Estimation of wave and wind fields from spaceborne SAR imagery in the Mediterranean Sea

This paper is focused on the analysis of SAR imagery of the Mediterranean Sea to estimate the directional wave spectrum and the wind vector. It is discussed the potential of using fetch-limited wave spectral parameterisation, which is currently used to represent wind generated waves, in the case of SAR imaging of swells. As the interest is also focused on the role of the SAR-estimated wind vector to get reliable estimates of the wave spectra, the spectral form used in this study is that due to Donelan et al.. ERS-1 SAR imagery, which is co-located with instrumented directional buoys belonging to the Italian Buoy Network (RON, Rete Ondametrica Nazionale), was exploited. The main purpose is to study SAR capability to discriminate between locally generated wind waves and old wave systems. Three case studies were selected and analysed. They are devoted to compare wave spectral properties typical of swell systems observed at buoy stations located off-shore La Spezia, Ponza island and Alghero with SAR inverted directional wave spectra.