Antarctica’s ice shelves buttress the continent’s terrestrial ice, helping slow the loss of grounded ice into the ocean and limiting sea level rise. Ice-ocean interaction plays a critical role ice shelf stability by driving basal melt rates. Consequently, improved prediction of the future state of ice shelves lies in understanding the coastal ocean mechanics that deliver heat to their cavities. Here, we present autonomous glider-based observations of a coherent structure at the calving front of a cold-water cavity ice shelf (Nansen Ice Shelf, East Antarctica). This ~10 km-wide eddy dominated the local ocean circulation, promoting an upwelling of cold ice shelf water and a deepening of warm surface water. Microstructure turbulence measurements show resulting vertical heat transport of ?(10 W m-2) at depths equivalent to the ice shelf draft. Similar eddy-driven heat transport further into the ice shelf cavity would support enhanced summertime melt in regions of shallower ice draft.

Microstructure turbulence measurements were made via a Slocum autonomous underwater glider with a Rockland Scientific Microrider and were processed using Rockland's Odas MATLAB library. Ocean conductivity, temperature, and depth measurements were made with both glider- and ship-based (RV Araon) Seabird CTDs, and further oceanographic parameters were derived using the Gibbs Seawater and MIT Seawater MATLAB libraries. Lowered Acoustic Doppler Current Profiler (ADCP) data was also recorded from the RV Araon.

All of these data are .csv files and are able to be opened in Microsoft Excel or equivalent.