Results of the Second Ice Shelf-Ocean Model Intercomparison Project (ISOMIP+)

Authors

• Claire K. Yung, The Australian National University
• Xylar S. Asay-Davis, Los Alamos National Laboratory
• Alistair Adcroft, Princeton University
• Christopher Y. S. Bull, Australian National University
• Jan De Rydt, Northumbria University
• Michael S. Dinniman, Old Dominion UniversityFollow
• Benjamin K. Galton-Fenzi, University of Tasmania
• Daniel Goldberg, University of Edinburgh
• David E. Gwyther, The University of Queensland, Australia
• Robert Hallberg, Princeton University
• Matthew Harrison, NOAA/Geophysical Fluid Dynamics Laboratory
• Tore Hattermann, Norwegian Polar Institute
• David M. Holland, New York University
• Denise Holland, New York University
• Paul R. Holland, British Antarctic Survey
• James R. Jordan, Swansea University
• Nicolas C. Jourdain, Univ. Grenoble Alpes/CNRS/IRD/G-INP/INRAE
• Kazuya Kusahara, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
• Gustavo Marques, National Center for Atmospheric Research
• Pierre Mathiot, Univ. Grenoble Alpes/CNRS/IRD/G-INP/INRAE
• Adele K. Morrison, The Australian National University
• Yoshihiro Nakayama, Dartmouth College
• Olga Sergienko, Princeton University
• Robin S. Smith, University of Reading
• Alon Stern, Princeton University
• Ralph Timmermann, Alfred-Wegener-Institut für Polar- und Meeresforschung
• Qin Zhou, Akvaplan-niva AS

Document Type

Article

Publication Date

2026

DOI

10.5194/tc-20-2053-2026

Publication Title

The Cryosphere

Volume

20

Issue

4

Pages

2053-2088

Abstract

Ocean-driven basal melting of Antarctic ice shelves plays an important role in the mass loss of the Antarctic Ice Sheet. Ice shelf cavity-resolving ocean models are a valuable tool for understanding ice shelf-ocean interactions and for simulating projections of ice shelf and ocean states under future climate. Designed to assess the current state of ice shelf–ocean modelling, the second Ice Shelf–Ocean Model Intercomparison Project, ISOMIP+, consists of 12 ocean model configurations submitted with a common, idealised experimental setup. Here, we focus on the experiments Ocean0–2 (Asay-Davis et al., 2016), which are ocean models with idealised, static ice shelf geometries, but where the ocean reaches a balance with prescribed far-field ocean conditions. Different thermal transfer coefficient values (ranging from 0.011 to 0.2) are used for each model in the melting parameterisation to achieve a common, tuned melt rate since the models cover a range of types of vertical coordinates, ice–ocean boundary layer treatments, and numerical schemes. These model differences lead to spread in the resultant ocean properties, circulation, boundary-layer structure and spatial distribution of melting. We also highlight similarities between models, such as a shared linear relationship across most models between melt rate and overturning and barotropic streamfunctions during the spin-up and spin-down, demonstrating a robust relationship between melt and circulation across models and forcing conditions. The ISOMIP+ results provide a systematic comparison of ice shelf cavity-capable ocean models. However, we also demonstrate the need for realistic ice shelf–ocean model intercomparison projects (some already underway) to assess model biases and inter-model variation against sparse observations. Further research is needed to understand the differences between models and further improve our modelled representations of the ice–ocean boundary layer and ice shelf cavity circulation.

Rights

© Authors 2026.

This work is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0) License.

Data Availability

Article states: "The code used to prepare the figures is available at https://github.com/misomip/isomip-plus, last access: 1 April 2026 and archived at Yung et al. (2026). Submitted model data and metadata (PDF information sheets) is available on the platform Open Science Framework (https://osf.io/, last access: 1 April 2026) using the Digital Object Identifiers in Table 3."

Original Publication Citation

Yung, C. K., Asay-Davis, X. S., Adcroft, A., Bull, C. Y. S., De Rydt, J., Dinniman, M. S., Galton-Fenzi, B. K., Goldberg, D., Gwyther, D. E., Hallberg, R., Harrison, M., Hattermann, T., Holland, D. M., Holland, D., Holland, P. R., Jordan, J. R., Jourdain, N. C., Kusahara, K., Marques, G.,…Zhou, Q. (2026). Results of the second Ice Shelf–Ocean Model Intercomparison Project (ISOMIP+). The Cryosphere, 20(4), 2053-2088. https://doi.org/10.5194/tc-20-2053-2026

Repository Citation

Yung, Claire K.; Asay-Davis, Xylar S.; Adcroft, Alistair; Bull, Christopher Y. S.; Rydt, Jan De; Dinniman, Michael S.; Galton-Fenzi, Benjamin K.; Goldberg, Daniel; Gwyther, David E.; Hallberg, Robert; Harrison, Matthew; Hattermann, Tore; Holland, David M.; Holland, Denise; Holland, Paul R.; Jordan, James R.; Jourdain, Nicolas C.; Kusahara, Kazuya; Marques, Gustavo; Mathiot, Pierre; Morrison, Adele K.; Nakayama, Yoshihiro; Sergienko, Olga; Smith, Robin S.; Stern, Alon; Timmermann, Ralph; and Zhou, Qin, "Results of the Second Ice Shelf-Ocean Model Intercomparison Project (ISOMIP+)" (2026). CCPO Publications. 415.
https://digitalcommons.odu.edu/ccpo_pubs/415

ORCID

0000-0001-7519-9278 (Dinniman)