[ESMF_info] ESMF 8.9.0 released
Ann Tsay
Dear all,
The ESMF Core Team is pleased to announce the ESMF 8.9.0 release. It is now available for download at https://github.com/esmf-org/esmf/releases/tag/v8.9.0.
The 8.9.0 release of ESMF is backward compatible with ESMF 8.8.1 for all the interfaces that are marked as backward compatible in the Reference Manual. ESMF 8.9.0 introduces feature enhancements, better troubleshooting tools, and 8 bug fixes in different areas of the framework and interface layers. Below are some highlights of the change:
Regarding feature enhancements within the framework, an ESMF_InternalState API was added that allows user code to attach private data allocations to ESMF components, and later retrieve them. The output of stdout and stderr streams of the ESMF component classes can now be redirected into user specified files. Lastly, to help with debugging ESMF errors, two new ESMF runtime settings, ESMF_RUNTIME_ABORT_LOGMSG_TYPES and ESMF_RUNTIME_ABORT_ACTION have been added. The NUOPC layer is also enhanced with the addition of a HierarchyConnectors attribute, allowing users to manually define hierarchy connections and have more control over the connections made between levels of component hierarchies.
Although there are some API changes to add more options for users, in general this release requires no user code changes. There are some notable feature enhancements in the interface layer such as supporting multiple decomposition elements (DEs) on a single Persistent Execution Thread (PET) in ESMPy, adding an optional grid_to_field_map argument in ESMPy, and supporting vector regridding in both the C and ESMPy APIs.
Lastly, ESMF 8.9.0 introduced some roundoff level bit-for-bit changes compared with ESMF 8.8.1 due to modifications to the mesh dual algorithm. These changes could occur in bilinear or patch regridding weights when the source Field is built on the ESMF_MESHLOC_ELEMENT location.
The ESMF Team also would like to take this opportunity to notify the community that the next version of ESMF (9.0.0), tentative release date in February 2026, may include features that are not backward compatible. Up-to-date information can be found on the Github Discussion Board. We welcome community input and feedback on the Discussion Board. The final list of features will be announced via the esmf...@ucar.edu mailing list.
The ESMF team is grateful for the many years of support, ideation, feedback, testing, and code contributions that the ESMF user community has provided since its inception. We look forward to continuing this partnership with the community to further improve and add features to ESMF. As always, please utilize ESMF Discussions (https://github.com/orgs/esmf-org/discussions) or write esmf_s...@ucar.edu with any questions or issues concerning ESMF.
With best regards,
The ESMF Core Team