- The life cycle of the most powerful internal waves in the world There are sea waves on the sea level which are easily seen and enjoyed on the seafront; however, there are also waves hidden in the sea which are called internal waves. Both the sea waves and the internal waves are kinds of gravity waves, which are generated due to the density difference from two fluids. The fluctuation between air and water would cause sea waves; similarly, the internal waves are produced from water with different solidity and temperature. The largest internal waves in the world are located in the South China Sea, but the related information had been limited because of the difficulty of underwater observation. Nevertheless, the energy pattern of internal waves is a sensitive factor to the numerical climate model; thus, the understanding of internal waves is an urgent issue. Since 2000, a group at Institute of Oceanography in NTU had led a large national project cooperated with the US, targeting to collect data in the South China Sea and provide it to further research. Supported by the Taiwan National Science Council and the US Office of Naval Research, this project was participated by hundreds of researchers, technicians, and students. On May 2015, a letter published on Nature to announce their achievement, which was authored by 28 researchers from Taiwan, the USA, Canada, and South Korea. By the help of this project, the life cycle of the grand internal waves is deduced from formation to fate. This study used in situ data from synthetic aperture radars, mooring, pressure inverted echo sounders, ship stations, and glider tracks, so that the mechanism of the internal waves could be fully realized. The internal waves are stated generated from the Luzon Strait and related to the internal tides forced by the Sun and the Moon, which are a combination of semidiurnal (twice a day) and diurnal (once a day) tides. As the waves are propagating to the west through the Kuroshio Current, its energy fluxes were measured to be around 40kW/m, which are about 100 times than typical open-ocean values and exceed any present generation stations in the world. The lee wave phenomena were also observed at the ridge of the Batanes Islands at about 121。E, and the vertical displacements of the ocean layers steepen to 200m, even reach up to 500m. By 115。E, the internal waves are dissipated and breaking because of the shoaling effect over the continental shelf. This research investigated the mechanism of the generation, propagation, steepening, and dissipation of the largest internal waves in the world. In addition, the huge data collected from numerous sources would provide to future study, which would be a great contribution to the climate model around the globe. Reference: [1] Matthew H. Alford et al., The formation and fate of internal waves in the South China Sea, Nature, vol. 521, pp.65, 2015. Reference Matthew H. Alford, Thomas Peacock, Jennifer A. MacKinnon, Jonathan D. Nash, Maarten C. Buijsman, Luca R. Centuroni, Shenn- Yu Chao, Ming-Huei Chang, David M. Farmer, Oliver B. Fringer, Ke- Hsien Fu, Patrick C. Gallacher, Hans C. Graber, Karl R. Helfrich, Steven M. Jachec, Christopher R. Jackson, Jody M. Klymak, Dong S. Ko, Sen Jan, T. M. Shaun Johnston, Sonya Legg, I-Huan Lee, Ren-Chieh Lien, Matthieu J. Mercier, James N. Moum, Ruth Musgrave, Jae-Hun Park, Andrew I. Pickering, Robert Pinkel, Luc Rainville, Steven R. Ramp, Daniel L. Rudnick, Sutanu Sarkar, Alberto Scotti, Harper L. Simmons, Louis C. St Laurent, Subhas K. Venayagamoorthy, Yu-Huai Wang, Joe Wang, Yiing J. Yang, Theresa Paluszkiewicz & Tswen-Yung (David) Tang. The formation and fate of internal waves in the South China Sea, Nature, vol. 521, pp.65, 2015. DOI: 10.1038/nature14399. Assistant Professor Ming-Huei Chang Institute of Oceanography minghueichang@ntu.edu.tw Professor Sen Jan Institute of Oceanography senjan@ntu.edu.tw Professor Joe Wang Institute of Oceanography wang@oc.ntu.edu.tw Professor Yiing Jang Yang Institute of Oceanography yjyang67@ntu.edu.tw Professor Tswen-Yung (David) Tang Institute of Oceanography (Deceased) Life cycle of the internal waves in the South China Sea