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Dynamics of the Sediment Plume Over the Yangtze Bank in the Yellow and East China Seas
Author(s) -
Luo Zhifa,
Zhu Jianrong,
Wu Hui,
Li Xiangyu
Publication year - 2017
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2017jc013215
Subject(s) - plume , sediment , geology , advection , stratification (seeds) , oceanography , sediment transport , hydrology (agriculture) , geomorphology , geotechnical engineering , meteorology , seed dormancy , physics , germination , botany , dormancy , biology , thermodynamics
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 29 December 2016 to 16 January 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.