Modeling Small-Scale Physics of Waves and Ice in the MIZ
Mark Orzech1, Jayaram Veeramony2, Fengyan Shi3, Samuel P Bateman2 and Joe Calantoni1, (1)Naval Research Lab, Stennis Space Center, MS, United States, (2)US Naval Research Laboratory, Stennis Space Center, MS, United States, (3)University of Delaware, Center for Applied Coastal Research, Newark, DE, United States
Abstract:
The physics of wave attenuation and ice edge retreat in the marginal ice zone (MIZ) is investigated at small (O(m)) scales with a coupled model system. Waves are simulated with the phase-dependent, finite-volume/finite-difference model NHWAVE (Ma et al., 2012) and ice floes are represented as bonded collections of individually tracked smaller particles using the discrete element method in LIGGGHTS (Kloss et al., 2012). The physical and mechanical properties of fluid and ice are recreated as authentically as possible, with the aim of creating a system that can supplement and/or substitute for more costly and demanding field experiments. The presentation will first describe the development and validation of the coupled system, then discuss the results of a series of virtual experiments in which ice floe and wave characteristics are varied to examine their effects on energy dissipation, MIZ floe size distribution, and ice pack retreat rates. In general, small-scale mechanisms for the dissipation of energy in waves passing through the MIZ remain poorly understood and have not been well delineated or measured. The wave-ice virtual experiments include a range of scenarios, each of which investigates a specific, varying property or process of waves or ice while keeping other parameters fixed. For all cases, the exchange of energy and momentum between waves and ice is tracked and recorded throughout the experiment. Simulation results shed light on the relative importance of processes such as ice floe collisions, fracturing, and drag, in comparison to properties such as wave energy levels, ice floe size distribution and material strength, and wave/floe length-scale ratios. Discussion will focus on how the coupled system will be used to test existing wave-ice parameterizations for large-scale climate models and to develop new, improved alternatives. References:>Kloss, C., et al. (2012). Prog. in Comp. Fluid Dyn. 12(2/3), 140-152.>Ma, G., et al. (2012). Oc. Mod. 43-44, 22-35.
