The study of mesoscale ocean winds

SAR data gathered over the U.S. East Coast are used to infer near-surface wind speed, using a simplified model to relate the strength of the 30 to 40 cm SAR backscatter to surface wind speed. It is found that the SAR backscatter is nearly isotropic with a wind speed exponent of 0.4. Using this exponent, the model is tested against an independent data set. Subsequent agreement between wind speeds simultaneously determined by SAR and the Seasat-A Satellite Scatterometer (SASS) is within 0.7 m/s rms. A one-dimensional Fourier transform of the SAR-derived wind field shows an increasing energy content in rough agreement with the Van der Hoven spectrum.