Impact of climate warming on the stability of the Filchner Ronne Ice Shelf and implications for the drainage of the vast Antarctic Ice Sheet

• Applicant: Dr. Malte Thoma
• Subject Area: Oceanography
• Term: from 2012 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 219495779

New ocean-modelling data indicates that the impact of global warming might lead to a substantial regime shift of the Warm Deep Water path in the Weddell Sea, Antarctica, during the 21stcentury. This coincides with a significant increase of ice-shelf basal melting underneath the second largest Antarctic ice shelf, the Filchner-Ronne Ice Shelf (FRIS), which is located in the southern Weddell Sea. When ice shelves shrink, the reduced buttressing presumably triggers an increased drainage of the ice sheet in the hinterland. Significant parts of the West- and East Antarctic Ice Sheet drain through the FRIS. Hence, the possible impact on sea-level rise is expected to be large. Melting and an adjusting ice-shelf geometry then again have an impact on the ocean circulation. This emphasises the necessity of a coupled ice sheet-ice shelf-ocean model to project the overall contribution of increased FRIS-melting to sea-level rise. We propose to quantify this contribution in three steps: First, a coupled ice sheet/shelf model of the FRIS region will be forced with basal melting, attained from Ocean General Circulation Modells (OGCMs). Second, the altered ice shelf geometry modifies the ocean model's geometry. Finally, the feedbacks between ice and ocean are iteratively coupled. As a final result, we will quantify the drainage of the Antarctic Ice Sheet through FRIS and hence its likely contributionto sea-level rise for the next centuries.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas - with renewal proposal 2025 - 2030
• Participating Person: Dr. Hartmut H. Hellmer