Investigating variability in ocean heat content on the Antarctic continental shelf and its relationship to coastal ice dynamics

Abstract:

One of the most important elements of uncertainty associated with sea level rise estimates is the contribution of Antarctica’s floating ice shelves, particularly when it comes to iceberg calving. Iceberg calving is often unpredictable in its magnitude and timing, and the dynamics of a rapidly retreating ice shelf are not well understood. Using recent high-resolution laser altimetry data from ICESat-2, we examine frontal ablation at ice fronts and infer ice shelf basal shape. In this study, we investigate the interaction of these ice surfaces with the surrounding water masses from three sites around the Antarctic coast. By quantifying the heat content of surrounding waters and locating the ice-ocean interface, we aim to better characterize how submarine ice-melt may trigger large iceberg calving events. Such calving events are also likely related to ice cliff height and stability, possibly enabling faster ice front retreat. The covariance between ocean heat content at depth and heterogeneous frontal ablation of ice cliffs around Antarctica has yet to be empirically demonstrated. This investigation, which incorporates remotely sensed observational data from sites in West and East Antarctica, seeks to improve understanding of the spatial and temporal variation in ice front dynamics and their relation to relative changes in ocean heat on the continental shelf.