Shoaling of large-amplitude nonlinear internal waves at Dongsha Atoll in the northern South China Sea
St. Laurent, Louis C.
Simmons, Harper L.
MetadataShow full item record
Shoaling of large-amplitude (~100 m) nonlinear internal waves over a steep slope (~3°) in water depths between 100 m and 285 m near Dongsha Atoll in the northern South China Sea is examined with an intensive array of thermistor moorings and a bottom mounted Acoustic Doppler Current Profiler. During the 44 h study period in May 5–7, 2008, there were four groups of large internal waves with semidiurnal modulation. In each wave group a rapid transition occurred during the shoaling, such that the front face of the leading depression wave elongated and plunged to the bottom and the rear face steepened and transformed into a bottom-trapped elevation wave. The transitions occur in water depths of 200 m and deeper, and represent the largest documented internal wave shoaling events. The observations repeatedly capture the detailed temperature and velocity structures of the incident plunging waves. Strong horizontal convergence and intense upward motion are found at the leading edge of transformed elevation waves, suggesting flow separation near the bottom. The observations are compared with the previous observations and model studies. The implication of the shoaling internal waves on coral reef ecology also is discussed.
Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Continental Shelf Research 37 (2012): 1-7, doi:10.1016/j.csr.2012.01.010.
Showing items related by title, author, creator and subject.
South China Sea internal tide/internal waves-impact on the temporal variability of horizontal array gain at 276 Hz Orr, Marshall H.; Pasewark, Bruce H.; Wolf, Stephen N.; Lynch, James F.; Schroeder, Theodore; Chiu, Ching-Sang (IEEE, 2004-10)The temporal variability of the spatial coherence of an acoustic signal received on a bottomed horizontal array has been calculated for 276-Hz narrow-band signals. A conventional plane wave beamformer was applied to the ...
Internal tide and nonlinear internal wave behavior at the continental slope in the northern south China Sea Duda, Timothy F.; Lynch, James F.; Irish, James D.; Beardsley, Robert C.; Ramp, Steven R.; Chiu, Ching-Sang; Tang, Tswen Yung; Yang, Yiing-Jang (IEEE, 2004-10)A field program to measure acoustic propagation characteristics and physical oceanography was undertaken in April and May 2001 in the northern South China Sea. Fluctuating ocean properties were measured with 21 moorings ...
Duda, Timothy F.; Rainville, Luc (American Geophysical Union, 2008-03-25)Barotropic (surface) and baroclinic (internal) tides were measured at four mooring sites during a field investigation of acoustic propagation characteristics and physical oceanography in the northern South China Sea. The ...