The parallelization strategy used is to decompose the problem domain into geographical patches and assign each processor to do the computation associated with a distinct subset of patches. With this decomposition, the physics calculations involve only grid points and data local to a processor and are performed in parallel. Using parallel algorithms developed for the semi-Lagrangian transport, the fast Fourier transform and the Legendre transform, both physics and dynamics are computed in parallel with minimal data movement and modest change to the original CCM2 sourse code.
J. B. Drake, R. E. Flanery, P. H. Worley, D. W. Walker, I. T. Foster, J. G. Michalakes, R. L. Stevens, J. J. Hack and D. L. Williamson, The Message Passing Version of the Parallel Community Climate Model, in Parallel Supercomputing in Atmispheric Science: Proceedings of the Fifth ECMWF Workshop on the Use of Parallel Processors in Meterology, held November 23-25, 1992. Edited by G.-R. Hoffmann and T. Kauranne. Published by World Scientific Publishing, 1993.