Study Of Numerical Simulation And Analysis Of Internal Waves In Northern South China Sea

This study is mainly on the generation of internal waves in the Northern SouthChina Sea. The non-hydrostatical MITgcm is used to do this simulation. For theKuroshio effect on generation of internal waves,2-D and simplified topographyexperiments are launched, and the generation process of internal waves andmechanism are invested and discussed with the help of statistical analysis of SARimages. Also the3-D simulation is carried out to discuss the3-d effect on thegeneration of internal waves. This study shows that:Firstly, Four years of satellite synthetic aperture radar (SAR) images from2007to2010are used for the statistical analysis of IW occurrence. The monthlySAR-observed IW occurrence frequencies show that the high frequencies aredistributed from May to August and reach a peak in June with a maximum frequencyof29%. The low occurrence frequencies are distributed in winter from November toFebruary of next year with a minimum frequency of0.5%in both December andJanuary.Secondly, the2-D, non-hydrostatical and simplified topography experimentsimulates the generation process of internal solitary waves well, and the mechanism iscertified to be the lee-wave mechanism.Thirdly, the experiment with the current of K-branch shows that the generationprocess of internal waves is changed. The energy of depression is distributed by themean current and the amplitude of internal waves is much smaller compared to theexperiment without the current of K-branch. This is well matched with the seasonalvariability of SAR-observed frequency of internal waves and is thought to be the keyfactor for the explanation.Fourthly, the3-D, non-hydrostatical and realistic topography experimentsimulates the generation process of IWs well especially for the hand in handphenomenon which has been frequently detected by SAR images. The simulationshows that during the generation process of internal waves, two adjacent internal waves could turn into one long crest internal wave by propagating hand in hand.Fifthly, the comparison of2-D simulation and3-D simulation in four profilesshows that the3-D effect especially the zonal changed topography has a great effecton the generation of internal waves.