Synoptic Estimates of Waves and Currents via Real-Time Assimilation of In-Situ Observations

Abstract

The long-term goal of this effort is to develop a methodology to monitor near-shore waves and currents over large spatial scales using data from in-situ sensors. OBJECTIVESThe proposed program will develop the capability of monitoring nearshore waves and currents over large scales, and will allow the timely use of information from in-situ sensors. The specific objectives to be addressed are to: 1. Develop a near-real-time capability for assimilating single-or multiple-point in-situ observations into a phase-resolving wave model; 2. Test and validate the methodology against both simulated data and archival field data for both simple and complex beach types; and 3. Conduct a full-scale test of the methodology by applying it in near-real time to a comprehensive field experiment on complex topography. APPROACHThe procedure being developed makes use of a variational data assimilation capability for the extended-Boussinesq wave model of Wei et al. (1996). The approach is to use time-series data from instruments in the interior of a region to estimate the time-dependent boundary conditions for the Boussinesq model at the boundaries of the region. These boundary conditions will yield a Boussinesqmodel prediction, which matches the data. WORK COMPLETEDThe work completed during the past fiscal year includes development of the mathematical framework for the assimilation procedure, improvements in the numerical implementation of the extended Boussinesq model and its adjoint, and addition of improved wavemaker and run-up models in the parallel Boussinesq code.