Shoaling of the internal solitary waves over the continental shelf of the northern South China Sea

2020-05-1244

Title: Shoaling of the internal solitary waves over the continental shelf of the northern South China Sea

Journal: Acta Oceanologica Sinica, 34(9): 35-42.

Authors: QIAO H.-B., X. -D. Huang*, J. -W. Tian, and W. Zhao

Abstract: The activities of internal solitary waves (ISWs) over the continental shelf of the northern South China Sea (SCS) are of high complexity. In this study, we investigated the spatial-temporal characteristics of the shoaling ISWs over the northern SCS continental shelf using the satellite images and the results of numerical simulation. The examination of the ISW signals in the satellite optical images revealed the existence of three types of ISWs in the region north to the Dongsha Island, namely, mode-1 depression ISW, mode-1 elevation ISW, and mode-2 convex ISW. The geographical distributions of these ISWs were derived from the satellite images. Numerical results exhibited the process of polarity conversion of ISWs, by which mode-1 elevation waves were transformed from the shoaling mode-1 depression waves. The mode-2 convex ISWs generally followed the mode-1 depression ISWs. The numerical results suggested that the interaction of the mode-1 depression ISWs with the up-slope topography locally generated mode-2 ISWs, and such waves of high vertical mode dissipated rapidly during the inshore propagation.