Water circulation forecasting in Spanish harbours

Abstract

This paper describes the first harbour circulation forecasting system implemented in Spain. The configuration design was based on previous analyses of the morphologic and hydrodynamic behaviour of three harbours: Barcelona, Tarragona and Bilbao. A nested system of oceanic models was implemented, with a scope ranging from the regional scale (with a mean horizontal resolution of 5 km) to the harbour scale (with a mean horizontal resolution of 40 m). A set of sensitivity tests was carried out in order to determine the optimal configurations. The results of the operational system were compared with available observations, revealing that the intermediate models are able to reproduce the averaged hydrodynamic behaviour but not the spatio-temporal variability. With the harbour models the quality of the forecasts improves, reaching a correlation and RMSE of similar to 0.6 and 6 cm s(-1), respectively, for Bilbao harbour. In addition, numerical experiments were carried out to evaluate the sensitivity of the forecasts to error sources. The results suggest that the errors in the information prescribed in the lateral boundary conditions are the most influential in the quality of the predictions. Errors in the wind field also have a smaller but non-negligible influence. Although the system is in the initial implementation phase and should be improved upon in the future, it is now a useful tool for harbour