Strong effects of thermodynamic ice-shelf/ocean interactions in a globalsea-icea-ocean isopycnal model

Melting/refreezing of ice shelves have strong impacts both on ice shelves (through modification of their shape) and on the ocean circulation ( through modification of their water masses). Representation of ice-shelf/ocean interaction in the global ocean circulation models continues to be challenging. Using a high-resolution (1/8 deg) global isopycnal ocean model, MOM6, and a sea-ice model, SIS, we investigate the effects of thermodynamic coupling of the Antarctic ice shelves on the various aspects of ocean circulation. Such high (3-8 km) horizontal spatial resolution allows for detailed resolution of the sub-ice-shelf cavity circulations. The computed ice-shelves melt rates are in very good agreement with observationally derived melt rate estimates. The spatial distributions of simulated melting/freezing rates indicate enhanced melting in the vicinity of the grounding line and very strong melting at the ice-shelves front. Results of our simulations show strong effects of sub-ice-shelf melt water on circulation of the Southern Ocean. We also find that simulations accounting for the thermodynamic coupling of the Antarctic ice shelves produce consistently thicker sea ice compared to the uncoupled simulations.