A description of Validation Processes and Techniques for Ocean Forecasting

Abstract. Operational forecasting systems architecture requires clear identification of best practices for assessing the quality of ocean products: it plays a key role not only for the qualification of predictions skill, but also for advancing in the scientific understanding of the ocean dynamics from global to coastal scales. The Authors discusses on the role of observing network for performing validation of ocean model outputs, identifying current gaps (i.e., different capacity in assessing physical essential ocean variables versus biogeochemical ones), but also emphasizing the need of new metrics (tailored for end-users comprehension and usages). An analysis on the level of maturity of validation processes from global to regional systems is provided. A rich variety of approaches exist, and the most we move towards the coast the higher is the complexity in calculating such metrics, due to increased resolution but also somehow limited by the lack of coastal observatories worldwide. It is provided as example how the Copernicus Marine Service currently organizes the product quality information from producers (with dedicated scientific documentation, properly planned and designed) to end-users (with publication of targeted estimated accuracy numbers for its whole product catalogue).