黄海陆架表层水温的低频振动     

周发琇  于慎余 《中国海洋大学学报(自然科学版)》1987,(4)

本文在对位于黄海南部陆架上的朝连岛站30年水温资料进行分析时发现,该站的表层水温有周期大于20个月的低频振动,其中以准两年周期和6年周期最显著。陆架水温的这种低频振动是对东亚季风异常的响应。这种低频振动在冬季与渤海冰情的变化同步;在夏季与黄海底层冷水团的强弱相关。同时,这种低频振动在对马暖流上也有一定的反映。  相似文献   

In-line response of a cylinder in oscillatory flow     

C.H.K. Williamson 《Applied Ocean Research》1985,7(2):97-106

The most widely used mathematical model to represent flow-induced in-line forces on structures is based on the Morison¹ equation. The present paper investigates the validity of using an extension of Morison's equation for non-stationary structures, by comparing predictions with results from a simple laboratory experiment. An elastically-mounted circular cylinder is placed in the sinusoidal flow of a U-tube, and responds in-line with the flow. Cylinder forces and responses are recorded over a range of Keulegan Carpenter numbers up to 35. An equation of motion is solved simply by using relative coordinates and by employing equivalent linearisation. The linear results are compared over a wide variation of parameters with solutions using the full nonlinear equation. Thereafter experimental results are compared with linear predictions.  相似文献   

进入渤海的热带气旋路径特点分析     

张晓慧  卢霞  陈金龙 《海洋预报》2003,20(4):1-4

热带气旋是夏季影响渤海的灾害性天气系统之一。其影响路径主要有三类，各类路径在影响时前期中高纬500hPa高空环流形势及夏季西太平洋副热带高压特征指数有显著差异。  相似文献   

Crustal Structures of the Northernmost South China Sea: Seismic Reflection and Gravity Modeling   总被引：2，自引：0，他引：2  

Yi-Ching Yeh  Shu-Kun Hsu 《Marine Geophysical Researches》2004,25(1-2):45-61

The South China Sea (SCS) is a marginal sea off shore Southeast Asia. Based on magnetic study, oceanic crust has been suggested in the northernmost SCS. However, the crustal structure of the northernmost SCS was poorly known. To elaborate the crustal structures in the northernmost SCS and off southwest Taiwan, we have analyzed 20 multi-channel seismic profiles of the region. We have also performed gravity modeling to understand the Moho depth variation. The volcanic basement deepens southeastwards while the Moho depth shoals southeastwards. Except for the continental margin, the northernmost SCS can be divided into three tectonic regions: the disturbed and undisturbed oceanic crust (8–12 km thick) in the southwest, a trapped oceanic crust (8 km thick) between the Luzon-Ryukyu Transform Plate Boundary (LRTPB) and Formosa Canyon, and the area to the north of the Formosa Canyon which has the thickest sediments. Instead of faulting, the sediments across the LRTPB have only displayed differential subsidence offset of about 0.5–1 s in the northeast side, indicating that the LRTPB is no longer active. The gravity modeling has shown a relatively thin crust beneath the LRTPB, demonstrating the sheared zone character along the LRTPB. However, probably because of post-spreading volcanism, only the transtension-shearing phenomenon of volcanic basement in the northwest and southeast ends of the LRTPB can be observed. These two basement-fractured sites coincide with low gravity anomalies. Intensive erosion has prevailed over the whole channel of the Formosa Canyon.  相似文献   

Isotopic and Elemental Variations of Carbon and Nitrogen in a Mangrove Estuary   总被引：6，自引：0，他引：6  

L.A. Cifuentes  R.B. Coffin  L. Solorzano  W. Cardenas  J. Espinoza  R.R. Twilley 《Estuarine, Coastal and Shelf Science》1996,43(6):781-800

