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

• Main Authors: Sun, S, Pattyn, F, Simon, EG, Albrecht, T, Cornford, S, Calov, R, Dumas, C, Gillet-Chaulet, F, Goelzer, H, Golledge, NR, Greve, R, Hoffman, MJ, Humbert, A, Kazmierczak, E, Kleiner, T, Leguy, GR, Lipscomb, WH, Martin, D, Morlighem, M, Nowicki, S, Pollard, D, Price, S, Quiquet, A, Seroussi, H, Schlemm, T, Sutter, J, Van De Wal, RSW, Winkelmann, R, Zhang, T
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2020
• Subjects: Antarctic glaciology; ice-sheet modelling; ice shelves; Meteorology & Atmospheric Sciences; Physical Geography and Environmental Geoscience; Antarctic; East Antarctica; The Antarctic; West Antarctic Ice Sheet; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Ice Shelves; Journal of Glaciology
• Online Access: https://escholarship.org/uc/item/4zv1d5cx

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.