• Investigation of thermal regimes of lakes used for water supply and examination of drinking water system in Kotzebue, Alaska

      Bendlova, Tereza; Arp, Christopher D.; Duffy, Lawrence K.; Schnabel, William E.; Barnes, David L. (2012-08)
      Many villages in Arctic Alaska rely on lakes for water supply, such as the Alaskan City of Kotzebue, and these lakes may be sensitive to climate variability and change, particularly thermal regimes and corresponding effects on water quality. Thus, I initiated a study of water supply lakes in Kotzebue to collect data for developing a model to hindcast summer thermal regimes. Surface (Tws) and bed (Twb) temperature data collected from two water supply lakes and two control lakes from June 22nd-August 28th 2011 showed a similar pattern in relation to air temperature (Ta) and solar radiation with more frequent stratification in the deeper lakes. The average Tws for all lakes during this period was 14.5°C, which was 3.4°C higher than Ta for the same period. I modeled Tws from 1985 to 2010 using Ta, and theoretical clear-sky solar radiation (TCSR) to analyze interannual variability, trends, and provide a baseline dataset. Similar to patterns in Ta for this period, I found no trend in mean Tws for the main lake used for water supply (Devil's Lake), but considerable variation ranging from 12.2°C in 2000 to 19.2°C in 2004. My analysis suggests that 44% of years during this 25 year period maximum daily Tws surpassed 20°C for at least one day. This hindcasted dataset can provide water supply managers in Kotzebue and other Arctic villages with a record of past conditions and a model for how lakes may respond to future climate change and variability that could impact water quality.
    • Investigation of thin midlevel ice clouds in the Arctic using calipso data and radiative transfer modeling

      Kayetha, Vinay Kumar; Collins, Richard; Meyer, Franz; Prakash, Anupma; Bhatt, Uma (2015-08)
      In this research we investigate the global occurrence and properties of optically thin midlevel ice clouds. These clouds are difficult to detect with passive radiometric techniques and are under-represented in current studies. We use the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data set to identify thin midlevel ice clouds and determine their global occurrence and distribution. For the first time, we find that the global mean occurrence of these clouds is at least 4.5%, being at least 7.3% of all the tropospheric clouds detected at a horizontal scale of 10 km. Seasonally, these clouds are found most commonly in the polar regions. These clouds occur most commonly in the Arctic in winter and least commonly in the summer. In winter these clouds can occur up to 19% of the time. The occurrence of these clouds decreases with increasing spatial scale and are most commonly found at spatial scales of 25 km or less. We found five large distinct clouds over the Arctic and investigated them for their meteorological conditions and radiative effects. These thin midlevel ice clouds are formed along the frontal zones in weakly ascending air masses. Our model simulations show that thin midlevel ice clouds have a net warming effect on the surface of 23-48 W/m². We conclude that these clouds have a significant impact on the radiation budget in Arctic winters. Our study highlights the importance of active satellite-based remote sensing in globally detecting and characterizing optically thin clouds. Our estimates of occurrence and fraction of clouds represents a lower bound, as these clouds can be obscured by optically thicker clouds. The volume of measurements provided by the satellite allowed us to identify a small but consistent set of large clouds with which we could conduct a contemporary radiative analysis. These findings can be used to improve the representation of clouds and their impacts in regional and global climate models.
    • Investigation On Cirrus Clouds By The Cloud-Aerosol Lidar And Infrared Pathfinder Satellite Observation Data

