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Sample records for china sea

  1. South China Sea Challenge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China's attempts to solve disputes with ASEAN over the South China Sea help regional peace China's marine economy and security are currently faced with new challenges, requiring careful handling, especially in disputes with ASEAN countries and in promoting common development of the South China Sea. The outcome of how this is dealt with could undoubtedly pave the way for solutions to other oceanic disputes. The South China Sea is located south of

  2. South China Sea.

    Science.gov (United States)

    Morton, B; Blackmore, G

    2001-12-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the

  3. South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Brian [Hong Kong Univ., Swire Inst. of Marine Science, Hong Kong (China); Hong Kong Univ., Dept. of Ecology and Biodiversity, Hong Kong (China); Blackmore, Graham [Hong Kong Univ. of Science and Technology, Dept. of Biology, Hong Kong (China)

    2001-07-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshops and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km{sup 2} and depths range from the shallowest coastal fringe to 5377m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economics on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken

  4. India and the South China Sea Dispute

    Institute of Scientific and Technical Information of China (English)

    Ma Jiali

    2012-01-01

    South China Sea is a sea area of great significance. It lies between the Pacific and Indian Oceans, a crucial waterway bridging East Asia, Southeast Asia and South Asia. In general, South China Sea is a rich deposit of oil and fishing resources, a transportation hub of strategic importance, and an important buffer zone to safeguard China's maritime rights and interests.

  5. South China Sea: Controversies And Solutions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Disputes have recently broken out between China and some Southeast Asian countries and the United States in the South China Sea. The Beijing-based Economic Information Daily spoke to Liu Nanlai, a research fellow at the Institute of International Law under the Chinese Academy of Social Sciences, on the origin of the South China Sea issue and China’s position on it. Excerpts follow:

  6. The South China Sea Deep: Introduction

    Science.gov (United States)

    Wang, Pinxian; Li, Qianyu; Dai, Minhan

    2015-12-01

    The South China Sea (SCS) has increasingly become a global focus in ocean research and hydrocarbon explorations. Over the last two decades, at least 17 international cruises including two ODP/IODP expeditions were conducted in the SCS, and more than 2000 exploratory wells were drilled (Wang et al., 2014a). While its sedimentary basins on the continental shelf and slope are explored for offshore resources, the deep basin below 3500 m in depth that overlies the basaltic oceanic crust preserves the key to understanding their formation and development. In order to better understand the life history and functional system of the marginal sea, a major research program "Deep Sea Processes and Evolution of the South China Sea", or "The South China Sea Deep" for short, was launched in January 2011 by the National Natural Science Foundation (NSFC) of China. This venture represents the first ever large-scale basic-research program in ocean science in the country (Wang, 2012).

  7. Ecological studies on Prochlorococcus in China seas

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Prochlorococcus, a tiny oxygenic photosynthetic picoplankton with unique pigment composition, has been found to be ubiquitous and abundant in the world oceans, and has been recognized to be closely related to living resources and environmental issues. It has attracted the interest of marine biologists since its discovery, and field data on it over global oceans have accumulated rapidly in the past 10 years. In China, we have studied Prochlorococcus for 8 years, achieving a basic ecological understanding. The presence of Prochlorococcus in China seas, marginal seas of the west Pacific, was confirmed, and its distribution patterns were also brought to light. Prochlorococcus is very abundant in the South China Sea and the offshore regions of the East China Sea. It is seasonally present in the southeast part of the Yellow Sea and absent in the Bohai Sea. Temporal and spatial variations of the abundance of Prochlorococcus and their affecting factors, physiological and ecological characteristics of Prochlorococcus and their relationships to the other groups of picoplankton, and the importance of Prochlorococcus in total biomass and possible roles in living resources and environmental problems are discussed. In the future, isolation of different Prochlorococcus strains from the China seas and their physiological characteristics, genetic diversity, phylogenies and gene exploiture, etc. are important issues to be addressed.

  8. Navigation Issues in the South China Sea

    OpenAIRE

    2005-01-01

    The South China Sea is one of the most important sea lanes with numerous competing sovereignty disputes. The freedom of navigation in this region is critical to all major trading States in the world. After an introduction to the navigational regimes of UNCLOS, this article describes the whole navigation situation in this region, by separately introducing the navigation issues in the territorial sea, straits, archipelagic waters and the Spratly area. Meanwhile, since the legal status of the ma...

