solution of the implicit formulation of high order diffusion for the canadian atmospheric gem model
An efficient implementation of the implicit high order diffusion in grid point global Environmental Multiscale (GEM) model is presented. The method expresses the high order diffusion equation as a sequence of equations involving the spherical Laplace operator ? 2 . The solution is obtained by a direct method where, we combine fast Fourier transforms in longitude with a block LU solver in latitude. The performance of the parallel Direct solution on IBM supercomputer is given.
fast fourier transforms block lu solver global transposition implicit high-order diffusion