      Zhu, Jiang; Sassen, Kenneth (2011)
      Understanding and describing the role of clouds in the climate system need intensive and extensive research on cloud properties. The albedo and greenhouse effects of clouds and their relations with the physical properties of clouds are analyzed. Cloud-top height and ice water content are key factors in impacting the longwave and shortwave radiation, respectively. Lidar and infrared radiometer measurement technologies are introduced. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) level 1 Lidar profile, level 2 cloud layer, and level 2 Lidar/IIR track products are briefly reviewed. The algorithms for identification of cirrus clouds, Linear Depolarization Ratio (LDR), and effective diameter are presented. An average LDR profile is calculated by using the sum of total attenuated backscattering profiles and the sum of perpendicular attenuated backscattering profiles. A weight-average method is applied to calculate the average LDR. A split-window method is applied to estimate the effective diameters of clouds. A set of bulk ice crystal models and a radiative transfer model are applied to produce a look-up table that includes the radiative transfer simulation results. The macro-physical properties of cirrus clouds are analyzed. The frequency of occurrence of cirrus clouds varies with latitude, and strongly relates to the atmospheric circulation. Cirrus clouds are few in high-pressure zones and abundant where seasonal monsoonal circulation occurs. Cloud-top height decreases with increasing latitude. Cloud-top temperature is lower in the tropical regions than in the midlatutude and the polar regions. The measured cloud thickness shows a great diurnal variation.
    • Investigation on the impacts of low-sulfur fuel used in residential heating and oil-fired power plants on PM₂.₅₋ concentrations and its composition in Fairbanks, Alaska

      Leelasakultum, Ketsiri; Mölders, Nicole; Bhatt, Uma; Collins, Richard (2013-08)
      The effects of using low-sulfur fuel for oil-heating and oil-burning facilities on the PM₂.₅-concentrations at breathing level in an Alaska city surrounded by vast forested areas were examined with the Weather Research and Forecasting model coupled with chemistry packages that were modified for the subarctic. Simulations were performed in forecast mode for a cold season using the National Emission Inventory 2008 and alternatively emissions that represent the use of low-sulfur fuel for oil-heating and oil-burning facilities while keeping the emissions of other sources the same as in the reference simulation. The simulations suggest that introducing low-sulfur fuel would decrease the monthly mean 24h-averaged PM₂.₅-concentrations over the city's PM₂.₅-nonattainment area by 4%, 9%, 8%, 6%, 5% and 7% in October, November, December, January, February and March, respectively. The quarterly mean relative response factors for PM₂.₅ of 0.96 indicate that with a design value of 44.7 µg/m³ introducing low-sulfur fuel would lead to a new design value of 42 .9µg/m³ that still exceeds the US National Ambient Air Quality Standard of 35µg/m³ . The magnitude of the relation between the relative response of sulfate and nitrate changes differs with temperature. The simulations suggest that in the city, PM₂.₅-concentrations would decrease more on days with low atmospheric boundary layer heights, low hydrometeor mixing ratio, low downward shortwave radiation and low temperatures. Furthermore, a literature review of other emission control measure studies is given, and recommendations for future studies are made based on the findings.
    • Investigations in the funhouse

      Overton, Quentin T.; Hill, Sean; Harney, Eileen; Stanley, Sarah; Hirsch, Alexander (2017-05)
      The poems of Investigations in the Funhouse represent a kind of movement through outrage. The poems sit at the convergence of the personal and the national interest story, at the rise of anti-intellectual fervor and ultra-conservative populism. They move between ravings and reverie through which we come to know the various politics of our speaker. The resulting structure is designed to create the sense of a descent into madness. Counterpoised against the irreverent, if callous, lyrics of the rest of the book, the "investigation with letter x" and "the funhouse" are a kind of sterile, formulaic act. They are positioned throughout the collection in order to engage with the themes of the surrounding lyrics in their own way. They are not designed to be directly conversant with the content of these lyrics, but instead function as a renegotiation of their themes. There is a latent sense of confusion in the investigations' hyper-focus on meaning. Though meaning-making is the premise, the resulting effect is miscommunication or unmeaning. Think of this in terms of cryptography and each investigation functions as a kind of cypher, a node that analyzes, and in some ways corrupts, the meaning of its attached lyrics. This lends a tangible interiority and complexity to the speaker of the poems: the disparity between the investigations and the lyrics is not a fracturing of the continuity of the speaker's thoughts or experiences but are inexact replications of the same convictions. Contradiction in voice is then a more accurate portrayal of the evolution of opinion into meaning, the personal into the national. In Investigations in the Funhouse the attempts of the speaker to make meaning, or at the very least arrive at an understanding of the personal/national interest story, are a response to the descent, from exuberance to outrage and further down, into the political, and deeper still, into the heaven of the hell of self.
    • Investigations into model systems of neurodegeneration: Organotypic brain slice culture and in vivo microdialysis

