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Abstract: The objective of this study is to investigate the generation and evolution of mode-two internal waves on the shelf break. In this study, some historical mooring and satellite data have been investigated for the detection of mode-two solitons in the ocean. A recent field experiment in May 2009 near Dong-Sha Island in the South China Sea (SCS) is first described and analyzed. During the experiment, a small mode-two wave was observed following a huge mode-one soliton on the shelf. Then, the environmental conditions for the evolution of mode-two internal waves were assessed for parametric and sensitivity study based on the CTD data from previous experiment in SCS. The generation of mode-two waves on the shelf by disintegration of mode-one solitons in the deep ocean is proposed and analyzed based on the theory of modal-decomposition. For comparison, the soliton characteristics of mode-one and -two waves from environmental parameters have been estimated. It’s been shown that the soliton width of large mode-two waves is much wider than mode-one waves. [Copyright &y& Elsevier]

In the present study, theories based on the Korteweg-de Vries equation are extended to the Benjamin-Ono equation to allow the determination of internal solitary wave (ISW) amplitude from satellite images. The free surface flow induced by an ISW is derived for deep water. As a coherent structure, the amplitude of the ISW has a unique relation to the convergence/divergence of surface flow, such that the flow convergence/divergence will increase/decrease the backscattering cross section and generate bright/dark bands in satellite images. The distance between bright and dark bands can be related to the amplitude of ISW. To validate the theory, a multi-ship measurement made on 9-11 May 2005 during the spring tide period is used. A systematic approach to determine the thickness and density of the upper and lower layers is also included so that the free surface flow can be determined with a relatively high accuracy. [ABSTRACT FROM AUTHOR]

Satellite altimeter sea level data from 1993 to 2008 are used to analyze the interaction of nonlinear Rossby eddies with the Kuroshio at the Luzon Strait (LS). The sea level anomaly data show that the west Pacific (WP) is a source of nonlinear Rossby eddies, and the South China Sea (SCS) is a sink. The LS serves as a gateway between the two. The scale analysis indicates that eddies with a radius larger than 150 km are strong enough to significantly alter the Kuroshio and are able to modify the local circulation pattern. Statistical analysis indicates that the probability for eddies to penetrate through the Kuroshio may reach at least 60%. A case study of an anticyclonic mesoscale eddy passing through the LS in June-July 2004 indicates that the Kuroshio behaves as an unsteady flow with its stream path frequently modified, in a way of cutting off, meandering and branching during its interaction with the eddy. We therefore suggest that nonlinear Rossby eddies may play a significant role in modification of the local circulation system near the LS and in exchanges of the mass, momentum and energy between the WP and the SCS. [ABSTRACT FROM AUTHOR]