation. The surveys and interviews were analyzed using coding principles to generate themes. The researcher was contacted by the American Samoan Department of Education to provide training for educators and parents on utilizing evidence-based practices to support children with autism. The results of this study inform the content of the ongoing training efforts.
    • Exploring infrasound wavefields to characterize volcanic eruptions

      Iezzi, Alexandra M.; Fee, David; Tape, Carl; West, Michael; Izbekov, Pavel; Haney, Matthew (2020-08)
      Infrasound has become an increasingly popular way to monitor and characterize volcanic eruptions, especially when combined with multidisciplinary observations. Regardless of how close the infrasound instruments are to the eruption, the effects from propagation must be considered prior to characterizing and quantifying the source. In this dissertation, we focus on modeling the effects of the atmosphere and topography on the recorded infrasound waveforms in order to better interpret the acoustic source and its implications on the volcanic eruption as a whole. Alaska has 54 historically active volcanoes, one third of which have no local monitoring equipment. Therefore, remote sensing (including that of infrasound arrays) is relied upon for the detection, location, and characterization of volcanic eruptions. At long ranges, the wind and temperature structure of the atmosphere affects infrasound propagation, however, changes in these conditions are variable both in time and space. We apply an atmospheric reconstruction model to characterize the atmosphere and use infrasound propagation modeling techniques for a few recent eruptions in Alaska. We couple these atmospheric propagation results with array processing techniques to provide insight into detection capability and eruption dynamics for both transient and long-duration eruptions in Alaska. Furthermore, we explore the future implementation of this long-range infrasound propagation modeling as an additional monitoring tool for volcano observatories in real time. The quantication of volcanic emissions, including volume flow rate and erupted mass, is possible through acoustic waveform inversion techniques that account for the effects of propagation over topography. Previous volcanic studies have generally assumed a simple acoustic source (monopole), however, more complex source reconstructions can be estimated using a combination of monopole and dipole sources (multipole). We deployed an acoustic network around Yasur volcano, Vanuatu, which has eruptions every 1-4 minutes, including acoustic sensors along a tethered aerostat, allowing us to better constrain the acoustic source in three dimensions. We find that the monopole source is a good approximation when topography is accounted for, but that directionality cannot be fully discounted. Inversions for the dipole components produce estimates consistent with observed ballistic directionality, though these inversions are somewhat unstable given the station conguration. Future work to explore acoustic waveform inversion stability, uncertainty, and robustness should be performed in order to better estimate and quantify the explosion source. Volcanic explosions can produce large, ash-rich plumes that pose great hazard to aviation. We use a single co-located seismic and infrasound sensor pair to characterize 21 explosions at Mount Cleveland, Alaska over a four-year study period. While the seismic explosion signals were similar, the acoustic signals varied between explosions, with some explosions exhibiting single main compressional phase while other explosions had multiple compressions in a row. A notable observation is that the seismo-acoustic time lag varied between explosions, implying a change in the path between the source and receiver. We explore the influence of atmospheric effects, nonlinear propagation, and source depth within the conduit on this variable seismo-acoustic time lag. While changes in the atmospheric conditions can explain some of the observed variation, substantial residual time lags remain for many explosions. Additionally, nonlinear propagation does not result in a measurable difference for the acoustic onset. Therefore, using methods such as seismic particle motion analysis and cross correlation of waveforms between events, we conclude that varying source depth within the conduit likely plays a key role in the observed variation in the seismo-acoustic time lags at Mount Cleveland.