  9. SMOS Sea Surface Salinity Validation in the South China Sea

    Science.gov (United States)

    Ren, Yongzheng; Li, Xiaoming; Dong, Qing

    2013-01-01

    In November 2009, the European Space Agency (ESA) launched the first soil moisture and ocean salinity (SMOS) satellite, which represented the first use of spaceborne remote sensing tools to probe global sea surface salinity (SSS). The SMOS satellite carries a microwave imaging radiometer with aperture synthesis (MIRAS) for detection in the microwave L-band as the only payload. The MIRAS instrument is expected to provide a global SSS distribution with a spatial resolution of approximately 100 km and an accuracy of 0.1-0.2 practical salinity units (psu). The South China Sea is semi-enclosed, and the sea conditions are relatively complex. The suitability of ESA SMOS salinity products for the South China Sea has not been validated. Therefore, using SSS data measured during an expedition in the South China Sea, which was sponsored by China Natural Science Foundation and conducted in the fall of 2011, this paper validated the SSS products released by ESA, which were retrieved using three sea surface roughness models. To analyze the effect of the spatial resolution on the weekly average SMOS SSS distribution, the weekly average salinity data were averaged to reduce the spatial resolution to 0.25 ° x 0.25°. These average data were then compared to the measured data, followed by an analysis of the error variation. In addition, the effects of the orbital track (ascending or descending) on the SSS retrieval were analyzed.

  10. Deep-sea pollen research in China

    Institute of Scientific and Technical Information of China (English)

    SUN Xiangjun; LUO Yunli; CHEN Huaicheng

    2003-01-01

    This paper briefly presents the progress of deep-sea pollen research in China since the beginning ofninetieths of the last Century. All the deep-sea pollen contri-butions mainly come from the South China Sea (SCS) andthe East China Sea (ECS). The German-Chinese joint cruise(Sonne 95) and ODP 184 cruise initiated by Chinese scientistsin the SCS provided excellent material for the deep-sea pol-len research. So far a number of pollen results of 20-30 kaand million years from the SCS have been published. A couple of deep-sea pollen records from Okinawa Through of the ECS also came out. The high resolution pollen records obtained from the continuous deposits with high sedimentation rates and reliable age control of the deep-sea sediments provided a high time resolution history (hundred to millennial scales) of vegetation, environment and monsoon evolution of the pollen source areas (southern China and Japan). Spectral analysis of deep-sea pollen records from the SCS discovered orbital (100, 41, 23, 10 ka) and suborbital cyclicities (Heinrich and Dansgaard/Oscheger-O/D events) in the vege-tation changes. Moreover, cross spectral analysis showed that the trend of vegetation changes in northern SCS was regulated mainly by changes of the ice volume in the Northern Hemisphere. The pollen record of the last 20 ka from the Okinawa Through of the ECS indicates that the marine environmental change lagged that on the terrestrail by about 1000 year. The asynchronous environmental changes between land and sea were probably caused by the time difference in thermohaline circulation. This study underscored the role of the deep-sea plant fossils as a bridge across the land and sea.

  11. A Survey of Coral Reefs in South China Sea Completed

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ An investigation of coral reefs in South China Sea has recently completed by CAS scientists at South China Sea Institute of Oceanography (SCSIO) in Guangzhou. The compilation and analysis of the obtained data is now under way.

  12. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  13. Kuroshio Variability on the Shelf of the East China Sea

    Science.gov (United States)

    2016-06-07

    Kuroshio Variability on the Shelf of the East China Sea Mark Wimbush & D. Randolph Watts Graduate School of Oceanography University of Rhode...and transport of the Kuroshio in the East China Sea (ECS) in conjunction with the ONR-supported project, “Variability of the Kuroshio in the East... China Sea, and its Relationship to the Ryukyu Current.” OBJECTIVES Through the aforementioned ONR-supported project, an array of eleven IESs