Variations in elemental and isotopic ratios of suspended particulate matter (SPM) were investigated in the Guayas River Estuary Ecosystem (GREE) that empties into the Gulf of Guayaquil, Ecuador. Detritus in the system was identified on the basis of extremely high carbon:chlorophyll aratios (>1000). This material had mean δ¹³C of −26·4±0·3, δ¹⁵N of +4·8±0·2, and (C:N)_atomicof 14·1±0·9. The isotopic data were comparable to measurements reported for fresh and degrading mangrove leaves, whereas the elemental ratio was comparatively enriched in nitrogen. Isotope measurements of SPM throughout the GREE were more similar to values for riverine material and detritus compared with that for the coastal end-member. Values indicative ofin situproduced algae, sewage and shrimp pond effluent were only found at selected sites. Bacterial bioassays, which were used to document potential sources of dissolved organic matter in the GREE, were isotopically similar to SPM. This correspondence coupled with the relatively low (C:N)_aof SPM could be explained by bacterial immobolization of nitrogen onto detritus. Finally, tidal variations of (C:N)_aand δ¹³C at a brackish mangrove site were similar in magnitude to spatial variations encountered throughout the GREE. Based on these results, the authors caution that care must be taken when samples are taken for food-web studies in these systems.  相似文献   

旋转谱理论探讨     

刘玉光  余宙文 《中国海洋大学学报(自然科学版)》1988,(4)

本文应用向量随机过程分解模型对旋转谱作出物理解释;此外,还修改了线性振荡度的定义,导出了极化度、线性振荡度和旋转系数之间的关系式,并讨论了它们与总相干、同相相干、异相相干之间的关系。  相似文献   

雷州半岛灯楼角海岸地貌演变   总被引：10，自引：0，他引：10  

王丽荣  赵焕庭  宋朝景  袁家义  于红兵 《海洋学报》2002,24(6):135-144

灯楼角岬角位于雷州半岛的西南端,地处热带北缘.过去几次开展的区域地貌和第四纪地质调查及制图,均包括本区1),2),[1～2].宋朝景曾做过涉及本区海底的地貌与浅地层调查3),又指导学生研究本段海岸地貌4).近年赵焕庭等[3]开展该区珊瑚礁研究,使用了1960年版航空照片和1964年版1:10000地形图,结合野外调查,进一步研究了本区海岸地貌的演变.  相似文献   

珠江口水域微表层中的痕量金属     

陈金斯  李飞永  朱卓洪 《热带海洋学报》1994,(3)

采用自制滚筒式自动采样器采样，研究了珠江口水域微表层中Ｆｅ，Ｍｎ，Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ的含量、分布变化及富集状况。并通过颗粒痕量金属／颗粒Ｆｅ比值计算，探讨了痕量金属的来源。结果表明：Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ在微表层的平均富集系数分别为２．３，１．４，３．０和１．９。颗粒态Ｆｅ，Ｍｎ的平均富集系数为１．１和０．９。各种金属有明显的季节和空间变化，有各种不同的来源。  相似文献   

Spatial and temporal variability of heat content above the thermocline in the tropical Pacific Ocean   总被引：1，自引：0，他引：1  

Pu Shuzhen  Yu Fei  Hu Xiaomin  Chen Xingrong 《海洋学报(英文版)》2003,22(2):179-190

Abstract-Heat content of the upper layer above the 20℃ isotherm in the tropical Pacific Ocean isestimated by using the sea temperature data set with a resolution 2°latitude×5°longitude (1980～1993)for the water depths (every 10 m) from 0 m to 400 m, and its temporal and spatial variabilities are an-alyzed. (1) The temporal variability indicates that the total heat in the upper layer of the equatorial Pa-cific Ocean is charcterized by the interannual variability. The time series of the equatorial heat anomaly5 months lead that of the El Nino index at the best positive lag correlation between the two, and theformer 13 months lag behind the latter at their best negative lag correlation. Therefore the equatorialheat content can be used as a better predictor than the El Nino index for a warm or cold event. In addi-tion, it is also found that less heat anomaly in the equator corresponds to the stronger warm events inthe period (1980～1993) and much more heat was accumulated in the 4 years including 1992/1  相似文献   

山东省9216号强热带气旋风暴期间的海岸侵蚀灾害   总被引：14，自引：0，他引：14  

王文海  吴桑云 《海洋地质与第四纪地质》1994,14(4):71-78

本文比较详细地报导了山东省沿岸在９２１６号强热带气旋风暴潮期间的海岸侵蚀灾害情况，分析了灾害的形成原因、特点。最后讨论了与之有关的问题。  相似文献