Data for "Scaling of Ice Stream Spacing and Flux from Numerical Simulation"

Corridors of fast ice flow, ice streams, dominate the discharge of contemporary ice sheets. Ice streams are points of vulnerability for ice sheet instabilities, and so to understand past and future ice sheet change we need to understand ice stream behaviour. Computer simulations can replicate the spacing and flux of palaeo and contemporary ice streams, but for accurate future projections we need confidence that simulated ice streams will evolve in a dynamic and realistic manner.

This is much harder to constrain with empirical evidence, and there is still considerable uncertainty regarding ice stream behaviour in our warming world. To explore controls on the spacing and flux of ice streams, we run simulations of a circular ice sheet on a flat bed. We simulate a series of idealised circular ice sheets of various radii, finding that plausible ice stream spacing and magnitude is simulated even on a flat bed, and that ice stream magnitude and frequency scales with ice volume.

We apply the idealised model to the bed of an idealised Icelandic Ice Sheet, resulting in a greater magnitude of streaming relative to the idealised case. The realistic setting makes ice stream position broadly insensitive to changes in topography and geothermal heat flux. These simulations demonstrate the sensitivity of ice stream behaviour to ice sheet size and bed geometry, with potential implications for how we simulate ice sheet change over medium and long timescales.