    • Experimental investigation of the role of different clays in low salinity waterflooding

      Ivuawuogu, Henry; Zhang, Yin; Dandekar, Abhijit; Khataniar, Santanu; Awoleke, Obadare (2020-08)
      Various studies have demonstrated that Low Salinity Water Flooding (LSWF) can enhance oil recovery effectively, and its typical recovery mechanisms have been recognized. However, there is still a significant debate on the functions of clay during LSWF. This study investigates the impact of different clays, including montmorillonite, illite, and kaolinite, on the performance of LSWF. The zeta potentials of sand, montmorillonite, illite, and kaolinite in the presence of high salinity water (HSW) and low salinity water (LSW) were first examined. Then, the swelling factors of the three clay minerals in the HSW and LSW were measured in succession to determine their swelling characteristics. Subsequently, coreflooding experiments were conducted using one clay-free sand pack column and five sand pack columns respectively containing 10 wt% of montmorillonite, 10 wt% of illite, 10 wt% of kaolinite, compound clays (5 wt% of montmorillonite + 2.5 wt% of illite + 2.5 wt% of kaolinite), and 5 wt% of montmorillonite and the cumulative oil production and pressure drops were recorded. A produced crude oil sample with the American Petroleum Institute (API) gravity of 34° and viscosity of 14 cP (60°F) was used in the experiments. The total dissolved solids (TDS) of the HSW and LSW are 27,501 mg/L, and 2,485 mg/L respectively. It has been found that LSW could generate more negative zeta potential values for sand, montmorillonite, illite, and kaolinite, which made them more water-wet and thus favor oil recovery. Montmorillonite obviously swelled in HSW, and it could further swell significantly by contacting LSW. Although illite showed some swelling in HSW, LSW could not further expand it. Kaolinite did not swell in both HSW and LSW. The results from six coreflooding experiments showed that after high salinity waterflooding, the subsequent LSWF could generally further improve the oil recovery. The sand pack columns containing montmorillonite showed higher incremental oil recovery during LSWF (17.42% from sand pack column with 10 wt% of montmorillonite, 10.27% from sand pack column with compound clay, and 8.90% from sand pack column with 5 wt% of montmorillonite). Also, LSWF could improve oil recovery for the clay-free sand pack column, the sand pack column with kaolinite, and the sand pack column with illite by 0.73%, 0.83%, and 1.03%, respectively. Therefore, clay minerals would play an important role in determining oil recovery performance in LSWF, and the more swelling there is in clay in LSW, the more favorable it is in LSWF. This study proved that both clay swelling and wettability alteration could attribute to the improved oil recovery by LSWF.
    • Mental health problems in the mountains: needs, assets, and recommendations for managing mental health problems in mountain-focused wilderness-based education and related fields

      Johnson, Samuel H.; Dulin, Patrick L.; Lopez, Ellen D. S.; Gifford, Valerie M.; Rivkin, Inna D. (2020-08)
      Background: Through controlled exposure to stress, wilderness-based education programs can buildcapacity for adaptive coping and produce long lasting improvements to participants' quality of life.However, stress can also overwhelm them, resulting in the emergence and exacerbation of mental health vulnerabilities in the field. However, empirically grounded best practices for training, pre-trip screening, and protocol/policy for mental health specific to the wilderness context are not well developed. Aim: The aim of this study was to assess needs and assets, and develop recommendations for training, pre-trip screening, and organizational protocol/policy to assist with successful management of mental health problems in mountain-focused, wilderness-based education and related fields such as outdoor leadership, guiding, environmental education, snow safety, search and rescue, and wilderness therapy. Methods:A pragmatic, two phase, sequential mixed methods approach was utilized to explore this topic within the context of an overarching collaborative community based participatory research (CBPR) framework with organizational partners: National Outdoor Leadership School, Outward Bound USA and Canada, the Wilderness Risk Management Conference, and the Alaska Mountaineering School. A preliminary quantitative study utilized a cloud-based survey to determine baseline characteristics for 64 wilderness-based educators, guides, outdoor leaders, snow safety professionals, and search and rescue personnel. Qualitative interviews with 16 experienced and prepared key informants addressed the study aim in more depth, consistent with partnering organization priorities, in the tradition of CBPR. Findings: Mental health topics and skills are underemphasized in current training, and training was found to be of less value than personal and professional experiences with mental health. In the future, mental health should be increased and emphasized, possibly through the utilization of existing resources such as the stress continuum or curriculum such as Psychological