IWISE: Observations of Internal Wave and Tide Generation in the Luzon Strait Using Shipboard Surveys and Oceanographic Moorings

摘要

The long-term goal of this research is to enhance our understanding of coastal oceanography by means of applying simple dynamical theories to high- quality observations obtained in the field. The objective of this grant is to improve our understanding of how the large-amplitude internal waves and tides in the northeastern South China Sea are generated via the interaction of the barotropic tide with the ridges and islands in the Luzon Strait. In addition to the problem's inherent scientific interest, understanding the generation problem is essential for developing a forecast model to predict the wave characteristics in the deep basin and on the Chinese continental slope and shelf. We will participate in a major ONR-sponsored field program in the Luzon Strait and northeastern South China Sea during 2010-2011. Called the Internal Waves in Straits Experiment (IWISE), the program is a logical follow-on to the Nonlinear Internal Waves Initiative (NLIWI), but it will focus more closely on the generation problem rather than on free propagation and wave dissipation that were the focus of NLIWI. A large team of investigators from the United States and Taiwan will participate. Our primary collaborator in Taiwan is Prof. Y. J. Yang of the Marine Sciences Department, Naval Academy. He and Dr. Ramp will be the co-leaders of cruises on Taiwanese vessels during the pilot study (summer 2010) and the intensive observations program (IOP, summer 2011). We have two key thrusts: moored and shipboard observations south of Taiwan on the northern Heng-Chun ridge, and two far-field deep-water moorings near 18 degrees 30' East to monitor wave arrivals. The Heng-Chun site has not been previously explored, even though numerical studies suggest it is an important generation site. The far-field moorings are specifically to test the multi-source hypothesis advanced by Zhang et al., 2011.