The NWP and DA software infrastructure is in the middle of a transition. Up until now, each organization and model used their own software stack; but these stacks only worked for that single model, which led to an immense amount of duplicated effort and a lot of catch-up for bug fixes that had to be applied to individual organizations’ codes one at a time. The design limitations of these separate stacks also made it difficult to build consistent library sets, especially when incorporating complex Python environments.

That started changing in 2021, when JCSDA and NOAA EMC began exploring Spack as an option for creating a single software stack that could be used for both the JEDI DA software environment and the Unified Forecast System (UFS) ecosystem. Since then both teams have combined their efforts to put together a new stack that works with not only JEDI and the UFS, but also with MPAS, NEPTUNE, the Unified Model and soon GEOS, and that eliminates the confusion and upkeep demands of keeping dozens of different software stacks running. What is more, spack-stack builds seamlessly on Linux and macOS laptops, high performing computing systems, and cloud platforms. With Spack-stack new users can have JEDI set up on their laptops in less than a week, sometimes even less than a day, as opposed to weeks or months with the previous solutions.

Last year EPIC came on board with the project as well, with the goal to support spack-stack on additional cloud platforms and to the community. As of today, all of JEDI and several UFS applications have already transitioned to spack-stack. In addition, NOAA’s National Center of Operations (NCO) has chosen spack-stack as the software environment on their operational supercomputers. This will reduce the uncertainty in the research-to-operations transition as well as saving time and energy spent keeping their old software stack operational.

Last week’s 1.5.0 release is the first spack-stack release to be officially used by UFS, marking this collaboration between NOAA EMC, JCSDA, EPIC, and our other partners a definite success!

Photo by Richard Gatley on Unsplash