The aim of the project OPERATIONS is an operating system with an extensive degree of automatization of the decadal prediction based on the MPI-ESM model on the high-performance computer of the German Meteorological Service (DWD). During the first phase of Miklip simulations were performed on the high-performance computing facility of the German Climate Computing Center (DKRZ). The plan of MiKlip II is to compute the decadal predictions at DWD in the final stage of the second phase of MiKlip.
Progress made by other modules and projects will be incorporated into the operational system and the optimal model configuration for the operational system will be selected in close co-operation with the Max Planck Institute in Hamburg (MPI-M). The model system MPI-ESM and the evaluation software FREVA, developed in the first phase of MiKlip, will be updated at the system of the DWD in co-operation with the Freie Universität Berlin (FUB).
Following the example of the operational weather forecast system, a workflow environment for the decadal prediction system will be established. This workflow environment is provided by the use of the software “ecFlow”; it facilitates routine decadal predictions and the evaluation of the model output. “ecFlow” is a task scheduling software, which is developed and used by the European Centre for Medium Range Weather Forecasts (ECMWF).
Three groups (Deutscher Wetterdienst (DWD), Max Planck Institut für Meteorologie (MPI-M) and Freie Universität Berlin (FUB)) co-operate in Workpackage D2-WP2.1. The topic of this work package is the transfer of the global decadal prediction system und of the evaluation system to the systems of the DWD.
The tasks of the project can be outlined in two topics. The first half of the project duration (DS4) is dedicated to the transfer of the decadal forecast system to the infrastructure of the DWD. The workflow, the computational and storage demand are evaluated by setting up a “toy”-workflow with the global model. During the second half of the project duration the “toy” workflow is replaced by the agreed coupled climate model setup. This system will be capable of producing initial conditions for the global model in real time, in order to provide decadal predictions starting every year. The evaluation system will be finalized and the results will be supplied.
All tasks require a close collaboration with other work packages in module D.
Successful porting and testing of the model MPI-ESM to the HPC of DWD is completed. The testing included a benchmark, where the model was run with different numbers of CPUs and different discretization settings to find the optimum between wall clock time and CPU load. Obtaining the shortest possible wall clock time per model year by maximizing the number of CPUs makes calculations more expensive by 30% compared to a scheme with the least possible number of CPUs.
A toy-workflow was established for simulations and post-processing. The toy-workflow features ecFlow as the managing software. The workflow was tested by calculating an additional set of re-forecasts in lower resolution (LR). These simulations can be used as reference data-set for project partners further developing the forecast suite with the LR version of the model. The data-set can also be used to compare the LR version to the HR version of the MPI-ESM model and deduce the benefit of the higher model resolution.