First Aid as well as practical training opportunities that emphasize experiential learning around mental health. Current screening can present both risks and benefits for clients, instructors, and organizations. Nondisclosure and the impacts of stigma and prejudice on the interpretation and utilization of mental health screening information were major concerns. However, screening can guide preventive and proactive efforts, and build working relationships with potential participants. Future screening should be used to inform participants about course stress, encourage disclosure, and direct curriculum development. Multi-step screening, utilizing multiple interactions with participants before the course, was identified as a utilitarian way to facilitate improvements for future screening. In protocol/policy, field management of mental health problems is underemphasized relative to evacuation, resulting in overutilization of disruptive evacuation processes. While many organizations do well at responding to instructor mental health needs after incidents such as a fatality in the line of work, inconsistencies in implementation can create unintended barriers to instructor self-care. Future protocol/policy should prioritize instructor mental health by addressing inconsistencies in implementation, removing barriers to self-care and guiding the deployment of resources such as responsive staffing or free counseling benefits. Implications: This study contributes uniquely to the literature by providing an empirically-based perspective into a little researched topic, and multiple avenues for implementation of findings such as increasing mental health content and experience-based training, utilization of multi-step screening processes, and consistent implementation of organizational protocol/policy in support of client and instructor mental health. Recommendations for implementation address weaknesses and build upon strengths already present in training, screening, and protocol/policy. Overall, practice and research in this area are in need of further investigation and development. Future dissemination, research, and practice development could help develop measures or resources to support the improvement of training, screening, and protocol/policy across wilderness-based education and related fields.
    • Environmental impacts on reproductive responses of Pacific walruses (Odobenus rosmarus divergens) and subsistence users of St. Lawrence Island

      Larsen Tempel, Jenell T.; Atkinson, Shannon; Kruse, Gordon H.; Fugate, Corey; Pyenson, Nick (2020-08)
      An interdisciplinary approach is used in understanding change and resiliency in St. Lawrence Island (SLI) resources and resource users throughout this dissertation. Historically SLI inhabitants have relied on the Pacific walrus (Odobenus rosmarus divergens) for their survival and this resource is still highly valued for cultural and dietary purposes. The responses of Pacific walruses and SLI subsistence users to environmental change was analyzed. In walruses, reproductive capacity was analyzed using an anatomical approach as well as reproductive plasticity which was determined using a physiological approach to characterize their estrus cycle. A suite of anatomical measurements were developed to characterize reproductive capacity of walruses by analyzing ovaries from three distinct time frames during a 35-year period. Reproductive capacity was reduced during time frames when carrying capacity (K) was reached and when large environmental changes occurred in the Bering Sea, including years of very low sea ice extent. Reproductive capacity was high in times when K was lower and harvest levels were greater. Our results explained how perturbations in K and environmental changes may have influenced reproductive capacity of the population in the past. Endocrine techniques were used in ovarian tissues to determine if progesterone and total estrogens are useful indicators of female reproductive status in walruses harvested during the spring hunt. Progesterone and total estrogen concentrations were greater in the reproductive tissues of unbred and pregnant females than postpartum females, however neither hormone could distinguish between pregnant and unbred animals. These results provide the first physiological evidence for pseudopregnancy in this species, rather than a postpartum estrus. Lastly, discussions were held with SLI community members to determine changes in key subsistence resources and community resiliency with regard to food security. Walruses ranked highest among key resources. Stakeholders reported limited access and increased effort to hunt walruses, changes in crab abundance, and increases in commercially exploitable fish stocks. Changes were attributed to loss of sea ice, "bad" weather, and climate change. In order for SLI communities to continue their subsistence-based way of life, inhabitants may need to expand their diet to include less-preferred food items in place of harvested ice-associated species. In conclusion, loss of sea ice and rapid environmental changes in the Bering Sea have the potential to greatly impact walrus reproduction and the marine subsistence way of life that is practiced by SLI stakeholders.
