Multidisciplinary geophysical measurements on the ocean floor usingdecommissioned submarine cables: VENUS project

To perform geophysical and multidisciplinary real-time measurements on the ocean floor, it has been attempted to reuse decommissioned submarine cables. The VENUS project reuses the TPC-2, which is one of these systems and runs across the entire Philippine Sea Plate between Guam Island and Okinawa Island. The VENUS system comprises an ocean floor observatory, a submarine cable, and a land system. The major components of the ocean floor observatory are geophysical instruments and a telemetry system. There are seven scientific instrument units including broadband seismometers and a hydrophone array. Digital telemetry using the old analog telephone cable obtains high data accuracy and real-time accessibility to data from a laboratory on land. The bottom-telemetry system and a part of sensor units were installed at a depth of 2157 m on the landward slope of the Ryukyu (Nansei-Syoto) Trench on August 29, 1999. The data from the hydrophone array and tsunami gauge have been correctly transmitted to the data center. The rest of the scientific instruments will be deployed by deep-tow equipment and a remotely operated vehicle. Using a decommissioned submarine cable will greatly reduce construction costs compared to using a new cable system     

Down-scaled regional ocean modeling system (ROMS) for high-resolution coastal hydrodynamics in Korea

A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a regional ocean modeling system(ROMS).The operational oceanographic modeling system consists of atmospheric and hydrodynamic models.The hydrodynamic model,ROMS,is coupled with wave,sediment transport,and water quality modules.The system forecasts the predicted results twice a day on a 72 h basis,including sea surface elevation,currents,temperature,salinity,storm surge height,and wave information for the coastal waters of Korea.The predicted results are exported to the web-GIS-based coastal information system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies.The ROMS is two-way coupled with a simulating waves nearshore model,SWAN,for the hydrodynamics and waves,nested with the meteorological model,WRF,for the atmospheric surface forcing,and externally nested with the eutrophication model,CE-QUAL-ICM,for the water quality.The operational model,ROMS,was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea.To validate the predicted results,we used real-time monitoring data derived from remote buoy system,HF-radar,and geostationary ocean color imager(GOCI).This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system(KOOS) with other operational oceanographic systems.     

海底观测网深水设备精准定点布放方法研究

海底观测网因其实时、长期、连续、高精度时钟同步及原位等优势而逐渐成为人类研究海洋的新型平台,建设规模和应用水深都在不断扩大。海底观测网系统建设中,深水设备的精准定点布放及湿插拔作业是施工的难点。针对国内海底观测网精准定位布放作业存在的困难和问题,结合国内现有施工条件,提出一种大深度海底设备精准定点布放安装方法,实现南海深海海底观测网试验系统深水设备精准定位布放与ROV湿插拔作业,对未来大规模海底观测网及其它深水工程中设备的精准定点布放和安装,具有参考和借鉴意义。     

平潭近岸海域浮子漂移轨迹及其数值模拟

平潭近岸海域岸线曲折,周边岛礁众多,海底地形复杂,是福建省海难事故的高发区.本研究建立了平潭近岸海域海上目标物漂移轨迹的预测系统,该系统通过风场和流场的数值模型获取海面动力环境信息,采用拉格朗日算法实现对海上目标物漂移轨迹的预测追踪.其中海流模型采用ROMS（regional ocean modeling system）模型构建,模型水平方向上最高分辨率为100m,垂向上分为16层,并考虑干湿边界,以体现复杂海岸线和水深地形.通过验证分析,潮位、流速和流向的模拟平均绝对误差分别为0.20 m、0.12 m/s和26°.通过平潭近岸2个浮子实验,结果表明,浮子漂移过程中受潮流和局地地形的影响明显,对漂移模型在平潭近岸海域的适用性进行初步验证,浮子模拟轨迹与实际漂移过程基本吻合,模拟时段内最大偏差距离为2.8km,系统可以为平潭近岸海域海上突发事故应急决策提供参考.     

