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Optimizing numerical weather forecasting models for the CRAY-1 and cyber 205 computers

✍ Scribed by A. Dickinson


Publisher
Elsevier Science
Year
1982
Tongue
English
Weight
877 KB
Volume
26
Category
Article
ISSN
0010-4655

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✦ Synopsis


The Meteorological Office has recently acquired a Cyber 205 computer system which will be used to run large numerical models of the atmosphere and weather forecasting models. In particular a new operational forecast model has been developed for this computer and this is being coded to take full advantage of the vector capabilities of this machine. Development versions of this model have also been run on a Cray-I at the European Centre for Medium Range Weather Forecasts. This has presented the opportunity to compare some of the features of these two computers. It is shown that in general numerical weather prediction models can be split into two Sections, the dynamical and physical processes. In the dynamical processes the same operations are applied at every point in the integration domain and so these processes are readily vectorizable. However, the physical processes are conditional and intermittent in nature and use must be made of the mask/merge, compress/expand and gather/scatter class of instructions in order to vectorize these processes.