  14. A Note on the South China Sea Shallow Interocean Circulation

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The existing estimates of the volume transport from the Pacific Ocean to the South China Sea are summarized, showing an annual mean westward transport, with the Taiwan Strait outflow subtracted, of 3.5±2.0 Sv (1 Sv=106 m3 s-1). Results of a global ocean circulation model show an annual mean transport of 3.9 Sv from the Pacific to the Indian Ocean through the South China Sea. The boreal winter transport is larger and exhibits a South China Sea branch of the Pacific-to-Indian Ocean throughflow, which originates from the western Philippine Sea toward the Indonesian Seas through the South China Sea, as well as through the Karimata and Mindoro Straits. The southwestward current near the continental slope of the northern South China Sea is shown to be a combination of this branch and the interior circulation gyre.This winter branch can be confirmed by trajectories of satellite-tracked drifters, which clearly show a flow from the Luz6n Strait to the Karimata Strait in winter. In summer, the flow in the Karimata Strait is reversed. Numerical model results indicate that the Pacific water can enter the South China Sea and exit toward the Sulu Sea, but no observational evidence is available. The roles of the throughflow branch in the circulation, water properties and air-sea exchange of the South China Sea, and in enhancing and regulating the volume transport and reducing the heat transport of the Indonesian Throughflow, are discussed.

  15. Toxic Algae and Early Warning Management in Yellow Sea and Bohai Sea of China

    Institute of Scientific and Technical Information of China (English)

    Song; Lun; Song; Guangjun; Song; Yonggang; Xu; Xiaohong

    2014-01-01

    The research status of toxic algae in Yellow Sea and Bohai Sea are reviewed from the aspects of toxicity characteristics,toxic mechanism and early warning management,and the existing toxic algae and their toxicity in Yellow Sea and Bohai Sea are analyzed in the paper. The early warning level of toxic algae in Yellow Sea and Bohai Sea of China is put forward,and the research direction of shellfish poisoning in future is summarized.

  16. Open Ocean Internal Waves, South China Sea

    Science.gov (United States)

    1989-01-01

    These open ocean internal waves were seen in the south China Sea (19.5N, 114.5E). These sets of internal waves most likely coincide with tidal periods about 12 hours apart. The wave length (distance from crest to crest) varies between 1.5 and 5.0 miles and the crest lengths stretch across and beyond this photo for over 75 miles. At lower right, the surface waves are moving at a 30% angle to the internal waves, with parallel low level clouds.

  17. Comparison among four kinds of data of sea surface wind stress in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    谢强; 王卫强; 毛庆文

    2002-01-01

    By using remote sensing (ERS) data, FSU data, GOADS data and Hellerman & Rcsenstein objective analysis data to analyze the sea surface wind stress in the South China Sea, it is found that the remote sensing data have higher resolution and more reasonable values. Therefore we suggest that remote sensing data be chosen in the study of climatological features of sea surface wind stress and its seasonal variability in the South China Sea, especially in the study of small and middle scale eddies.

  18. Intensified Springtime Deep Convection over the South China Sea and the Philippine Sea Dries Southern China

    Science.gov (United States)

    Li, Zhenning; Yang, Song; He, Bian; Hu, Chundi

    2016-07-01

    Springtime rainfall, accounting for 25-40% of the annual rainfall in southern China, exerts great agricultural and socioeconomic impacts on the region. In the recent decades, southern China has experienced a significant declining trend of precipitation in boreal spring. Meanwhile, precipitation has increased over the South China Sea and the Philippine Sea (SCS-PhS). This paper presents observational and modeling evidences suggesting that the intensified latent heating released by the convection over SCS-PhS leads to suppressed springtime rainfall over southern China. Moisture budget analysis indicates that the drying trend over southern China is due mainly to weakened convergence of moisture flux, which is controlled by a heat-induced anomalous overturning circulation reinforced by the convection over SCS-PhS. Further idealized simulations support the feature that the heat-induced overturning circulation and its corresponding anomalous cyclone can be well established in several days under the spring mean flow condition. Thus, this rapid dynamic process is associated with both the intraseasonal-to-interannual variations and the long-term change of the springtime rainfall over southern China.