    • Stigma, self-efficacy, and adherence behaviors in people with type 2 diabetes: unexpected outcomes

      Laweryson, Annie N.; Campbell, Kendra; Dulin, Patrick; David, EJR; Rivkin, Inna (2020-08)
      Type 2 diabetes mellitus is a health condition treated with behavioral modifications including changes in diet, exercise, foot care regimens, and medication. Stigma associated with type 2 diabetes negatively effects health outcomes, whereas patient-provider relationships positively affects health outcomes. The growing literature base on type 2 diabetes stigma and health outcomes is mostly conducted outside of the United States. The present study used online crowdsourcing methods to gather cross-sectional survey data from people (n=152) who have been diagnosed with type 2 diabetes and are living in the United States. Participants completed the survey battery measuring stigma, self-efficacy, patientprovider relationships, and health behaviors. It was predicted that 1) internalized stigma would have a negative impact on self-care behaviors including diet, exercise, foot care, and medication adherence as well as glycated hemoglobin [HbA1C] levels 2) self-efficacy would mediate each of those relationships, and 3) the patient-provider relationship, characterized by trust in providers would moderate the relationship between stigma and self-efficacy thus indirectly moderating self-care behaviors and HbA1C. To test these hypotheses, a set of five moderated-mediation analysis were conducted to test each outcome variable of diet, exercise, foot care, medication adherence, and HbA1C. Main findings of this study revealed paradoxical relationships between stigma, self efficacy, and trust in providers, although consistent with psychological reactance theory. Stigma was associated with medication non-adherence and worse HbA1C, which is consistent with literature. Results of this study suggest that patients who exhibit psychological reactance may struggle to adhere to recommendations despite being more likely to report that everything is okay. This dynamic may make it difficult for providers to accurately gauge patient engagement in care, ability, or progress in health behavior change. However, one could argue responding to stigma with reactance may be protective in other ways. There was some evidence to suggest providers can attend to reactance by attuning to trust within the patient-provider relationship. In summary, this study adds to the pool of literature on stigma and type 2 diabetes, specifically within the US which is important considering variances in social climates and health care systems across nations. Future research should corroborate our suppositions about the relationships between stigma, self-efficacy, and psychological reactance.
    • Assessing adverse effects of mercury in two pinniped species

      Lian, Marianne; O'Hara, Todd M.; Rea, Lorrie D.; Kuhn, Thomas B.; Van Wijngaarden, Edwin (2020-08)
      This dissertation studies measures of adverse effects in free-ranging pinnipeds associated with relatively high total mercury ([THg]) or monomethylmercury ([MeHg+]) concentrations, relatively low total selenium ([TSe]) concentrations and/or low TSe:THg molar ratios. Both the Steller sea lion (SSL, Eumetopias jubatus) and Pacific harbor seal (HS, Phoca vitulina richardii) inhabit coasts of the North Pacific, and are considered important sentinel species for One Health (environmental, animal and human health). Relatively high [THg] is reported for some animals in both species, causing concern for adverse effects especially in the developing fetus. Maternal piscivorous diet can expose the fetus to MeHg⁺ at a vulnerable developmental stage, with potential for adverse effects on several organ systems. This dissertation focused on two of these: nervous system development and function and oxidant/antioxidant homeostasis. In Chapter 2 I outlined capture and field anesthesia of free-ranging SSL. I found faster induction times for sevoflurane over isoflurane, with a significant interaction for anesthetist. Difference among the two agents is most likely