Study On The Circulation And Mixing In The East China Sea

The ocean circulation and mixing are the universal phenomena in the ocean. Not only do they play an essential role in studying the marine dynamics, but also they are important to the exploration and protection of the marine environment and resources, and to the intensive study of the correlative subjects. In this paper, the author studies the currents and mixing in the East China Sea (ECS) by combining the in situ observations and numerical modeling. The main work and conclusions are as follows.Firstly, based on the POM, a three-dimensional baroclinic assimilation model is constructed to simulate the current and temperature fields in the ECS. The author utilizes the computing results of the global model (OCCAM) as the open boundary conditions to match the current fields and the temperature-salinity fields to a good extent, so that the problem of the Kuroshio extending to about 31oN, which does not accord with the observation can be sloved.Meanwhile, the nudging assimilation technique is improved for the temperature remote sensing data, which to some extent eliminates the influence of the error of the heat flux data on temperature simulation. The model results reflect the characteristics of the circulation and temperature fields in the ECS well. The undetermined coefficient in the relaxation factor affects the computing stability and the simulation accuracy greatly, and the assimilation results are optimal when the coefficient is 0.5. In addition, the computing accuracy varies with seasons, and the sequence of the accuracy from high to low is autumn, summer, winter and spring.Secondly, utilizing the high resolution turbulence profile(TurboMAP-II), the micro-structure mixing over the shelf break of the ESC is measured for the first time , on the basis of which the author discuss the turbulence and double-diffusive mixing in this sea area. By calculating the Turner Angle of the...