On the role of wind direction in ERS SAR signatures of internal waves on the Iberian shelf

Results of an investigation of ERS SAR signatures of internal waves (IWs) on the Western Iberian shelf are shown. The mode of signature is defined by a parameter that evaluates the IW intensity profiles in relation to the mean backscatter of the image background. The signature mode parameter is found to be correlated with the angle between the IW propagation direction and the wind velocity. A simple model which takes into account modulation of short-scale surface waves by relative wind velocity to the surface current generated by the IWs is considered and was found to be in good qualitative agreement with the experimental results.