      Clapp, Kimberly Lara; Duffy, Lawrence K. (2000)
      The mechanisms behind neurodegeneration in disease and injury have yet to be fully defined. Many in vitro and in vivo model systems, have been developed to investigate the mechanisms of neurotoxicity and its relation to human disease and injury. There are a few resounding connections between most types of neurological disorder; namely oxidative stress and inflammation. The glutamate receptor agonist, N-methyl-D-aspartate, can be used to imitate excitotoxicity during stroke as it overstimulates the glutamate receptor, leading to rises in intracellular calcium levels, which in turn lead to oxidative stress within the cell. Amyloid-beta protein (Abeta) a useful in many of its isoforms in creating in vitro model systems of Alzheimer's disease (AD). Abeta can directly cause the production of potentially harmful free radicals. This study investigates the formation of model systems of neurodegeneration: in vivo microdialysis and organotypic brain slices culture in order to assess the role of oxidative stress and inflammation morphologically and biochemically. The effect of melatonin, an endogenous antioxident, on oxidative stress associated with NMDA and Abeta neurotoxicity was determined through morphological analysis and biochemical markers of oxidative stress. This study reports that both NMDA and Abeta(25--35) cause oxidative stress in an organotypic brain slice culture model system of stroke and Alzheimer's disease as established by: (1) morphological analysis of tissue and ultrastructure, (2) redox-active assay, (3) heme-oxygenase assay, (4) 8-hydroxyguanosine assay and (5) interleukin IL-1beta and IL-6 assay (Abeta only) These investigations also demonstrate that melatonin can attenuate the oxidative stress associated with NMDA and Abeta exposure. These findings expand upon previous evidence from cell culture analysis of oxidative stress induced by NMDA and Abeta. Therefore, this evidence supports the theory that oxidative stress is involved in neurodegeneration in both excitotoxicity in stroke and in Abeta-mediated damage in Alzheimer's disease, and that endogenous antioxidant treatment may be a useful therapeutic approach in such injury and disease.
    • Investigations Into Some Of The Major Controls On The Productivity Of A Black Spruce (Picea Mariana (Mill.) B.S.P.) Forest Ecosystem In The Interior Of Alaska (Photosynthesis, Nutrient Use, Soil Temperatures, Moss Microclimate)

      Hom, John Lun (1986)
      The purpose of this study was to determine the major factors which affect tree and moss productivity in a black spruce (Picea mariana Mill. B.S.P.) forest ecosystem, occurring on permafrost dominated soil. The cold, shallow rooting zone was heated 8(DEGREES) - 10(DEGREES)C above ambient which resulted in increased forest floor nutrient cycling and increased productivity in black spruce. The soil heat sum increased from 563 to 1133 soil degree days and the depth of thaw increased from 57 to 115 cm. Heating increased tree ring radius by 33% relative to the control. Foliar analysis showed significant increases in nitrogen (25%), phosphorus (73%) and potassium (14%), indicating that heating increased nutrient availability to the spruce trees. This resulted in a 22% increase in the maximum photosynthetic rates over the control. The 1 year old tissue had the highest photosynthetic rates, whereas the oldest needles maintained 40% of the maximum photosynthetic rates after 13 seasons. The highest levels of nitrogen and phosphorus were measured in the current tissue and declined with age. Nutrient use efficiency was highest in the 1 year old tissue and declined with needle age. Studies on microclimatic limitations to moss production on the forest floor indicated that water content was the most variable and potentially the most limiting factor. Light was also very limiting, but the range of limitation was small between different day types, demonstrating the moderating influence of the spruce canopy. Temperature was not as limiting a factor during the summer growing season. Limitation by microclimate allowed only 1% of maximum photosynthesis by mosses on dry, clear days and 9% on wet overcast days, with a potential of 20% under sunny and wet conditions. When data was combined for all days, moss photosynthesis ranged from 8 - 14% of maximum, similar to the low 13% efficiency of production calculated from biomass studies.
    • Investigations of health status and body condition of harbor seals (Phoca vitulina) in the Gulf of Alaska

