Toward the massively parallel solution of 3-D ice sheet flow models

The flow of polar ice sheets is characterized by a wide range of length scales, with localized flow features many orders of magnitude smaller than continental scales. To capture this wide range of scales in 3-D ice sheet models, we employ adaptive mesh refinement and higher-order methods. We investigate the application of multigrid preconditioners to the resulting systems, as well as issues arising from capturing the free surface at the ice/air boundary.