Since 2005, the US Office of Naval Research has been conducting a series of observational campaigns to observe the generation of internal tides in Luzon Strait, the westward propagation of these tides, and their subsequent evolution into solitary internal waves. the authors have participated in this effort, using shipboard Doppler Sonar and profiling CTD instrumentation to track the generation, development, and eventual shoaling of these waves. The tide appears as a quasi-sinusoidal wave for the first several hundred km of its westward propagation. It subsequently develops non-sinusoidal, soliton-like, .instabilities that grow to amplitudes greater than 100m in .the deep sea. The strong velocity strain-rate, dU/dx, affects the propagation of both smaller internal waves and surface waves, producing easily visible surface signatures. The rotation of the earth acts to inhibit soliton formation at diurnal period. Thus, even though the diurnal tides are very strong in Luzon Strait, the solitons are primarily associated with the semi-diurnal tides. Significant ocean-mixing is associated with both the tidal generation process and the eventual shoaling of the tide on the Chinese continental slope. Overturns of over 100m in height produce mixed regions of water that extend ~300m above the sea floor as the tide shoals. Similar phenomena are found at generation sites.
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