Rollover of apparent wave attenuation in ice covered seas
Kohout, Alison L.
Doble, Martin J.
Shen, Hayley H.
Date of Issue2017
Nanyang Environment and Water Research Institute
Wave attenuation from two field experiments in the ice‐covered Southern Ocean is examined. Instead of monotonically increasing with shorter waves, the measured apparent attenuation rate peaks at an intermediate wave period. This “rollover” phenomenon has been postulated as the result of wind input and nonlinear energy transfer between wave frequencies. Using WAVEWATCH III®, we first validate the model results with available buoy data, then use the model data to analyze the apparent wave attenuation. With the choice of source parameterizations used in this study, it is shown that rollover of the apparent attenuation exists when wind input and nonlinear transfer are present, independent of the different wave attenuation models used. The period of rollover increases with increasing distance between buoys. Furthermore, the apparent attenuation for shorter waves drops with increasing separation between buoys or increasing wind input. These phenomena are direct consequences of the wind input and nonlinear energy transfer, which offset the damping caused by the intervening ice.
Journal of Geophysical Research: Oceans
© 2017 American Geophysical Union. This paper was published in Journal of Geophysical Research: Oceans and is made available as an electronic reprint (preprint) with permission of American Geophysical Union. The published version is available at: [http://dx.doi.org/10.1002/2017JC012978]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.