Buoyancy-adjusting Profiling Floats for Exploration of Heat Transport, Melt Rates, and Mixing in the Ocean Cavities Under Floating Ice Shelves

Recent successes using EM-APEX velocity profiling floats under sea ice (in an “ice contacting” mode which allows floats to measure ice draft to an accuracy a few centimeters after applying an atmospheric pressure correction) have inspired an innovative study of the seawater cavity under a floating ice shelf. We report here on a recent (January 2018 through March 2019) experiment using acoustically-tracked EM-APEX along with Seagliders to survey the distribution of temperature, salinity, shear, and melt rates in the Dotson Ice Shelf cavity. The 4 floats released in front of the ice shelf were carried by the warm inflow nearly to the grounding line 80 km back from the calving face, and one even furtherthrough a sub-glacial connection into the adjoining Crosson Ice Shelf cavity.