GPU-based implementation of a diagnostic wind field model used in real-time prediction of atmospheric dispersion of radionuclides

This work is focused on the Wind Field module, which uses a mass-consistent approach, based on Winds Extrapolated from Stability and Terrain (WEST) model. Due to the strong sequential nature of the algorithm, domain decomposition by a 3D-Red-Black partitioning was proposed and a new parallel GPU-based algorithm was implemented using the Compute Unified Device Architecture (CUDA) and C programming language. As a result, the execution time of a fine-grained simulation decreased from about 450 s (running on an Intel-I7) to 18 s (running on a GTX-680 GPU). Here, the most important issues of the parallel implementation, as well as comparative results, are presented and discussed.