Performance of a parallel finite difference atmospheric general circulation model 1

A new version of the Institute of Atmospheric Physics (IAP) 9-Layer (9L) atmospheric general circulation model (AGCM) suitable for Massively Parallel Processor (MPP) has been developed. This paper presents the principles of the parallel code design and examines its performance on a variety of state-of-the-art parallel computers in China. Domain decomposition strategy is used to achieve parallelism that is implemented by Message Passing Interface (MPI). Only the one dimensional domain decomposition algorithm is shown to scale favorably as the number of processors is increased. This work is partly supported by the National Natural Science Foundation of China (Grant Nos. 49775268 and 49823002), the China National Key Development Planning Project for Basic Research (Grant No. G1998040905) and the CAS Key Innovation Direction Project (Grant No. KZCX2208).