A network-based telemetry architecture developed for the Martha'sVineyard Coastal Observatory

Underwater observatories with real-time data and virtually unlimited power transmission capabilities compared to traditional oceanographic moorings are beginning to provide scientists with continuous access to the coastal and open ocean. However, for any coastal observatory to serve as a cost-effective system for the collection of long-term scientific and environmental data, it must have a simple, upgradeable power and telemetry system and an instrument interface that is compatible with existing standards. It must be designed for extended environmental exposure and ease of service to avoid high maintenance costs. Most importantly, the observatory must be accessible to all potential users, including students, scientists, engineers, and policy makers. This strategy was applied to the design of the Martha's Vineyard Coastal Observatory on the south shore of the island of Martha's Vineyard. The new facility, and in particular its system architecture, as developed by the Woods Hole Oceanographic Institution with support from the National Science Foundation, are described     

珠江口近海海域海浪预报方法研究

根据珠江口近海海域的风区和水深等特点,将该海域划分为4个区域,结合港口规范方法、SMB 方法、适用于深浅水的风浪要素计算方法、原苏联预报模式以及莆田海堤试验站方法等 5 种风浪经验预报模式,对该海域 2004～2005 年的风浪进行后报、检验和订正,总结出对应不同区域最适合的风浪预报方法.     

Improvement of earthquake locations with the Marine Cable Hosted Observatory (MACHO) offshore NE Taiwan

In order to improve the locating capability for offshore earthquakes and tsunamis monitored off northeastern Taiwan, a cable-based ocean bottom seismographic observatory named “Marine Cable Hosted Observatory” (MACHO) was constructed and began operation at the end of 2011. The installed instruments of the observatory include a broadband seismometer, a strong-motion seismometer and a pressure gauge. In addition, various scientific instruments could be deployed for other purposes as well. At present, the seismic data are transmitted in real-time via a fiber cable, and integrated into the current inland seismographic network in Taiwan. The ocean bottom station has contributed to provide high quality seismic data already. According to observations from January 2012 to June 2013, there were a total of 15,168 earthquakes recorded by the system. By using the data from the ocean bottom station, the number of relocated earthquakes with an azimuth gap less than 180 degrees substantially increase about 34 %. Meanwhile, the root–mean–square of the time residual, the error in epicenter, and the error in depth of the earthquake locations decrease. Therefore, the implementation of MACHO has the advantage of extending the coverage of existing the Taiwan seismic network to the offshore, providing more accurate and real-time seismic data for offshore earthquakes monitoring. The results show that MACHO is crucial and necessary for monitoring seismic activities in northeastern Taiwan.     

A real-time,event-triggered storm surge forecasting system for the state of North Carolina

A new real-time, event-triggered storm surge prediction system has been developed for the State of North Carolina to assist emergency managers, policy-makers and other government officials with evacuation planning, decision-making and resource deployment during tropical storm landfall and flood inundation events. The North Carolina Forecast System (NCFS) was designed and built to provide a rapid response assessment of hurricane threat, accomplished by driving a high-resolution, two-dimensional, depth-integrated version of the ADCIRC (Advanced Circulation) coastal ocean model with winds from a synthetic asymmetric gradient wind vortex. These parametric winds, calculated at exact finite-element mesh node locations and directly coupled to the ocean model at every time step, are generated from National Hurricane Center (NHC) forecast advisories the moment they are inserted into the real-time weather data stream, maximizing the number of hours of forecast utility. Tidal harmonic constituents are prescribed at the open water boundaries and applied as tidal potentials in the interior of the ocean model domain. A directional surface roughness parameterization that modulates the wind speed at a given location based on the types of land cover encountered upwind, a forest canopy sheltering effect, and a spatially varying distribution of Manning’s–n friction coefficient used for computing the bottom/channel bed friction are also included in the storm surge model. Comparisons of the simulated wind speeds and phases against their real meteorological counterparts, of model elevations against actual sea surface elevations measured by NOAA tide gauges along the NC coast, and of simulated depth-averaged current velocities against Acoustic Doppler Current Profiler (ADCP) data, indicate that this new system produces remarkably realistic predictions of winds and storm surge.     