  19. Intensified Springtime Deep Convection over the South China Sea and the Philippine Sea Dries Southern China.

    Science.gov (United States)

    Li, Zhenning; Yang, Song; He, Bian; Hu, Chundi

    2016-07-27

    Springtime rainfall, accounting for 25-40% of the annual rainfall in southern China, exerts great agricultural and socioeconomic impacts on the region. In the recent decades, southern China has experienced a significant declining trend of precipitation in boreal spring. Meanwhile, precipitation has increased over the South China Sea and the Philippine Sea (SCS-PhS). This paper presents observational and modeling evidences suggesting that the intensified latent heating released by the convection over SCS-PhS leads to suppressed springtime rainfall over southern China. Moisture budget analysis indicates that the drying trend over southern China is due mainly to weakened convergence of moisture flux, which is controlled by a heat-induced anomalous overturning circulation reinforced by the convection over SCS-PhS. Further idealized simulations support the feature that the heat-induced overturning circulation and its corresponding anomalous cyclone can be well established in several days under the spring mean flow condition. Thus, this rapid dynamic process is associated with both the intraseasonal-to-interannual variations and the long-term change of the springtime rainfall over southern China.

  20. Two new records of Pyramidellidae (Gastropoda, Heterobranchia) from China seas

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhiyun; ZHANG Suping

    2011-01-01

    This paper reports two species of the family Pyramidellidae (Gastropoda,Heterobranchia),Otopleura nitida (A.Adams,1854) and Rugadentia manzakiana (Yokoyama,1922).The former was from the South China Sea and the latter was from the Yellow Sea and East China Sea.The study was based on the collections deposited in the Marine Biological Museum,Chinese Academy of Sciences.This is for the first time that these species have been recorded in China seas.In the current contribution,we describe and illustrate these two species,and compare them with similar species.

  1. Mineral Resources and Their Comprehensive Utilization in China Sea

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@It was said that mineral resources in oceans might be a reliable source for the material production. Ocean water is regarded as a huge “liquid deposit” for its ability to dissolve many kinds of elements. The total amount of elements in ocean water is greater than that in land. At the seafloor or below, occur a large number of mineral resources besides those in the water.China Sea, situated in the junction between North China block, Yangtze block and the Pacific plate and the Philippines plate, is excellent in ore-forming geological conditions, resulting in the presence of many kinds of deposits and abundant reserves. Mineral resources found in China Sea mainly include oil-gas resources, sea-beach placer and submarine coalfield.In addition, the manganese nodule and cobalt-rich crust are also discovered in South China Sea. Furthermore, the hydrothermal metalliferous deposit and gas hydrate may also be present in South China Sea.

  2. For the South China Sea “Militarization”: China should not be to Blame

    Institute of Scientific and Technical Information of China (English)

    An Gang

    2016-01-01

    Since the summer of 2015,with the situation in the South China Sea again getting complex,the word"militarization"continuously jumps into our ears.This is one of the terms most frequently used by the U.S.military commanders and government officials to blame China’s maritime rights protection actions in the South China Sea.Regarding the so-called"South China Sea

  3. New production in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    CAI; Pinghe

    2002-01-01

    estuary, Acta Oceanologica Sinica (in Chinese), 1993, 15(4): 50-55.[12]Okubo, T., Furuyama, K., Sakanoue, M., Distribution of 228Ra in surface sea water of the east Indian Ocean, Geochimica Journal, 1979, 13: 201-206.[13]Moore, W. S., Oceanic concentrations of 228Ra, Earth and Planetary Science Letters, 1969, 17: 437-446.[14]Sakanoue, M., Okubo, T., Furuyama, K., 228Ra in sea water, in Isotope Marine Chemistry (eds. Goldberg, E. D., Horibe, Y., Saruhashi, K.), Tokyo: Uchida Rokakuho Publishing Co. Ltd, 1980.[15]Dunne, J. P., Murray, J. M., Rodier, M. et al., Export flux in the western and central equatorial Pacific: Zonal and temporal variability, Deep-Sea ResearchⅠ, 2000, 47: 901-936.[16]Diego-McGlone, M. L. S., Jacinto, G. S., Dupra, V. C. et al., A comparison of nutrient characteristic and primary produc-tivity in the Sulu Sea and South China Sea, Acta Oceanographica Taiwanica, 1999, 37(3): 219-229.[17]Emerson, S., Quay, P., Karl, D. et al., Experimental determination of organic carbon flux from open-ocean waters, Nature, 1997, 389: 951-954.

