DESIGN AND PERFORMANCE OF A SCALABLE PARALLEL COMMUNITY CLIMATE MODEL

We describe the design of a parallel global atmospheric circulation mo del, PCCM2. This parallel model is functionally equivalent to the Nati onal Center for Atmospheric Research's Community Climate Model, CCM2, but is structured to exploit distributed memory multicomputers. PCCM2 incorporates parallel spectral transform, semi-Lagrangian transport, a nd load balancing algorithms. We present detailed performance results on the IBM SP2 and Intel Paragon. These results provide insights into the scalability of the individual parallel algorithms and of the paral lel model as a whole.