A real-time, event-triggered storm surge forecasting system for the state of North Carolina

A new real-time, event-triggered storm surge prediction system has been developed for the State of North Carolina to assist emergency managers, policy-makers and other government officials with evacuation planning, decision-making and resource deployment during tropical storm landfall and flood inundation events. The North Carolina Forecast System (NCFS) was designed and built to provide a rapid response assessment of hurricane threat, accomplished by driving a high-resolution, two-dimensional, depth-integrated version of the ADCIRC (Advanced Circulation) coastal ocean model with winds from a synthetic asymmetric gradient wind vortex. These parametric winds, calculated at exact finite-element mesh node locations and directly coupled to the ocean model at every time step, are generated from National Hurricane Center (NHC) forecast advisories the moment they are inserted into the real-time weather data stream, maximizing the number of hours of forecast utility. Tidal harmonic constituents are prescribed at the open water boundaries and applied as tidal potentials in the interior of the ocean model domain. A directional surface roughness parameterization that modulates the wind speed at a given location based on the types of land cover encountered upwind, a forest canopy sheltering effect, and a spatially varying distribution of Manning’s–n friction coefficient used for computing the bottom/channel bed friction are also included in the storm surge model. Comparisons of the simulated wind speeds and phases against their real meteorological counterparts, of model elevations against actual sea surface elevations measured by NOAA tide gauges along the NC coast, and of simulated depth-averaged current velocities against Acoustic Doppler Current Profiler (ADCP) data, indicate that this new system produces remarkably realistic predictions of winds and storm surge.     

海上警戒浮标实时监控系统

为有效保护近海海底观测网观测安全,免受渔船拖网和抛锚等损坏的问题,设计了一套多警戒浮标(直径2.4~3.0 m)的实时监控系统,该警戒浮标可获取浮标本身工作状态,并能实时、动态、连续的将警戒浮标的运行状态发送到陆基岸站,实现对保护目标海域的实时监控,同时该浮标系统可进行扩充实现对海洋环境要素的观测。警戒浮标布设采用正多边形(三角形、正方形和正五边形等)预警保护方式,浮标以保护节点为中心等距布放,组网形成有效的海上保护围栏,保障海底观测系统的安全运行;供电系统采用太阳能电池和蓄电池组合供能方式,可保证在连续阴天的情况下警戒浮标系统运行100天。该警戒浮标技术已在东海海底观测网保护中成功示范运行6个月,该技术可为近海海底观测保护提供有效技术保障。     

Tsunami Wave Interaction with Data Buoys

To plan for proper mitigation measures, one should have an advanced knowledge of the phenomenon of tsunami propagation from the deep ocean to coastal waters. There are a few methods to predict tsunamis in the ocean waters; one method is the effective use of data buoy measurements. Although data buoys have been used along the Indian waters there has been a tremendous growth in the number of buoy deployment recently. Under the National Data Buoy Programme (NDBP) of India, the 2.2 m diameter discus data buoys were deployed along the east and west coasts of India for measuring meteorological and ocean parameters. It would be advantageous if these buoys could be efficiently used to measure rare events such as tsunamis. Understanding the dynamic behavior of the buoy is of prime importance if a tsunami warning system is to be successful. This may be accomplished through experimental or numerical studies. A comprehensive experimental study has been conducted to understand the dynamic behavior of a wave rider buoy exposed to a variety of waves. It is common that tsunami waves are represented in terms of shallow water waves, namely solitary and cnoidal waves. Hence, in the present study, the discus type data buoy is scale modeled and tested under the action of solitary and cnoidal waves in the laboratory. The time histories of wave elevations, as well as heave and pitch motions of the buoy model, were analyzed through a spectral approach as well as through wavelet transformations. The wavelet approach gives more detailed insight into the spectral characteristics of the buoy motion in the time scale. The harmonic analyses were performed for the cnoidal wave elevations and subsequent motion characteristics that give an insight into the energy variations. The details of the model, instrumentation, testing conditions and the results are presented in this paper.     

