Floe Size Effect on Wave-Ice Interactions: Possible Effects, Implementation in Wave Model, and Evaluation

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Boutin, Guillaume, Ardhuin, Fabrice, Dumont, Dany, Sevigny, Caroline, Girard-Ardhuin, Fanny, Accensi, Mickael
• Other Authors: Centre National de la Recherche Scientifique (CNRS), Université de Brest (UBO), University of Quebec in Rimouski Canada, DGA, ANRFrench National Research Agency (ANR) ANR-14-CE01-0012 MIMOSA, ANR-10-LABX-19-01, EU-FP7 project SWARP 607476, ONROffice of Naval Research N0001416WX01117, Canadian Networks of Centers of Excellence ArcticNet, MEOPAR
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; Arctic; Svalbard; Sea ice
• Online Access: https://hal.science/hal-02929084; https://doi.org/10.1029/2017JC013622

Wind waves may play an important role in the evolution of sea ice. That role is largely determined by how fast the ice layer dissipates the wave energy. The transition from a continuous layer of ice to a series of broken floes is expected to have a strong impact on the several attenuation processes. Here we explore the possible effects of basal friction, scattering, and dissipation within the ice layer. The ice is treated as a single layer that can be fractured in many floes. Dissipation associated with ice flexure is evaluated using an anelastic linear dissipation and a cubic inelastic viscous dissipation. Tests aiming to reproduce a Marginal Ice Zone are used to discuss the effects of each process separately. Attenuation is exponential for friction and scattering. Scattering produces an increase in the wave height near the ice edge and broadens the wave directional spectrum, especially for short-period waves. The nonlinear inelastic dissipation is larger for larger wave heights as long as the ice is not broken. These effects are combined in a realistic simulation of an ice break-up event observed south of Svalbard in 2010. The recorded rapid shift from a strong attenuation to little attenuation when the ice is broken is only reproduced when using a nonlinear dissipation that vanishes when the ice is broken. A preliminary pan-Arctic test of these different parameterizations suggests that inelastic dissipation alone is not enough and requires its combination with basal friction.