Fitting Cotidal Charts of Eight Major Tidal Components in the Bohai Sea, Yellow Sea Based on Chebyshev Polynomial Method

High-precision tidal harmonic constants are necessary for studies involving tides. This study proposes a new method combined with the adjoint assimilation model and Chebyshev polynomial fitting (CPF) to obtain in shallow-water region of Bohai Yellow Sea (BYS). Based on CPF method, full-field reliable cotidal charts eight major constituents (M2, S2, K1, O1, N2, K2, P1 Q1) were fitted from X-TRACK products briefly this was effectively coastal conditions. Compared observations gauges, M2 constituent, TPXO9, Finite Element Solutions 2014 (FES2014), National Astronomical Observatory 99b (NAO.99b) Empirical Ocean Tide 20 (EOT20) models yield root-mean-square errors (RMSEs) 18.50, 7.31, 18.73 13.32 cm, respectively, while yields an RMSE 10.74 cm. These results indicate that could maintain high resolution accurate consistent simulations four regions.