Marine ice sheets are largely based below sea level and are therefore influenced directly not only by the atmosphere, but also by sea level and ocean temperature, circulation and salinity. The West Antarctic Ice Sheet, which is part of the south polar Antarctic Ice Sheet, is today's only truly marine ice sheet. Rising levels of trace gases in the atmosphere may cause a climatic warming which in turn may initiate a change in glacial ice volume and a rise in sea level. The West Antarctic Ice Sheet may be unstable to such a sea level rise. Coupled ice sheet- climate modeling studies are needed to gain insight into the transient response of the Antarctic Ice Sheet to rising trace gas levels, and will help set guidelines for managing the large scale consequences of a potential rise in sea level. The long term goal is to develop a three-dimensional Antarctic Ice Sheet-climate model. The first stage of this project consists of a two-dimensional modeling study of marine ice sheet dynamics and of a parallel study of ice sheet-atmosphere model coupling methods. This investigation will develop a high resolution, thermomechanical, two-dimensional finite-element marine ice sheet- ice shelf model to be used in a sensitivity study to a variety of physical processes of potential importance in West Antarctic Ice Sheet behavior. These modeling studies will help set priorities for the development of a three-dimensional Antarctic Ice Sheet model.
