• Using rate transient analysis and bayesian algorithms for reservoir characterization in hydraulically fractured horizontal gas wells during linear flow

      Yuhun, Pirayu; Awoleke, Obadare; Ahmadi, Mohabbat; Hanks, Catherine (2019-05)
      Multi-stage hydraulically fractured horizontal wells (MFHWs) are currently a popular method of developing shale gas and oil reservoirs. The performance of MFHWs can be analyzed by an approach called Rate transient analysis (RTA). However, the predicted outcomes are often inaccurate and provide non-unique results. Therefore, the main objective of this thesis is to couple Bayesian Algorithms with a current production analysis method, that is, rate transient analysis, to generate probabilistic credible interval ranges for key reservoir and completion variables. To show the legitimacy of the RTA-Bayesian method, synthetic production data from a multistage hydraulically fractured horizontal completion in a reservoir modeled after Marcellus shale reservoir was generated using a reservoir (CMG) model. The synthetic production data was analyzed using a combination of rate transient analysis with Bayesian techniques. Firstly, the traditional log-log plot was produced to identify the linear flow production regime, which is usually the dominant regime in shale reservoirs. Using the linear flow production data and traditional rate transient analysis equations, Bayesian inversion was carried out using likelihood-based and likelihood-free Bayesian methods. The rjags and EasyABC packages in statistical software R were used for the likelihood-based and likelihood-free inversion respectively. Model priors were based (1) on information available about the Marcellus shale from technical literature and (2) hydraulic fracture design parameters. Posterior distributions and prediction intervals were developed for the fracture length, matrix permeability, and skin factor. These predicted credible intervals were then compared with actual synthetic reservoir and hydraulic fracture data. The methodology was also repeated for an actual case in the Barnett shale for a validation. The most substantial finding was that for all the investigated cases, including complicated scenarios (such as finite fracture conductivity, fracturing fluid flowback, heterogeneity of fracture length, and pressure-dependent reservoir), the combined RTA-Bayesian model provided a reasonable prediction interval that encompassed the actual/observed values of the reservoir/hydraulic fracture variables. The R-squared value of predicted values over true values was more than 0.5 in all cases. For the base case in this study, the choice of the prior distribution did not affect the posterior distribution/prediction interval in a significant manner in as much as the prior distribution was partially informative. However, the use of noninformative priors resulted in a loss of precision. Also, a comparison of the Approximate Bayesian Computation (ABC) and the traditional Bayesian algorithms showed that the ABC algorithm reduced computational time with minimal loss of accuracy by at least an order of magnitude by bypassing the complicated step of having to compute the likelihood function. In addition, the production time, number of iterations and tolerance of fitting had a minimal impact on the posterior distribution after an optimum point--which was at least one-year production, 10,000 iterations and 0.001 respectively. In summary, the RTA-Bayesian production analysis method implemented in relatively easy computational platforms, like R and Excel, provided good characterization of all key variables such as matrix permeability, fracture length and skin when compared to results obtained from analytical methods. This probabilistic characterization has the potential to enable better understanding of well performance, improved identification of optimization opportunities and ultimately improved ultimate recovery from shale gas resources.
    • Using remote camera techniques to study black-legged kittiwake (Rissa tridactyla) productivity in Resurrection Bay in the northern Gulf of Alaska

      Tanedo, Sarah; Hollmén, Tuula; Winsor, Peter; Beaudreau, Anne (2016-05)
      Monitoring sentinel species in environments undergoing ecosystem change is essential to understanding how the organisms living in these habitats will respond. Seabirds are considered sensitive to shifts in their local environment and have been used as sentinels but many species occupy remote locations, posing logistical challenges for long-term studies. Remote camera techniques offer a possible alternative to other methods of monitoring seabirds during their breeding seasons. To investigate the use of remote camera techniques to study cliff-nesting seabirds and identify factors influencing their productivity, a remote video-camera system was used to collect 6 years (2010-2015) of reproductive data from a sub-colony of Black-legged Kittiwakes (Rissa tridactyla) in Resurrection Bay near Seward, Alaska. The first objective was to refine remote camera techniques by investigating the influence of 1) observation frequency and 2) observation type (video or still image) on estimates of productivity. Observation frequency from daily up to one week intervals did not have a significant effect on estimates of productivity. Observations made twice annually were found to be significantly different from estimates of productivity calculated using daily observation frequency. Still image and video methods of observation did not significantly affect estimates of productivity. The second objective was to identify factors that influence reproductive success of kittiwakes at Cape Resurrection by 1) determining the effect of nest characteristics on individual nest success, 2) identifying the effect of behavior of breeding adults during the incubation period on hatch success, 3) determining the effect of seasonal weather patterns on loss events, and 4) investigating the relationship between annual productivity and sea surface temperature (SST) over a 5 year period. Model analysis of nest characteristics on individual nest success indicated that mainland/island location and nest height above water influenced individual nest success. Behavior of breeding adults did not influence hatch success. Nest loss was influenced by average wind speeds. Annual SST was not correlated with annual productivity over a 5 year time period. Based on the results of this study, I recommend remote camera technologies for the purpose of studying cliff-nesting seabirds in remote locations and found them a useful tool for identifying and tracking factors that influence the breeding success of these populations over a multiyear time period.
    • Using remote sensing to examine changes of closed-basin surface water area in Interior Alaska from 1950-2002

