ACCESS-ISSM: Release Information

ACCESS-NRI Releases
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What is this?

A topic that will be used to announce release information and updates for ACCESS-ISSM.

What is ACCESS-ISSM?

ACCESS-ISSM is the supported release of the Ice-sheet and Sea-level System Model (ISSM) optimised for NCI hardware.

How is this topic used?

This topic will be the place where release information and updates to ACCESS-ISSM will be announced, with details of what those updates entail.

What should I do to be notified of any updates?

You can watch this topic, and be notified by email of every update.

Where do I ask questions about releases?

Replies to this topic are disabled.

If you have specific questions about this release follow the guidelines for requesting help from ACCESS-NRI.

If you have questions about access-issm please create a topic in the relevant channel within Cryosphere > ACCESS-ISSM community space. If you require assistance follow the guidelines for requesting help from ACCESS-NRI.

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ACCESS-ISSM release

:rocket: 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 gadi and 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 main branch of the ACCESS-ISSM deployment repository.

:loudspeaker: THIS IS A BETA RELEASE :loudspeaker:

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

Features

:white_check_mark: ISSM source at 2026.05.18, built and deployed using the ACCESS-NRI pipeline.
:white_check_mark: Pre-compiled executables, no build required for standard use.
:white_check_mark: Python and C++ wrappers enabled (+wrappers, +py-tools), for use with the pyISSM Python API.
:white_check_mark: Production build (+production), with an optimised PETSc configuration for improved solver performance.
:white_check_mark: Built with Spack 1.1 and access-spack-packages 2026.05.002, with full build provenance published as a spack.lock with each release.
:white_check_mark: Deployed as an environment module on gadi under vk83.
:white_check_mark: 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

:stop_sign: No ACCESS-NRI released model configuration accompanies this deployment. Users supply their own model setup, meshes and input data.
:stop_sign: This release is the default build; automatic differentiation is not enabled. Use access-issm+ad if you need adjoint capability.
:stop_sign: Limited testing undertaken.
:stop_sign: CPU only. GPU-enabled solver work is ongoing and not part of this release.

Known Issues

:warning: Model output is written to /scratch. It is currently a user responsibility to copy output to long term storage if that is a requirement.
:warning: At the time of release pyISSM is in beta development and its API may change between versions.

Future developments

:construction: Associated release of an open community whole-Antarctic configuration, ACCESS-AIS3.
:construction: Continued development of the associated pyISSM Python API for model setup, execution, visualisation and analysis.
:construction: Release of GPU-enabled linear solves via a CUDA-enabled PETSc.

Credits (Latest developments only)

:star: Optimised PETSc build for the production release (@justinh2002)

:star: Adjoint (+ad) build and Spack recipe (@justinh2002)

:star: Default ISSM build and deployment (@justinh2002 @lawrenceabird @mtetley)

:star: Build and deployment infrastructure (@TommyGatti @harshula @Aidan)

:star: pyISSM development (@lawrenceabird @justinh2002 @mtetley )

:star: 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).

Resources