Our current understanding of the small-scale fluid processes occurring in the glacier-ocean boundary layer is incomplete, and so parameterizations used in ice-ocean modeling are largely borrowed from the classic literature of heat transfer in engineered systems that do not represent glaciological conditions. The result is large departures between model predictions and observations of ocean melting of glaciers, which consequently leads to large uncertainties in projections of future sea level rise, particularly from Antarctica. Preliminary work on part of this project has been funded by the Georgia Tech Small Bets seed grant. We plan to:
- Characterize the conditions under which subglacial plumes melt glaciers
- Quantify heat and mass transfer across the ice-ocean interface under different plume source configuration and ice surface roughness
- Predict melt rates for a range of field conditions in a revised numerical model
We will address these goals by laboratory experiments that will, for the first time, simultaneously measure temperature, salinity, and fluid velocity of subglacial plumes at high (~mm scale) spatiotemporal resolutions under realistic field conditions. The experiments will be conducted in a purpose-built water tank, inside a climate-controlled cold room, using state-of-the-art particle image velocimetry (PIV) and laser-induced fluorescence (LIF) techniques for measurements. These experiments will allow us to systematically re-examine the assumptions and simplifications made in existing melt-rate models, with the goal of deriving a revised and (for the first time) complete theory of melt at the ice-ocean interface. In related work, we are developing a new generalized theory and parameterization of seawater intrusion under grounded ice sheets.
Current and past researchers: Madeline Mamer (EAS PhD Student), Muhammad Ahmad Mustafa (CEE PhD Student, advised by Prof. Chris Chungkei Lai)