Deploying the ICON model on cloud architectures (ICONIC for Central Asia)

The ICON model, which is developed by the Deutscher Wetterdienst (DWD) and its partners, represents an example for modern NWP models with their intricate structure of numerous subcomponents. Besides, parallel processing is massively needed, where workloads often change in the short term and the dynamic requirements exceed the available local hardware. This increasingly complex setup and software stack is contrasted with the limited staff resources of small NMHSs or university groups. Even large developer communities, such as that of the ICON model, do not have the necessary support capacity for this situation. During the past decade two key answers to these problems have been identified: container deployment and cloud service models.
The ICONIC project, developed at DWD and financially supported by the World Bank, addresses the use case of the Central Asian region. Its technical concept employs user-friendly,  auto-scaling Slurm clusters and Singularity containers for the ICON model. The project results confirm that flexible short-term NWP workload demands can be handled by IaaS service models. We show by example that commercial and community cloud infrastructure is sufficiently capable for small and medium-size applications in a cost-effective scenario. The ICONIC setup is integrated into the data supply of the DWD weather service and takes into account a separation of the roles of administrators, operators, and forecasters. Portability between on premise software deployment community clouds and several commercial cloud providers is shown under the condition of minimal hardware requirements. The outlook discusses the impact of this deployment model on current operational centers.