      Fadely, Brian Scott; Castellini, Michael A. (1997)
      Harbor seal (Phoca vitulina) declines during the past 20 years in the Kodiak Island and Prince William Sound regions contrast with stable or slightly increasing populations in southeastern areas of Alaska. Aspects of health status and body condition were investigated to test the hypothesis that these declines were driven by nutritional limitation, and to determine whether recent differential population trajectories among Kodiak Island, Prince William Sound, and southeast Alaska could have health-related components. For comparisons between 1992-96, three aspects of health status were examined; blood chemistry, blubber distribution and quantity; and blubber quality. Clinical ranges of plasma chemistries and hematologies were established for free-ranging seals in the Gulf of Alaska. Significant handling, individual, and seasonal effects were found on many blood parameters that could bias interannual and interregional comparisons if not incorporated in models. Based on statistical modeling, some seals showed more clinically aberrant values than expected by chance, but these were not clumped among regions or years. Differences existed in interannual blood chemistry and hematology patterns between juveniles and adults. Likewise, there were regional differences in blood chemistries of unknown significance. Morphometric indices were poor indicators of condition defined as size-at-age or blubber content. This was related to patterns of blubber distribution and variability, which differed between males and females. Blubber quality, measured as lipid content, did not substantially vary seasonally or between geographic regions, but blubber from Prince William Sound was less hydrated than blubber from non-declining areas. There were no detectable differences in body condition of seals from the Gulf of Alaska sampled during 1963/64 (pre-decline), 1976-78 (during decline) and 1995-96. However, sample sizes were small and patchily distributed throughout locations and years. Thus, the likelihood of detecting body condition changes in response to environmental conditions was poor. Body condition was not substantially different among seals from Prince William Sound, Kodiak Island and southeast Alaska measured during 1993-96. However, interannual blood chemistry and body condition patterns were evident among Prince William Sound seals that may have been associated with environmental conditions.
    • Investigations of patterns of vegetation, distribution and abundance of small mammals and nesting birds, and behavioral ecology of arctic foxes at Demarcation Bay, Alaska

      Burgess, Robert M. (1984-05)
      Analyses of habitat use, activity budget and activity patterns of arctic foxes (Alopex lagopus) at known distribution and abundance of prey are presented. Behavioral data on foxes were collected by direct observation of 2 radio-collared females and their mates in summer 1979. Prey availability was determined through monitoring bird nest success and phenology, mark-recapture studies of small mammals, and analysis of vegetation patterns and distribution of prey in 1978 and 1979. Prey availability fluctuated dramatically within each season and between years. Foxes relied almost exclusively on avian prey in 1979. Small mammal densities were extremely low in 1979 and foxes failed to rear pups in that year. Fluctuating prey availability did not affect fox activity patterns, activity budget or habitat use. The significance of caching in regulating food availability and the relationship between scent-marking and foraging efficiency are discussed.
    • Investigations of the role of lipids in marine mammal diets, health and ecology

