Microstructure turbulence, conductivity-temperature-depth, and current velocity measurements of a submesoscale eddy in Terra Nova Bay (2018-2019)

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.