Real-time geophysical measurements on the deep seafloor usingsubmarine cable in the southern Kurile subduction zone

A permanent real-time geophysical observatory using a submarine cable was developed and deployed to monitor seismicity, tsunamis, and other geophysical phenomena in the southern Kurile subduction zone. The geophysical observatory comprises six bottom sensor units, two branching units, a main electro-optical cable with a length of 240 km and two land stations. The bottom sensor units are: 1) three ocean bottom broadband seismometers with hydrophone; 2) two pressure gauges (PGs); 3) a cable end station with environmental measurement sensors. Real-time data from all the undersea sensors are transmitted through the main electro-optical cable to the land station. The geophysical observatory was installed on the continental slope of the southern Kurile trench, southeast Hokkaido, Japan in July 1999. Examples of observed data are presented. Sensor noises and resolution are mentioned for the ocean bottom broadband seismometers and the PGs, respectively. An adaptable observation system including very broadband seismometers is scheduled to be connected to the branching unit in late 2001. The real-time geophysical observatory is expected to greatly advance the understanding of geophysical phenomena in the southern Kurile subduction zone     

虚拟海洋场景构建与技术研究

随着传统GIS应用向三维立体方向发展,三维虚拟场景在信息认知、空间规划管理、时空挖掘与分析等方面的应用逐渐成为研究热点。本文基于Skyline平台集成遥感影像数据、地形数据、纹理特征数据、倾斜摄影测量数据、三维全景数据和三维模型数据,构建了集虚拟海岛海岸带模型、虚拟海底地形模型和虚拟水体模型于一体的虚拟海洋场景,并针对场景构建中涉及的多源影像数据集成技术、多尺度影像实时切片技术和基于OGC服务的数据集成技术开展了研究。构建形成的虚拟海洋场景在海洋应用服务系统中开展了实践应用。     

浙江省海洋水质监测浮标设计与实现

作为一种高技术监测手段,海洋浮标可实现现场自动监测而不受恶劣海况的影响,近年来得到了广泛的重视和快速发展。文中介绍了浙江近岸海域海洋水质监测浮标的结构设计和自动监测实现。浮标设计为生态浮标、海滨浮标和专项浮标3种类型,由浮体、标架、供电设备、防护设备、锚系、传感器、数据采集传输、电子/电池舱、岸站接收系统等9个部分组成。浮体设计为圆饼形,浮体下方正中安装稳定锤以保证具备足够的稳定性。供电设备由太阳能电池板、大容量蓄电池组成,可保障海上30 d连续阴雨天气、恶劣海况下的不间断供电。浮标经喷防污漆、牺牲阳极保护、裹铜皮、加过滤网和人工清除等5种方法防腐、防污处理后投放入海,采用常规维护、应急维护和年度维护等3种方式保障浮标系统运行稳定。投放后可实现对标浮所在海域水质、气象、生态等参数的连续、实时、自动监测。最后对浮体直径设计和浮标投放点选址提出了建议和要求。该设计可为其它类似区域的水质监控提供良好的参考。     

Cost and value of multidisciplinary fixed-point ocean observatories

Sustained ocean observations are crucial to understand both natural processes occurring in the ocean and human influence on the marine ecosystems. The information they provide increases our understanding and is therefore beneficial to the society as a whole because it contributes to a more efficient use and protection of the marine environment, upon which human livelihood depends. In addition the oceans, which occupy 73% of the planet surface and host 93% of the biosphere, play a massive role in controlling the climate. Eulerian or fixed-point observatories are an essential component of the global ocean observing system as they provide several unique features that cannot be found in other systems and are therefore complementary to them. In addition they provide a unique opportunity for multidisciplinary and interdisciplinary work, combining physical, chemical and biological observations on several time scales. The fixed-point open ocean observatory network (FixO3) integrates the 23 European open ocean fixed-point observatories in the Atlantic Ocean and in the Mediterranean Sea. The programme also seeks to improve access to key installations and the knowledge they provide for the wider community, from scientists, to businesses, to civil society. This paper summarises the rationale behind open ocean observatories monitoring the essential ocean variables. It also provides an estimate of the costs to operate a typical fixed-point observatory such as those included in the FixO3 network. Finally an assessment of the type of data and services provided by ocean observations and their value to society is also given.     

