ACCESS-ISSM release
Release: access-issm_ad 2026.05.0
What can you expect to be able to do with this?
A user should be able to
- load ACCESS-ISSM as a module on
gadiand run ISSM simulations of ice sheet, glacier and ice shelf dynamics, using the ISSM executables and Python/C++ wrappers built by the ACCESS-NRI deployment pipeline. - build the model themselves with Spack (on non-NCI systems), using the
mainbranch of the ACCESS-ISSM deployment repository.
THIS IS A BETA RELEASE
This is a beta release while rolling out features and getting feedback from the community.
More information on release stages are available on the Hive Docs:
Release stages - ACCESS-Hive Docs
Feedback
We welcome all feedback from all interested users. This provides a chance to work together and improve this release.
Please provide feedback through relevant channels within Cryosphere > ACCESS-ISSM community space on this forum.
ACCESS-NRI is interested in all feedback, positive or negative, but in particular we would like to know:
- Are the instructions clear and easy to follow? Is there anything unclear, missing or incorrect?
How to use
ACCESS-ISSM is deployed on gadi under the vk83 project. You need to be a member of vk83 to use ACCESS-NRI deployments.
module use /g/data/vk83/modules
module load access-issm_ad/2026.05.0
To see all available ACCESS-ISSM versions:
module avail access-issm
- ACCESS-ISSM deployment repository — includes build instructions for compiling the model yourself with Spack
- Release notes and build provenance for 2026.05.0 — including
spack.location(paths to executables ongadi), thespack.lockprovenance document and thespack.yamlused for deployment - ISSM documentation (NASA JPL) — upstream model documentation and tutorials
- ACCESS-ISSM Hive-Docs - How to run a model - Walkthrough on how to setup and run an ACCESS-ISSM model using the pyISSM Python API
Features
ISSM source at 2026.05.18, built and deployed using the ACCESS-NRI pipeline.
Pre-compiled executables, no build required for standard use.
Python and C++ wrappers enabled (+wrappers, +py-tools), for use with the pyISSM Python API.
Production build (+production), with an optimised PETSc configuration for improved solver performance.
Built with Spack 1.1 and access-spack-packages 2026.05.002, with full build provenance published as a spack.lock with each release.
Deployed as an environment module on gadi under vk83.
An adjoint-capable (+ad) build is also available as access-issm+ad/2026.04.0 for inverse and sensitivity work.
Key components
| Component | Version |
|---|---|
| ISSM | git.2026.05.18 |
| PETSc | 3.21.1 |
| MUMPS | 5.8.2 |
| METIS / ParMETIS | 5.1.0 / 4.0.3 |
| ScaLAPACK | 2.2.0 |
| Triangle | 1.6.1 |
| OpenMPI | 4.1.5 |
| Python / NumPy | 3.11.14 / 1.26.4 |
| Compilers | Intel oneAPI 2025.2.0 |
Limitations
No ACCESS-NRI released model configuration accompanies this deployment. Users supply their own model setup, meshes and input data.
This release is the default build; automatic differentiation is not enabled. Use access-issm+ad if you need adjoint capability.
Limited testing undertaken.
CPU only. GPU-enabled solver work is ongoing and not part of this release.
Known Issues
Model output is written to /scratch. It is currently a user responsibility to copy output to long term storage if that is a requirement.
At the time of release pyISSM is in beta development and its API may change between versions.
Future developments
Associated release of an open community whole-Antarctic configuration, ACCESS-AIS3.
Continued development of the associated pyISSM Python API for model setup, execution, visualisation and analysis.
Release of GPU-enabled linear solves via a CUDA-enabled PETSc.
Credits (Latest developments only)
Optimised PETSc build for the production release (@justinh2002)
Adjoint (+ad) build and Spack recipe (@justinh2002)
Default ISSM build and deployment (@justinh2002 @lawrenceabird @mtetley)
Build and deployment infrastructure (@TommyGatti @harshula @Aidan)
pyISSM development (@lawrenceabird @justinh2002 @mtetley )
Documentation (@lawrenceabird @mtetley )
Support
Replies to this topic are disabled.
If you have specific questions about this release please add a topic on this forum and tag with help (more information about support for ACCESS-NRI’s released software).