Ice-mass changes in Aurora basin, East Antarctica, in coupled and uncoupled ice-ocean simulations

Ice mass loss of Greenland and Antarctic ice sheets is a major contributor to sea level change with an expected major impact on the world's infrastructures over the next decades. Therefore, precise estimates of sea level change are needed. However, estimates of future changes in sea level are either provided by earth system models, which rarely include ice sheet models, or by standalone ice sheet models. Hence, feedbacks between ice and atmosphere-ocean are overseen. Local scale coupled models help bridging this gap by estimating how feedbacks between the different earth systems affect global sea level estimates.

Here, we present results from a coupled simulation of the ocean-sea ice model NEMO3.6-LIM3 (1/24° grid ~ less than 2 km grid spacing) and the ice sheet model BISICLES (on 0.5 - 4km spatial resolution). The coupling routine is done via python code including variable exchange, pre- and post-processing, done offline every 3 months.

Simulated ice mass changes, grounding line position and ice velocity changes of this high-resolution coupling scheme (between 1993-2014) are compared to observations and results of uncoupled simulations. We further discuss which processes might be neglectable and which are the main drivers of ice velocity acceleration and changes in sub-shelf ocean circulation.