Publications and engagements

Theses

Armstrong, W.H., 2017. Glacier sliding from space: multi-scale remote sensing, geodesy, and numerical modeling to understand glacier mechanics. University of Colorado at Boulder (pdf; web)

Armstrong, W.H., 2010. Trends in New England Flood Magnitudes and Frequencies Revealed by Partial Duration Flood Series Analyses of Long Gauge Records. Boston College (pdf)

Publication profiles & social media

Google Scholar

ResearchGate

ORCID

Twitter

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.

Student research advisees

Jordan Ulmer ('24), BS Environmental Science Life Science Science concentration. Thesis: Geomorphic response of braided streams to modern deglaciation

Adam Lucas ('24), BS Environmental Science Earth System Science concentration. Thesis: Modeling the role of frontal ablation in the 21st century evolution of lake-terminating glaciers: A case study from the Juneau Icefield, Alaska, USA. Post-graduation: MS in Oceanography at University of Oregon.

Noah Caldwell ('23), BS Geology with Quantitative Geoscience concentration. Thesis: Quantifying Rates of Retreat and Frontal Ablation for Alaska’s Lake-Terminating Glaciers: Investigating Potential Physical Controls with Implications for Future Stability. Post-graduation: MS in Snow Hydrology at Colorado State University

Lily Vowels ('23), BS Geology with Quantitative Geoscience concentration. Thesis: Investigating drivers of changes in proglacial stream suspended sediment concentration using large scale remote sensing. Post-graduation: MS in Coastal Processes at Louisiana State University

Jacob Hanson ('21), BS Environmental Science Earth System Science concentration

Anton Hengst ('21), BS Geology with Quantitative Geoscience concentration. Thesis: Sub-annual to annual dynamics of Alaskan ice-marginal lakes from automated image classification using Google Earth Engine. Post-graduation: Mine geologist in Tuscon, AZ; PhD Candidate in Aerospace Engineering, Arizona State University

Hannah Field ('20), BS Geology with Quantitative Geoscience concentration. Thesis: Climatic, glaciologic, and geomorphic controls on northwestern North American proglacial lake area change between 1984-20218. Post-graduation: MS in Hydrology at The Ohio State University

Invited talks

Dartmouth College

Department of Earth Sciences. May 2024

Virginia Tech

Department of Geosciences. Mar 2023

University of Georgia

Geology Department. Oct 2021

Western Washington University

Geology Department. Mar 2018

Boston College

Earth and Environmental Sciences Department. Nov 2017

University of Minnesota

Earth Sciences Department. Apr 2017

Appalachian State University

Department of Geological * Environmental Sciences. Mar 2017, Oct 2018

Awards

Chancellor’s Award for Inclusive Excellence Faculty Award (App State)

Presented to Dr Jamie Levine and a 5-member departmental committee on which I serve, 2022

CU Boulder Department of Geological Sciences

Travel grant, 2016

GIS Colorado

Scholarship, 2015

Shell Research Award

Graduate student research grant, 2015

Best Education Research Poster

CU Graduate Teacher Program pedagogy research award, 2015

Best Should Teach

CU Graduate Teacher Program Pedagogy award, 2014

Outreach, service, and community engagement

National Science Foundation

Grant funding panelist

American Geophysical Union Fall Meeting

Convener for "Glacier-lake interactions in a changing climate" session at the 2022 AGU Fall Meeting 

National Science Foundation

Proposal reviewer for Hydrological Sciences and Arctic Natural Sciences

Department of Geological & Environmental Sciences (App State)

Member of Diversity, Equity, and Inclusion action committee

American Geophysical Union Fall Meeting

Coordinator for all Cryosphere Section outstanding student presentation award (OSPA) activities

Department of Geological & Environmental Sciences (App State)

Departmental colloquium series organizer

American Geophysical Union Fall Meeting

Convener for "Glacier processes from large-scale remote sensing" session at the 2018 AGU Fall Meeting 

Appalachian Geological Society

Faculty mentor for student geology club

Juneau Icefield Research Program

Guest faculty; 2016 & 2018

CU Graduate Teacher Program

Lead graduate teacher for Geological Sciences

Institute of Arctic and Alpine Research (INSTAAR)

Graduate speaker series organizer. Graduate representative on INSTAAR directorate.

Open API Challenge (AGU)

Web application judge

EarthCache (GSA)

Glaciology lecture to general public

Science fairs and conferences

Poster judge for AGU outstanding student poster award, as well as elementary-to-university level science fairs.

Journal of Glaciology

Peer reviewer

The Cryosphere

Peer reviewer

Geophysical Research Letters

Peer reviewer

Frontiers in Earth Science

Peer reviewer

Remote Sensing of Environment

Peer reviewer

Remote Sensing

Peer reviewer

Journal of Geophysical Research: Earth Surface

Peer reviewer

Earth and Planetary Science Letters

Peer reviewer

Earth Surface Processes and Landforms

Peer reviewer

Earth Surface Processes

Peer reviewer

Water Resources Research

Peer reviewer

Water

Peer reviewer