      Riordan, Brian Alan (2005-05)
      Over the past fifty years Alaska has experienced an increase in mean annual temperature. This warming may be causing significant changes in hydrology and permafrost dynamics. In recent decades, Native Americans and land managers have reported losses of water bodies and surface water area in interior Alaska. We conducted a study to determine the degree to which these informal observations were representative of a regional trend in surface water area loss. This study examines closed-basin water bodies in nine regions across Alaska: 1) Copper River Basin, 2) Talkeetna, 3) Tetlin National Wildlife Refuge, 4) Denali National Park, 5) Innoko Flats National Wildlife Refuge, 6) Minto Flats State Game Refuge, 7) Stevens Village, 8) Yukon Flats National Wildlife Refuge, and 9) Prudhoe Bay/Arctic Coastal Plain. The study included approximately 850,000 hectares and over 40,000 water bodies. To conduct such a large-scale study, GIS and Remote Sensing techniques were applied. Water body change detection was conducted over a fifty-year time period. A minimum of three time periods were used for each area. Imagery included black and white aerial photography (1950 -1957), color infrared aerial photography (1978 -1982), Landsat TM (1986 - 1995), and Landsat ETM+ (1999 - 2002). Based on these images, water body polygons were digitized for each time period. Area was calculated for each polygon and compared to corresponding ponds from images at later times. Of the nine regions, six showed substantial reductions in surface water area: Copper River Basin, Minto Flats, Innoko Flats, Yukon Flats, Stevens Village, and Denali National Park. The Innoko Flats and Copper River Basin regions showed the most loss at 31% and 28% respectively. There are several mechanisms possible for reductions of surface water in a warming climate including increased formation of taliks, increased soil water holding capacity, increased evapotranspiration, and terrestrialization.
    • Using remote sensing, occupancy estimation, and fine-scale habitat characterization to evaluate fall chum salmon (Oncorhynchus keta) spawning habitat usage in Arctic Alaska

      Clawson, Chelsea M.; Falke, Jeffrey; Westley, Peter; Prakash, Anupma; Martin, Aaron (2017-08)
      Groundwater upwellings provide stable temperatures for overwinter salmon embryo development and this process may be particularly important in cold, braided, gravel-bed Arctic rivers where rivers may freeze solid in the absence of upwellings. Aerial counts and remote sensing were used during 2013-2015 to estimate fall chum salmon (Oncorhynchus keta) spawner abundance states (e.g., low or high), classify river segments by geomorphic channel type (primary, flood, and spring), and map thermal variability along a 25.4 km stretch of the Chandalar River in interior Alaska. Additionally, I used on-the-ground examination of fine scale variation in physical habitat characteristics at 11 representative sites to characterize habitat variability, placed temperature loggers to assess overwinter thermal conditions in redds, and used a developmental model to predict hatching and emergence timing given known spawning dates and incubation temperatures. I delineated 330 unique river segments (mean length = 536 m) and used a multi-season multistate occupancy model to estimate detectability, occupancy, and local colonization and extinction rates. Triplicate surveys performed in 2014 allowed me to estimate detectability and the influence of observer bias. I found that detectability did not vary by observer, channel type, or segment length, but was better for high abundance (0.717 ± 0.06 SE) relative to low abundance (0.367 ± 0.07 SE) aggregations. After correcting for imperfect detection, the proportion of segments occupied by spawning fall chum salmon was highest in 2014 (0.41 ± 0.04 SE), relative to 2013 (0.23 ± 0.04) and 2015 (0.23 ± 0.04). Transition probabilities indicated unoccupied segments were likely to remain so from year to year (2013→2014 = 0.67; 2014→2015 = 0.90), but low abundance spawning segments were dynamic and rarely remained in that state. One-third of high abundance sites remained so, indicating the presence of high quality spawning habitat. Mean segment temperatures ranged from -0.5 to 4.4°C, and occupancy varied positively with temperature. I predicted a 50% probability of occupancy in segments with temperatures of 3°C. With my on-the-ground work, I found that habitat characteristics varied among the three channel types, with most significant differences between main channel and off-channel habitats. Dissolved oxygen and pH decreased with increasing temperature, and conductivity increased with temperature. Predicted hatching and emergence timing ranged from 78 and 176 days (December 11th and March 18th) to 288 and 317 days (July 8th and August 6th), respectively, post-spawning, and were highly variable within sites and among channel types owing to high habitat thermal heterogeneity. Because the Chandalar River supports 30% of the fall chum salmon run in the Yukon River Basin, information such as provided by this study will be critical to allow resource managers to better understand the effects of future climate and anthropogenic change in the region.
    • Using self-organizing maps to detail synoptic connections between climate indices and Alaska weather

