Sea state modelling in regions dominated by surface current variations, and its application to the prediction and inversion of radar imagery

Imaging radars have produced remarkable representations of the sea surface, with many imaged features being attributable to the effects of spatially variable surface currents. Two tractable limits are those of a purely straining current (swell, internal waves, tidal flow over simple bathymetry) and of a purely shearing current (fronts, eddies). In these limits, the variation in the sea state at radar probed wavelengths may be predicted with a degree of insight and theoretical radar signatures produced. The modelling approach is described and it is shown how fine structure may be observable in radar imagery. The ultimate aim of the work is to determine how measured radar signatures may best be inverted in order to obtain good estimates of the surface currents involved and of the ocean structures giving rise to the currents