attributed to the different chemical properties for these gases (blood solubility), whereas personal experience/comfort level most likely explains the differences between the human operators. Severe hypothermia was also documented, associated with the time of year, sex and duration of anesthetic event. There was an overall low mortality rate, and the protocols were effective for relatively safe field anesthesia of a large mammal. Chapter 3 assessed oxidant/antioxidant status and associations with [THg], [MeHg⁺], [TSe] and TSe:THg molar ratio in anesthetized free-ranging SSL pups. The anesthesia protocols described in Chapter 2 were used as a physiological stressor for measuring oxidative stress in SSL. Pinnipeds as diving mammals are naturally adapted with high antioxidant activity to survive long breath-holds during foraging. However, the relatively high [THg] found in some SSL cause concern for sequestration of Se due to its high binding affinity to Hg, and subsequently decreased antioxidant capacity (Se-dependent glutathione peroxidase (GPx)). I found a significant negative relationship between lipid peroxidation and [TSe], suggesting the potential for decreased antioxidant protection from Se. There were also significant associations between increased GPx activity and lipid peroxidation, possibly protecting pups with relatively high [THg] and low TSe:THg molar ratios. In Chapter 4 I repeatedly evaluated live-stranded HS pups admitted to The Marine Mammal Center, using weekly clinical and behavior assessments, which were analyzed for associations with [THg]. There was a significant association between [THg] in hair and/or blood and decreased response to tactile stimulation, less movement and longer stays in rehabilitation. These findings will help us better assess similar [THg] in hair and blood of SSL in Alaska that we currently study as well as other pinnipeds. In summary, this dissertation confirms the potential for adverse effects in two free-ranging species of pinnipeds exposed to MeHg⁺ in utero.
    • Development of scalable energy distribution models to evaluate the impacts of renewable energy on food, energy, and water system infrastructures in remote Arctic microgrids of Alaska

      Karenzi, Justus; Wies, Richard; Huang, Daisy; Al-Badri, Maher (2020-08)
      Experience and observations from remote Alaska communities have shown that energy is inarguably at the center of food, energy, and water (FEW) security. The availability of potable water, fresh produce, food storage, or processed seafood ultimately depends on a reliable and adequate energy supply. For most communities, diesel fuel is the primary source of power, which comes at high cost because of the logistics associated with importing the fuel to these relatively isolated communities. Integrating locally available renewable energy resources not only enhances energy supply, but the impacts further translate to food and water security in remote microgrids. The focus of this work is to investigate how intermittent renewable energy sources impact community level food and water infrastructure systems in a remote Arctic microgrid. Energy distribution models are mathematically developed in MATLAB® Simulink® to identify, describe, and evaluate the connections between intermittent renewable resources and the FEW loads. Energy requirements of public water systems, greenhouses, cold storage units, seafood processing loads, and modular water and food system loads are evaluated. Then energy sources including solar PV, solar thermal collectors, wind, hydro, energy storage, and diesel electric generation are modeled and validated. Finally, simulations of scenarios using distributed energy resources to serve water and food infrastructure loads are carried out including the incorporation of dispatchable loads. The results indicate that the impacts of renewable energy on FEW infrastructure systems are highly seasonal, primarily because of the variability of renewable resources. The outcome of this work helps in gaining firsthand insights into FEW system dynamics in a remote islanded microgrid setting.
