Wave-induced surge motion and collisions of sea ice floes: finite-floe-size effects
AbstractAmong many mechanisms potentially contributing to wave energy attenuation in sea ice are wave-induced ice floe collisions. At present, little is known about collision patterns and their phase-averaged effects under different combinations of sea ice properties (ice thickness, floe size, etc.) and wave forcing (wavelength and steepness). The existing parameterizations of collision-related effects are therefore based on several simplifying, unverified assumptions. In this work, wave-induced motion and collisions of ice floes are analyzed numerically with a model based on momentum equations for an arbitrary number of floes, with source terms computed by integrating local forcing (wave-induced dynamic pressure, surface drag, etc.) over the surface area/volume of each floe. It is shown that this simple model, with prescribed wave forcing (i.e., no wave-ice interactions), is capable of reproducing observed surge amplitudes up to floe sizes comparable with wavelength. A full Hertzian contact model is used instead of a simple hard-disk algorithm, which makes the model suitable for simulating both rapid collisions and prolonged contact between floes. The model equations are used to formulate heuristic collision criteria based on relative floe size, ice concentration, and wave steepness. The model is then run for different combinations of those three parameters, together with different restitution and drag coefficients, in order to analyze possible motion/collision patterns within the multidimensional parameter space, and phase-averaged effects of collisions: kinetic and contact stress, granular temperature, and work done by forces acting on the ice.
|Journal series||Journal of Geophysical Research-Oceans, ISSN 2169-9275, (0 pkt)|
|Publication size in sheets||1.1|
|Score|| = 0.0, 04-04-2019, ArticleFromJournal|
= 5.0, 04-04-2019, ArticleFromJournal - czasopismo zagraniczne spoza list
|Publication indicators||= 0; : 2017 = 2.711 (2) - 2017=3.207 (5)|
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