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dc.contributor.authorHendricks, Amy Sakura
dc.date.accessioned2025-02-04T02:02:18Z
dc.date.available2025-02-04T02:02:18Z
dc.date.issued2024-12
dc.identifier.urihttp://hdl.handle.net/11122/15680
dc.descriptionThesis (Ph.D.) University of Alaska Fairbanks, 2024en_US
dc.description.abstractClimate change impacts in the Arctic and Alaska vary widely, providing opportunities to study regional complexities. This thesis, guided by insights from Yup'ik Elders from the Yukon-Kuskokwim Delta, explores the significant impacts of climate change and examines four key topics: climate-vegetation connections, shifting hydroclimate regimes, the role of large-scale climate patterns in tundra wildfires, and fostering community relationships. The first paper investigates tundra vegetation productivity trends which have decreased in the Yukon-Kuskokwim Delta despite increasing temperatures during the growing season, contrasting with other Arctic tundra regions. Using available long-term climate datasets, a coherent multi-decadal pattern involving spring sea-ice concentration in the East Bering Sea, growing season temperatures, and tundra productivity is revealed. This finding highlights that low-frequency variability can obscure long-term climate relationships. The second paper examines moisture dynamics in the Yukon-Kuskokwim Delta, revealing significant variability in moisture-related climatic factors. A comprehensive analysis of atmospheric data indicates a shifting hydroclimate regime in the Yukon-Kuskokwim Delta, with decreasing large-scale precipitation, increasing convective precipitation and evaporation, and fewer synoptic storms. The study underscores that warmer conditions and changing precipitation patterns can alter vegetation and overall landscape vulnerability to climatic changes. The third paper delves into early-season climate drivers of tundra wildland fires in the Yukon-Kuskokwim Delta. It establishes a baseline climatology for early fire seasons, connecting warmer temperatures and earlier snow-off dates with increased fire activity. It identifies May and June temperatures exceeding 15°C and snow-off dates before May 8 as key indicators for large fire seasons, emphasizing that lightning stroke counts crucially influence the area burned. Contrary to previous research, this study finds that May and June precipitation and spring sea-ice concentration are not primary drivers of tundra fires in the region. The findings suggest a future increase in fire frequency due to projected climate conditions. The fourth topic synthesizes perspectives on regional climate research, relationshipbuilding, and community engagement in Alaska. It discusses the importance of focusing on smaller regions for climate studies to build relevant, credible, and legitimate scientific endeavors with local communities. It emphasizes the value of cultural humility, self-reflection, and active community participation for effective climate science communication and relationship-building. This piece also addresses the systemic challenges of community work within academia and highlights the significance of volunteerism to enhance community-based climate research. Collectively, these papers underscore the intricate relationships between climate variables, tundra landscapes, and wildfire dynamics in Alaskan tundra regions, and the need for region-specific research approaches. The research concludes that community collaboration and culturally sensitive approaches are essential for impactful climate science.en_US
dc.description.sponsorshipNASA ABoVE initiative under grant numbers 80NSSC22K1256 and 80NSSC22K1257, NASA grant NNH16CP09C; Alaska EPSCoR NSF award OIA-1757448; Alaska Sea Grant under NA18OAR4170078; the Alaska Center for Climate Assessment and Policy under grant numbers NA16OAR4310162 and NA21OAR4310314; The National Science Foundation's Division of Arctic Sciences grant number PLR-1928794; the USDA National Institute of Food and Agriculture Hatch project 1018914; the State of Alaskaen_US
