ICESat Observations of Ocean Swells and Possible Long-Period Ocean Waves Propagating Through Antarctic Sea Ice

Several ICESat profiles taken across sea ice in the Weddell Sea exhibit wavelike patterns that suggest the passage and attenuation of ocean swells and long-period (200 s) waves through sea ice over distances of hundreds of kilometers. Detailed examination of the profiles, associated sensor telemetry, and MODIS imagery excludes sensor artifacts and other phenomena in the atmosphere and ice as explanations for the patterns. Wavelet analysis of the patterns shows that, as expected, shorter waves decay most rapidly after crossing the ice edge. Calculation of attenuation coefficients for the ocean swells provides values that are reasonable when compared to previous work using airborne laser altimetry and other measurements. Multiple possible explanations exist for the cause of the long-period waves, including lee waves, internal waves, infragravity waves, and rissaga (meteotsunamis).