Dynamics of the Sediment Plume Over the Yangtze Bank in the Yellow and East China Seas

Autor: Xiangyu Li, Zhifa Luo, Jianrong Zhu, Hui Wu
Rok vydání: 2017
Předmět:
Zdroj: Journal of Geophysical Research: Oceans. 122:10073-10090
ISSN: 2169-9291
2169-9275
DOI: 10.1002/2017jc013215
Popis: A distinct sediment plume exists over the Yangtze Bank in the Yellow and East China Seas (YECS) in winter, but it disappears in summer. Based on satellite color images, there are two controversial viewpoints about the formation mechanism for the sediment plume. One viewpoint is that the sediment plume forms because of cross-shelf sediment advection of highly turbid water along the Jiangsu coast. The other viewpoint is that the formation is caused by local bottom sediment resuspension and diffused to the surface layer through vertical turbulent mixing. The dynamic mechanism of the sediment plume formation has been unclear until now. This issue was explored by using a numerical sediment model in the present paper. Observed wave, current and sediment data from December 29, 2016, to January 16, 2017 were collected near the Jiangsu coast and used to validate the model. The results indicated that the model can reproduce the hydrodynamic and sediment processes. Numerical experiments showed that the bottom sediment could be suspended by the bottom shear stress and diffuse to the surface layer by vertical mixing in winter; however, the upward diffusion is restricted by the strong stratification in summer. The sediment plume is generated locally due to bottom sediment resuspension primarily via tide-induced bottom shear stress rather than by cross-shelf sediment advection over the Yangtze Bank.
Databáze: OpenAIRE
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