Airborne remote sensing of ocean wave directional wavenumber spectra in the marginal ice zone. Issue 10 (17th May 2016) - Sutherland, Peter
Abstract: Interactions between surface waves and sea ice are thought to be an important, but poorly understood, physical process in the atmosphere‐ice‐ocean system. In this work, airborne scanning lidar was used to observe ocean waves propagating into the marginal ice zone (MIZ). These represent the first direct spatial measurements of the surface wavefield in the polar MIZ. Data were compared against two attenuation models, one based on viscous dissipation and one based on scattering. Both models were capable of reproducing the measured wave energy. The observed wavenumber dependence of attenuation was found to be consistent with viscous processes, while the spectral spreading of higher wavenumbers suggested a scattering mechanism. Both models reproduced a change in peak direction due to preferential directional filtering. Floe sizes were recorded using colocated visible imagery, and their distribution was found to be consistent with ice breakup by the wavefield. Key Points: Airborne scanning lidar provides directional wavenumber spectra of waves in sea ice Wave spectral evolution suggests that both scattering and dissipation are important in the MIZ Ice floe size distribution can be related to the wave attenuation rate and the spectral peak wavelength