The estimation of a critical shear stress based on a bottom tripod observation in the southwest off Jeju Island,the East China Sea

作     者：ZHAO Liang XU Yajun YUAN Ye 

作者机构：College of Marine and Environmental ScienceTianjin University of Science and Technology National Marine Environmental Forecasting CenterState Oceanic Administration 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2016年第35卷第11期

页      面：105-112页

核心收录：

学科分类：070704[理学-海洋地质] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学] 

基　　金：The Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11020305 the National Natural Science Foundation of China under contract Nos 41276016,41306009 and 41376006 the New Century Excellent Talents in University under contract No.NCET-11-0475 

主　　题：suspended sediment critical shear stress settling velocity East China Sea 

摘      要：The resuspension and deposition of sediment within a bottom boundary layer（BBL） is the main dynamic processes that control the fate of the suspended sediment in shelf *** numerical study of sediment transport patterns relies on the knowledge of some critical parameters that describe sediment erosion and deposition.A critical shear stress is estimated based on field observations at the edge of a mud area southwest off Jeju Island,the East China *** the basis of the simultaneous observation of velocity and suspended sediment concentrations within the BBL by means of acoustic instruments including an acoustic Doppler velocimeter and an acoustic Doppler current profiler,the settling velocity is estimated by turbulent oscillations of the SSC under the assumption of inertial-dissipation *** method gives a mean value of 0.91 mm/s and standard deviation of 0.20 mm/s,which is an order of magnitude larger than the value obtained by an empirical method of Soulsby and by an in situ submersible particle size *** difference is possibly due to the distinct natures of two methodologies,the inertial-dissipation method is more indicative of the BBL dynamics and is thus believed to provide reasonable in situ estimates of the settling velocity,whereas Soulsby＇s method is usually suitable for still water.A novel method for estimating the critical stresses of erosion and deposition based on statistical analyses of the temporal variability of the SSC（which is defined as a derivative of the depth-averaged SSC with respect to time） and the corresponding bottom shear stress is *** critical stresses of erosion and deposition vary between 0.11 Pa and 0.25 Pa with corresponding median values of 0.20 Pa and 0.16 Pa,respectively,which confirms that the critical stresses of erosion is somewhat higher than the critical stresses of *** method of estimating the critical shear stress by means of the settling velocity is also employed,which yields reas