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Observation of ocean current response to 1998 Hurricane Georges in the Gulf of Mexico

Acta oceanologica Sinica 2006年第1期25卷 1-14页

作者： ZHENG Quanan LAI Ronald J HUANG Nortlen E PAN Jiayi LIU W Timothy Department of Atmospheric and oceanic Science University of Maryland College Park Maryland 20742 USA Minerals Management Service U S Department of the Interior Hemdon Virginia 20170 USA ocean and Ice Branch NASA Goddard Space Flight Center Greenbelt Maryland 20771 USA Department of Environmental and Biomolecular Systems Oregon Graduate Institute Beaverton Oregon 97006 USA Jet Propulsion Laboratory California Institute of Technology Pasadena California 91109 USA

The ocean current response to a hurricane on the shelf-break is examined. The study area is the DeSoto Canyon in the northeast Gulf of Mexico, and the event is the passage of 1998 Hurricane Georges with a maximum wind speed of 49 m/s. The data sets used for analysis consist of the mooring data taken by the Field Program of the DeSoto Canyon Eddy Intrusion Study, and simultaneous winds observed by NOAA （National oceanic and Atmospheric Administration） Moored Buoy 42040. Time-depth ocean current energy density images derived from the observed data show that the ocean currents respond almost immediately to the hurricane with important differences on and offthe shelf. On the shelf, in the shallow water of 100 m, the disturbance penetrates rapidly downward to the bottom and forms two energy peaks, the major peak is located in the mixed layer and the secondary one in the lower layer. The response dissipates quickly after external forcing disappears. Offthe shelf, in the deep water, the major disturbance energy seems to be trapped in the mixed layer with a trailing oscillation; although the disturbance signals may still be observed at the depths of 500 and 1 290 m. Vertical dispersion analysis reveals that the near-initial wave packet generated offthe shelf consists of two modes. One is a barotropic wave mode characterized by a fast decay rate of velocity amplitude of 0.020 s^-, and the other is baroclinic wave mode characterized by a slow decay rate of 0.006 9 s^-1. The band-pass-filtering and empirical function techniques are employed to the frequency analysis. The results indicate that ialf frequencies shift above the local inertial frequency. On the shelf, the average frequency is 1.04fin the mixed layer, close to the diagnosed frequency of the first baroclinic mode, and the average frequency increases to 1.07fin the thermocline. Offthe shelf, all frequencies are a little smaller than the diagnosed frequency of the first mode. The average frequency decreases from 1.035

关键词： shelf dynamics hurricane ocean current air-sea interaction

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Study on the influence of the subsurface buoy＇s vibration on the vector sensor due to ocean current

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High Technology Letters 2014年第3期20卷 223-229页

作者：师俊杰 Sun Dajun Lv Yunfei Lan Hualin Mei Jidan Key Laboratory of Underwater Acoustic Technology Underwater Acoustic Engineering College HarBin Engineering University Harbin 150001 P. R. China

Subsurface buoy systems,especially equipped with the vector sensor,have more and more extensive applications in military and civilian ***,their acoustic performances are constrained by the vibration resulting from the unavoidable ocean current in some *** influence of such vibrations is quantitatively analyzed by means of modeling the simplified models of two deployment configurations involving the positive buoyant buoy and neutral buoy *** corresponding formulas are deduced respectively for the deployment configuration buoy systems in the motion state *** the simulation software is developed and some numerical simulations are put up via the Runge-Kutta *** simulation results and theoretical analysis indicate that the neutral buoy will be an excellent design protocol in engineering application in comparison with the positive buoyant buoy.

关键词： subsurface buoy system vector sensor ocean current neutral buoy

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A Dedicated MAC Protocol Package for Real-Time ocean current Field Estimation Using Distributed Underwater Acoustic Sensor Networks

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Journal of Communications and Information Networks 2019年第3期4卷 71-79页

作者： Hao Chen Huifang Chen Lei Xie Kuang Wang College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027China Zhejiang Provincial Key Laboratory of Information Processing Communication and NetworkingHangzhou 310027China Zhoushan ocean Research Center Zhejiang UniversityZhoushan 316021China

Distributed underwater acoustic sensor networks(UASNs)are envisioned in real-time ocean current velocity ***,UASNs at present are still dominated by post-processing partially due to the complexity of on-line detection for travel times and lack of dedicated medium access control(MAC)*** this study,we propose a dedicated MAC protocol package for real-time ocean current velocity estimation using distributed ***,we introduce the process and requirements of ocean current velocity ***,we present a series of spatial reuse time division multiple access(TDMA)protocols for each phase of real-time ocean current field estimation using distributed UASNs,followed by numerical *** divide UASNs into two categories according to their computing ability:feature-complete and feature-incomplete *** feature-complete systems that have abundant computing ability carry out the presented MAC protocol package in three phases,whereas the feature-incomplete ones do not have enough computing ability and the presented MAC protocol package is reduced to two phases plus an additional downloading *** analysis shows that feature-complete systems using mini-slot TDMA have the best real-time performance,in comparison with feature-incomplete systems and other feature-complete ***-incomplete systems are more energy-saving than feature-complete ones,owing to the absence of in-network data exchange.

