Variations in late Quaternary upper ocean structure of Okinawa Trough: A nannofossil approach

The relative abundance ofFlorisphueru profunda, a calcareous nannofossil species in lower euphotic zone, affords an opportunity to study variations in upper ocean structure such as thickness of mixed layer. As revealed by the nannofossil analysis in sediments since 20 ka B. P. from three Okinawa Trough cores, the percentage ofF. profunda increased significantly from glacial to Holocene, with a declining event ca 4 ka B. P. in its southern part. Its downcore trend is similar to that ofPulleniatina obliquiloculuta, a tropical planktonic foraminifera1 species which lives in subsurface water below thermocline in the modern ocean. Their similar variations imply an eastward shift of the Kuroshio Current, a reduction in thickness of the mixed layer, a shallowing of thermocline and a possible increase of turbidity in the upper ocean during the glaciation. The eastward shift of the Kuroshio might be repeated again about 4 ka B.P. Project supported by the National Natural Science Foundation of China (Grant Nos. 49776289 and 49406067)     

关于亚洲夏季风爆发及北半球季节突变的物理机理的诊断分析:Ⅰ季风爆发的阶段性特征

该工作将亚洲季风区作为一个复杂的海-陆-气耦合系统,来深入考察季风区海-气、陆-气相互作用的基本事实和物理过程,探讨它们在决定亚洲季风爆发及北半球行星尺度大气环流的季节突变的物理机理。本文是系列文章的第一篇,着重研究亚洲夏季风爆发的区域性和阶段性特征,以及过渡季节热带、副热带地区海-气、陆-气相互作用的基本事实,初步分析了它们之间的联系。研究表明,热带季风对流于4月底到5月初越过赤道进入北半球,首先出现在孟加拉湾东部-中南半岛西南部地区,然后于5月中旬和6月上旬末分别出现在南海和印度半岛地区,呈阶段性爆发的特征。季风对流在孟加拉湾东部-中南半岛西南部地区爆发阶段,在大气环流变化和对流活动中心位置出现区别于南海季风和印度季风爆发的特征。通过对地表感热通量和海表潜热通量的分析,表明热带海洋上海表感热通量甚小于海表潜热通量,南海季风爆发时期印度洋上海表潜热通量显著增大,印度季风爆发后海表潜热通量的高值中心在孟加拉湾和阿拉伯海上建立起来。印度洋上低层增强的过赤道气流引起的强烈的海-气相互作用导致海表水汽的大量蒸发,并通过其输送作用,为季风对流的爆发提供了充足的水汽来源。过渡季节在副热带地区(沿27.5～37.5°N纬带上), 青藏高原和西太平洋上地(海)表感热通量和潜热通量均有迅速的季节变化性, 但趋势相反。当青藏高原上地表感热通量和潜热通量呈阶段性的显著加大, 西太平洋上海表感热通量和潜热通量迅速减小。这种大陆和海洋对大气加热的显著的季节化的差异, 影响着大气环流的季节转变。     

GPS测站的海洋潮汐改正

利用ＣＲＳ３．０海潮模型计算了海潮对我国沿海地区ＧＰＳ测站的影响。结果表明海潮对我国ＧＰＳ测站的影响由东至西逐渐减小,垂直方向的影响远远大于水平方向,对东南部沿海的影响一般可达厘米量级。海潮改正对ＧＰＳ基线解算的实例表明,这一影响不仅反映在基线向量上,而且也反映在基线分量上。     

Ocean Response to a Climate Change Heat-Flux Perturbation in an Ocean Model and Its Corresponding Coupled Model

State-of-the-art coupled general circulation models(CGCMs)are used to predict ocean heat uptake(OHU)and sealevel change under global warming.However,the projections of different models vary,resulting in high uncertainty.Much of the inter-model spread is driven by responses to surface heat perturbations.This study mainly focuses on the response of the ocean to a surface heat flux perturbation F,as prescribed by the Flux-Anomaly-Forced Model Intercomparison Project(FAFMIP).The results of ocean model were compared with those of a CGCM with the same ocean component.On the global scale,the changes in global mean temperature,ocean heat content(OHC),and steric sea level(SSL)simulated in the OGCM are generally consistent with CGCM simulations.Differences in changes in ocean temperature,OHC,and SSL between the two models primarily occur in the Arctic and Atlantic Oceans(AA)and the Southern Ocean(SO)basins.In addition to the differences in surface heat flux anomalies between the two models,differences in heat exchange between basins also play an important role in the inconsistencies in ocean climate changes in the AA and SO basins.These discrepancies are largely due to both the larger initial value and the greater weakening change of the Atlantic meridional overturning circulation(AMOC)in CGCM.The greater weakening of the AMOC in the CGCM is associated with the atmosphere–ocean feedback and the lack of a restoring salinity boundary condition.Furthermore,differences in surface salinity boundary conditions between the two models contribute to discrepancies in SSL changes.     

