Alaskan Arctic coastlines are protected seasonally from ocean waves by presence of coastal and shorefast sea ice. This study presents field observations collected during the autumn freeze up of 2019 near Icy Cape, a coastal headland in the Chukchi Sea of the Western Arctic. The evolution of the coupled air-ice-ocean-wave system during a four-day wave event was monitored using drifting wave buoys, a cross-shore mooring array, and ship-based measurements. The incident wave field was attenuated by coastal pancake and frazil sea ice, reducing significant wave height by 1 m over less than 5 km of cross-shelf distance spanning water depths from 13 to 30 m. Spectral attenuation coefficients are evaluated with respect to wave and ice conditions and the proximity to the ice edge. Attenuation rates are found to be three times higher within 500 m of the ice edge, relative to values farther in the ice cover. Attenuation rates follow a power-law dependence on frequency, with an exponent in the range of (2.3,2.7) m^-1.
