Ross Ice Shelf frontal zone subjected to increasing melting by ocean surface waters

• Published in: Science Advances
• Main Authors: Sheehan, Peter M. F., Heywood, Karen J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2024
• Subjects: Ross Ice Shelf; Antarc*; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.1126/sciadv.ado6429; https://www.science.org/doi/pdf/10.1126/sciadv.ado6429

Solar-warmed surface waters subduct beneath Antarctica’s ice shelves as a result of wind forcing, but this process is poorly observed and its interannual variability is yet to be assessed. We observe a 50-meter-thick intrusion of warm surface water immediately beneath the Ross Ice Shelf. Temperature in the uppermost 5 meters decreases toward the ice base in near-perfect agreement with an exponential fit, consistent with the loss of heat to the overlying ice. Ekman forcing drives a heat transport into the cavity sufficient to contribute considerably to near-front melting; this transport has increased over the past four decades, driven by the increasing heat content of the ice-front polynya. Interannual variability of the heat transport is driven by zonal wind stress. These results provide a benchmark against which model performance may be assessed as we seek to reduce uncertainty around the contribution of basal melting to sea level rise.