William Armstrong

Appointments

Appalachian State University

Associate Professor (July 2024 - present)

Appalachian State University

Assistant Professor (Dec 2018 - June 2024)

University of Alaska Fairbanks

Affiliate Faculty (Aug 2019 - present)

Appalachian State University

Visiting Assistant Professor (Aug 2017 - Dec 2018)

University of Colorado at Boulder

Research and Teaching Assistant (2012-2017)

National Oceanic and Atmospheric Administration, Restoration Center

Research Associate (2011)

Congaree National Park

Guest Scientist (2010)

US Department of Justice, Environment and Natural Resources Division

Paralegal and Office Assistant (2009)

Record of external funding

Frontal ablation processes on lake-terminating glaciers and their role in glacier change

National Science Foundation, Office of Polar Programs, Arctic Natural Sciences (Award  2334775)

Lead PI with co-investigators Dave Sutherland (University of Oregon) and Irina Overeem (University of Colorado)

$941,900 ($303,391 to App State); 2024 - 2027

Around the world, lakes have formed and grown at glacier termini following glacier retreat (Carrivick & Tweed, 2013; Shugar et al., 2020; Rick et al., 2022; Zhang et al., 2024). The presence of these lakes could have significant impacts for downstream water quality & habitat, as well as upstream glacier dynamics. Many terminal lakes have grown substantially in past decades, but it is is unclear how much these lakes are a cause or symptom of rapid glacier treat. In this multidisciplinary project spanning the glacier-lake interface, we will directly quantify how much ice is lost through melting and subaqueous melt at three Jnueau Icefield outlet glaciers, and assess the importance of lake presence for the glaciers past & future change. We will partner with the Juneau Icefield Research Program (JIRP) and Alaska Native Science and Engineering Program (ANSEP) to constrain glacier-wide processes and expand demographic representation within the cryospheric sciences. See my research page for more information.

A half century of changing glacier dynamics at Athabasca Glacier

National Science Foundation, Office of Polar Programs, Arctic Natural Sciences (Award 1821002)

Lead PI with co-investigator Martin Truffer (University of Alaska Fairbanks)

$700,874 ($288,248 to App State); 2018-2024

The evolution of glacier speed in a warming world affects the timing and amount of glacier ice that is transferred to downstream river systems and the global ocean. Glacier motion is sensitive to meltwater, and recent work suggests that climate warming will slow glacier motion due to more efficient drainage of the glacier bed (e.g., van de Wal, 2015; Tedstone et al., 2015). However, these conclusions are drawn from relatively short time spans and we know that a glacier's sensitivity to water inputs can evolve over decadal timescales (Iken & Truffer, 1997). Our project builds on pioneering work (Raymond, 1971) to investigate how the dynamics of Athabasca Glacier evolved over the 55 years as the glacier has thinned and retreated in response to climate change. Our work combined numerical modeling, remote sensing, and an extensive field campaign including 12 instrumented full ice-thickness boreholes. We found that Athabasca Glacier's speed halved since the 1960s, and that 70-100% of that slowing is attributable to declining basal motion due to increased basal friction that likely resulted from changes in glacier geometry as well as surface melt (Armstrong et al., 2022; Polashenski et al., accepted). Slowing basal motion should help stabilize the glacier in a warming climate, but the glacier still thinned rapidly (~1 m/yr on average; Tennant & Menounos, 2013; Armstrong et al., 2022), suggesting that the magnitude of climate warming has overwhelmed any stabilizing feedback associated with glacier dynamics. See my research page for more information.

"Picture yourself as a geoscientist" outreach activity

American Geophysical Union Centennial Grant

Co-investigator with Lead PI Marta Toran (Appalachian State University)

$5,700 (2019-2020)

Misperceptions about career opportunities are cited as a leading cause for the earth sciences being the least diverse STEM field (Sherman-Morris & McNeal, 2016), with little sign of improvement over the past 40 years (Bernard and Cooperdock, 2018). We will develop educational materials and a costume and green screen-based K12 outreach activity to familiarize young people (with particular focus on underrepresented groups) on viable careers in earth science, many of which feature more lab or computer-based work than field work.

Click here for a profile about this project in Appalachian Today.