Computational aspects of a code to study rotating turbulent convection in spherical shells

The coupling of highly turbulent convection with rotation within a full spherical shell geometry, such as in the solar convection zone, can be studied with the new anelastic spherical harmonic (ASH) code developed to exploit massively parallel architectures. Inter-processor transposes are used to ensure data locality in spectral transforms, a sophisticated load balancing algorithm is implemented and the Legendre transforms, which dominate the workload for large problems, are highly optimized by exploiting the features of cache memory and instruction pipelines. As a result, the ASH code achieves around 120 Mflop/s per node on the Gray T3E and scales nearly linearly for adequately large problem sizes. (C) 1999 Published by Elsevier Science B.V. All rights reserved.