Measurement and parameterization of wave attenuation and scattering in the Marginal Ice Zone using Sentinel-1 SAR data

Monday, 15 December 2014
Fabrice Collard1, Fabrice Ardhuin2, Gilles Guitton1, Dany Dumont3, Paul Nicot3, Mickael Accenti2 and Fanny Girard-Ardhuin2, (1)OceanDataLab, Plouzané, France, (2)IFREMER, LOS, Plouzané, France, (3)University of Quebec at Rimouski UQAR, Rimouski, QC, Canada
Sentinel-1A launched by the European Space Agency in April 2014 will complete its full calibration and validation phase including Level2 products early in 2015 but image quality is already good enought for scientific exploitation of observed wave modulations. The larger frequency bandwidth and new acquisition modes are providing a much improved capability for imaging ocean waves in the open water and in the ice compared to Envisat. Here we estimate wave spectra in the Arctic assuming a spatially uniform modulation transfer function where the backscatter over ice is homogeneous, matching the wave heights in open ocean and ice at the ice edge. These wave properties are used to estimate attenuation scales for wavelength longer than twice the radar image resolution. These estimated attenuations are compared to model results based on WAVEWATCH III, where attenuation and scattering uses a combination of friction below the ice and scattering adapted from Dumont et al. (2011) and Williams et al. (2013).