Chronic sublethal effects of the water soluble fractions of no. 2 fuel oils on the marine isopod, Sphaeroma quadridentatum     

Wen Yuh Lee 《Marine environmental research》1978,1(1):5-17

Two series of experiments were carried out to assess the long-term effects of the water soluble fractions (WSF) of fuel oils on the marine isopod, Sphaeroma quadridentatum. In one experiment, juvenile isopods (one month old) were exposed to sublethal concentrations (0·1% to 15% WSF) of a fuel oil (Baytown, Exxon) at room temperatures of 24 ± 1–6°C for nine months. These isopods survived to maturity and reproduced. However, growth rate was adversely affected at concentration ≥ 3% WSF and fecundity was depressed at concentrations ≥ 1% WSF. Survival of offspring in clean seawater was dependent to a large extent on the history of the previous generation. Offspring from groups exposed to ≥ 1% WSF experienced high mortality (> 70% within five weeks) even in clean seawater. This may imply that a population of Sphaeroma exposed to WSF as low as 0·2 ppm may eventually disappear, although animals can grow to maturity and reproduce at concentrations < 3 ppm.In another experiment, adult Sphaeroma (three months old) were subjected to the WSFs of four fuel oils (Baton Rouge, Baytown, Montana and New Jersey) for one month. Fecundity was depressed at a concentration > 15% WSF, regardless of the kind of fuel oil. On the other hand, the number of young produced bythe surviving females varied with the type of fuel oil for the same level of WSF. This may be attributed to different relative amounts of toxic components present in the WSF.  相似文献   

Nocdap results: On the relationship of extreme waves and currents for design of offshore structures     

R. Lee Gordon  Finn-Erik Dahl  David J.H. Peters 《Ocean Engineering》1985,12(4):293-308

Simultaneous wind, wave, and current data during 21 storms spanning four winters at Tromsøflaket (230 m depth) were analysed to determine joint probabilities of occurrence. Waves were measured with a Waverider Buoy, winds with a recording anemometer onboard a vessel and currents at up to five depths with Aandera RCM-4 current meters. Measured currents were filtered to separate tidal currents from residual currents. In most of the statistical analyses, the actual current profiles were replaced with a simplified “equivalent” profile (constant above 50 m depth) whose magnitude was chosen to give the same drag load on a single pile as the actual profile when both profiles were combined with wave orbital velocities. The data suggest that the equivalent current is weakly correlated with the wave height. Within the range of the data analysed, an in-line equivalent residual current of 30 cm sec⁻¹ is adequate for design drag force calculations.The data presented here are used to illustrate a procedure for data analysis and are not suitable for use as design criteria.  相似文献   

ARGO剖面浮标数据质量控制过程剖析   总被引：12，自引：4，他引：12  

童明荣  刘增宏  孙朝辉  朱伯康  许建平 《海洋技术学报》2003,22(4):79-84

ARGO计划的观测目标是能取得精度分别为0．5℃和0．01PSU的海水温度和盐度资料。然而，由于目前海水盐度是采用海水电导率间接导出的，而测量海水电导率的传感器很容易产生偏差。因此，必须对获得的ARGO数据进行质量控制。文章详细介绍了ARGO剖面浮标资料实时质量控制模式和延时质量控制模式及其采用的质量控制方法等。  相似文献   

使用GAMIT进行高精度基线向量解算的方法与实践   总被引：2，自引：0，他引：2  

徐杰  任超  孟黎 《海洋测绘》2007,27(6):29-32

GAM IT是国际上常用的GPS定位定轨软件,但由于其安装的平台(UN IX/LINUX)与我们通用的W indow s平台有所差异,使得GAM IT的入门较难。因此本文结合具体实例,介绍GAM IT的安装、基本操作以及应用GAM IT进行高精度基线向量解算,供初学者参考。  相似文献   

Three cletodid copepods of the genera<Emphasis Type="Italic">limnocletodes</Emphasis> and<Emphasis Type="Italic">kollerua</Emphasis> (harpacticoida,cletodidae) from coastal marshes and estuaries in south Korea     