关键词： distributed underwater acoustic sensor networks ocean current dedicated medium access control protocol package spatial reuse time division multiple access real-time

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Radial velocity of ocean surface current estimated from SAR Doppler frequency measurements—a case study of Kuroshio in the East China Sea

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Acta oceanologica Sinica 2021年第12期40卷 135-147页

作者： Lihua Wang Benwei Shi Yunxuan Zhou Hui Sheng Yanghua Gao Li Fan Ziheng Yang Department of Geography and Spatial Information Techniques/Center for Land and Marine Spatial Utilization and Governance Research Ningbo UniversityNingbo 315211China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200062China Chongqing Institute of Meteorological Sciences Chongqing 401147China College of Resources and Environment Chengdu University of Information TechnologyChengdu 610225China

ocean currents are a key element in ocean processes and in meteorology,affecting material transport and modulating climate change *** Doppler frequency shift information of the synthetic aperture radar(SAR)echo signal can reflect the dynamic characteristics of the sea surface,and has become an essential sea surface dynamic remote sensing *** have verified that the instantaneous Doppler frequency shift can realize the SAR detection of the sea surface ***,the validation of SAR-derived ocean current data and a thorough analysis of the errors associated with them remain *** this study,we derive high spatial resolution flow measurements for the Kuroshio in the East China Sea from SAR data using a theoretical model of shifts in Doppler frequency driven by ocean surface *** ocean multi observation(MOB)products and global surface Lagrangian drifter(GLD)data are used to validate the Kuroshio flow retrieved from the SAR *** show that the central flow velocity for the Kuroshio derived from the SAR is 0.4–1.5 m/*** error distribution between SAR ocean currents and MOB products is an approximate standard normal distribution,with the 90%confidence interval concentrated between–0.1 m/s and 0.1 m/*** analysis of SAR ocean current and GLD products,the correlation coefficient is 0.803,which shows to be significant at a confidence level of 99%.The cross-validation of different ocean current dataset illustrate that the SAR radial current captures the positions and dynamics of the Kuroshio central flow and the Kuroshio Counter current,and has the capability to monitor current velocity over a wide range of values.

关键词： Doppler frequency radial velocity ocean current SAR Kuroshio

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FEM Analysis of ocean current Effects on the Postures of Submerged Buoys

FEM Analysis of Ocean Current Effects on the Postures of Sub...

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2012年计算机应用与系统建模国际会议

作者： Wang Zhongqiu Wang Yiming Wang Hongru Zheng Yi Shandong Provincial Key Laboratory of ocean Environment Monitoring Technology Shandong Academy of Sciences Institute of Oceanographic Instrumentation The First Institute of oceanography SOA

The ocean current affection on the posture of two type of submerged buoy is analyzed through FEM analysis. By comparing the factors of impact pressure coefficient distribution, ocean current speed distribution, impact pressure force in horizontal direction and vertical direction, Turbulence Kinetic Energy distribution and vortex generation, the advantage and disadvantage of the two structure are compared. By considering these affect factors, the horizontal buoy structure is better than horizontal buoy structure.

关键词： FEM Submerged buoy ocean current Posture analysis

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MECHANISM OF ocean current-INDUCED SUSPENDING OF SUBMARINE PIPELINE

MECHANISM OF OCEAN CURRENT-INDUCED SUSPENDING OF SUBMARINE P...

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中国力学学会学术大会'2005

作者： Yang Bing Gao Fuping Wu Yingxiang Zheng Zhichu (Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China)

The pipe span is a potential threat to the pipeline’s safety, so it is essential to analyze the mechanism of the pipeline’s suspending properly when designing pipelines. In this paper, the mechanism of submarine pipeline’s suspending under the current action is studied by means of numerical simulation. The incompressible N-S equation is solved and the property of the flow around the pipe under the ocean current action is analyzed. The

关键词： submarine pipe ocean current suspending seepage analysis

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Experi mental Study on Vortex-Induced Vibrations of Submarine Pipeline near Seabed Boundary in ocean currents

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China ocean Engineering 2006年第1期20卷 113-121页

作者：杨兵高福平吴应湘李东晖 Institute of Mechanics Chinese Academy of Sciences Beijing100080China

Unlike most previous studies on vortex-induced vibrations of a cylinder far from a boundary, this paper focuses on the influences of close proximity of a submarine pipeline to a rigid seabed boundary upon the dynamic responses of the pipeline in ocean currents. The effects of gap-to-diameter ratio and those of the stability parameter on the amplitude and frequency responses of a pipeline are investigated experimentally with a novel hydro-elastic facility. A comparison is made between the present experimental results of the amplitude and frequency responses for the pipes with seabed boundary effects and those for wall-free cylinders given by Govardhan and Williamson （2000） and Anand （1985）. The comparison shows that the close proximity of a pipeline to seabed has much influence on the vortex-induced vibrations of the pipeline. Both the width of the lock-in ranges in terms of Vr and the dimensionless amplitude ratio Amax/D become larger with the decrease of the gap-to-diameter ratio e/D, Moreover, the vibration of the pipeline becomes easier to occur and its amplitude response becomes more intensive with the decrease of the stability parameter, while tire pipeline frequency responses are affected slightly by the stability parameter.

