01/06/2012

# Reformulated Ice Sheet Model Is Easier and Cheaper To Solve

## Summary

The gold standard in ice sheet modeling is the “full-Stokes model,” which solves the nonlinear (non-Newtonian) Stokes equations for the three components of velocity and the pressure. However, it is a computationally difficult and expensive problem to solve and has inspired the creation of numerous approximate models that are cheaper and often inaccurate. A DOE scientist at Los Alamos National Laboratory used an approximate method that maximizes or minimizes functions for the full-Stokes model and showed how to reformulate the resulting system of equations into an equivalent, but much smaller problem for just the horizontal velocity components that has much more favorable properties. These features of the new formulation are illustrated and validated using a simple, but nontrivial Stokes flow problem involving a sliding ice sheet. This procedure will lead to new and efficient directions in ice sheet modeling.

## References

Dukowicz, J. K. 2012. “Reformulating the Full-Stokes Ice Sheet Model for a More Efficient Computational Solution,” *The Cryosphere* 6, 21-34, DOI: 10.5194/tc-6-21-2012.