    • Analysis of the 2015 Sagavanirktok River flood: associated permafrost degradation using InSAR and change detection techniques

      McClernan, Mark Timothy; Meyer, Franz; Zwieback, Simon; Minter, Clifton (2020-08)
      In 2015, the Sagavanirktok River experienced a sequence of high, early-winter temperatures that lead to a buildup of aufeis. The buildup displaced the spring runoff causing widespread flooding. Flood waters inundated the surrounding tundra introducing heat into ground ice-baring soils. The Sagavanirktok River flood was caused by an extensive ice dam that developed the previous winter. The first flooding pulse started in April 2015, when an aufeis obstruction diverted river water to the surface. The obstruction caused flooding along 24 km of the Dalton Highway and its surroundings, necessitating a prolonged highway closure and emergency repairs. A second flooding pulse was caused by annual spring runoff in May 2015, which was driven by rapid snowmelt due to warm seasonal temperatures. The washed-out highway had to be closed again. Field investigations showed that thermal erosion of ice wedges in the tundra adjacent to the Dalton Highway caused local subsidence by several meters. However, the full environmental impact of the flood has not yet been quantified regionally or temporally. Thermokarst formation, can cause rapid ecological and environmental changes. Thawing of permafrost can lead to terrain instability as the melting of ground ice induces subsidence and loss of soil strength. The processes involved in permafrost degradation are complex, as is predicting terrain stability and the associated impacts to permafrost surrounding infrastructure. The immediate impact of the 2015 Sagavanirktok River flood is evident, which caused rapid terrain collapse in the vicinity of the Dalton Highway and the Trans-Alaska Pipeline near Deadhorse, North Slope Borough, Alaska. Thermal degradation of permafrost can be expressed as the change in the surfacemicrotopography over several years following a flood. Change detection, digital elevation model differencing, and InSAR were employed within the area of interest to understand the extent of the flood and deformation within inundated areas. To determine the likely impacted areas within the area of interest and expanse of the flood, an unsupervised change detection technique of high resolution TerraSAR-X and Sentinel-1 amplitude images was utilized. The topographic deformation analysis to determine the motion on the ground surface used a short baseline subset InSAR analysis of Sentinel-1 data during the summer season following the Sagavanirktok River flooding events. Additional deformation analysis was conducted with ALOS-2 data for annual comparison of the 2015 to 2019 summers. TanDEM-X digital elevation model differencing compared surface models generated from before and after the Sagavanirktok River flood. Elevation model differencing would identify the absolute change between the acquisition time of the surface models. A joint data analysis between deformation and differenced elevation models analyzed the contrast within inundated and flood-unaffected areas; thus, the changes and impact to the permafrost following the 2015 Sagavanirktok River flood. The Sagavanirktok River flood highlights the vulnerability of ice-rich permafrost to flooding. A change in the vicinity of the Sagavanirktok River Delta to the hydrological cycle led to widespread increases in terrain instability. Analysis of summer season deformation data suggested inundated permafrost areas showed lower seasonal deformation in years following the flood. Analysis of annual deformation shows permafrost subsidence intensified in inundated areas in the years following the flood. Digital elevation model differencing produced a statistically ambiguous result. This research illustrates the value of combining TerraSAR-X, TanDEM-X, Sentinel 1, and ALOS-2 microwave remote sensing missions for evaluating widespread surface changes in arctic environments. However, annual deformation data proved the most usable tool in observing the changing permafrost ecosystems around the Sagavanirktok River.
    • Landscape characteristics influence climate change effects on juvenile chinook and coho salmon rearing habitat in the Kenai River watershed

      Meyer, Benjamin; Rinella, Daniel; Wipfli, Mark; Schoen, Erik; Falke, Jeffrey (2020-08)
      Changes in temperature and precipitation as a result of ongoing climate warming in south-central Alaska are affecting juvenile salmon rearing habitat differently across watersheds. Work presented here simulates summer growth rates of juvenile Chinook and coho salmon in streams under future climate and feeding scenarios in the Kenai River (Alaska) watershed across a spectrum of landscape settings from lowland to glacially-influenced. I used field-derived data on water temperature, diet, and body size as inputs to bioenergetics models to simulate growth for the 2030-2039 and 2060-2069 time periods, comparing back to 2010-2019. My results suggest decreasing growth rates under most future scenarios; predicted changes were of lower magnitude in the cooler glacial watershed and main stem and more in montane and lowland watersheds. The results demonstrate how stream and landscape types differentially filter a climate signal to juvenile rearing salmon habitat and contribute to a broader portfolio of habitats in early life stages. Additionally, I examined two years of summer water temperature data from sites throughout our study tributaries to assess the degree to which lower-reach sites are representative of upstream thermal regimes. I found that the lower reaches in the lowland and glacial study watersheds were reasonably representative of daily and seasonal main stem thermal conditions upstream, while in the montane study watershed (elevation and gradient mid-way between the lowland watershed) upstream conditions were less consistent and thus less suitable for thermal characterization by a lower-reach site alone. Together, this work highlights examples of the importance of accounting for habitat diversity when assessing climate change impacts to salmon-bearing streams.