      Mau, Tamara Lynn (2004-05)
      Lipids are essential to many aspects of marine mammal biology. I investigated the amount, type and flux of lipids under a variety of natural and controlled nutritional and dietary conditions, in order to increase our knowledge of marine mammal diets, health and ecology. First, I examined the influence of biological and environmental variables on the quantity and quality of blubber, and their importance in establishing condition indices in the bowhead whale. Blubber was heterogeneous in composition, varying by both site and depth. Sex, age-class, season and body length were all significant factors in determining lipid content (quality) of blubber. Blubber thickness (quantity) was highly correlated with body length after?9 m. Blubber lipid content at umbilicus sites and inner depths was most variable and presumably most responsive to nutritional changes. Blubber properties appeared to exceed what was necessary for insulation, further supporting the concept for the need to store energy as a consequence of the large seasonal and annual variability of food availability in the arctic environment. These data establish a baseline for long-term monitoring of bowhead whale health and population condition. Second, I addressed post-mortem changes in blubber composition of a stranded humpback whale. Lipid content decreased due to tissue decomposition by as much as 24%, limiting the ability to accurately assess nutritional status and health. Finally, in response to a growing need for validation of the use of fatty acid profiles as dietary tracers in top marine predators, I investigated the effects of prey switching on fatty acid profiles in plasma and red blood cell membranes (RBCs) of captive harbor seals. In plasma, nine of fifteen fatty acids responded significantly with prey switching, compared to only three plus one ratio in RBCs. Season and total daily lipid intake also affected the level of some plasma fatty acids. Diet was reliably predicted from fatty acid profiles in plasma after two weeks and in RBCs at four months using discriminant function analysis. Plasma and RBC fatty acid profiles provided an integration of dietary history, representing short-term and long-term 'dietary windows, ' respectively.
    • Investigations On The Impacts Of Land-Cover Changes And/Or Increased Carbon Dioxide Concentrations On Four Regional Water Cycles And Their Interactions With The Global Water Cycle

      Li, Zhao; Molders, Nicole (2007)
      A suite of simulations that combine reference (355ppmv), doubled and tripled CO2 concentrations alternatively without and with land-cover changes in four similar-sized study regions, the Yukon, Ob, St. Lawrence and Colorado basin and adjacent land, are performed with the fully coupled Community Climate System Model to investigate the impact on global and regional water cycles and the interaction of these regional water cycles with the global water cycle. The relative changes in water-cycle quantities caused by increased CO 2 enhance with latitude and CO2 concentrations. Regional and global water cycles interactions are more pronounced in a warmer climate, but regional precipitation and evapotranspiration is affected differently in high-latitudes (Yukon, Ob) than mid-latitudes (Colorado, St. Lawrence). Land-cover changes can have comparable impacts on regional water cycles than increased CO2 concentrations do. Land-cover changes substantially alter the high-latitude water cycles through enhanced snow-albedo feedback and mid-latitude water cycles through vegetation activity in the warm season. The land-cover changes in different regions interact with each other through heat and moisture advections and secondary effects. This interaction enhances with increasing CO2 concentrations. Interactions between land-cover changes and increasing CO2 concentrations enhance with increasing CO2 due to the high sensitivity of regional water cycles to temperature changes.
    • Iñupiat Ilitqusiat: inner views of our Iñupiaq values

      Topkok, Charles Sean Asiqłuq; Leonard, Beth; John, Theresa; Lewis, Jordan; Counceller, April (2015-12)
      Iñupiat Ilitqusiat: Inner Views of Our Iñupiaq Values examines how Iñupiat pass down elements of our cultural heritage to future generations. The research is community-driven by the Pavva Iñupiaq Dancers of Fairbanks, families with Iñupiaq children in their household, and other Iñupiat worldwide. My doctoral research addresses how we view each Iñupiat Ilitqusiat (Iñupiaq Values), how our Iñupiat Ilitqusiat have been passed down, and how we pass down our Iñupiaq cultural heritage to our future cultural-bearers. Participants talk about our Iñupiat Ilitqusiat to acknowledge that we are Iñupiat wherever we live. I assert that in order to conduct culturally appropriate research with Iñupiaq people, it is imperative to observe cultural protocols and values, to equally include Indigenous narrative history and Western literature in the review process, and to observe Iñupiaq methods and methodology when gathering data. I examined and applied the ways my ancestors have gathered and presented data, formalizing for academia an Iñupiaq way of conducting research. I have conducted 17 group interviews corresponding to the 17 Iñupiat Ilitqusiat. In my findings, I acknowledge that our Iñupiaq values help define our heritage. They are embedded in our lives and in our stories. They are in our spirit, passed down to us through our ancestors. Each Iñupiat Ilitqusiat converges with each other when we examine how each cultural value applies to our lives. We need to continue talking about our cultural values in every village to ensure our descendants live their cultural heritage.
    • Ion dynamics in auroral potential structures and formation of ion conic distribution

