Simulating the evolution of the Amundsen Sea Sector with a coupled ice-ocean model
Abstract
Ice shelves and floating glacier termini play an important role in the stability of ice sheets and interact strongly with the ocean. They account for much of the buttressing against the flow of inland glaciers that drain the Antarctic ice sheet. Changes in their geometry due to ice-front retreat, thinning or even collapse profoundly affect the flow of their tributary glaciers, which in turn affects the volume of grounded ice carried by these tributary glaciers into the ocean, and the extent of resulting sea level rise. Recent simulations of glaciers in Antarctica show that the largest climatic impact on ice dynamics is the rate of ice shelf melting, which rapidly affects glaciers' speed over several hundreds of kilometers upstream of the grounding line. These melting rates, however, as well as their spatial and temporal evolution remain largely unknown. In the absence of direct long-term observations, coupled ice-ocean models are the best available approach to address this question. In a previous study, we simulated the coupled ice-ocean system near Thwaites Glacier using a new two-way coupled system between the Massachusetts Institute of Technology general circulation model (MITgcm) and the Ice Sheet System Model (ISSM). Our results highlighted the impact of ocean conditions on glacier evolution and demonstrated the importance of simulating the coupled ice-ocean system to produce accurate melting rates under the ice shelf and at the grounding line. In this study, we focus on the entire Amundsen Sea sector, a region that experienced glacier acceleration, thinning and grounding line retreat over the past three decades. We investigate the feedbacks between changes in the ice and ocean, and the dynamic response of the glacier to changes in the ocean circulation. The simulations suggest that this region is likely to undergo substantial changes in the coming decades. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration, Cryospheric Sciences and Modeling, Analysis and Prediction Programs.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.C43A..01S
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0726 Ice sheets;
- CRYOSPHERE;
- 0774 Dynamics;
- CRYOSPHERE;
- 0798 Modeling;
- CRYOSPHERE