      Winnan, Reynir C.; Bhatt, Uma S.; Collins, Richard L.; Walsh, John E.; Wackerbauer, Renate A. (2015-12)
      Seasonal forecasts for Alaska strongly depend on the phases of Pacific Decadal Oscillation (PDO), El Niño-Southern Oscillation (ENSO), and warm water in the North Pacific called the North Pacific Mode or more popularly the "Pacific blob." The canonical descriptions of these climate indices are based on seasonal averages, and anomalies that are based on a long-term mean. The patterns highlight general geographical placement and display a sharp contrast between opposing phases, but this may be misleading since seasonal averages hide much of the synoptic variability. Self-organizing maps (SOMs) are a way of grouping daily sea level pressure (SLP) patterns, over many time realizations into a specified set of maps (e.g. 35 maps) that describe commonly occurring patterns. This study uses the SOMs in the context of climate indices to describe the range of synoptic patterns that are relevant for Alaska. This study found that the patterns common during a given phase of the PDO include subtle differences that would result in Alaska weather that is very different from what is expected from the canonical PDO description, thus providing some explanation for recent studies that find the PDO link to Alaska climate is weakening. SOMs analysis is consistent with recent studies suggesting that the pattern responsible for the 2014 Pacific warm blob is linked to tropical sea-surface temperature (SST) forcing. An analysis of the summer SLP SOMs in the context of Alaska wildland fires was also conducted. This analysis identified several commonly occurring patterns during summers with large areas burned. These patterns are characterized by low pressure in the Bering Sea, which would be consistent with increased storm activity and thus an ignition source for the fires. Identifying synoptic patterns that occur during a particular phase of a teleconnection index contributes towards understanding the mechanisms of how these indices influence the weather and climate of Alaska.
    • Using strontium isotopes to track Pacific salmon migrations in Alaska

      Brennan, Sean Reiss; Wooller, Matthew; Fernandez, Diego; Cerling, Thure; Zimmerman, Christian; McPhee, Megan; Weingartner, Thomas (2014-08)
      Pacific salmon (Oncorhynchus spp.) are an important cultural, ecological, and economic natural resource in Alaska. Not only do salmon maintain an important mechanism of nutrient transport between marine, aquatic, and terrestrial ecosystems, but they also provide a sustainable food and economic resource for human communities. A challenging issue in the management, conservation, and research of Pacific salmon is tracking their responses to perturbations across the multiple scales of population structure that characterize these species. Research has shown how the inherent biodiversity of Pacific salmon imparts resiliency to environmental change, and temporal stability to their overall productivity and the human systems dependent upon such productivity (e.g., fisheries). The vast biodiversity of salmon arises primarily via precise natal homing of adults to their rivers of origin, resulting in locally adapted populations. Thus, there have been considerable efforts to develop methods to effectively manage and monitor Pacific salmon biodiversity. One important example is using genetic differentiation among populations to discern the relative contributions of genetically distinct stocks in mixed stock fishery harvests. In the Bristol Bay region, sockeye salmon (O. nerka) harvests can be discerned at the watershed level (i.e., the nine major watersheds contributing to the fishery). However, tens to hundreds of locally adapted populations exist within each of these watersheds and methods to apportion fishery harvests to this finer scale population structure are lacking. This dissertation presents a new method in Alaska to discern fine-scale population structure (i.e., within watersheds) of Chinook salmon (O. tshawytscha) harvests using a naturally occurring geochemical tracer in rivers, strontium (Sr) isotopes (⁸⁷Sr/⁸⁶Sr). To this end, in Chapter 1, I characterize the statewide geographic variation on multiple spatial scales in ⁸⁷Sr/⁸⁶Sr ratios of Alaska's rivers and discuss the geochemical and geological controls of observed ⁸⁷Sr/⁸⁶Sr ratios. In Chapter 2, I approach the persistent problem of evaluating site-specific temporal variation, especially in remote Subarctic and Arctic regions, by employing the non-migratory behavioral ecology of slimy sculpin (Cottus cognatus). Finally, in Chapter 3, I demonstrate how the development of temporally and spatially robust ⁸⁷Sr/⁸⁶Sr baseline datasets within the Nushagak River was able to apportion a mixed stock fishery harvest of Chinook salmon conducted in Nushagak Bay back to natal sources at the sub-basin watershed level. Because of the conservative nature of the ⁸⁷Sr/⁸⁶Sr ratio during physical and biological processes, the development of this method is applicable not only to Chinook salmon, but also to other salmon species (e.g., sockeye and coho salmon, O. kisutch). Additionally, the development of baseline ⁸⁷Sr/⁸⁶Sr information (e.g., waters) and an overall research framework to employ this tracer in provenance studies, have statewide implications for the research and management of other migratory animals.
    • Using SuperDARN to predict polar irregularities that cause GPS scintillation