Adaptability of the ocean and earth tidal models based on global observations of the superconducting gravimeters

As the gravity field is the most primary and direct physical quantity reflecting the density variation of the Earth’s interior and its geodynamic properties under various environmental changes and as the knowledge of the fine structure of the Earth’s interior and its geo-dynamics has a strong impact on space research, grav-ity observations become more and more important in Earth sciences. Therefore based on a global network of superconducting gravimeters (SGs), the Global Geo-dynamic Proje…     

BOOK REVIEWS

Book Reviewed in this article: Geography and the Third World. International Seminar, 14–18 May 1980, Kuala Lumpur, Malaysia . Ishmail Ahmad and Jamaluddin Md Jahi, eds. The Growth Dilemma: Residents' Views and Local Population Change in the United States . Mark Baldassare. Sport and Place: A Geography of Sport in England, Scotland & Wales . John Bale. The Deindustrialization of America: Plant Closings, Community Abandonment, and the Dismantling of Basic Industry . Barry Bluestone and Bennett Harrison. Selected Essays 1963–1975: Carl O. Sauer . Bob Callahen, ed. Housing and Planning in the Countryside . G. Clark. Conflict, Politics and the Urban Scene . Kevin R. Cox and R. J. Johnston, eds. Thematic Maps: Their Design and Production . David J. Cuff and Mark T. Mattson. Wine: A Geographic Appreciation . Harm Jan de Blij. USSR in Maps . J. C. Dewdney. Political Geography: A Contemporary Perspective . Ramesh D. Dikshit. Rethinking Human Adaptation . Rada Dyson-Hudson and Michael A. Little, eds. Sacred Sands: The Struggle for Community in the indiana Dunes . J. Ronald Engel. Geography of the Biosphere . A. Furley and Walter W. Newey. Disaster and Reconstruction . Robert Geipel. Glasgow: The Making of a City . Andrew Gibb. Design for Arid Regions . Giden S. Golany, ed. Urbanization and Cancer Mortality: The United States Experience, 1950–1975 . Michael R. Greenberg. Geology in the Nineteenth Century: Changing Views of a Changing World . Mott T. Greene. Colonización y Destrucción de Bosques en Panamá . Stanley Heckadon Moreno and Alberto McKay, eds. Urban Geography: A First Approach . David T. Herbert and Colin J. Thomas. The Visual and Spatial Structure of Landscapes . Tadahiko Higuchi. Climate from Tree Rings . M. K. Hughes, P. M. Kelly, J. R. Pilcher, and V. C. LaMarche, Jr., eds. The structure of Nineteenth Century Cities . James H. Johnson and Colin G. Pooley, eds. The American Planner: Biographies and Recollections . Donald A. Krueckeberg, ed. Urban Land Policy For the 1980s, the Message for State and Local Government . George Lefcoe, ed. Regional Planning: Evolution, Crisis and Prospects . Gill C. Lim, ed. Relevance and Ethics In Geography . Bruce Mitchell and Dianne Draper. China: The Geography of Development and Modernization . Clifton W. Pannell and Laurence J. C. MA. The Urban Retailing System . Robert B. Potter. Hants. Nonconventional Energy Resources . Philip R. Pryde. Caribbean Migrants: Environment and Human Survival on St. Kitts and Nevis . Bonham C. Richardson. Population and Resources . Harry Robinson. East Los Angeles: History of A Barrio . Ricardo Romo. Integrated Impact Assessment . Frederick A. Rossini and Alan L. Porter, eds. Environmental Aesthetics: Essays in Interpretation . Barry Sadler and Allen Carlson, eds. Earthwatch . Charles Sheffield. Field Techniques and Research Methods in Geography . Robert H. Stoddard. Haiti: Land of Poverty . Robert J. Tata. Weathering and Erosion: Sources and Methods in Geography . Stephen T. Trudgill. Once Beneath the Forest. Prehistoric Terracing in the Río Bec Region of the Maya Lowlands . B. L. Turner, II. The Historical Geography of Scotland since 1707 . David Turnock.     

环渤海的经济开发与减灾

渤海是一个自然灾豁隐患严重的地区之一，为了使渤海建成一个经济繁荣，环境优美的海区，本文提出必须将渤海区位优势和经济环境条件与防御灾害结合，实现综合开发，提高我国北方开发潜力和综合国力，推动我国现代化进程。     

Ocean Drilling Program (ODP) deep sea coring techniques

The coring techniques and systems of the Ocean Drilling Program (ODP) were developed to satisfy a scientific need for better quality and improved recovery of oceanic core samples. Some of the ODP systems in use today evolved from refinements to earlier systems developed by the Deep Sea Drilling Project (DSDP) or were adaptions of available industry technology. Other systems were conceived and designed by DDP engineers. The evolution of these progressive scientific coring systems began with the Rotary Core Barrel (RCB) used by the DSDP and proceeded to the highly advanced Diamond Coring System (DCS) currently under development by ODP engineers. During the evolution several other key systems were developed. These included hydraulic piston coring, extended coring, pressure coring, bare rock spudding and several systems using high speed diamond coring technology. These include the positive displacement coring motor (PDCM), the Navi-drill core barrel, and a top driven diamond coring system (DCS). This article describes the evolution and conceptual design of these systems including the required bottom hole assemblies, and the sinker bar/sandline configurations.All data, text, figures, photo's etc. contained within this chapter are public domain and free from copywrite. All rights of ODP, NSF, JOI, or other private individuals to use any or all of this material in future published documents is reserved.     

Analysis of Collision Protection for Ocean and Offshore Structures

1 .Introduction Many accidents of ocean and offshore structuresinvolve impact loadings .Some famous ship colli-sion cases arethe Tj rn Bridge (Sweden) ,the West Bridge of the Great Belt Link (Denmark) andtheMaracaibo Bridge (Venezuela) . Most studies usedthe Hertzian contact law(Zukaset al .,1982) tocalculate the impact force and analyze structures subjectedtoimpact loadings .Other alternative meth-ods such as the spring-dashpot and momentumbalance methods utilizedthe coefficient of rest…