Investigating Propagation of Short-Period Ocean Waves Into the Periphery of Arctic Pack Ice Using High-Resolution Upward-Looking Sonar

Abstract

Springtime fetch in the Cape Bathurst Polynya System may present opportunities for winds to generate waves capable of propagating into the thick pack ice formed over the winter. A waves-in-ice event at a study site located on the Canadian Shelf in the southern Beaufort Sea that occurred 22–23 May 2011 is presented and analyzed for wave energy attenuation and dissipation characteristics. The event was monitored near the ice edge and, therefore, presents information on attenuation of waves from the ice edge into the pack. Waves of T = 5 s, λ = 37.5 m were observed up to approximately 143 m and approximately 77 m away from the ice edge during two separate observation periods of ice edge wave propagation. We estimated reflection coefficients of 53% and 52% and wave attenuation coefficients of α = 2.4 × 10−2 m−1 and α = 5.4 × 10−2 m−1, respectively, for the two periods. Estimated attenuation rates are an order of magnitude greater than in comparable studies and are inconsistent with previous findings of a “rollover” effect in attenuation rates for short-period waves.