RAPID: International Collaborative Research into Ice-ocean Iteractions & Fractures at Thwaites (ICE-RIFT)

Multiple independent satellite remote sensing datasets indicate that the Amundsen Sea Embayment (ASE) sector of the West Antarctic Ice Sheet (WAIS) is losing mass faster than anywhere else in Antarctica. Thwaites Glacier, which drains over a half a meter of global sea level potential from its catchment alone, is one of the fastest retreating glaciers in the ASE. Although the ocean is generally understood to drive rapid melting of glaciers in the ASE, the ocean state and sea floor shape near most of the largest glaciers remains sparsely sampled. These unknowns challenge efforts to validate coupled numerical ocean and ice sheet models needed to predict future ice melt and sea level rise. This project will acquire key new profiles of ocean temperature, salinity, and depth near the Thwaites Glacier Tongue (TGT) from airborne platforms. Data collected during previous collaborations with the Korea Polar Research Institute (KOPRI) indicate higher concentrations of glacial meltwater and warmer temperatures in the upper 300 meters of the water column near Thwaites Glacier. Motivated by these results, this project will continue these helicopter-based oceanographic measurements from the RV Araon icebreaker in 2023/24 to obtain water column profiles near Thwaites’ grounding line. These new ocean state data will enable the team to confirm their previous results, determine the amount of interannual variability in this region, and evaluate ocean conditions in a wider area near the TCT. Additionally, movement of ice in the two years between observations will enable new seafloor depth observations from Airborne Expendable Conductivity Temperature and Depth (AXCTD) sensors, adding to a growing database of constraints useful for improving gravity-derived bathymetry models. Through this deepened collaboration with KOPRI, the project will demonstrate refined procedures and test new capabilities for helicopter-based airborne oceanography in Antarctica. The PI will partner with the UC San Diego Birch Aquarium in the creation of new polar exhibits designed to offer new types of immersive and interactive experiences that capture active expeditions aboard research vessels and at polar field stations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.