dc.description.tableofcontentsChapter 1: General introduction -- 1.1 Motivation -- 1.2 The Yukon-Kuskokwim Delta study region -- 1.2.1 Climate of the Yukon-Kuskokwim Delta -- 1.2.2 Landscape of the Yukon-Kuskokwim Delta -- 1.2.3 People of the Yukon-Kuskokwim Delta -- 1.3 Datasets for Arctic research -- 1.3.1 Satellite observations -- 1.3.1.1 Advanced very-high resolution radiometer -- 1.3.1.2 Special sensor microwave imager -- 1.3.2 Atmospheric reanalysis -- 1.3.3 Climate projections -- 1.3.4 Local observations and knowledge -- 1.4 Project overviews -- 1.4.1 Climate drivers of tundra productivity in the Yukon-Kuskokwim Delta -- 1.4.2 Shifting hydroclimate in the Yukon-Kuskokwim Delta -- 1.4.3 Climate drivers of tundra fire in the Yukon-Kuskokwim Delta -- 1.5 Summary -- 1.6 References. Chapter 2: Decadal variability in spring sea-ice concentration linked to summer temperature and NDVI on the Yukon-Kuskokwim Delta -- 2.1 Abstract -- 2.2 Introduction -- 2.3 Methods -- 2.3.1 Yukon-Kuskokwim Delta study region -- 2.3.2 Datasets -- 2.3.2.2 Sea-ice concentration and open water -- 2.3.2.3 Summer warmth index and temperature -- 2.3.3 Analysis methods -- 2.4 Results -- 2.5 Discussion -- 2.7 References. Chapter 3: Increasing importance of local hydroclimatology during the growing season on the Yukon-Kuskokwim Delta for 1982-2022 -- 3.1 Abstract -- 3.2 Introduction -- 3.3 Methods -- 3.3.1 Study region -- 3.3.2 Data -- 3.3.2.1 ERA5 reanalysis -- 3.3.2.2 AVHRR satellite sensor -- 3.3.2.3 Weather station observations -- 3.3.2.4 Conversations with residents in Southwest Alaska -- 3.3.2.5 CMIP6 climate projections -- 3.3.2 Analysis -- 3.4 Results -- 3.4.1 Temperature -- 3.4.2 Precipitation -- 3.4.3 Regional storms -- 3.4.4 Vertically integrated moisture convergence and moisture flux -- 3.4.5 Evaporation and surface winds -- 3.4.6 Precipitation minus evaporation -- 3.4.7 NDVI relationship with seasonal temperature and precipitation -- 3.4.8 Projected changes -- 3.5 Discussion -- 3.5.1 Enhancement of local hydroclimatology -- 3.5.2 Stronger coastal trends linked to earlier sea-ice retreat -- 3.5.3 Regional climate links to tundra productivity -- 3.6 Conclusions -- 3.7 References. Chapter 4: Early season climate drivers of tundra wildland fires of the Yukon-Kuskokwim Delta -- 4.1 Abstract -- 4.2 Introduction -- 4.3 Methods -- 4.3.1 Study region -- 4.3.2 Data -- 4.3.2.1 ERA5 reanalysis -- 4.3.2.2 Fire data -- 4.3.2.3 Alaska Lightning Detection Network -- 4.3.2.4 Satellite-derived data -- 4.3.3 Analysis -- 4.4 Results -- 4.4.1 Acres burned in the Yukon-Kuskokwim Delta -- 4.4.2 May through June climatology -- 4.4.2.1 Temperature -- 4.4.2.2 Precipitation -- 4.4.2.3 Evaporation -- 4.4.2.4 Snow-off -- 4.4.2.5 Sea level pressure -- 4.4.2.6 Spring sea-ice concentration -- 4.4.3 Analysis of recent fire years -- 4.4.3.1 Climate relationships for large fire years in the YKD -- 4.4.3.2 Canadian fire weather indices: climatology and case study of large fire seasons -- 4.4.3.3 Temperature -- 4.4.3.4 Precipitation -- 4.4.3.5 Evaporation -- 4.4.3.6 Sea level pressure -- 4.4.4 Summary of climate analysis and stochasticity of lightning -- 4.5 Discussion -- 4.6 Conclusions -- 4.7 References. Chapter 5: Reflections on regional climate research, relationship-building, and community engagement in Alaska -- 5.1 Abstract -- 5.2 Introduction -- 5.3 Project 1: Relationship-building with Calista Education and Culture, Inc. elders with reflections on fostering community and doing regional climate research -- 5.3.1 Background -- 5.3.2 Reflection on comfort and discomfort -- 5.3.3 Food for cultural humility -- 5.3.4 Shifting the language of science -- 5.3.5 On the focus and outcomes of regional climate research --5.3.6 Evolving the relationship -- 5.3.7 A guide for self-reflection for relationship-building -- 5.3.8 Shortfalls of working with CEC as a climate scientist -- 5.4 Project 2: Reflecting on challenges of community work in academia and evaluating the sea ice for walrus outlook -- 5.5 Project 3: Practicing cultural sensitivity through volunteering at the Literacy Council of Alaska -- 5.6 Conclusions -- 5.7 References. Chapter 6: General conclusions -- 6.1 Summary -- 6.2 Conclusions.en_US
dc.language.isoen_USen_US
dc.subjectClimatic changesen_US
dc.subjectYukon-Kuskokwim Deltaen_US
dc.subjectPrecipitation anomaliesen_US
dc.subjectPrecipitation variabilityen_US
dc.subjectTundra plantsen_US
dc.subjectWildfiresen_US
dc.subjectCommunication in climatologyen_US
dc.subjectIntercultural communicationen_US
dc.subjectEthnoscienceen_US
dc.subject.otherDoctor of Philosophy in Atmospheric Sciencesen_US
dc.titleClimate variability, trends, and impacts on the Yukon-Kuskokwim Delta with insights into relationship-building to enhance climate scienceen_US
dc.typeDissertationen_US
dc.type.degreephden_US
dc.identifier.departmentDepartment of Atmospheric Sciencesen_US
dc.contributor.chairBhatt, Uma
dc.contributor.committeePolyakov, Igor
dc.contributor.committeeFrost, Gerald
dc.contributor.committeeKettle, Nathan
dc.contributor.committeeTrainor, Sarah
refterms.dateFOA2025-02-04T02:02:19Z


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