Empirical modelling of surface currents for maritime operations

The urgent nature of research and rescue operations in coastal areas requires a rather precise prediction of surface currents in a timely manner. Given the relatively long running time of numerical hydrodynamic models, they may not be appropriate for use in operational use. Hence, a faster model is desirable and HF ocean surface radar can be applied to solve this problem. An example is given to demonstrate the process by using historical surface current data from an area in Bass Strait collected by HF ocean surface radar. Tidal analysis shows that the significance of tides varies greatly with the location. Variability ellipse analysis reveals the response of surface currents to relatively strong wind from different directions at each grid point. Finally, a fast empirical model is established based on the physical process calibrates the response of surface currents to winds and tides respectively. Residual currents are shown to be small and noisy compared to the observed currents from HF radar. The effects of geostrophic currents and mesoscale eddies do not appear above the noise