Damping of Gravity Waves Due to Ice Floes. Wave Tank Study and Numerical Modeling

It is well known that the initial stages of ice such as grease ice, pancake ice etc. act as absorbers of surface waves thus affecting possibilities of ice margin zone mapping using, e.g. microwave radar. Besides the wave attenuation influences the dynamics of very ice floes. The motivation of this study is to improve our understanding of the process of wave damping due to ice floes for further elaboration of physical models of wave damping. New wave tank experiments were carried out to investigate the damping of mechanically generated waves as well as wind waves due to ice floe imitators. Numerical analysis of the floe dynamics and of wave damping was performed at different relations between the floe sizes and wavelengths and was shown to be consistent with experiment. Resonance-like behavior of wind wave damping was revealed indicating the damping maximum when the floe size was about half the wavelength.