Simulation of SAR images of submesoscale ocean phenomena

Patterns are observed on radar images of the ocean surface on scales of 10-1000 meters which are related to phenomena such as internal waves, current or temperature fronts, and tidal flow over shallow bottom topography. These features are caused by a complex set of interactions between surface waves, air flow above the surface, current fields at and below the surface, and the electromagnetic waves which are used to form the images. Simulation models provide a means of synthesizing our present knowledge of these interactions in order to make predictions that can be tested by comparison with actual radar images. The authors summarize the status of SAR simulation models, present comparisons between simulated and actual images for several types of ocean surface features, and make some inferences about the present state of knowledge of the interactions incorporated in these models. In general, the present models are capable of predicting or explaining features observed with radar wavelengths larger than about 10 cm (e.g. L-band) but do not perform well at shorter wavelengths. Uncertainties in wave growth and dissipation, as well as increasing importance of strong nonlinear effects at short wavelengths, are thought to contribute to this breakdown