05/01/2018
An Overview of Interactions and Feedbacks between Ice Sheets and the Earth System
Tight coupling between ice sheets and the Earth system of critical importance for sea level projections.
The Science
Motivated by the impact of Antarctic and Greenland ice sheet change on future sea level rise, this review article summarizes the state of knowledge of ice sheet/Earth system interactions and feedbacks. It also describes emerging observation and model-based methods that can improve understanding of ice sheet/Earth system interactions and feedbacks.
The Impact
The work will be of large importance to accelerating efforts to build interactions between ice sheets and other Earth system components and forcings into models that are used to project future climate sea level changes in a consistent manner.
Summary
Sea level rise from ice sheets depends closely on interactions between ice sheets and the surrounding Earth system. These interactions determine how forcings to the climate system (such as from anthropogenic climate influences) translate to ice sheet change, which in turn impact the surrounding environment. This set of two-way interactions between ice sheets and the Earth system forms the basis for important, yet poorly understood feedback loops. This review article describes the current state of knowledge of ice sheet/Earth system interactions and feedbacks and describes promising observational techniques for better understanding their behavior. It also highlights challenges and opportunities in modeling these interactions and feedbacks using coupled ice sheet/Earth system models, which will ultimately be used to predict future sea level rise caused by ice sheet loss. It particularly focuses on the development of Earth system models that incorporate current understanding of Earth system processes, ice dynamics, and ice sheet/Earth system couplings. The strength and balance of ice sheet/Earth system interactions are markedly different for the two present-day ice sheets: ice sheet/atmosphere interactions are arguably dominant for GrIS (Greenland Ice Sheet), while ice sheet/ocean interactions play a more critical role in AIS change. Internal ice sheet dynamics play an important role in translating ice sheet/Earth system interactions into ice dynamic discharge, for both ice sheets. Careful observation and modeling-driven consideration of the coupled ice sheet/climate system will generate new hypotheses regarding ice sheet/climate interactions, which observations and modeling can subsequently test. This type of consideration requires simultaneously deep expertise in disparate aspects of the coupled Earth system, ranging from ocean eddies to polar cloud radiative properties to ice stream dynamics.
Principal Investigator(s)
Jeremy Fyke
Associated Engineering Group, Ltd.
[email protected]
Funding
This research is supported as part of the Department of Energy, Office of Science, Biological and Environmental Research EESM Energy Exascale Earth System Model project.
References
Fyke, J.G., O. Sergienko, M. Lofverstrom, S. Price, and J.T.M. Lenaerts, M. An Overview of Interactions and Feedbacks Between Ice Sheets and the Earth System. Reviews of Geophysics 56(2) 361-408 (2018). DOI:10.1029/2018RG000600