Dr. Sarah Evans collaborates with CAS student, faculty on permafrost research

BOONE, N.C. — The Arctic has warmed three times the rate of the global average, resulting in extensive thaw of perennially frozen ground known as permafrost. The thawing of permafrost has the potential to accelerate global warming through carbon dioxide and methane releases, creating a vicious cycle. As warming continues, scientists are working to understand the complex interactions between vegetation and permafrost. Dr. Sarah Evans, a quantitative hydrogeologist and an associate professor in the Department of Geological and Environmental Sciences, is at the forefront of these efforts.

Evans collaborated with researchers from the University of Colorado Boulder, University of California Santa Cruz, University of Alaska Fairbanks and Appalachian State University Department of Geography and Planning to investigate factors impacting permafrost vulnerability in a new study published this month in the Journal of Geophysical Research (JGR): Biosciences. The paper, entitled "Control of Short-Stature Vegetation Type on Shallow Ground Temperatures in Permafrost Across the Eastern Canadian Arctic," leverages environmental data to study permafrost sites with shorter vegetation on Baffin Island, Canada.

Few studies have explored how shorter vegetation impacts permafrost thaw due to difficulty accessing these remote parts of the Arctic. However, Evans leveraged previously collected soil temperature measurements taken by her co-authors for 22 sites across eastern Baffin Island in 2018 and 2019. Evans et al.'s study compared temperature and vegetation data collected in the field with topographic variables derived from remotely sensed imagery. The findings indicate that the exact type of short vegetation is not always the primary control on ground temperatures. Instead, ground temperatures in these regions seem to be controlled by how long snow is on the ground, due to other factors like small depressions or wind buffering.

Since joining the Department of Geological and Environmental Sciences as an assistant professor in 2017, Evans has collaborated with students and researchers from many departments and institutions to explore the relationship between climate change and groundwater flow systems. Alexander Brodie, an environmental science major from Hillsborough, is one of Evans' current undergraduate mentees. Brodie contributed to the soil temperature analysis in the study. Additionally, Dr. Maggie Sugg, an associate professor in the Department of Geography and Planning, contributed statistical modeling guidance.

Evans et al.'s article was selected for an Editors' Highlight in Eos, a science news magazine published by the American Geophysical Union (AGU). In "It's Cool to be Short When You're in the Arctic Permafrost," JGR: Biosciences journal editor Ankur R. Desai provides a brief summary of the article, emphasizing its contributions to future permafrost prediction studies. Notably, fewer than two percent of papers are selected to be featured in Editors' Highlights.

The research was funded by the National Science Foundation, National Geographic Society and an Appalachian State University College of Arts and Sciences Faculty Research/Proposal Development Summer Grant.


About the Department of Geological and Environmental Sciences
Located in Western North Carolina, Appalachian State University provides the perfect setting to study geological and environmental sciences. The Department of Geological and Environmental Sciences provides students with a solid foundation on which to prepare for graduate school or build successful careers as scientists, consultants and secondary education teachers. The department offers six degree options in geology and two degree options in environmental science. Learn more at https://earth.appstate.edu.

About the Department of Geography and Planning
The Department of Geography and Planning promotes the understanding of the spatial dimensions of human behavior within the physical and cultural systems of the earth, and the role of planning in achieving improvement in those systems. The department offers degrees in geography and in community and regional planning. Learn more at https://geo.appstate.edu.

By Lauren Andersen
July 19, 2022

Dr. Sarah Evans, associate professor in the Department of Geological and Environmental Sciences at Appalachian State University. Photo by Chase Reynolds.
Published: Jul 19, 2022 1:15pm