Tidal Elevations in the Yellow and East China Seas from a Data-Assimilative, Barotropic Tidal Model.

Abstract

Abstract : The Yellow Sea is a very shallow water body with a strong tidal signal. Its strategic importance had led the U.S. Navy to study tidal response in the Yellow and East China Seas using the Colorado University (CU) data assimilative, barotropic tidal model. The CU model has been adapted to accept open-ocean boundary forcing from the Grenoble global tidal data base, which is considered more reliable than tides currently obtained from the CU global tidal model. Furthermore, the number and quality of the data assimilation stations utilized by the CU Yellow Sea model is improved. A detailed, semi-automated procedure for assigning data stations for assimilation into the CU model domain has been developed. Characterization of the tidal elevations in the Yellow and East China Seas from CU model simulations demonstrate that the M2 constituent is the dominant tidal frequency in the Yellow Sea with amplitudes of nearly 2 m along the coast of west Korea. K1 is the most significant diurnal component with amplitudes 1/4 of the M2 tide. A series of experiments is conducted to test the influence of the location of assimilated data on predictions of the dominant tidal constituents M2 and K1. From an analysis of four data station groupings, coastal, shallow, deep, and open boundary located stations, observations located on the continental shelf away from the coastline are most influential in the prediction of primary tides, M2 and K1 in the Yellow Sea. Coastal station data may be more influential in the prediction of nonlinear tidal interactions, since these gauges are often located in harbors or inlets where nonlinear tidal interactions are prominent and wave action may be present.