| Abstract: |
| It is well known that deterministic two-dimensional marine ice
sheets can only be stable if the grounding line is positioned at a
sufficiently steep, downward sloping bedrock. When bedrock
conditions favour instabilities, multiple stable ice sheet
profiles may occur. Here, we employ continuation techniques to
examine the sensitivity of a two-dimensional marine ice sheet to
stochastic noise representing short time scale variability, either
in the accumulation rate or in the sea level height. We find that
in unique regimes, the position of the grounding line is most
sensitive to noise in the accumulation rate and can explain
excursions observed in field measurements. In the multiple
equilibrium regime, there is a strong asymmetry in transition
probabilities between the different ice sheet states, with a
strong preference to switch to the branch with a
steeper bedrock slope. |
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