NSF Award
2303344
The Antarctic Ice Sheet has not always been the same shape or size, and past changes have left behind a record of ice mass loss and gain. Our modern observational record indicates mass loss and glacial retreat responses consistent with climatic trends, but the specifics of that retreat, and our projections of future change, remain a tangle of internal dynamics of ice and its interactions with its surroundings. The challenge of making credible projections of the Antarctic contribution to sea-level change from our current generation of ice-sheet models rests on accurately reproducing past changes. This project aims to merge archived constraints on past ice-sheet behavior collected from around, above, and beneath the Antarctic Ice Sheet with a state-of-the-art ice-sheet model to improve projections of future sea-level rise. In addition, the project will support intellectual exchange between researchers across every career stage focusing on past glacial reconstructions and future projections as well as lower the barrier to entry into polar sciences by developing modular curricula to be delivered in community college classrooms and online learning environments.<br/><br/>With hundreds of constraints on deglacial grounding-line retreat and associated ice-surface lowering around Antarctica, the availability of paleo constraints on past ice sheet behavior no longer limits integrating these observations into modeling efforts. This project will integrate paleo-glaciological observations from the Holocene into the BISICLES model framework used to project future sea level. The goals of this project are to (i) establish the conditions that switched the mode of grounding line migration from retreat to re-advance during the mid-to-late Holocene in West Antarctica; (ii) use differences in forcing, geologic conditions, and geographic conditions between responses in the Amundsen Sea and Ross Sea embayments to investigate the differences in marine ice sheet sensitivity between an "unstable" and "stable" sector of the ice sheet; and (iii) apply the findings of (i) and (ii) to improve constraints on future sea-level projections. Investigating the interplay of external forcing, internal forcing, and geological response to ice-mass loss in West Antarctica is essential for reducing uncertainty in future sea-level-rise projections. This project will employ a multidimensional education plan focused on a mentorship structure that promotes intellectual exchange between researchers across every career stage focusing on paleo-glaciological reconstructions and future projections. The project team will co-produce three educational modules with the Colorado School of Mines Trefny Innovative Instruction Center focused on paleo-glaciological reconstruction, modern glaciological observations, and models of future sea-level rise.<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.
