NSF Award
2223352
Today, 80% of all glaciers are smaller than 0.5 km2, and many larger valley glaciers are in the process of transitioning to small cirque glaciers in response to modern warming. Despite their small size, cirque glaciers play an outsized geomorphic and ecological role in alpine landscapes, largely through regionally variable changes in hydrology and sediment transport. Understanding how these glaciers responded to past climate changes and how they will respond to future climate changes is prerequisite for understanding the past evolution and future fate of alpine catchments in the western U.S. and elsewhere. This project will address this need by developing detailed glaciological datasets, both modern and paleo, from an exceptionally well-constrained study site in the Teton Range, Wyoming, and integrating them with a state-of-the-art model to accurately represent glaciers as they shrink and disappear. Ultimately, this work will produce insight into the past, present, and future role of glaciers as agents of alpine landscape evolution while developing an open-source glacier model, which will be applicable to glacial settings globally. The project will also foster new collaborations between four early career PIs, improve STEM education at two public research institutions and one liberal arts college through increased participation of underrepresented minorities in the Earth sciences, and promote climate science literacy and public engagement.<br/><br/>This research will advance our fundamental understanding of deglaciation in alpine landscapes by integrating diverse datasets into a new glacier model to simulate past and ongoing glacier retreat in the western U.S. This model represents a transformative advance in that it includes novel representation of topographically-mediated effects on mass balance—processes that are increasingly important as glaciers shrink into shaded cirques. Importantly, the new open-source glacier model (PyG2D) can be applied to other settings worldwide to quantify the effects of climate change on mountain ecosystems, hydrology, and landscapes. By applying and testing this model in the Teton Range, a site with exceptional geologic constraints on past glacier fluctuations and a suite of cirque glaciers that are representative of small glaciers globally, this project will produce the first detailed simulations of future glacier evolution in the contiguous U.S. We will place modern and future glacier change in context by constraining and simulating glacier states from the Last Ice Age to 2100 CE. This work, while focused on a single natural laboratory, has broad implications for glacierized regions elsewhere on the planet and offers an important space-for-time substitution to inform how more heavily glaciated landscapes will evolve in the future. With a continuous record of glacier extent, thickness, and volume this work will lay the foundation for future studies, both geomorphic and ecological in scope, that quantify the impact of glacier change on alpine landscapes facing complete deglaciation. Anticipated results will serve as key examples of the tangible impacts of climate change on the cryosphere that can be readily understood by resource managers, policymakers, and the broader public.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
