Basal Melting of Ross Ice Shelf based on ROSETTA-Ice Radio-echo Sounding Observations

Ross Ice shelf (RIS) - the largest ice shelf in Antarctica - provides critical stability and buttressing for large parts of the grounded ice from both West and East Antarctica. The stability of RIS is fundamentally controlled by the influences of ocean forcing on basal melting, marine ice formation, and ice shelf calving. However, observations on RIS's basal melting and other ocean-related processes are limited and they often display disagreements depending on the methodology deployed. Here, we provide new basal melt rate observations directly from englacial attenuation analysis using ROSETTA-Ice airborne radar sounding survey. Different from a previous study using the same dataset, we develop a model-integrated method that enables us to directly relate ice shelf temperatures, englacial attenuation, and ice shelf basal rates. Using this empirical relationship, we produce an updated map of RIS's basal melt that extends from the ice shelf front to the grounding line regions where previous methods struggled. Our basal melt rates produce a greater range of values with significantly higher rates along the ice flow lines of Byrd Glacier and several Siple Coast ice streams. Generally, we observe higher basal melt rates along deep ocean troughs in the West Antarctica side of RIS. We also compare these modern basal melt patterns with historical maps of marine ice distribution to examine the effect of recent ocean warming on ice shelf melting. These new basal observations over Ross Ice Shelf would enable us to further examine linkage between ice shelf basal conditions to modern oceanographic, climate, and sea-ice changes in the Ross Sea.