Numerical Simulation And Research Of SAR Signatures Of Lager-amplitude Internal Solitary Waves In The Deep Sea In The Northeast South China Sea

In this paper, the simulation of propagation of the large-amplitude internal solitary waves in the deep sea in the Northeast South China Sea is made on the basis of continuous stratified oceanic model and by using the generalized K-dV(GK-dV) equation. Moreover, the simulation research of SAR signatures of the large-amplitude internal solitary waves is made.In the ocean generally the background shear current and ocean stratification must be taken into the eigenvalue problem of nonlinear internal waves, but this takes some difficulty for equation solution. In this paper, a numerical calculation method of eigenvalue problem of nonlinear internal waves is presented on the basis of the Thompson-Haskell's calculation method. It is perfectly solved the eigenvalue problem of nonlinear internal waves on the basic of continuous stratified oceanic model. And it is used in the follows when solves the eigenvalue problem of internal solitary waves.Based on the works that precede, it uses the model, which is on the basis of continuous stratified oceanic model and using the GK-dV equation, to simulation of large-amplitude internal solitary waves in the deep sea (the sea basin and the continental slope area) in the Northeast South China Sea. And the model is used in two conditions: one is that the background current is composed of circulation and flood current, and the other is composed of circulation and ebb current. The impact of barotropic tidal current on internal wave mode structure function ? ( z), the nonlinearity coefficientαand the dispersion coefficientβof GK-dV equation, the phase speed c of long internal waves, as well as the amplitude and shape of internal solitary waves is considered. It is found that barotropic tidal current has a small effect on ? ( z) andβ, but has a great effect onαandc . The effect onαin the shallow sea is larger than that in the deep sea, but on c is consistent. When barotropic tidal current has the same direction as circulation, the value ofα(absolute value) and c are larger. Furthermore the difference of impaction between flood current case and ebb current case on the amplitude and shape of the first soliton is small, but on nonlinear evolution process of internal solitary waves is lager.On the basis of simulation of internal solitary waves, the simulation research of SAR signatures of the large-amplitude internal solitary waves is made. A new simulation model of SAR signatures of internal solitary waves is put forward by us, which is based on continuous stratified ocean model. In contrast with the simulation results of SAR signatures on the basis of two-layer ocean model, either under HH(Horizontal) or VV(Vertical) polarization, the substantial improvement in simulation of the half width is obtained by using the new model, and the simulated value of half width is close to the reality.?...