Future sea-level rise due to projected ocean warming beneath the Filchner Ronne Ice Shelf: A coupled model study

- Modelling FRIS, Antarctica with a coupled ice-sheet/shelf-ocean model.
- Response of the coupled system to climate warming based on IPCC scenarios.
- Sea level rise contribution is 0.05 mm/yr for the next 500 years.

A general ocean circulation model is coupled with a 3D-thermodynamical ice-sheet/shelf model to simulate the response of the Filchner-Ronne Ice Shelf (FRIS, Antarctica) and coastal parts of its catchment basin to a postulated inflow of Warm Deep Water into the ice-shelf cavity on a 1000-yr timescale. Prescribed ocean warming (based on climate projections) enters the ice-shelf cavity in the up to 1500 m deep Filchner Trough and penetrates deep into the sub-ice cavity. Increasing basal melt rates induce geometry changes of the cavity, which in turn have an impact on the ocean circulation and therefore the modelled melt rates. Highest melt rates of about 20 m yr−1 follow the (up to 180 km) retreating grounding line. Basal mass loss reaches about 250 km3 yr−1, doubling the present-day value. The most vulnerable areas below the FRIS are the Bailey Ice Stream and the area between the Institute and Moeller Ice Streams, where the increased melting accounts for about 80 km of the modelled grounding line retreat on the backward sloping bedrock. The potential additional contribution to the eustatic sea level rise due to the grounded-ice loss, simulated in an ensemble approach against a transient control experiment, is about 0.05 mm yr−1 during the first 500 yr and about 0.17 mm yr−1 thereafter.