      Yang, Wei-hong (1981-12)
      This thesis is concerned with the problem of how the positive ions are energized by the two-dimensional potential structures along auroral field lines; these auroral potential structures are known to be responsible for accelerating electrons into the ionosphere to produce discrete auroras. A systematic numerical study of the test ion dynamics in auroral potential structures, either V-shaped or S-shaped, has been carried out. Transverse ion accelerations occur if the width of the auroral potential structure (Lx ≤ ρi). This result shows that the conic distribution of upstreaming ions observed on auroral field lines can be generated by the same potential structures which produce the thin auroral arcs (Lx ≤ ρi). This transverse acceleration mechanism operates more effectively on heavier ions, resulting in O+ ions more energetic than H+ ions as indicated by observations.
    • Ionospheric correction of interferometric SAR data with application to the cryospheric sciences

      Liao, Heming; Meyer, Franz J.; Freymueller, Jeffrey T.; Tape, Carl; Watkins, Brenton (2018-08)
      The ionosphere has been identified as an important error source for spaceborne Synthetic Aperture Radar (SAR) data and SAR Interferometry (InSAR), especially for low frequency SAR missions, operating, e.g., at L-band or P-band. Developing effective algorithms for the correction of ionospheric effects is still a developing and active topic of remote sensing research. The focus of this thesis is to develop robust and accurate techniques for ionospheric correction of SAR and InSAR data and evaluate the benefit of these techniques for cryospheric research fields such as glacier ice velocity tracking and permafrost deformation monitoring. As both topics are mostly concerned with high latitude areas where the ionosphere is often active and characterized by turbulence, ionospheric correction is particularly relevant for these applications. After an introduction to the research topic in Chapter 1, Chapter 2 will discuss open issues in ionospheric correction including processing issues related to baseline-induced spectrum shifts. The effect of large baseline on split spectrum InSAR technique has been thoroughly evaluated and effective solutions for compensating this effect are proposed. In addition, a multiple sub-band approach is proposed for increasing the algorithm robustness and accuracy. Selected case studies are shown with the purpose of demonstrating the performance of the developed algorithm. In Chapter 3, the developed ionospheric correction technology is applied to optimize InSAR-based ice velocity measurements over the big ice sheets in Greenland and the Antarctic. Selected case studies are presented to demonstrate and validate the effectiveness of the proposed correction algorithms for ice velocity applications. It is shown that the ionosphere signal can be larger than the actual glacier motion signal in the interior of Greenland and Antarctic, emphasizing the necessity for operational ionospheric correction. The case studies also show that the accuracy of ice velocity estimates was significantly improved once the developed ionospheric correction techniques were integrated into the data processing flow. We demonstrate that the proposed ionosphere correction outperforms the traditionally-used approaches such as the averaging of multi-temporal data and the removal of obviously affected data sets. For instance, it is shown that about one hundred multi-temporal ice velocity estimates would need to be averaged to achieve the estimation accuracy of a single ionosphere-corrected measurement. In Chapter 4, we evaluate the necessity and benefit of ionospheric-correction for L-band InSAR-based permafrost research. In permafrost zones, InSAR-based surface deformation measurements are used together with geophysical models to estimate permafrost parameters such as active layer thickness, soil ice content, and permafrost degradation. Accurate error correction is needed to avoid biases in the estimated parameters and their co-variance properties. Through statistical analyses of a large number of L-band InSAR data sets over Alaska, we show that ionospheric signal distortions, at different levels of magnitude, are present in almost every InSAR dataset acquired in permafrost-affected regions. We analyze the ionospheric correction performance that can be achieved in permafrost zones by statistically analyzing correction results for large number of InSAR data. We also investigate the impact of ionospheric correction on the performance of the two main InSAR approaches that are used in permafrost zones: (1) we show the importance of ionospheric correction for permafrost deformation estimation from discrete InSAR observations; (2) we demonstrate that ionospheric correction leads to significant improvements in the accuracy of time-series InSAR-based permafrost products. Chapter 5 summarizes the work conducted in this dissertation and proposes next steps in this field of research.
    • Isolation and characterization of Photobacterium phosphoreum from migrating Alaskan salmon