    • Long-term shifts in community structure, growth, and relative abundance of nearshore Arctic fishes: a response to changing environmental conditions

      Priest, Justin T.; Sutton, Trent M.; Mueter, Franz J.; Raborn, Scott W. (2020-08)
      Environmental conditions influence the presence, species composition, abundance, and growth of fish species in the nearshore Arctic ecosystem. With ongoing shifts in Arctic conditions due to climate change, how fish communities and individual species respond to such changes to environmental variability more broadly is unknown. This study analyzed catch and length data from a long-term fish monitoring project near Prudhoe Bay, Alaska, 2001-2018, to quantify the effects of environmental variables on the overall fish community and on the juveniles of two important whitefishes, Arctic Cisco Coregonus autumnalis and Broad Whitefish Coregonus nasus. Abundance data (n = 1.78 million fish) from daily sampling (July-August) at four stationary sampling locations showed distinct shifts in fish community metrics. Since 2001, annual species richness has significantly increased by one species per decade while water temperature warmed by over 1.4°C. The species composition based on biweekly catch data has significantly changed across years, with distinct variations among sample locations and throughout the season. Species composition was significantly affected by both salinity and water temperature. The effects of environmental conditions on growth showed that water temperature was positively and linearly associated with increases in growth for juvenile whitefish, while salinity negatively affected growth of age-0 Arctic Cisco. Changes in the abundance of juvenile whitefishes were related to both water temperature and salinity. Results from all analyses suggest that species positively associated with observed warming in the aquatic environment are generalist species such as Broad Whitefish. This study concluded that continued climate change, and especially Arctic warming, will likely increase growth, change the species composition, and alter abundance in the Arctic nearshore ecosystem. These changes will have impacts on subsistence harvests and on upper trophic level species that prey on nearshore fishes.
    • Seasonal variation in nutritional biomarkers and fecal cortisol concentrations in a northern population of snowshoe hares

      Montgomerie, Claire Kornet; Kielland, Knut; Breed, Greg; Lian, Marianne (2020-08)
      Blood biomarkers indicative of nutritional status, fecal cortisol metabolite concentrations and an established body condition index (BCI), were collectively examined from snowshoe hares(Lepus americanus) inhabiting northern Alaska in 2018, during five ecologically significant times of year. As a novel approach to increase our understanding of the effects of diet and predation pressure on hare physiology, I addressed how these markers were associated with seasonal timing of energetic demands and adult survival rates. Mean decreases in concentrations of total protein (TP), blood urea nitrogen (BUN), hematocrit (HCT) and glucose during spring and autumn, suggest that snowshoe hare nutritional status decreased during these two seasons in 2018. The shoulder seasons of spring and autumn coincide with energetic challenges, including molt, changes in diet and breeding. Because available forage during these seasons largely consists of winter-dormant twigs, the energy expenditure of growing a new winter coat (autumn) and breeding behavior (spring) may compromise the energy balance of hares during these periods. Male hares, whose activity levels increase during breeding, exhibited lower BCI scores and were slower to molt from white to brown than female hares in May. Furthermore, adult survival rates were lowest during spring months. Snowshoe hare mean fecal cortisol metabolite concentrations did not show associations with seasons of apparent low nutritional status. Adult hare survival rates peaked during summer and early autumn, during which mean values of TP, BUN, Hct, Cl (chloride), Na (sodium) and glucose also increased. By contrast, this period coincided with a 2-fold increase in mean fecal cortisol metabolite concentrations, suggesting that the apparent stressor was not related to nutrition. Interestingly, after having decreased in autumn, BUN, Hct, TP, and glucose mean concentrations increased in midwinter. Free calcium (iCa) and potassium (K) mean concentrations were also highest in December. Hares may have reduced activity during winter months, and metabolic rates may have increased to cope with thermoregulation demands. BCI scores decreased by December, suggesting use of endogenous reserves. Lowest seasonal mean cortisol metabolite concentrations were also observed in mid-winter. This study demonstrates the value of examining both physiological and morphological metrics of snowshoe hare condition to better our understanding of how seasonal trends in food and fear may unfold into cyclic patterns.
