Observations on the Gulf Stream frontal zone using Almaz-1 SAR and measurements taken on board the R/V Akademik Vernadsky

Analyzed is the data of quasisynchronous observations of the Gulf Stream fr ontal zone with Almaz-1 Synthetic Aperture Radar (SAR) and concurrent measu rements taken on board the R/V Akademik Vernadsky. Sea surface temperature fields from NOAA satellites are additionally used, Imaging from space was a ccompanies by measurement of the hydrologic and meteorological parameters, and registration of surface currents along the ship tracks crossing frontal zone. Comparison of satellite and in situ wave measurements has shown that Almaz-1 SAR allowed to measure the basic parameters of long waves(waveleng th and orientation) rather precisely. On a basis of SAR image spectra the e ffects of waves refraction are investigated. The surveys were carried out a t moderate westerly winds when the waves evolved in along current direction . At these conditions the effects of wave reflection produced the zones of wave concentration and wave "shadow". Linear-like structures registered by a radar were located in vicinity of large cross current shifts and areas of sargassum accumulations (convergence). The strips were oriented along the Gulf Stream thermal front and reflected the structure of current.