We applied a modified version of the Miami isopycnic coordinate ocean general circulation
model (MICOM) to the ocean cavity beneath the Ross Ice Shelf to investigate the circulation of ocean waters
in the sub-ice shelf cavity, along with the melting and freezing regimes at the base of the ice shelf. Model
passive tracers are utilized to highlight the pathways of waters entering and exiting the cavity, and output is
compared with data taken in the cavity and along the ice shelf front. High Salinity Shelf Water on the
western Ross Sea continental shelf flows into the cavity along the sea floor and is transformed into Ice Shelf
Water upon contact with the ice shelf base. Ice Shelf Water flows out of the cavity mainly around 180°, but
also further east and on the western side of McMurdo Sound, as observed. Active ventilation of the region
near the ice shelf front is forced by seasonal variations in the density structure of the water column to the
north, driving rapid melting. Circulation in the more isolated interior is weaker, leading to melting at deeper
ice and refreezing beneath shallower ice. Net melting over the whole ice shelf base is lower than other
estimates, but is likely to increase as additional forcings are added to the model.