The Study Of The Internal Tide 3-D Numerical Simulation With Assimilation In The South China Sea

Internal tide is a very important physical process for studying total ocean energy budget and balance. Internal tide is an important component of ocean dynamic, which will be not only beneficial to ocean environment and resource's exploiting and protecting. It has handsome progress about ocean internal tide studying and surface tide assimilation model based on TOPEX/POSEIDON satellite altimeter data. However, much of assimilation work is related to surface tide, there is little about internal tide. It is still at the beginning to assimilate T/P data into internal model.Firstly the method of harmonic analysis is used to withdraw tidal wave from T/P satellite altimeter data in the South China Sea. Then we get internal tide signals from them based on the characteristic of internal tide. The results show that the altimeter data can give a good distribution of tides in the South China Sea, especially in the deep region of the South China Sea.Three-dimension tidal models with assimilation are built which based on POM. The interior results are good because we assimilate T/P data into our model. The result agrees well with observations. The cotidal charts drawn by our results are believable. Our studies confirm that an anticlockwise rotating M₂ and aclockwise rotating S₂ amphidromic system at the southwest of the Sunda Shelf.The energetic internal tides are generated in the Luzon Strait, the southwest and northeast of the Taiwan Island and the Dongsha Islands. The conversion rate from the surface M₂ to the internal tide energy integrated over the whole model domain amount to 14GW, 8.5GW of which are found in the Luzon Strait, 2.1GW in the Taiwan Strait, 2.0GW in the northeast of the Taiwan Island, 0.2GW in the Dongsha Islands. The internal energy flux in the LuzonStrait is up to 6kW/m, 100W/m in the DongSha Islands as well. The intense of internal tide in the Luzon Strait is due to topographic features and the characteristic of M2 tide. The northeast of the Taiwan Island is due to the Kuroshio and its topography.