      Simon, Michelle R.; Bristow, William; Hawkins, Joe; Thorsen, Denise (2016-12)
      High levels of scintillation caused by strong magnetic storms can cause GPS devices to lose connection with the necessary satellites. Current research has shown a correlation between major magnetic storms and higher levels of the recorded Total Electron Content (TEC) seen in GPS receivers. The research presented in this thesis examines the idea that observations from the Super Dual Auroral Radar Network (SuperDARN) can be used to predict scintillation levels in GPS receivers at polar latitudes by using GPS scintillation values σφ and S4 that were collected from January, 2013 till November, 2015. These values were gathered from Poker Flat, Alaska, and McMurdo Station, Antarctica. Using various graphical methods the GPS data was compared with the recorded velocity, power and spectral width measurements from Kodiak, Alaska, and South Pole, Antarctica, SuperDARN sites. The SuperDARN values were ignored in the comparison if they did not fall within the specified GPS field of view, they were tagged with a ground scatter flag, or the data quality flag indicating they were erroneous. These bar and scatter graphs indicate that many of the irregularities identified by SuperDARN do not cause scintillation of a GPS signal. When the GPS scintillation variables are examined as a function of the SuperDARN signal parameters (power, velocity, and spectral width) only a small dependence is shown, demonstrating little correlation between the GPS scintillation variables and SuperDARN's variables. Based on these results SuperDARN cannot be used to predict higher levels of GPS scintillation in polar latitudes.
    • Using the generalized interpolation material point method for fluid-solid interactions induced by surface tension

      Chen, Liangbiao; 陈 良彪; Lee, Jonah; Lee, Jonah; Chen, Cheng-fu; Kim, Sun Woo; Misra, Debasmita (2013-12)
      This thesis is devoted to the development of new, Generalized Interpolation Material Point Method (GIMP)-based algorithms for handling surface tension and contact (wetting) in fluid-solid interaction (FSI) problems at small scales. In these problems, surface tension becomes so dominant that its influence on both fluids and solids must be considered. Since analytical solutions for most engineering problems are usually unavailable, numerical methods are needed to describe and predict complicated time-dependent states in the solid and fluid involved due to surface tension effects. Traditional computational methods for handling fluid-solid interactions may not be effective due to their weakness in solving large-deformation problems and the complicated coupling of two different types of computational frameworks: one for solid, and the other for fluid. On the contrary, GIMP, a mesh-free algorithm for solid mechanics problems, is numerically effective in handling problems involving large deformations and fracture. Here we extend the capability of GIMP to handle fluid dynamics problems with surface tension, and to develop a new contact algorithm to deal with the wetting boundary conditions that include the modeling of contact angle and slip near the triple points where the three phases -- fluid, solid, and vapor -- meet. The error of the new GIMP algorithm for FSI problems at small scales, as verified by various benchmark problems, generally falls within the 5% range. In this thesis, we have successfully extended the capability of GIMP for handling FSI problems under surface tension in a one-solver numerical framework, a unique and innovative approach.
    • Using the USDA wind erosion equation for comparative modeling of natural and anthropogenic sources of particulates measured at the Fort Greely PM₁₀ monitoring station, Alaska, a case study

      Becker, Steven R.; Perkins, Robert; Barnon, David; Whitaker, Keith; Aggarwal, Srijan (2015-05)
      In April of 2010, the Alaska Department of Environmental Conservation (ADEC) opened a compliance case against the U.S. Army Garrison Fort Greely, Alaska (FGA), for then repeated failure to comply with a permit condition requiring the collection of one year of Prevention of Significant Deterioration (PSD)-quality data on ambient levels of particulate matter less than 10 microns in effective aerodynamic diameter (PM₁₀). During the monitoring period of 2012-2013, background levels of PM₁₀ were more than 80% the Alaska Ambient Air Quality Standards (AAAQS) for a total of seven days in the winter of 2012-2013. On March 17, 2014, ADEC requested that FGA provide substantive documentation that PM₁₀ exceedances observed during the monitoring period were of natural provenance and not from anthropogenic sources. In response to this request, the author used Geographic Information System (GIS) technology to analyze basic meteorological data and outputs from the USDA Wind Erosion Equation (WEQ) to generate a simple back-trajectory model for determining the sources and relative contributions to PM₁₀ experienced at a given receptor. Using this model, the author was able to show that the vast majority of PM₁₀ at Fort Greely was natural rather than anthropogenic in nature. The ADEC Division of Air Quality determined that results of this study constituted substantive documentation that PM₁₀ exceedances observed during the monitoring period were of natural provenance and not from anthropogenic sources, and issued a compliance case closure letter on June 20, 2014. In addition to the direct results of the study, the project also serves to demonstrate a low-complexity model that can be used to assess the relative contribution of anthropogenic and natural sources of PM₁₀ at a given receptor. Additionally, it can be used in complex situations as a screening tool to focus data collection efforts on significant sources of PM₁₀ and facilitate the prioritization of PM₁₀ sources for more precise quantitative dispersion or receptor models when precise quantitative data are required.
    • Using work-based learning as a vehicle for student engagement and community investment