Ji Min Lee  Cheon Young Chang 《Ocean Science Journal》2007,42(4):255-267

  相似文献   

Barotropic tidal mixing effects in a coupled climate model: Oceanic conditions in the Northern Atlantic   总被引：3，自引：0，他引：3  

Hyun-Chul Lee  Anthony Rosati  Michael J. Spelman 《Ocean Modelling》2006,11(3-4):464-477

Impacts of mixing driven by barotropic tides in a coupled climate model are investigated by using an atmosphere–ocean–ice–land coupled climate model, the GFDL CM2.0. We focus on oceanic conditions of the Northern Atlantic. Barotropic tidal mixing effects increase the surface salinity and density in the Northern Atlantic and decrease the RMS error of the model surface salinity and temperature fields related to the observational data.  相似文献   

Circulation and currents in the southwestern East/Japan Sea: Overview and review     

K.-I. Chang  W.J. Teague  S.J. Lyu  H.T. Perkins  D.-K. Lee  D.R. Watts  Y.-B. Kim  D.A. Mitchell  C.M. Lee  K. Kim 《Progress in Oceanography》2004,61(2-4):105

A review is made of circulation and currents in the southwestern East/Japan Sea (the Ulleung Basin), and the Korea/Tsushima Strait which is a unique conduit for surface inflow into the Ulleung Basin. The review particularly concentrates on describing some preliminary results from recent extensive measurements made after 1996. Mean flow patterns are different in the upstream and downstream regions of the Korea/Tsushima Strait. A high velocity core occurs in the mid-section in the upstream region, and splits into two cores hugging the coasts of Korea and Japan, the downstream region, after passing around Tsushima Island located in the middle of the strait. Four-year mean transport into the East/Japan Sea through the Korea/Tsushima Strait based on submarine cable data calibrated by direct observations is 2.4 Sv (1 Sv = 10⁶ m³ s⁻¹). A wide range of variability occurs for the subtidal transport variation from subinertial (2–10 days) to interannual scales. While the subinertial variability is shown to arise from the atmospheric pressure disturbances, the longer period variation has been poorly understood.Mean upper circulation of the Ulleung Basin is characterized by the northward flowing East Korean Warm Current along the east coast of Korea and its meander eastward after the separation from the coast, the Offshore Branch along the coast of Japan, and the anticyclonic Ulleung Warm Eddy that forms from a meander of the East Korean Warm Current. Continuous acoustic travel-time measurements between June 1999 and June 2001 suggest five quasi-stable upper circulation patterns that persist for about 3–5 months with transitions between successive patterns occurring in a few months or days. Disappearance of the East Korean Warm Current is triggered by merging the Dok Cold Eddy, originating from the pinching-off of the meander trough, with the coastal cold water carried Southward by the North Korean Cold Current. The Ulleung Warm Eddy persisted for about 20 months in the middle of the Ulleung Basin with changes in its position and spatial scale associated with strengthening and weakening of the transport through the Korea/Tsushima Strait. The variability of upper circulation is partly related to the transport variation through the Korea/Tsushima Strait. Movements of the coastal cold water and the instability of the polar front also appear to be important factors affecting the variability.Deep circulation in the Ulleung Basin is primarily cyclonic and commonly consists of one or more cyclonic cells, and an anticyclonic cell centered near Ulleung Island. The cyclonic circulation is conjectured to be driven by a net inflow through the Ulleung Interplain Gap, which serves as a conduit for the exchange of deep waters between the Japan Basin in the northern East Sea and the Ulleung Basin. Deep currents are characterized by a short correlation scale and the predominance of mesoscale variability with periods of 20–40 days. Seasonality of deep currents is indistinct, and the coupling of upper and deep circulation has not been clarified yet.  相似文献   

A hierarchical real-time control architecture for a semi-autonomous underwater vehicle   总被引：1，自引：0，他引：1  

Ji-Hong Li  Bong-Huan Jun  Pan-Mook Lee  Seok-Won Hong 《Ocean Engineering》2005,32(13):282-1641

