Scaling Observations of Distance Limited Waves in the Seasonally Ice-Covered Beaufort Sea

In the Beaufort Sea, surface waves are affected by rapidly changing sea ice. Sea ice retreat in recent years has left larger expanses of open water for wave generation, leading to unprecedented large waves. Using wave data from 2012, the year of lowest ice extent on record, Thomson and Rogers (Geophys. Res. Lett., 41(9), 2014) showed that wave energy flux in the Arctic Ocean scales with the open water distance to land or ice edge (i.e., the fetch). We refine their results using in situ measurements of the sea state obtained from freely-drifting SWIFT buoys during the 2014 open water season. Satellite ice products are used to derive coincident open water distances and, when applicable, local ice concentrations. We determine that the scaling of wave energy and frequency with open water distance is only appropriate when the wind and wave field are relatively stationary, such that waves can be considered limited by the open water distance. Similarly, waves generated in partial ice cover can be categorized as distance limited using a newly defined "effective fetch" corresponding to the distance between ice floes, so long as the conditions are relatively stationary. Therefore, the evolution of the wave field in the Beaufort Sea is a function of the ice cover at both the local scale, where partial ice cover reduces the effective fetch, and at the basin scale, where the hard ice edge limits the fetch in a more conventional manner.