      Stickle, Stephanie; Gifford, Valerie; Dahl, Heather; Simpson, Joni (2017-05)
      Research indicates that rural communities with few labor market opportunities are at increased risk for social and economic unsustainability. As such, high-potential rural students often believe they must leave their homes for more populated areas with superior labor markets in order to obtain fulfilling employment, success, and life satisfaction. This out-migration trend places rural communities at risk for losing the youth that are most likely to contribute to their sustainability and growth. Rural education has been identified as a promising and central means to counter this risk. Effective work-based learning curriculums, which incorporate student engagement and talent development components, may facilitate school engagement, entrepreneurial interest, community involvement, intrinsic satisfaction, and extrinsic success among rural students, thus contributing to community investment.
    • Using WRF/Chem, in-situ observations, and Calipso data to simulate smoke plume signatures on high-latitude pixels

      Madden, James Michael; Mölders, Nicole; Sassen, Kenneth; Prakash, Anupma; Grell, Georg (2014-05)
      The transport of wildfire aerosols provides concerns to people at or near downwind propagation. Concerns include the health effects of inhalation by inhabitants of surrounding communities and fire crews, the environmental effects of the wet and dry deposition of acids and particles, and the effects on the atmosphere through the scattering and absorption of solar radiation. Therefore, as the population density increases in Arctic and sub-Arctic areas, improving wildfire detection increasingly becomes necessary. Efforts to improve wildfire detection and forecasting would be helped if additional focus was directed toward the distortion of pixel geometry that occurs near the boundaries of a geostationary satellite's field of view. At higher latitudes, resolution becomes coarse due to the curvature of the Earth, and pixels toward the boundaries of the field of view become difficult to analyze. To assess whether it is possible to detect smoke plumes in pixels at the edge of a geostationary satellite's field of view, several analyses were performed. First, a realistic, fourdimensional dataset was created from Weather Research and Forecasting model coupled with Chemistry (WRF/Chem) output. WRF/Chem output was statistically compared to ground observations through the use of skill scores. Output was also qualitatively compared to vertical backscatter and depolarization products from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. After the quantitative and qualitative examinations deemed the model output to be realistic, synthetic pixels were constructed, appropriately sized, and used with the realistic dataset to examine the characteristic signatures of a wildfire plume. After establishing a threshold value, the synthetic pixels could distinguish between clean and smoke-polluted areas. Thus, specialized retrieval algorithms could be developed for smoke detection in strongly distorted pixels at the edge of a geostationary satellite's field of view.
    • Utilizing animal assisted interventions in elementary schools

      France, Catherine E.; Cook, Christine; Morotti, Allan; Brashear, Dawn (2014)
      Animal Assisted Interventions in the elementary school counseling setting involves the school counselor choosing to bring in an animal, commonly a dog, to assist in counseling interventions with a student. The counselor uses the dog as a tool to build a secure and trusting rapport with the student. The counselor is the facilitator of the session; the dog is used in a variety of ways to increase and aide in the benefits of the counseling session. This project illustrates the positive impact of the human-animal bond, the steps necessary to bring animal assisted interventions into a school, and the theoretical base that supports animal assisted interventions. This information is also presented as a website to be easily accessible for counselors, parents, and educators.
    • Utilizing funds of knowledge to engage students in meaningful writing

      Webster, Bradley; Thorne, Steve; Shields, John; Siekmann, Sabine (2015-12)
    • Utilizing Multi-Source Abundance Estimation And Climate Variability To Forecast Pacific Salmon Populations

