Extending the Capabilities for Fully Coupled Land-Ice Simulations within the Community Earth System Model
Mass loss (primarily melting and iceberg discharge) from land ice is accelerating and will soon become the dominant contribution to long-term sea level rise. Accurate, physically-based projections of land-ice change are needed to assess the threats to coastal regions. While progress has been made, uncertainty still exists in sea level rise projections for the 21st century and beyond. This is in part because the models used for climate projections have traditionally incorporated very simple treatments of land ice. This award will allow for more accurate consideration of the role of land ice within predictive models, specifically through continued development of a sophisticated land ice component in the Community Earth System Model (CESM). One individual will work directly on the task, and will be available to train others. The Broader Impacts of this work include better predictions of sea level rise, which will provide coastal planners with better information to support the development of effective mitigation and adaptation strategies. Specific components of this project include adding conservative, two-way coupling between ice sheets, the land, and the atmosphere into the CESM. This will allow for improved long-term simulations to assess coupled ice-sheet/climate interactions. In addition, the project will support enhancements to the CESM's snow physics model, a component needed for accurate modeling of future ice-sheet mass changes. Finally, this project will provide support for improved model infrastructure that is needed to better simulate the future evolution of the Arctic and Antarctic ice sheets, as well as better hindcasting of paleo ice sheets that can be studied as analogs for the future. Together, these activities will result in refined research tools to address the important question of future sea level rise.