East Antarctic ice sheet most vulnerable to Weddell Sea warming

Published: Mar 1, 2017 by The PISM Authors

In practice, ice sheet models need to be re-run many times with slightly-altered parameters. This short paper describes the results of an ensemble of 42 PISM runs for the entire Antarctic ice sheet (AIS), starting from present-day conditions, each for 10,000 model years, to see which sectors of the continent are most affected by warming. The runs vary only in atmospheric (air temperature anomaly) and oceanic (sea surface temperature anomaly) warming. The results are clear and consistent when examined at drainage basin scale (Zwally et al 2012). The basins of the West Antarctic Ice Sheet (WAIS) show strong sensitivity to a modest amount of ocean warming, with a 0.5 C anomaly generating an essentially-complete collapse of WAIS, just as expected from other observational and simulation evidence. In the East (EAIS), however, the Recovery ice stream basin stands out as sensitive to //both// kinds of warming. Other EAIS basins such as Wilkes and Aurora are sensitive to atmospheric heat inputs but much less so to oceanic inputs.