      Shotwell, Stacey Anne Kaleinauialoha; Adkison, Milo D. (2004)
      Data limitation is a common property of many fisheries. Some Pacific salmon populations are a typical example of this situation because the monitoring of numerous tributaries within an area becomes logistically intractable. Fishery management often responds to this scenario with qualitative stock assessments in the form of harvest projections In some cases, fishery data, although limited, exists in a variety of sources and may be integrated to develop quantitative population estimates. The first objective of this investigation is to generate a modeling process that combines multiple data sources to estimate abundance and escapement estimates for data-limited salmon populations. Second, we consider the reliability of these estimates by testing for robustness to various simulated levels of measurement error in the data. Finally, we perform rigorous development and selection on an age structured spawner-recruit model that incorporates abundance and escapement estimates and identifies potential environment-recruit relationships. We demonstrate our technique with a case study on summer chum salmon from the Kuskokwim and Yukon Rivers, Alaska. Recent declines of summer chum returns to this salmon-dependent region have created hardships for the local area residents. We developed a maximum likelihood statistical framework that synchronously combined all available data sources from this management region to estimate abundance and escapement. Successful estimation was dependent on an independent estimate of abundance for a least a few years. We provide error estimates of the modeling process through bootstrap methods. Simulations showed that measurement error had negligible effect on abundance estimates, whereas performance for escapement estimation was tied to the sequence of abundance years. High explanatory power was attained by including environmental variables in the spawner-recruit relationship developed from these population estimates. We used a three-stage modeling process to maintain biological realism in the predictor variables. Recent changes in variables chosen for the best model were consistent with poor environmental conditions and estimates of forecasting error were much lower than models using no environmental information. Based on our findings, we recommend that managers consider the utility of multiple source estimation and environmental variability with our modeling approach for future regulatory decisions of Pacific salmon fisheries in data-limited regions.
    • Utilizing pasture resources for sub-Arctic agriculture: sustainable livestock production in Alaska

      Starr, Laura Marie; Rowell, Janice; Greenberg, Joshua; Seefeldt, Steven; Zhang, Mingchu (2017-05)
      It is estimated that the globe must produce 100% more food in the next 50 years to meet growing demand while addressing the compounding challenge of climate change. One potential solution to this challenge is to produce more on existing agricultural lands and put more land into production. The extremely cold and dry climate that characterizes much of Alaska has all but removed the state from the state and national discussions of agricultural production and development. Yet despite this apparent incompatibility with traditional agricultural models, some of the largest wild herds of grazing ungulates are indigenous to Alaska - and thriving. This is both a testament to the resilience of grazing systems in general as well as a statement to the suitability of grazing systems specifically for Alaska. To shift the paradigm towards ecological and economic sustainability, we need to develop sustainable agricultural strategies that are specific to this unique ecosystem. A two-fold approach was used in this body of research: Is there an indigenous livestock species that could be economically feasible enterprise option? Is there a grazing management regime for subarctic Alaska that would improve ecosystem services and optimize pasture resources? I conducted an economic feasibility study of farming muskoxen (Ovibos moschatus), a uniquely adapted Arctic ungulate, to address the first question. An enterprise budget was used to estimate the fixed and variable costs and to model different revenue scenarios using six different combinations of qiviut, sold as raw fiber or value added yarn, and livestock sales to estimate the total economic potential of farming muskoxen at two scales, 36 and 72 muskoxen. Farming muskoxen was economically sustainable under several revenue scenarios. The most profitable scenario for either herd size was selling all the qiviut as value added yarn coupled with livestock sales. The enterprise was profitable at either scale assuming all the yarn sold at full retail price. If no livestock were sold, selling the total qiviut harvest as yarn was the only profitable option. When selling raw fiber alone, the break-even point was at a herd size of 124 muskoxen. Economies of scale accounted for a decrease in costs of approximately 21% overall, 30% in labor, and 23% in herd health, as the herd doubled in size. To address the need for grazing management strategies that are both environmentally and economically sustainable in Alaska, I conducted a study to evaluate the potential of intensively managed rotational grazing (IMRG) regimes on sub-arctic pasture. This regime is designed to mimic the short but intense grazing of wild, migratory ungulates that could enhance ecosystem function while optimizing pasture usage and forage growth. I conducted simulated grazing, applied using IMRG methodology, to evaluate above and below ground response to an IMRG regime and to gain insight on the role of grazing disturbance mechanisms on sub-arctic soil and plant health. A full factorial experiment of muskox dung/urine deposition (M), simulated trampling (T), and herbivory (H) (forage clipping), mimicking IMRG timing and intensity, was conducted at the Large Animal Research Station (LARS), UAF. I used a randomized block design with 96-1 m² plots in two established pastures with different soil types, over the 2014 and 2015 grazing seasons. I documented a treatment effect on soil parameters, forage growth, and percentage of bare soil (p<0.05). Soil nitrogen cycling and the Haney Soil Health Index both increased in plots that received a combination M and T or MT and H. The forage yield was consistently increased by MH, MTH, and H treatments. Although the MT and T treatments had a negative impact on forage yield, they had the largest reduction in the amount of bare ground. The data from this simulated study suggest that theories that underpin the IMRG method are potentially useful to producers, in the unique Alaskan subarctic environment.
    • Validating a GPS collar-based method to estimate parturition events and calving locations for two barren-ground caribou herds

