Northwest Pacific forecast system equipped with data assimilation

Abstract

A regional framework for the Northwest Pacific ocean forecast system ispresented as an application of GFDL Modular Ocean Model Version 4.1 (MOM4p1) in alimited area domain. The open boundary condition, tidal mixing parameterization and dataassimilation are considered. The open boundary problem is central to the successful limitedarea model. A robust open boundary condition has been introduced to the GFDL ModularOcean Model Version 4.1 (MOM4p1) by controlling the barotropic velocity. The EnsembleOptimal Interpolation has been implemented to assimilate Sea Surface Temperature, SeaSurface Height Anomaly (SSHA) and temperature/salinity profiles to the Northwest PacificRegional Ocean Forecasting Model. In addition, the tidal mixing parameterization has beenapplied to the model. In the marginal seas of the Northwest Pacific, especially Yellow Seaand East China Sea, the tidal mixing is one of dominant oceanic processes. Without the tide,the numerical model could not capture the general circulation especially in summer.Conversely with the tide, it is not easy to handle the SSHA while assimilating it to the model.By applying the tidal mixing parameterization, the model resolves the tide-induced current aswell as the SSHA has been directly assimilated. We present the ocean reanalysis whichrepresents the general circulation and its variability in the Northwest Pacific regioncomparable to the obsedataassimilation are considered. The open boundary problem is central to the successful limitedarea model. A robust open boundary condition has been introduced to the GFDL ModularOcean Model Version 4.1 (MOM4p1) by controlling the barotropic velocity. The EnsembleOptimal Interpolation has been implemented to assimilate Sea Surface Temperature, SeaSurface Height Anomaly (SSHA) and temperature/salinity profiles to the Northwest PacificRegional Ocean Forecasting Model. In addition, the tidal mixing parameterization has beenapplied to the model. In the marginal seas of the Northwest Pacific, especially Yellow Seaand East China Sea, the tidal mixing is one of dominant oceanic processes. Without the tide,the numerical model could not capture the general circulation especially in summer.Conversely with the tide, it is not easy to handle the SSHA while assimilating it to the model.By applying the tidal mixing parameterization, the model resolves the tide-induced current aswell as the SSHA has been directly assimilated. We present the ocean reanalysis whichrepresents the general circulation and its variability in the Northwest Pacific regioncomparable to the obse