关键词： submarine pipeline vortex-induced vibrations ocean current seabed

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A Numerical Model for Ultimate Soil Resistance to An Untrenched Pipeline Under ocean currents

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China ocean Engineering 2012年第2期26卷 185-194页

作者：高福平韩希霆闫术明 Institute of Mechanics Chinese Academy of Sciences

One of the main concerns for pipeline on-bottom stability design is to properly predict ultimate soil resistance in severe ocean environments. A plane-strain finite element model is proposed to investigate the ultimate soil resistance to the partially-embedded pipeline under the action of ocean currents. Two typical end-constraints of the submarine pipelines are examined, i.e. freely-laid pipes and anti-rolling pipes. The proposed numerical model is verified with the existing mechanical-actuator experiments. The magnitude of lateral-soil-resistance coefficient for the examined anti-rolling pipes is much larger than that for the freely-laid pipes, indicating that the end-constraint condition significantly affects the lateral stability of the untrenched pipeline under ocean currents. The parametric study indicates that, the variation of lateral-soil-resistance coefficient with the dimensionless submerged weight of pipe is affected greatly by the angle of internal friction of soil, the pipe-soil friction coefficient, etc.

关键词： submarine pipeline on-bottom stability ultimate soil resistance ocean current sandy seabed

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Study on Free-Standing Riser Under Different Working Conditions Based on 3D Co-Rotational Beam Element

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China ocean Engineering 2024年第5期38卷 725-738页

作者： HUANG Chen GU Ji-jun JIA Ji-chuan CHEN Lei-lei WANG Shu-jiang GAO Lei College of Mechanical and Transportation Engineering China University of Petroleum-BeijingBeijing 102200China School of Safety and Engineering Xinjiang Institute of EngineeringUrumqi 830000China CNOOC Research Institute Beijing 100028China

When the free standing riser(FSR)is in service in the ocean,its mechanical properties are affected by various factors,including complex ocean current forces,buoyancy of the buoyancy can,and torque caused by the deflection of the upper floating *** loads have a great influence on the deformation and internal force of the *** static performance of FSR is investigated in this research under various working *** finite element model of FSR is established based on the co-rotational *** arc length approach is used to solve the *** load is exerted in *** current load on the riser changes with the configuration of the *** accuracy of the numerical method is verified by Abaqus *** calculation time is also ***,the effects of uniform current,actual current and floating body yaw motion on FSR are studied by parameter ***,the influence of the FSR on the ocean current after the failure of part of the buoyancy can chamber is *** results show that the numerical model based on the co-rotational method can effectively simulate the large rotation and torsion behavior of *** method has high computational efficiency and precision,and this method can quickly improve the efficiency of numerical calculation of static analysis of deep-water *** proposed technology may serve as an alternative to the existing proprietary commercial software,which uses a complex graphical user interface.

关键词： free standing riser(FSR) co-rotational method finite element method ocean current nonlinear analysis torsion

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Spatiotemporal patterns of sediment deposition on the northern slope of the South China Sea in the last 150,000 years

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Journal of Palaeogeography 2021年第3期10卷 399-415页

作者： Zhe Hu Bao-Qi Huang Le-Jun Liu Na Wang Key Laboratory of Orogenic Belts and Crustal Evolution MOESchool of Earth and Space SciencesPeking UniversityBeijing 100871China Marine Engineering Environment Center First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061Shandong ProvinceChina School of Urban Planning and Design Shenzhen Graduate SchoolPeking UniversityShenzhen 518055Guangdong ProvinceChina

The source-to-sink system of the northern South China Sea(SCS) has been widely discussed during the past few decades. Sr–Nd isotope, clay minerals and trace elements were extensively used as the proxies of sediment provenance, however, still little is known about the transport processes and controlling mechanisms on detailed spatiotemporal scales due to the limitations of these methods. Here we put forward the new provenance proxies RAKand RKCNbased on major element compositions to study the spatiotemporal changes in sediment provenance since 150 ka mainly from four sites, DLW3101, MD12-3429, ZHS-176 and MD12-3432, which are located on the northern SCS continental slope. Our results show that, spatially, the pathways and intensities of contour currents and gravity flows play important roles in sediment transport. For alongslope processes, the South China Sea Branch of Kuroshio current(SCSBKC) and the Deep Water current(DWC) transport sediments from southwestern Taiwan,while the Intermediate Water current(IWC) can carry sediments from Hainan, the Red River or the Indochina Peninsula. For downslope processes, gravity flows transport materials from the Pearl River delta and shelf to the slope. Moreover, seafloor bathymetry influences sediment transport by altering the pathways of ocean ***, the impacts of sea level and monsoon rainfall fluctuations are always superimposed over the last 150 ka. Sea level fluctuations could significantly change the distance from the Pearl River estuary to the slope, while variations in the East Asian summer monsoon(EASM) rainfall would affect continental erosion rates in the source regions.

关键词： South China Sea Sediment transport Element composition ocean current Sea level Quaternary

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