An introduction to operational chains in ocean forecasting

<strong class="journal-contentHeaderColor">Abstract.</strong> Operating the ocean value chain requires the implementation of steps that must work systematically and automatically to generate ocean predictions and deliver ocean data information in standard format. This task, which represents the backbone of operational forecasting systems, implies the design of robust workflows that organize pre-processing of the upstream data, run the core models, and handle post-processing before the final delivery. Operational chains require dedicated computational resources to supply demanding modeling runs but also processing and analysis of big volumes of data in relation to the specific spatial scale and consistently for the forecast lead times. The monitoring of each step of the workflow through key performance metrics can support not only timely delivery but also identifying problems and troubleshooting. The paper illustrates the main challenges foreseen by operational chains in integrating complex numerical frameworks from the global to coastal scale and discusses existing tools that facilitate orchestration of operational chain components, including examples of existing systems and their consolidated capacity to provide high-quality and timely ocean forecasts.