SAR measurements of ocean wind and wave fields in hurricanes

Abstract

Spaceborne synthetic aperture radar (SAR) is still the only instrument providing directional information on surface wind and ocean waves on a global and continuous basis. From RADARSAT-1, many SAR images have been collected over the past years, which cover several hurricanes and allow investigation of the wind and wave fields under these extreme situations. A time-frame of 27 days of ERS-2 SAR wave mode data was processed, which covers several tropical cyclones in the Atlantic Ocean, of which Hurricane Edouard has been investigated in detail together with additional data available from scatterometers, buoys and weather centers. The wind fields and wave parameters are extracted from SAR imagery and compared to results of the numerical model output provided by the European Centre for Medium-Range Weather Forecast (ECMWF) and co-located ERS-2 scatterometer measurements. For each wave system, spectral parameters such as wavelength, wave propagation direction and wave age are calculated and compared to the numerical model output provided by ECMWF.