Implementation of ICON 10km global coupled demonstrator and performance analysis (D2.12)

We have evaluated and improved the performance of a 5km-5km coupled ocean-atmosphere ICON set up. The set up makes use of ECHAM physics for the atmosphere component, but abstains from parameterisations for convection and gravity waves. The work was accomplished to enable simulations on bigger node counts, and column-blocking parameter tuning was carried out. Throughput on O(500) nodes suggests a performance of ca. 20 simulated days per day. Although the provided investigations are rather preliminary results than the end of the story on performance investigation for coupled high-resolution ICON simulations, the measured throughput rate is expected to already enable the investigation of selected science cases in the near future. Besides, the technical and modelling achievement lies in the fact that a 5km-5km coupled simulation could successfully be established. Yet, more work is required to enable simulations on even bigger node counts, that is beyond 550 nodes on the supercomputer MistralESiWACE has received funding from the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No 67519