Results of the third Marine Ice Sheet Model Intercomparison Project (MISMIP+)

• Main Authors: Cornford, Stephen L., Seroussi, Helene, Asay-Davis, Xylar S., Gudmundsson, G. Hilmar, Arthern, Rob, Borstad, Chris, Christmann, Julia, Dias dos Santos, Thiago, Feldmann, Johannes, Goldberg, Daniel, Hoffman, Matthew J., Humbert, Angelika, Kleiner, Thomas, Leguy, Gunter, Lipscomb, William H., Merino, Nacho, Durand, Gaël, Morlighem, Mathieu, Polllard, David, Rückamp, Martin, Williams, C. Rosie, Yu, Hongju
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications (EGU) 2020
• Subjects: Ice Sheet; Ice Shelf; Ice Shelves; The Cryosphere; The Cryosphere Discussions
• Online Access: https://oceanrep.geomar.de/id/eprint/49427/; https://oceanrep.geomar.de/id/eprint/49427/1/tc-2019-326.pdf; https://doi.org/10.5194/tc-2019-326

We present the result of the third Marine Ice Sheet Intercomparison project, MISMIP+. MISMIP+ is intended to be a test of ice flow models which include fast sliding marine ice streams and floating ice shelves and in particular a treatment of viscous stress that is sufficient for buttressing, where upstream ice flow is restrained by a downstream ice shelf. A set of idealized experiments test the models in circumstances where buttressing contributes to a stable steady state, and where a reduction in that buttressing causes ice stream acceleration, thinning, and grounding line retreat. We find that the most important distinction between models in this particular type of simulation is in the treatment of sliding at the bed, with other distinctions – notably the difference between the simpler and more complete treatments of englacial stress, but also the differences between numerical methods – taking a secondary role.