On the initiation of ice sheets

Abstract

The initiation and evolution of ice sheets are investigated using a two-dimensional thermo-mechanical ice-sheet model. The importance of the amount of snow accumulation on the ice sheet initiation is summarised in the following three points: (1) an ice sheet can grow from an initial area of less than 50 km diameter with a positive but large-enough accumulation rate; (2) the pattern of multiple steady-state solution branches critically depends on the surface mass balance; and (3) snow accumulation strongly controls the growth rate of the ice mass, which is crucial for ice sheets evolving in the limited time available during Milankovitch cycles.