我国主要海洋产业发展规模预测分析

通过收集整理1952—2002年50a的海洋经济统计数据,结合计量经济学手段进行时间序列分析。依样本空间和分析对象的不同,运用趋势外推法分别建立了线性模型、抛物线模型、生长曲线模型3种预测外延模型结构。并对预测外延模型结构进行了数据拟合与相关参数分析,总结出了适合预测海洋经济发展的线性模型和抛物线模型。根据海洋渔业、海洋油气业、海滨砂矿业、海洋盐业、海洋船舶工业、海洋交通运输业、滨海国际旅游业等7个主要海洋产业各自发展特点,用预测模型分别进行拟合,建立适合各海洋产业的预测模型。最终对2010年全国6个主要海洋产业、分产业总产值进行了预测。     

Coastal observatory for long-term measurement and real time data processing of oceanological parameters

A coastal observatory for long-term continuous measurements of oceanological parameters and real-time data transfer via the Internet to remote users is described. The observatory was designed at the Shirshov Institute of Oceanology (SIO) and tested at its southern branch (SB) in the Black Sea. The architecture, components, and design principles of the observatory are discussed along with its application for solving problems of water dynamics in the coastal zone. Results of field tests are given.     

鲸豚声信号实时采集与分析系统

本文设计了一套基于FPGA的鲸豚声信号实时数据采集与分析系统,在采集存储水族馆内声信号的同时,应用改进的HHT算法处理鲸豚叫声中的click信号,实现实时的甄别瓶鼻海豚和白鲸功能,可用于针对大型哺乳动物的远洋实时跟踪科考。     

Comparative Analysis of Chlorophyll-a Distribution from SeaWiFS,MODIS-Aqua,MODIS-Terra and MERIS in the Arabian Sea

The variability of Chlorophyll-a (Chl-a) distribution derived from MODIS (on Aqua and Terra platforms) and MERIS sensors have been compared with SeaWiFS data in the Arabian Sea. MODIS Aqua has overestimated the SeaWiFS Chl-a within 25–32% in the coastal turbid (eutrophic) waters and underestimated in open ocean waters with error within 20%. However, there is no significant bias (?0.1 on log-scale) observed as the slope is well within 0.97-1.1 (log transformed). MODIS-Terra has underestimated the Chl-a concentration in open ocean waters by about 29–31%, which is higher than MODIS-Aqua. MODIS-Terra is observed to be more accurate than MODIS-Aqua in the coastal waters. MERIS is overestimating the SeaWiFS Chl-a with log RMS error of ～0.15 and log bias of ～0.13–0.2. The differences in the Chl-a estimates between each sensor are possibly due to differences in the sensor design, bio-optical algorithms and also due to the time differences between the satellites over passes. We have examined that the MERIS is performing similar to SeaWiFS and the MODIS-Aqua (Terra) data are reliable in open ocean (coastal) waters. However, Chl-a retrieval algorithms need to be improved especially for coastal turbid waters to continue with SeaWiFS data for long-term studies.     

Study on 10 kVDC powered junction box for a cabled ocean observatory system

A cabled ocean observatory system that can provide abundant power and broad bandwidth communication for undersea instruments is developed. A 10 kV direct current (kVDC) with up to 10 kW power, along with 1 Gigabit/sec Ethernet communication, can be transmitted from the shore to the seafloor through an umbilical armored cable. A subsea junction box is fixed at a cable terminal, enabling the extension of up to nine connections. The box consists of three main pressure vessels that perform power conversion, power distribution, and real-time communication functions. A method of stacking modules is used to design the power conversion system in order to reduce the 10 kV voltage to levels that can power the attached instruments. A power distribution system and an Ethernet communication system are introduced to control the power supply and transmit data or commands between the terminals and the shore station, respectively. Specific validations of all sections were qualified in a laboratory environment prior to the sea trial. The ocean observatory system was then deployed at the coast of the East China Sea along with three in situ instruments for a 14-day test. The results show that this high voltage-powered observatory system is effective for subsea long-term and real-time observations.