Towards Earth System Modeling: Coupled Ocean Forecasting

Abstract. Modelling our planet is challenging, and forecasting the ocean component is crucial for better understating physical processes in a changing climate. To achieve this objective, numerical ocean models require more advanced approaches that aim at connecting different Earth system’s components in a more sophisticated way: this is offered by coupling methods, that involve exchanging information between discrete modelling systems. The paper explains the principles of two-way coupling, where models run simultaneously and exchange information both ways. As individual models reach better accuracy, coupling becomes a key factor to improve forecasting capability because it reproduces the natural complexity of the environment: a wealth of literature shows the benefits of coupling. However, coupling is still limited in operational oceanography by its large demands on computational resources, by data assimilation techniques (currently not very well harmonized between the different models) and by administrative separation of forecasts across different earth-system components. Overcoming these barriers will support ocean predictions towards a multi-hazard approach and a more accurate representation of the Earth systems’ components interaction, and improve collaborations between multi-disciplinary forecasting communities.