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The possibility to retrieve parameters of a current from radar data is under investigation. The study is based on ERS SAR and TU-134 RAR images. It is well-known that currents are difficult to detect directly in radar images. However, it is often possible to detect current manifestation by its impact on internal wave field, by the character of “wake-like” features and vortex streets behind islands, and by spatial pattern of natural and oil slicks.
Observation of internal waves transformation by nonuniform large-scale currents are considered. Specific manifestations of internal waves front distortions can be caused by following phenomenon: the influence of bottom relief, variability of water density, wave-wave interaction and refraction on the horizontally nonuniform large-scale currents. Radar data clearly demonstrate unusual disturbances of internal solitons fronts, which cannot be explained by bottom topography. The theoretical considerations show that the influence of stratification variability is weakly than the currents influence. For that, we assume that observed distortions of internal waves fronts are caused by transformation on the oceanic currents.
Available radar images obtained in the Bering Strait display a large variety of surface manifestations of vortex streets behind the Fairway Rock and lee waves behind Diomede Islands connected with the variability of the run-against flow. Based on well-known theoretical hypothesis, results of laboratory experiments, and analysis of radar data the estimation of speed and direction of sea currents has been done.
Summer/autumn concurrent experiments conducted near Gelendzhik, Black Sea shore, allowed to qualitatively estimate the sea current characteristics by means of analysis of surface slick manifestations on radar data.
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