Response of the cryosphere to ocean warming �below Filchner Ronne Ice Shelf (Antarctica)

Simulations of ice shelf - ocean interaction for several IPCC future climate change scenarios have revealed the potential of a rapidly increasing basal mass loss for the Filchner-Ronner Ice Shelf (FRIS) in the Weddell Sea. This result is consistent between two independent sea ice - ice shelf - ocean models forced with identical atmospheric data sets. However, both models assume a steady-state ice shelf geometry. To study ice-ocean interaction in a more consistent way, the ice flow model RIMBAY has been configured in a model domain that comprises the FRIS and the grounded ice in the relevant catchment area up to the ice divides. At the base of the model ice shelf, melt rates from the finite-element sea ice – ice shelf – ocean model FESOM are prescribed. For present-day conditions with ice shelf basal melting obtained from a 20th-century simulation with FESOM, the ice model yields a quasi-steady state with an ice shelf geometry and grounding line location very close to the presently observed configuration. With FESOM’s increasing melt rates modelled for future climate warming scenarios, the ice model predicts an accelerated grounding line retreat between the Möller and Institute Ice Streams. Simulated discharge of (formerly) grounded ice is converted to an estimated contribution to global sea level rise. The sub-ice shelf cavity geometry in FESOM is adjusted according to the ice thickness evolution in RIMBAY to investigate the effect of a dynamically varying ice shelf topography on simulated basal melt rates. A two-way coupling between the two models will be conducted as a natural next step