      Hepler, Joelle D.; Griffith, Brad; Falke, Jeff; Roach, Jen (2019-12)
      In remote landscapes, it is difficult and expensive to document animal behaviors such as location and timing of parturition. When aerial surveys cannot be conducted as a result of weather, personnel or fiscal constraints, analyses of GPS collar movement data may provide an alternate way to estimate parturition rates and calving ground locations. I validated two methods (population-based method and individual-based method), developed to detect calving events of sedentary woodland caribou, on multiple years of data for two different migratory barren-ground caribou herds in Alaska, the Porcupine and Fortymile herds. I compared model estimates of population parturition rates, individual calving events, calving locations and calving dates to estimates from aerial survey data for both herds. For the Porcupine herd we also compared model estimates of annual calving ground sizes and locations of concentrated calving area centroids to those found with aerial survey. More years of data would be required for additional statistical power but for both the Porcupine and Fortymile herds, we found no significant difference between the population-based and individual-based method in: 1) individual classification rate accuracy (0.85 vs. 0.88, respectively; t = -7, P = 0.09, df = 1 and 0.85 vs. 0.83, respectively; t = 0.46, P = 0.69, df = 2) or 2) annual average distance from aerial survey calving locations (8.9 vs. 7.8 km, respectively; t = 0.16, P = 0.90, and 5.2 vs. 3.7 km, respectively; t = 1.03, P = 0.20). Median date of calving was estimated within 0-3 days of that estimated by aerial survey for both methods. Population parturition rate estimates from aerial survey, the population-based and individual-based methods were not significantly different for the PCH or FCH (0.91, 0.88 and 0.95, respectively; F = 0.67, P = 0.60, df = 2, and 0.83, 0.83 and 0.96, respectively; F = 3.85, P = 0.12, df = 2). Ultimately, more years of data would be required to support or reject the lack of significant differences between methods that we observed.
    • Validation and application of infrared thermography for the assessment of body condition in pinnipeds

      Nienaber, Jeanette (2009-08)
      Infrared thermography (IRT) was used to collect baseline information on skin surface temperatures of two species of pinnipeds, the harbor seal (Phoca vitulina; n = 6) and the Steller sea lion (Eumetopias jubatus; n = 2). The IRT technique was validated against objects of known temperature and through post-collection software manipulation of environmental parameters that influence IRT output (emissivity, distance, relative humidity, ambient temperature and reflected temperature). From February 2007 to February 2008, biweekly measurements were taken of skin surface temperature (FLIR P25 infrared camera) with subsequent measurements of blubber depth (SonoSite Vet 180 portable imaging ultrasound system) on captive individuals at the Alaska SeaLife Center, Seward, Alaska. Once validated, skin surface temperatures in 10 defined regions (whole body, torso, head, eye, muzzle, shoulder, axillae, hip, fore and hind flipper) were used to determine seasonal variability as well as consistent hot or cold spots, and of those spots, which may act as thermal windows (defined areas of active heat loss and/or retention). Concurrent measurements of blubber depth were compared to skin surface temperatures at eight body sites to assess: a) the impact of insulation level on skin surface temperature on a site-specific scale, and b) the potential use of IRT as an alternative method for the non-invasive measurement of body condition. Both species varied seasonally in skin surface temperature from winter to reproductive and molt to winter, however, harbor seals had greater regional variation. Similar hot and cold spots were consistently recognized in both species with shoulder, axillae, fore and hind flipper identified as likely thermal windows. While some site-specific significant relationships were found between skin surface temperature and blubber thickness, insulation level alone explained a very small portion of the variance. Future studies to determine the factors influencing the variance on skin surface temperature (i.e., blood flow to the skin) warrant further exploration.
    • A validity study of the reasons for life scale with emerging adult college students

