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Modelling Procedures
Published in Vanesa Magar, Sediment Transport and Morphodynamics Modelling for Coasts and Shallow Environments, 2020
The frequency ωi of each of the tidal components is a constant, but the amplitude and the phase vary spatially. In most modelling efforts, researchers use at most 13 tidal components, determined from the TOPEX–POSEIDON (TPXO) global tidal model (Egbert et al. 1994, Egbert & Erofeeva 2002) (see http://volkov.oce.orst.edu/tides/global.html). TPXO is based on the Laplace Tidal Equation with satellite data assimilation from the TOPEX–POSEIDON missions. The first versions of TPXO provide 13 tidal constituents, including the following eight primary: M2, S2, N2, K2, K1, O1, P1, and Q1; two long-period: Mf and Mm; and three nonlinear: M4, MS4, and MN4. TPXO9 includes also the constituents 2N2 and S1. The model versions are improved by improving the bathymetry and by assimilating more satellite data. Thus, in the latest TPXO version, there are 15 tidal components.
Coastal water level variations
Published in Dominic Reeve, Andrew Chadwick, Christopher Fleming, Coastal Engineering, 2018
Dominic Reeve, Andrew Chadwick, Christopher Fleming
If detailed information on tidal elevations and flows is required over a large area, rather than at a few isolated points, then a numerical model can be set up. A tidal model will solve the equations of fluid flow to determine the tidal flows and elevation over a grid of points. Inputs to the model will be a detailed representation of the seabed surface over the model grid and boundary conditions to specify the elevation or flows at open sea boundaries. The boundary conditions will be specified from observations at tide gauges, as described in the previous section. Further details of the numerical prediction of tides are given in Section 4.7.
Numerical simulation of the hydrodynamic response of regulation engineering in the Deepwater Navigation Channel of the Yangtze Estuary
Published in Guojun Hong, Gongxun Liu, Liquan Xie, Hydraulic Engineering V, 2018
T.L. Xu, X.D. Mao, W. Chen, C.P. Kuang, C.H. Mao, J.S. Zhang, S.J. Shi
The open sea boundaries are specified as time-varying tidal levels derived from a calibrated model, covering all the China Sea and adjacent seas, whose open boundary is driven by the Global Tidal Model derived from 10 years of TOPEX/POSEIDON satellite altimeter data from 1992 to 2002. The wet and dry treatment for tidal flats is introduced into this model. The Courant Friedrich Levy (CFL) condition can be used as a guide for selecting the time step, and the self-adapting time step is in a range from 0.01 to 30 seconds to keep the CFL
Extraction of ocean tidal information based on global equal-area grid and satellite altimeter data
Published in International Journal of Digital Earth, 2022
Wenbo Wang, Huijun Zhou, Senyuan Zheng, Guonian Lü, Liangchen Zhou
From Table 4, we can see that the RMSE of the amplitude difference is less than 3cm, except for M2 component. The epoch errors of the N2 component and the O1 component are the largest, but they are not more than 15°, which is within the reasonable range of error. In general, the results of the proposed model are consistent with those of the TPXO9.5 global tidal model.