Wave-Ice interaction in the Marginal Ice Zone: Toward a Wave-Ocean-Ice Coupled Modeling System

Abstract

Our main objective is to improve an operational model for wind-generated surface gravity waves (WAVEWATCH III ®) such that it can accurately predict the attenuation and scattering of waves by interaction with ice in the Marginal Ice Zone (MIZ). The wave model physics developed here will later be part of an operational coupled model system, allowing feedback to ice, ocean, and atmospheric models. OBJECTIVES The specific objective of this proposal is to fully exploit the theoretical, observational, and ice/ocean/atmosphere numerical modeling work performed by various groups within the MIZ DRI and the "Sea State Sea State and Boundary Layer Physics of the Emerging Arctic Ocean" DRI to improve wave predictions. APPROACH The WAVEWATCH III model (Tolman 1991, Tolman et al. 2002, Tolman 2009) is a phase-averaged wave model solved by integrating the wave action conservation equation. Local rates of change of wave spectral density is determined by advection in four dimensions (two geographic and two spectral dimensions) and source terms representing various dynamic processes, such as energy transfer from the wind, and energy lost due to wave breaking. The approach in WAVEWATCH III ("WW3") version 3 (Tolman 2009) was to represent the effect of ice on waves as part of the advection, such that under partial ice cover, wave energy is partially blocked, with linear scaling of the blocked fraction according to ice concentration (Tolman 2003). This is a practical approach for an operational model, 1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.