Abstract: Earth system models (ESMs) are pivotal tools for understanding the mechanisms of past climate and environmental evolution and projecting future global change scenarios. However, the rapid advancement of computer technology has introduced significant challenges in programming, porting, and optimizing model development. To address these issues, OpenArray 2.0, an automatic parallel computing framework designed for ESMs, decouples model development from underlying parallel computing architectures by employing technologies such as custom operator interfaces, implicit parallelism, computational graph optimization, automatic code generation, just-in-time compilation, and dynamic I/O scheduling. OpenArray 2.0 allows users to write models using Matlab-like serial syntax while enabling parallel execution across heterogeneous platforms, including x86, Sunway, and GPUs. Models developed with OpenArray 2.0 achieve 75% parallel efficiency on an x86 platform with 19 200 cores, delivering performance close to manually optimized code. On the Sunway platform with a million-core environment, it demonstrates 70% scalability, while also exhibiting exceptional execution efficiency on GPU platforms. As a highly promising alternative tool for ESM advancement, OpenArray 2.0 is poised to significantly enhance both model development efficiency and computational performance.

Key words: operator, implicit parallelism, high performance computing, earth system model