An extreme wave field in the winter Antarctic marginal ice zone during an explosive polar cyclone

Propagation of energetic surface gravity waves over a $>40$,km transect of the winter Antarctic marginal ice zone comprised of pancake floes and interstitial frazil ice during an explosive polar cyclone are presented, obtained with a shipborne stereo-camera system. The waves are shown to attenuate at an exponential rate over distance, but, despite this, remain large, even at the deepest measurement locations and in 100% ice concentration, where they are up to 8,m in amplitude -- the largest waves measured in comparable conditions. The occurrence of large waves in the marginal ice zone is shown to be consistent with linear theory. Using concomitant measurements of wind speeds, evidence is given that wind-to-wave momentum transfer occurs through a 100% pancake/frazil ice cover, which is not permitted in most contemporary models.