Altitude Extraction And Assimilation Numerical Simulation And GIS Integration Of South China Sea Based On Satellite Altimeter

In this paper, with least-squares fit harmonic analyses of18.6years of TOPEX/Poseidon andJason-1/2altimetry data (which contains the3years interleaved data) in the South China Sea,harmonic constants for twelve constituents (Sa, Ssa, Mm, Mf, Q1, O1, P1, K1, N2, M2, S2, K2) werecarried out in South China Sea. Harmonic constants from18.6years of altimetry data showagreement with the data of58coastal and island stations well, the mean absolute error of amplitudesfor four primary constituents (M2, S2, K1and O1) were4.4cm,2.4cm,3.1cm and3.3cm, and meanabsolute error for phase-lags were7.7°,13.2°,7.2°and7.8°. The results indicate that longersequences altimeter data are obviously better, especially after adding the interleaved satellitealtimetry data.A three-dimensional barotropic tidal numerical model has been established in the South ChinaSea using the Finite Volume Coast and Ocean Model (FVCOM). Adopting the assimilation methodof Nudging, the data of45altimetry observation stations were assimilated. The results werecompared with the223tide stations. The mean absolute error of amplitudes for four primaryconstituents (M2, S2, K1and O1) were5.47cm,3.03cm,2.97cm and3.11cm, and mean absolute errorof phase-lags were10.58°,10.29°,6.50°and6.10°. Numerical simulation results show that, theshort-term numerical simulation by assimilation of the satellite altimeter data, which can achieveconsistent results of harmonic analyses of long time series altimeterdata, and covered moreextensively in the calculation of the model. Improving spatial resolution of numerical model incertain areas, using more sophisticated basal geographic data, such as the depth of water andcoastlines, and adding the measured data assimilation module can improve the model simulationaccuracy in some degree.Using the ArcGIS platform, combined with FME, MATLAB, SMS and other software, throughGeoprocessing scripting, and adopting loose integration numerical model integration of GIS andFVCOM has been finished. With the scripting language provided by the GIS platform, this paperdeveloped several modules which provide data input, storage, processing and display function for theFVCOM. Besides this paper also promoted pre and post processing efficiency for FVCOM, expanded the expression of calculation and visualization of temporal and spatial field of numericalmodel, and provided the necessary GIS technology support for building, running, debugging andexpressing the marine numerical simulation system.