AN: OS54G-03 TI: Simulating Forced Infragravity Long-waves With ROMS AU: * Uchiyama, Y EM: uchiyama@atmos.ucla.edu AF: Institute of Geophysics and Planetary Physics, University of California at Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095-1565 United States AU: McWilliams, J C EM: jcm@atmos.ucla.edu AF: Institute of Geophysics and Planetary Physics, University of California at Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095-1565 United States AB: A barotropic version of Regional Oceanic Modeling System (ROMS) [e.g., Shchepetkin and McWilliams, 1998; 2003; 2004] has been modified with incorporating a wave-averaged term based on the asymptotic theory by McWilliams, Restrepo and Lane [2004] to simulate forced infragravity long-waves in regional to basin scales. The reanalyzed wavenumber-spectral data provided by ECMWF/NCAR on a 1.5^o geographical grid is used to evaluate the wave-averaged forcing term. Orlanski's radiation scheme for open boundaries with an additional term for pressure gradient correction is introduced for the sakes of computational robustness and less boundary noises. The model is applied to demonstrate some numerical results with realistic settings including generation and propagation of IG waves forced by primary surface wind waves in the Central North Pacific basin (98^o E - 112^o W, 67^o N - 47^o S). A hypothesis proposed by seismologists [e.g., Rhie and Romanowicz, 2004] motivates to conduct the experiment since IG waves could yield significant pressure fluctuations on the seafloor for the frequency band 3-15 mHz (periods of 70-330 s) and thus excite seismic oscillations in the IG frequency band at almost every seismically quiet site in the world such as in the North Pacific [Webb, 1998; Tanimoto, 2005]. We will present our numerical solutions and further address dynamics of IG waves in conjunction with freely traveling IG waves leaked from continental shelf regions. DE: 4534 Hydrodynamic modeling DE: 4560 Surface waves and tides SC: Ocean Sciences [OS] MN: Ocean Sciences 2006