This paper describes a real-time control architecture for Dual Use Semi-Autonomous Underwater Vehicle (DUSAUV), which has been developed at Korea Research Institute of Ships and Ocean Engineering (KRISO) for being a test-bed of development of underwater navigation and manipulator technologies. DUSAUV has three built-in computers, seven thrusters for six DOF motion control, one 4-function electric manipulator, one ballasting motor, built-in power source, and various sensors. A supervisor control system with GUI and a multi-purpose joystick is mounted on the surface vessel and communicates with vehicle through a fiber optic link. Furthermore, QNX, one of real-time operating system, is ported on the built-in control and navigation computers for real-time control purpose, while Microsoft OS product is ported in the supervisor computer for GUI programming convenience. A hierarchical control architecture, which consists of application layer, real-time layer and physical layer, has been developed for efficient control system of above complex underwater robotic system. The experimental results with implementation of the layered control architecture for various motion control of DUSAUV in an ocean engineering basin of KRISO is also presented.  相似文献   

红树植物白骨壤叶片衰老过程中叶肉细胞Ca2+水平的变化     

杨盛昌  谢潮添  陈文列 《台湾海峡》2003,22(2):145-149,T001

用焦锑酸钙沉淀的电镜细胞化学方法，研究了白骨壤叶片衰老过程中叶肉细胞Ca^2 水平的变化．结果表明，在白骨壤幼叶和成熟叶叶肉细胞中，焦锑酸钙沉淀颗粒大量出现在液池和细胞间隙中，细胞壁中也可见少量沉淀，而细胞基质中则看不到焦锑酸钙沉淀．在衰老叶中，细胞基质和细胞膜上焦锑酸钙沉淀增加，而液泡和细胞间隙中的锑酸钙沉淀则显著减少，并且叶绿体外膜部分破损，结构破坏，核膜与液泡膜内部结构模糊，叶绿素含量、净光合速率、气扎手率和蒸腾速率显著下降．Ca^2 的区域性分布的变化与植物叶片衰老密切相关。  相似文献   

Identification of Pb sources in Yellow Sea sediments using stable Pb isotope ratios   总被引：1，自引：0，他引：1  

Man-Sik Choi  Hi-Il Yi  Shou Ye Yang  Chang-Bok Lee  Hyun-Ju Cha 《Marine Chemistry》2007

Rapid economic developments in East Asian countries have inevitably resulted in environmental degradation in the surrounding seas, and concern for both the environment and protection from pollutants is increasing. Identification of sources of contaminants is essential to environmental pollution management. In this study, the provenance of anthropogenic lead (Pb), a major pollutant of Yellow Sea sediments, was determined for river mouth sediments, including those of the Changjiang, Huanghe, Han, and Geum Rivers, and for age-determined shelf core sediments through the measurement of Pb isotope ratios in the HCl-leached fraction using multi-collector inductively coupled plasma-mass spectrometry (MC ICP/MS). Anthropogenic Pb has accumulated in shelf core sediments since 1910, and its isotope ratios were estimated as 0.863–0.866 and 2.119–2.125 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively, from the mixing relationships of the two endmembers. River mouth sediments exhibited enough distinction in anthropogenic Pb isotope ratios to be discriminated: 0.874 (2.144) in the Huanghe, 0.856 (2.129) in the Han, 0.857 (2.122) in the Geum, and 0.854 (2.101) in the Changjiang for ²⁰⁷Pb/²⁰⁶Pb (²⁰⁸Pb/²⁰⁶Pb), respectively. Although isotope ratios of geogenic Pb in sediments dating before 1910 showed narrow ranges (0.842–0.845 and 2.088–2.100 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively), distinct isotope ratios in each core permitted source identification of sediments in the Yellow Sea based on geographic locations and the geogenic Pb of each river. By comparing the isotope ratios of the estimated anthropogenic Pb to source-related materials, the provenances of anthropogenic Pb in Chinese river sediments were presumed to be Chinese coal or ore, which is also a major source of atmospheric particulate Pb. The anthropogenic Pb in the shelf core sediments in the northern Yellow Sea originated from northern Chinese cities such as Beijing and Tianjin through atmospheric pathways. Pb isotope ratios indicated that Pb in Korean river sediments was characteristic of local Korean ores.  相似文献