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

• Published in: Journal of Glaciology
• Main Authors: Sun, S., Pattyn, F., Simon, E., Albrecht, T., Cornford, S., Calov, R., Dumas, C., Gillet-Chaulet, F., Goelzer, H., Golledge, N., Greve, R., Hoffman, M., Humbert, A., Kazmierczak, E., Kleiner, T., Leguy, G., Lipscomb, W., Martin, D., Morlighem, M., Nowicki, S., Pollard, D., Price, S., Quiquet, A., Seroussi, H., Schlemm, T., Sutter, J., van de Wal, R., Winkelmann, R., Zhang, T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Antarc*; Antarctic; Antarctica; East Antarctica; Ice Sheet; Ice Shelf; Ice Shelves; Journal of Glaciology
• Online Access: http://hdl.handle.net/21.11116/0000-000F-BD78-6; http://hdl.handle.net/21.11116/0000-000F-BD7A-4

Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario enables gauging the sensitivity of an ensemble of 15 ice-sheet models to a total loss of buttressing, hence exhibiting the full potential of marine ice-sheet instability. All models predict that this scenario leads to multi-metre (1–12 m) sea-level rise over 500 years from present day. West Antarctic ice sheet collapse alone leads to a 1.91–5.08 m sea-level rise due to the marine ice-sheet instability. Mass loss rates are a strong function of the sliding/friction law, with plastic laws cause a further destabilization of the Aurora and Wilkes Subglacial Basins, East Antarctica. Improvements to marine ice-sheet models have greatly reduced variability between modelled ice-sheet responses to extreme ice-shelf loss, e.g. compared to the SeaRISE assessments. Introduction Experiments and model setup Description of the experiments Control run (ABUC) Ice-shelf removal or ‘float-kill’ (ABUK) Extreme sub-ice-shelf melt (ABUM) Model setup Participating models Results ABUC ABUK ABUM Discussion Sensitivity to basal friction Sensitivity to the forcing scheme Sensitivity to model physics and numerics Spatial resolution Initial geometry Basal sliding law Subglacial hydrology Sensitivity to hydro-fracturing and Marine Ice Cliff Instability Comparison to other studies Conclusions