NSFGEO-NERC: Investigating the Direct Influence of Meltwater on Antarctic Ice Sheet Dynamics

DESCRIPTION: When ice sheets and glaciers lose ice faster than it accumulates from snowfall, they shrink and contribute to sea-level rise. This has consequences for coastal communities around the globe by, for example, increasing the frequency of damaging storm surges. Sea-level rise is already underway and a major challenge for the geoscience community is improving predictions of how this will evolve. The Antarctic Ice Sheet is the largest potential contributor to sea-level rise and its future is highly uncertain. It loses ice through two main mechanisms: the formation of icebergs and melting at the base of floating ice shelves on its periphery. Ice flows under gravity towards the ocean and the rate of ice flow controls how fast ice sheets and glaciers shrink. In Greenland and Antarctica, ice flow is focused into outlet glaciers and ice streams, which flow much faster than surrounding areas. Moreover, parts of the Greenland Ice Sheet speed up and slow down substantially on hourly to seasonal time scales, particularly where meltwater from the surface reaches the base of the ice. Meltwater reaching the base changes ice flow by altering basal water pressure and consequently the friction exerted on the ice by the rock and sediment beneath. This phenomenon has been observed frequently in Greenland but not in Antarctica. Recent satellite observations suggest this phenomenon also occurs on outlet glaciers in the Antarctic Peninsula. Meltwater reaching the base of the Antarctic Ice Sheet is likely to become more common as air temperature and surface melting are predicted to increase around Antarctica this century. This project aims to confirm the recent satellite observations, establish a baseline against which to compare future changes, and improve understanding of the direct influence of meltwater on Antarctic Ice Sheet dynamics. This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.

BROADER IMPACTS: The project will support (1) junior PIs, postdocs and students, (2) three early-career scientists’ first experience of Antarctic fieldwork, (3) UK-US collaboration, (4) ongoing community outreach activities (e.g., Lamont’s Open House and the University of Sheffield’s Festival of the Mind that combined reach over 50,000 people), (5) Cycle For Science, a fledgling outreach non-profit, (6) the Juneau Icefield Research Program (JIRP), and (7) adoption of open data science approaches within our community. Cycle for Science sends early-career climate scientists on bicycle tours to teach in classrooms and community centers. We will run six one-week tours in the UK and US. We will also fund one team member per year to teach on JIRP, a unique science and education resource, which gives students immersive outdoor adventure and research experiences while completing a 6-week ski traverse of the Juneau IceField. Finally, we will collaborate with experts in a growing open-data science community called Pangeo, that facilitates scalable, open, reproducible analysis of big data in the cloud, with the aim of making our remote sensing analysis fully reproducible by anyone at no cost. This project will also produce a comprehensive set of freely-available field and remote sensing data that can be used to understand velocity changes in Antarctic outlet glaciers on a range of time scales and Antarctic meteorology