RRTMGP: A High-Performance Broadband Radiation Code for the Next Decade

: The radiation calculations needed for climate simulations require many independent and complicated calculations, and are therefore an inviting target for new computing architectures such as Many- Integrated-Cores (MICs) and Graphical Processing Units (GPUs). We are developing RRTMGP ( P stands for parallel ), a modern version of the radiation code (RRTMG) used by many climate models, directed at the current generation of vector- and cache-based computational architectures. This code will retain the high accuracy of RRTMG, but is being developed from scratch to make it more flexible and amenable to optimization across a wide range of platforms. The objective is a single wellmaintained, well-documented, and efficient radiation code that can be used by the modeling community for a diverse range of applications across a wide range of computing facilities. RRTMGP will exhibit profound improvements in speed for GPU and vector CPU machines and lesser, but still valuable, speed-ups on other CPU-based platforms relative to the current version of the code.