    • Timescales of magmatic processes from diffusional profiles recorded in minerals of the 2016-2017 eruption of Bogoslof Volcano, Alaska

      Moshrefzadeh, Jamshid Akhbar; Izbekov, Pavel; Loewen, Matthew; Larsen, Jessica; Regan, Sean (2020-08)
      Every volcanic eruption is unique, and creates opportunities for scientists to gain insights on magma processes. Studying active volcanoes not only adds to our understanding of fundamental processes that shape our planet, but it is also importantly aids the scientic community to assess and mitigate the many hazards that volcanoes pose. The products of the 2016-2017 eruption of Bogoslof Volcano provide a unique opportunity for the application of diusion chronometry, due to the abundance of distinct, stepwise boundaries within three mineral phases: clinopyroxene, plagioclase, and amphibole. Given that diusion is driven by the presence of a chemical gradient, the compositionally stepwise boundaries between distinct zones can be used to investigate the diusion of elements within the crystals in order to constrain timing of the magmatic processes that created them, as well as crystal residence times. Here we present our analyses of these stepwise boundaries, and discuss the potential correlation of acquired diusional timescales from clinopyroxene with the other two mineral phases, in order to determine what magma processes lead to the formation of these boundaries, and when these processes occurred. Our results suggest that the stepwise boundaries in crystalline phases of the magmas erupted by Bogoslof in August 2017 formed due to mac recharge that resumed in March 2017 and occurred repeatedly until the cessation of the eruption in August 2017. Activity at Bogoslof during March 2017 is additionally characterized by increased seismicity and SO₂ rates, suggesting that our petrologic results are consistent with multiple interdisciplinary observations.
    • Abundance, composition and distribution of predatory gelatinous zooplankton in the northern Gulf of Alaska

      Mendoza Islas, Heidi M.; Hopcroft, Russell R.; Coyle, Kenneth O.; Cieciel, Kristin; Danielson, Seth (2020-08)
      Jellyfish are conspicuous yet under-studied components of marine zooplankton communities. Abundance, biomass, size, and distribution of large-jellyfish were measured during July and September of 2018 and 2019 as part of the Northern Gulf of Alaska Long-Term Ecological Research (NGA-LTER) cruises. Nearly 1000 kg dispersed among ~13,800 jellies were collected using a 5 m² Methot net. Catches were dominated by two macro-jellies, the hydrozoan Aequorea sp. and the scyphozoan Chrysaora sp. During 2018, epipelagic macro-jellies biomass averaged 1.46 ± 0.36 g WW m⁻³ for July and 1.14 ± 0.23 g WW m⁻³ for September, while during 2019 they averaged 0.86 ± 0.19 g WW m⁻³ for July and 0.72 ± 0.21 g WW m⁻³ by September. Despite similar biomass among sampling seasons within the same year, July abundances were fivefold greater than abundances in September, with July catches dominated by juvenile jellyfish over the inner shelf, while during September jellyfish adults were more prominent and most predominant at offshore stations. Comparison to over 20 years of data from standard towed nets allowed determination of the relative magnitude of the three dominant predatory zooplankton components: Scyphozoans, Hydrozoans, and Chaetognaths in the NGA. The biomass of these smaller epipelagic predators (10 mg WW m⁻³ for hydrozoans and 8 mg WW m⁻³ for chaetognaths) is a low percentage of the macro-jellies, despite their much higher numerical abundance. Acknowledging that changes in gelatinous biomass could have profound effects on fisheries, we argue that jellyfish should be quantitatively monitored in ecosystems with high fisheries productivity.