Postdoctoral Fellowship: OPP-PRF: Spatiotemporal Evolution of Firn Hydrology on the Juneau Icefield, Alaska

The alpine glaciers of Alaska constitute some of the most rapidly changing parts of the Earth’s cryosphere and collectively contribute 25% of land-ice loss to global sea level. Understanding the physical processes involved in meltwater flow through a glacier remains a key challenge in predicting a glacier’s behavior and environmental impact. Specifically, the firn (the material through which freshly fallen snow compacts into glacial ice) influences the speed, volume, and geochemical composition of meltwater flow through a glacier. Water flow through the firn is, on a broad level, fundamental for characterizing glacier behavior, glacier mass loss and gain, and ultimately sea level, downstream ecology, and regional water resources. This research uses modeling and a variety of new and historical field data from the Juneau Icefield in Southeast Alaska to advance understanding of meltwater flow through the firn on Alaskan glaciers within the context of climate change. This project advances inclusive research practices by strengthening connections between the Juneau Icefield Research Program (JIRP) and Alaska Indigenous communities. This project: (1) measures changes in surface melt and firn properties that are key to understanding changes in firn hydrology on the Juneau Icefield, and (2) builds on novel applications of water-isotope stratigraphy to determine changes in timing and variability of meltwater infiltration in the firn. Accomplishing these objectives requires the assembly of ice-penetrating radar data, water-isotope records, meteorological data, and other in-situ measurements. This comprehensive dataset will facilitate analyses of field measurements and execution of meltwater-isotope model simulations to quantify surface-melt rates, melt timing, melt-infiltration rates, firn temperature, and englacial hydrological features such as firn-aquifer and ice-layer formation and evolution over sub-seasonal and inter-annual time periods. The comprehensive assessment of firn hydrology generated by this project will advance understanding of glacier change in Alaska and with broader implications for improved understanding of the Greenland and Antarctic ice sheets. 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.