Jayasuriya H1, Gatti T1, Leopardi P1, Heerdegen A1, Druken K1
1ACCESS-NRI, , Australia
Biography:
Harshula Jayasuriya is a Principal Research Software Engineer in the Model Release team at ACCESS-NRI. He is Free/Open-Source Software advocate and a Debian Developer with two decades of experience working with software build systems. Once upon a time, he was a Linux/Unix filesystem engineer working on NFS and UDF at Red Hat Inc and Silicon Graphics Inc.
Tommy Gatti is a Senior Research Software Engineer for the Model Release Team at ACCESS-NRI. He's a multidisciplinary programmer who enjoys developing CI/CD infrastructure and technical pathfinding in different domains. In previous industry roles he has been a driver developer and member of a third level support team.
Paul Leopardi is a Senior Research Software Engineer at ACCESS-NRI, currently working on supporting an Earth System Model. His qualifications include a PhD in computational mathematics and experience in teaching numerical linear algebra, optimization and combinatorics. His 40-year background in computing includes working with parallel Fortran codes, High-Performance Computing and postprocessing of operational weather forecasting data.
Aidan Heerdegen is the Model Release Team Lead for ACCESS-NRI. He is passionate about making software work for people. In previous roles he provided computational support to climate researchers in two ARC Centres of Excellence, and prior to that was a physical chemist working in a software role supporting X-ray scattering research.
Kelsey Druken is the Associate Director for Release Management and responsible for the software, data and training portfolio at ACCESS-NRI, Australia's Climate Simulator. She holds a PhD in Oceanography from the University of Rhode Island and prior to her current role, was the Associate Director of Data Management at the National Computational Infrastructure (NCI).
Abstract:
Trust in climate model projections depends not only on the underlying science, but also on the software processes used to produce them. As climate models increase in complexity and underpin major international activities (e.g., Intergovernmental Panel on Climate Change's CMIP7 process), modern software engineering practices are essential for ensuring reproducibility, transparency and confidence in model outputs.
Building legacy code requiring specific versions of scientific libraries, across heterogeneous platforms (HPCs), while targeting scientific reproducibility and longitudinal bitwise reproducibility, presents a formidable engineering challenge.
ACCESS-NRI has recently completed a significant shift on how Australian Community Climate and Earth System Simulator models are developed and deployed. Historically, much of the responsibility for building, configuring and maintaining complex model software rested with individual researchers, many of whom came from scientific rather than software engineering backgrounds. ACCESS-NRI has instead adopted a more structured and collaborative approach that embeds modern software development practices, shared tooling and dedicated research software engineering expertise into the model development lifecycle. This talk reflects on the project's five main phases, covering proof-of-concept development, national and international collaboration, contributions to upstream projects, and efforts to improve the user experience.
This case study demonstrates approaches that can be adopted by other projects seeking to modernise scientific software. It highlights lessons learned, challenges encountered and opportunities created through stronger collaboration and shared tooling.