      Budsberg, Kevin Jon (2004-05)
      We isolated luminous bacteria from drying chum salmon, Oncorhynchus keta, reported by Alaska native fishermen to be 'glowing in the dark.' The salmon were harvested for subsistence use from the Yukon River, Alaska. We identified our luminous bacterial isolates as Photobacterium phosphoreum based on nutritional versatility, and 16S rDNA and luxA gene sequences. P. phosphoreum has previously only been isolated from the marine environment. We tested whether our strains, isolated from fish harvested in freshwater, represent cold-adapted, freshwater-tolerant strains of P. phosphoreum. We also analyzed lux operon composition and organization, and examined the 5' promoter region of the lux operon for shared genes and regulatory elements from strains of P. phosphoreum from Alaska, the Black Sea, Oregon, and from near the Canary Islands. Our results indicate our P. phosphoreum strains have a lower optimal growth temperature than other strains but rapidly lose viability after inoculation into river water. Analyses of the P. phosphoreum lux operon reveal a striking pattern of conservation of composition and organization, and suggest there is conservation in the location of the transcriptional start among geographically separated strains of the same species.
    • Isostasy and origin of the Alpha-Mendeleev Ridge, Arctic Ocean

      Williams, Christina C. (2006-12)
      The Alpha-Mendeleev Ridge is an aseismic ridge bisecting the Amerasian Basin, Arctic Ocean. There is no widely accepted theory of formation. Gravity and bathymetry data from the poorly understood ridge are used to constrain the isostatic compensation of the feature in the frequency domain. Spectral analysis of the cross correlation between gravity and bathymetry along nine data transects collected from submarines and ice breakers over the ridge yield an average crustal thickness estimate of 30 km and density estimate of 2.75 g-cm⁻³. It also suggests compensation by local isostasy, as a near-ridge oceanic plateau or an extended fragment of continental shelf. These parameters are used to constrain gravity models of crustal structure. The analysis suggests no difference between the compensation of the Alpha and Mendeleev Ridges. These results are discussed in the broader tectonic context of the Amerasian Basin, in light of the current controversy over the formation of the ridge.
    • 'It's a magnifying glass': the communication of power in a remote field station

      McDermott, Victoria; May, Amy; Taylor, Karen; Richey, Jean (2019-05)
      Remote field stations play a critical role in advancing our understanding of the world and how humans cause environmental change. Remote field stations are sentinels of Earth's climate, environment, and biodiversity that provide scientists with the infrastructure to collect data in inaccessible areas of the globe. These research stations are considered isolated, confined and extreme (ICE) environments which provide people with unique opportunities and intensely stressful potentially life-threatening situations to overcome. Traditionally, remote field stations have been considered harassment hell for men and women, alike. There is little research on the impact of remote field stations on communication and factors that influence power communication within remote field stations. In the present study, the researcher traveled 10 hours north of Fairbanks, Alaska to Toolik Field Station in the Brooks Range of the Alaskan Mountains. The researcher interviewed 20 participants, 15 males and 5 females, willing to talk about their experiences in remote field stations and especially their experiences at Toolik. Using theories of power construction, standpoint theory, and contrapower harassment this study sought to understand how remote field stations impact communication dynamics and the influence of gender on communication within a remote field station. Findings in the present study suggest that gender is a crucial factor that impacts power dynamics in remote field station. Through the data collected in this study, three areas of opportunity were identified for overall camp improvement, including group cohesion, reintegration coping strategies and overcoming gender barriers.
    • It's all in the past

      Phillips, Jill; Marlow, Patrick; Martelle, Wendy; John, Theresa; Siekmann, Sabine (2015-12)
      This project is a response to what I noticed to be a challenge for both my ELL students and myself in multiple school settings--teaching and learning specific English grammar skills. Prior to beginning this program, over the past ten years I had the privilege of working in a number of schools--both internationally and stateside--teaching various ages/levels of ELL learners. It was, however, my time in rural Alaska that prompted me to seek out additional schooling for help in overcoming the challenges of teaching grammar skills.