      Curns, Daniel B.; Gonzalez, Vivian M.; Swift, Joshua K.; Skewes, Monica C.; Ashdown, Brien K. (2014-12)
      This study examined the validity of the Reasons for Life Scale (RFLS) with emerging adult college students. The RFLS measures "reasons for life." It was developed for use with Alaska Native youth as a way to assess potential risk of suicide without directly questioning about suicidal ideation or history of suicide attempts. This study sought to adapt the RFLS for use with emerging adult (age 18-25) college students, and to examine its factor structure and convergent validity with this population. First, a focus group was conducted to assist in rewording two Alaska Native-specific items from the RFLS for non-Natives. Then, with the additional items from the focus group, the revised version of the RFLS (RFLS-R) and other suicide-related measures were administered to a sample of 116 emerging adult college students. Exploratory factor analysis indicated a unidimensional factor structure for the RFLS-R with this sample. The RFLS-R showed a significant and strong correlation with the Reasons for Living Inventory (RLI; r = .70), which, like the RFLS-R, measures reasons for living but makes direct reference to suicide. There also were significant moderate negative correlations with the Suicidal Behavior Questionnaire - Revised (SBQ-R; r = -.36) and the Adult Suicidal Ideation Questionnaire (ASIQ; r = -.29). There was a significant moderate correlation between the RFLSR and a measure of socially desirable responding, the Balanced Inventory of Desirable Responding (BIDR; r = .31), with similar correlations found between the BIDR and other suicide-related measures included in this study. The results suggest that socially desirable responding did not strongly affect participants' responding or explain the associations found among the measures. The high correlation with the RLI suggests that the RFLS-R measures a similar construct, providing evidence of convergent validity; however, the RLI was more highly correlated with measures of suicidality than the RFLS-R -- suggesting that while the RFLS was moderately associated with measures of suicidality, it is a weaker predictor of suicide risk than the RLI. Although the RFLS-R was not as highly correlated with measures of suicidality as the RLI, which directly mentions suicide, the RFLS-R is the only known suicide measure that completely avoids items and instructions that mention suicide, therefore it may be useful in contexts where directly discussing suicide is not acceptable or appropriate.
    • Valuing residential energy efficiency in two Alaska real estate markets: a hedonic approach

      Pride, Dominique J.; Little, Joseph; Baek, Jungho; Lovecraft, Amy Lauren; Mueller-Stoffels, Marc (2017-05)
      Alaska households have high home energy consumption and expenditures. Improving the energy efficiency of the housing stock can reduce home energy consumption, thereby reducing home energy expenditures and CO₂ emissions. Improving the energy efficiency of a home may also increase its transaction price if the energy efficiency improvements are capitalized into the value of the home. The relationship between energy efficiency and transaction prices in the Fairbanks and Anchorage, Alaska residential real estate markets is examined. Using a hedonic pricing framework and difference-in-differences analysis, the impact of the Alaska Home Energy Rebate program on the transaction prices of single-family homes in the Fairbanks and Anchorage housing markets from 2008 through 2015 is examined. The results indicate that compared to homes that did not complete the program, homes that completed the program sell for a statistically significant price premium between 15.1% and 15.5% in the Fairbanks market and between 5% and 11% in the Anchorage market. A hedonic pricing framework is used to relate energy efficiency ratings and transaction prices of homes in the Fairbanks and Anchorage residential real estate markets from 2008 through 2015. The results indicate that homes with above-average energy efficiency ratings sell for a statistically significant price premium between 6.9% and 17.5% in the Fairbanks market and between 1.8% and 6.0% in the Anchorage market.
    • Variability in foraging by humpback whales (Megaptera novaenangliae) on the Kodiak, AK, feeding ground

      Wright, Dana Louise; Witteveen, Briana; Quinn, Terrance II; Wynne, Kate; Horstmann-Dehn, Lara (2014-12)
      The North Pacific humpback whale (Megaptera novaeangliae) population has been growing rapidly following a moratorium on commercial whaling in 1986. Knowledge of humpback whale foraging on feeding grounds is becoming increasingly important as the growing population consumes more prey, including economically important commercial fishes. The goal of this thesis is to better understand how marine resources are shared among the growing humpback whale population and sympatric apex predators, including western Steller sea lions (SSLs; Eumetopias jubatus), on the Kodiak, AK, feeding ground. To address this, we explored spatial and temporal (inter-annual and within-feeding season) variability in summer foraging by humpback whales along the eastern side of the Kodiak Archipelago as described by stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios of humpback whale skin (n = 118; 2004-2013). We found evidence for the existence of two sub-aggregations of humpback whales ('North', 'South') on the feeding ground that fed at different trophic levels (TLs) throughout the study period. Bayesian stable isotopic mixing models were applied to describe the proportional contribution of prey species to the diet of humpback whales for the two regions. The 'North' region humpback whale sub-aggregation consumed a mixed diet of euphausiids and forage fishes, whereas the 'South' region sub-aggregation foraged predominantly on euphausiids. Results from these analyses were compared to diet composition of Kodiak SSLs of the recovering western SSL population estimated from fecal samples (n = 656; 2000-2005), to explore spatial differences in the degree of overlap in trophic niche between these predators. Western SSLs underwent a marked population decline starting in the late 1970's and have shown slow and variable signs of recovery. Regional variability in SSL and humpback whale diets resulted in a higher degree of overlap in trophic niche, although not biologically significant (Ojk < 0.60), for individuals in the 'North' region compared with the 'South'. However, humpback whale consumption appears to overlap considerably with multiple piscivorous fishes that are prominent prey for SSLs, and thus, consumption by humpback whales may indirectly impact the prey resources of SSLs. Therefore, this study highlights the complexity of the Kodiak ecosystem and suggests consumption by an increasing population of humpback whales has the potential to indirectly impact the recovery of SSLs on a regional scale depending on the biomass of prey species and diet composition of humpback whales in the region.