An operational ocean circulation prediction system for the western North Atlantic: Hindcasting during July–September of 2006

A real-time ocean prediction system for the western North Atlantic (WNA) has been implemented operationally for the Mid-Atlantic Regional Association Coastal Ocean Observing System (MARACOOS). Based on the physical circulation model component of the Harvard Ocean Prediction System (HOPS), this system is built to capture the mesoscale dynamics of the Gulf Stream (GS), its meanders and rings, and its interaction with the shelf circulation, the mid-Atlantic shelf (MAS), and the buoyancy-driven circulation in the Gulf of Maine (GOM). To accomplish this, the multiscale velocity-based feature models for the GS region are melded with the water-mass-based feature model for the GOM and with shelf climatology across the shelf-slope front for a multiscale synoptic initialization. A ring and front analysis is fed into the feature modeling scheme for generating a three-dimensional initial field. The initialization field is dynamically adjusted with wind-forcing and used in an Sea Surface Temperature (SST)-assimilative forecast mode. For this study, 8 weekly forecasts are compared with GS paths and drifter trajectories during the 2006 Shallow Water Experiment (SW06) conducted during the months of July and September. GS path and ring formation/absorption events were compared and presented by Taylor diagrams (TD). For all of 8 weeks, the forecast skills were comparable or higher than that of the persistence. The model shows reasonable skill in simulating drifter trajectories, especially over days 1–3 of simulation.

► A real-time ocean prediction system for the western North Atlantic.
► Hindcasting during July–September of 2006.
► SST-assimilative ocean forecast model.
► Model skill assessment using GS path and drifter data.