Ezer, T., D.-S. Ko, and G. L. Mellor, 1992: Modeling and forecasting the Gulf Stream. Marine Technology Society Journal, 26(2), 5-14.

Abstract: Numerical simulations are performed to evaluate the forecast skill of a model of the Gulf Stream system. The model is a high resolution (eddy resolving) coastal ocean model, which includes thermohaline dynamics and a turbulence scheme to provide vertical mixing coefficients. In a series of forecast experiments, the model is initialized with synoptic temperature and salinity fields obtained from satellite observations and the U.S. Navy's Optimum Thermal Interpolation System (OTIS). It then calculates the forecast fields (e.g., temperature, salinity, and sea surface height) for the next two weeks. In the three cases presented here, the model forecst gave a better estimate of the ocean than did persistence (i.e., the assumption of no change), showing a forecast skill for at least two months.

Sensitivity studies demonstrate the effects of vertical grid resolution, horizontal diffusion, and smoothing on the forecast skill of the model when compared to OTIS fields. The forecast skill is improved when the vertical grid is refined and when smoothing or horizontal diffusion is large enough to remove small-scale spatial variations from the forecast fields; such variations are missing from the smoothed OTIS fields but may exist in the real ocean.

The study shows that numerical models can be used to aid commercial and navy operations in forecasting oceanic fields; nevertheless, there are still deficiencies in numerical models and difficulties in quantitative evaluation of the forecast skill of ocean models due to the sparse coverage of oceanic measurements.