Antarctic ice sheet response to sudden and sustained ice shelf collapse (ABUMIP)

S. Sun, F. Pattyn, E. G. Simon, T. Albrecht, S. Cornford, R. Calov, C. Dumas, F. Gillet-Chaulet, H. Goelzer, N. R. Golledge, R. Greve, M. J. Hoffman, A. Humbert, E. Kazmierczak, T. Kleiner, G. R. Leguy, W. M. J. Lazeroms, W. H. Lipscomb, D. Martin, M. Morlighem, S. Nowicki, D. Pollard, S. Price, A. Quiquet, H. Seroussi, T. Schlemm, J. Sutter, R. S. W. van de Wal, R. Winkelmann and T. Zhang


Abstract

The response of the Antarctic ice sheet to future climate forcing will likely happen through weakening of ice shelves. While the processes governing ice-shelf weakening are quite complex, uncertainties in the response of the grounded ice sheet in response to decreased buttressing are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) aims to compare ice sheet model responses to buttressing by investigating the end-member of total and sustained loss of all ice shelves. The scenario is unrealistic but enables gauging the sensitivity of different ice sheet models with respect to the loss of buttressing and the resulting grounding line retreat. The ensemble results show that a total loss of ice shelves leads to multi-metre sea-level rise over 500 years (between 1 and 12 m), where all models exhibit an (almost) collapse of the West Antarctic ice sheet and significant mass loss in the Recovery basin. Mass loss rates are a strong function of the sliding/friction law, with plastic sliding/friction laws leading to a further destabilization of the Wilkes and Aurora Basins. Improvements to marine ice sheet models have greatly reduced variability in ice sheet response to extreme ice shelf melting, e.g., compared to the SeaRISE assessments.


Journal of Glaciology (submitted).

 
Last modified: 2020-01-23