The role of HF radar within operational forecasting systems of the ocean

Operational forecasting of current and wave fields in coastal regions got more and more important in the last decades, both for coastal management and for security aspects. One of the key tools in this context are high-resolution numerical models, which however require accurate forcing and handling of the boundary conditions to give results which are close to nature. HF radar remotely sensed current and wave fields can significantly increase the data quality of the models, if these on-line measurements are assimilated. In some cases, when the oceanographic processes induce high local variability, such as mesoscale eddies and fronts, this approach might be the only way to get reliable now- and forecasts. In Europe, the European Radar Ocean Sensing (EuroROSE) project has demonstrated the feasibility and performance of an HF radar based ocean monitoring system in support of safe navigation in port approach areas and otherwise densely operated sea areas. Two demonstrations were carried out off the Norwegian coast north of Bergen, and at the North Spanish coast near Gijon. During each of these demonstrations, WERA (Wellen Radar) HF radars of the University of Hamburg were deployed. WERA measured surface currents within an area of about 40 km by 40 km with a spatial resolution of about 1 km and with a temporal sampling of 10 minutes.