Evaluation of a Coastal Circulation Model for the Changjiang River Plume

Regional Ocean Modeling System (ROMS) is used to develop a new three-dimensional hydrodynamic model for the Changjiang River estuary and the East China Sea. The model is forced with realistic forcing, and is nested within hindcasts from the HYCOM operational model. Hindcast simulations are conducted for 2004-2014 and are quantitatively evaluated with an extensive set of observations. The model shows skill in reproducing sea level height, tidal current, and the observed broad-scale plume features on both seasonal and inter-annual scales. Comparisons with moored buoys show that the model also reproduces the subtidal current on both the shelf and the continental slope faithfully. The sensitivity of the model skill to the wind forcing, the boundary forcing and the turbulent mixing parameterizations is examined. Both the model sensitivity study and the model/data comparison demonstrated that more realistic forcing and nesting within HYCOM is important in improving the model skill.