Date of Award
12-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Degree Statement
Doctor of Philosophy in Geophysics
Department
Department of Geosciences
Committee Chair
Zwieback, Simon
Committee Chair
Bolton, W. Robert
Committee Member
Leonard, Paul
Committee Member
Timm, Kristin
Table of Contents
Chapter 1: Introduction
Chapter 2: Evaluating augeis detection methods using landsat imagery: comparative assessment and recommendations
Chapter 3: Mapping spatial and temporal changes to aufeis distribution in northeastern Alaska
Chapter 4: Community engagement in practice: reflections from an Arctic research project
Chapter 5: General conclusions
Abstract
The Arctic is warming at a rate four times the global average, triggering rapid permafrost thaw with cascading impacts on the carbon cycle, ecosystems, atmospheric systems, and society. In response, the U.S. federal government has expanded investment in long-term Arctic science initia tives to enhance global climate models, support local adaptation, and inform policy. The purpose of these new research projects includes improving the accuracy of Earth system models, responding to climate adaptation needs, and informing global climate policy. This interdisciplinary dissertation presents three projects that advance environmental monitoring methods, assess regional change, and reflect on the role of science in local communities. The first two projects focus on ‘aufeis’, ice formations created by successive flooding and freezing events throughout winter. On Alaska’s north slope, aufeis fields, which are affected by changing permafrost conditions, are critical to lo cal hydrology and ecology. However, optical satellite imagery struggles to distinguish between snow and ice, limiting the ability to monitor long-term changes in the extent of aufeis. The first project evaluates the accuracy of different aufeis detection techniques for Landsat optical imagery. The second project develops a pixel-level logistic regression framework to detect spatio-temporal trends in aufeis across northeastern Alaska. The third project aims to understand how large-scale scientific research projects engage local communities through interviews with project leaders and other members of the Department of Energy’s Next-Generation Ecosystem Experiment in the Arc tic (NGEE Arctic) project. Together, these projects highlight the importance of technological in novation (Chapter 2), environmental observations (Chapter 3), and engagement with communities (Chapter 4) in Arctic science. In Chapters 2 and 3, we show that the persistence of aufeis changed substantially between 2005 and 2020, with a 1% increase on June 15, followed by a23% decrease on July 15 and a 38% decrease by August 15. In Chapter 4, we identified six factors that we perceived as critical to improving NGEE Arctic’s engagement with local communities: (1) understanding of community context, (2) development of local partnerships, (3) building internal culture, (4) having a strategy for engagement, (5) planning for decommission, and (6) that it was never too late to do better. The results of this dissertation emphasize the ways in which research programs can generate usable knowledge and foster lasting relationships in communities confronting climate change.
Recommended Citation
Dann, Julian, "Advancing monitoring of aufeis: science, satellites, and society in a changing Arctic" (2025). Geosciences. 333.
https://scholarworks.alaska.edu/uaf_grad_geosci/333