Wehner, M. F., 1995: Results from the parallel UCLA/LLNL
atmospheric general circulation model. Abstracts of the First International
AMIP Scientific Conference, Monterey, California, 51.
We have rewritten the UCLA AGCM in a form suitable for distributed
memory massively parallel processing computers. We have chosen to use Richardson's
1922 two-dimensional domain decomposition as the strategy to achieve parallelism.
This technique is well suited to the finite difference hydrodynamics scheme
of Arakawa and Lamb as well as for the column based physical parameterizations.
The performance of a wide variety of computers, including the IBM SP2,
Cray T3D and Meiko CS2 will be compared to that obtained on a single processor
CRAY C90. Validation of the rewritten code is complicated by propagation
of roundoff differences, principally by the Arakawa-Schubert cumulus convection
scheme. Therefore, to validate the parallel code and machines for long
term simulations, we are using the climate statistics obtained from 10
year AMIP simulations as the principal diagnostic regarding the correctness
of the new implementation. Preliminary results from several runs will be
presented.