Improving the Computational Efficiency of the Global SL-AV Numerical Weather Prediction Model

Mikhail A. Tolstykh; Rostislav Yu. Fadeev; Vladimir  V. Shashkin; Gordey S. Goyman

doi:10.14529/jsfi210402

Authors

Mikhail A. Tolstykh Marchuk Institute of Numerical Mathematcis RAS, Hydrometeorological Research Center
Rostislav Yu. Fadeev Marchuk Institute of Numerical Mathematcis RAS, Hydrometeorological Research Center
Vladimir V. Shashkin Marchuk Institute of Numerical Mathematcis RAS, Hydrometeorological Research Center
Gordey S. Goyman Marchuk Institute of Numerical Mathematcis RAS

DOI:

https://doi.org/10.14529/jsfi210402

Keywords:

numerical weather prediction, global atmosphere model, computational efficiency, I/O optimization

Abstract

The recent works on improving the efficiency of the Russian SL-AV global numerical weather prediction model both for medium- and long-range forecasts are described. The algorithmic improvements of SL-AV dynamical core, implementation of parallel I/O and several code optimizations are presented. We investigate the impact of single precision computations in some parts of the code on present climate simulations. As a result of efforts described in this article, we are now able to compute a 24-hour forecast for the model version having about 10 km horizontal resolution and 104 vertical levels in 13 min using 2916 processor cores of Cray XC40 system. This timing allows multiple experiments for tuning this new model and fits the requirements for operational weather forecast. The single long-range forecast with low-resolution SL-AV version now takes just 89 minutes instead of 111. We have also verified that the partial utilization of single precision computations produces approximately the same model climate as the previous version with fully double precision computations.

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