Balancing EC‐Earth3 Improving the Performance of EC‐Earth CMIP6 Configurations by Minimizing the Coupling Cost

Abstract Earth System Models (ESMs) are complex systems used in weather and climate studies generally built from different independent components responsible for simulating a specific realm (ocean, atmosphere, biosphere, etc.). To replicate the interactions between these processes, ESMs typically use coupling libraries that manage synchronization field exchanges individual components, which run parallel as Multi‐Program, Multiple‐Data application. As get more (increase resolution, number of configurations, etc.), achieving best performance when running High‐performance Computing platforms has become increasingly challenging major concern. One critical bottlenecks is load‐imbalance, where fastest will have to wait slower ones. Finding optimal processing elements assign each multiple constituents minimize loss due synchronizations maximize overall efficiency impossible without right metrics, methodology, tools. This paper presents results balancing Coupled Model Intercomparison Project phase 6 configurations EC‐Earth3 ESM. We show intuitive approaches can lead suboptimal resource allocations propose new setups up 25% fasters while reducing computational cost by 72%. prove methods needed deal with load‐balance hope our study serve guide optimize any other coupled system.