EGU25-15073, updated on 14 Jul 2025
https://doi.org/10.5194/egusphere-egu25-15073
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Version 3 of the Community Ice Sheet Model
Gunter Leguy1, William Lipscomb1, Kate Thayer-Calder1, Samar Minallah1, Michele Petrini2, Heiko Goeltzer2, Tim van den Akker3, Bill Sacks1, Mariana Vertenstein4, and Mira Berdahl5
Gunter Leguy et al.
  • 1NSF National Center for Atmospheric Research, CGD, Lafayette, United States of America (gunterl@ucar.edu)
  • 2NORCE Norwegian Research Centre AS, Bjerknes Centre for Climate Research, Climate & Environment, Norway
  • 3Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Netherlands
  • 4Norwegian Meteorological Institute, Oslo, Norway
  • 5Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA

Version 3 of the Community Ice Sheet Model (CISM) is scheduled for release later this year along with version 3 of the Community Earth System Model (CESM). CISM is a parallel, open-source ice flow code, written in Fortran and Python, which can be run as a standalone ice sheet or glacier model or as a coupled component of CESM and NorESM. The model supports several Stokes-flow approximations and has participated in many community intercomparison projects, including ISMIP6, CalvingMIP, and GlacierMIP3.

CISM3 will include new physics options for basal sliding, basal hydrology, iceberg calving, and extrapolating sub-ice-shelf temperature and salinity. A new initialization procedure allows the rate of ice mass change to match observations at the beginning of a projection simulation.  Coupled CISM–CESM simulations can include two-way climate coupling with multiple ice sheets, including Antarctica. CISM3 also has an exciting new capability to initialize and simulate mountain glaciers.

To improve user experience, CISM3 will include new Python tools for setting up glacier and ice sheet simulations and analyzing ice-sheet-relevant fields from other CESM components. CISM is now more integrated with CESM than ever before, by leveraging the Common Infrastructure for Modeling the Earth (CIME) case control and testing system for verification and validation. 

This presentation showcases examples and results using CISM3’s new tools and capabilities. 

How to cite: Leguy, G., Lipscomb, W., Thayer-Calder, K., Minallah, S., Petrini, M., Goeltzer, H., van den Akker, T., Sacks, B., Vertenstein, M., and Berdahl, M.: Version 3 of the Community Ice Sheet Model, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15073, https://doi.org/10.5194/egusphere-egu25-15073, 2025.