Remote Sensing of Waves Propagating in the Marginal Ice Zone by SAR

Wave-ice interactions are important in high sea state conditions, when waves propagate from the open ocean into the marginal ice zone (MIZ) and the pack ice. In situ observations of waves and wave-ice interactions can be obtained at a small number of MIZ locations in costly and challenging experiments, whereas remote sensing using satellite RADARSAT-2 SAR (synthetic aperture radar) images can observe waves throughout the MIZ, in all weather conditions. We present a methodology to retrieve MIZ wave parameters from polarimetric SAR data. As an application, we describe the characteristics of waves propagating from open water into the MIZ, as generated by a strong low pressure system that developed to the east of Greenland. As waves penetrate the MIZ, SAR remote sensing observations suggest increased dominant wavelengths, attenuated wave energy and shifted mean wave directions. The SAR observations and estimates for retrieved wave attenuation in the MIZ are shown to be consistent with wave attenuation theory and in situ field observations. Thus, valuable estimates of MIZ waves over large spatial scales at high-resolution are provided by the SAR measurements.