Elements: simulating glacier terminus evolution and iceberg calving with icepack

University Of Washington, Seattle WA

Investigators

Abstract

Predicting sea-level rise over the coming decades is one of the key problems of glaciology. The results of these predictions are important for hazard mitigation, urban planning, and coastal infrastructure development. Glaciologists use computer simulations of ice physics to make these predictions, but there are critical aspects of ice physics that are not adequately understood. The goal of this project is to develop new mathematical models and simulation tools for studying the breaking off or calving of icebergs from glaciers that terminate in the ocean. Calving makes up for half of the total mass loss from Antarctica and Greenland, but there is no widely agreed upon mathematical model that predicts how often icebergs break off and how large they are. The mathematical models developed by this project represent a substantial advance in the field of glaciology and will enable physical scientists to provide better predictions to policy makers and engineers. This project is also incorporated as part of the curriculum for the Juneau Icefield Research Program, a field program that takes undergraduates on a summer-long traverse of the Juneau Icefield in southeast Alaska where they learn about environmental science and glaciology from experts. The goal of this project is to develop new methods for simulating the calving of icebergs from tidewater glaciers and ice shelves. There is no mathematical model for calving event magnitude and frequency which reproduces observations of Alaska, Greenland, and Antarctica. A substantial limiting factor in the development of such models is the difficulty of testing them using computer simulations. Calving makes the geometry of the problem evolve in time, and dynamic geometries are one of the hardest challenges in scientific computing. This project develops new approaches for simulating calving based on applying the principal of convex duality to the momentum balance equation of glacier flow, implements several common calving models and calibrates them to observational data, and compares and selects among these models. The key methods will be mathematical and numerical modeling of glacier flow; concretely, this will take the form of new features added to the software library Icepack, an open-source package for glacier modeling. This project will contribute to the broader goal of predicting how much and how fast global sea levels will rise in the coming decades, a question of broad societal relevance. Moreover, the methods developed in this project are used as instructional material for the Juneau Icefield Research Program, an educational field program for undergraduates where students conduct field work and learn from researchers in glaciology. This award by the Office of Advanced Cyberinfrastructure is jointly supported by the National Discovery Cloud for Climate initiative within the Directorate for Computer and Information Science and Engineering. 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.