  4. A sea temperature data assimilation system for the China Seas and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    YOU Xiaobao; ZHOU Guangqing; ZHU Jiang; LI Rongfeng

    2003-01-01

    A sea temperature data assimilation system for the China Seas and adjacent areas is developed based on a nested regional ocean circulation model and variational optimal interpolation assimilation method. A 12-year assimilation experiment is performed by using the observational temperature profiles from World Ocean Database 1998 (WOD98) and ECMWF reanalysis surface wind stress. Experimental results indicate that the variational scheme shows good skill in assimilating the observed sea temperature into a regional ocean circulation model. Compared with simulation alone, the sea temperature data assimilation significantly improves the performance of a regional ocean model and obtains comprehensive description of the circulations in the China Seas and adjacent areas. Assimilation results, such as the strength and flowing axis of the Kuroshio, Yellow Sea Cold Water Mass and its corresponding horizontal circulation in summer and dipole eddies in the South China Sea in the late summer/early autumn and the eastward jet between them, are well consistent with the observed evidences.

  5. Polycyclic aromatic hydrocarbons in sediments of China Sea.

    Science.gov (United States)

    Li, Yanxia; Duan, Xiaoyong

    2015-10-01

    Increasing pollution pressures were placed in the coastal and estuarine ecosystems in China because of the elevated pollutants discharged from various sources. Polycyclic aromatic hydrocarbons (PAHs) in the environment were closely linked to human activities, which have been intensively studied for their geochemical interest as markers. In this review, the status of PAH contamination in China Sea was assessed by comprehensive reviews of the concentrations, sources, and fates of PAHs in sediments of China Sea. PAH concentrations in China Sea sediments decreased from north to south due to the higher emissions in North China. Atmosphere was probably the main carrier of PAHs in the north due to the higher contents of atmospheric fine particles and higher wind speeds. However, riverine inputs were probably the most important sources of PAHs in the coastal sediments of South China due to higher rainfall.

  6. Deep Circulation in the South China Sea

    Science.gov (United States)

    Zhao, Xiaolong; Zhao, Wei; Xu, Xiaobiao; Tian, Jiwei; Zhou, Chun

    2016-04-01

    The South China Sea (SCS) is the largest marginal sea of the northwest Pacific. The deep circulation in the SCS is investigated on the basis of the Hybrid Coordinate Ocean Model (HYCOM). All the experiments show reasonable agreement with observation from mooring arrays. Analysis of these results provides a detailed spatial structure and temporal variability of the deep circulation in the SCS. The major features of the SCS deep circulation are basin-scale cyclonic gyre and concentrated deep western boundary current (DWBC). The transport of the DWBC is ~2 Sv at 16.5°N with a width of ~53 km. As flowing southwestward, the DWBC becomes weaker with a wider range. Deep upwelling in the SCS is estimated of 0.19 to 1.15 m d-1 with the strongest area around the DWBC. The model results reveal the existence of 80 to 120 days oscillation in the deep northeastern circulation and the DWBC, which are also the areas with large eddy kinetic energy. This seasonal oscillation is northwestward with a velocity amplitude of ~1.0~1.5 cm s-1. The distribution of mixing parameters in the deep SCS plays a role in both spatial structure and volume transport of the deep circulation. Compared with the north shelf of the SCS with the Luzon Strait, deep circulation in the SCS is more sensitive to the large vertical mixing parameters of the Zhongsha Island Chain area.

  7. Chemical Composition of Sea Fog Water Along the South China Sea

    Science.gov (United States)

    Yue, Yanyu; Niu, Shengjie; Zhao, Lijuan; Zhang, Yu; Xu, Feng

    2012-12-01

    The chemical and microphysical properties of sea fog were measured during a field experiment on Donghai Island, Zhanjiang of China from March 15 to April 18, 2010. The average pH and electrical conductivity (EC) value of the six sea fog cases during the experiment was 5.2 and 1,884 μS/cm. The observed total ion concentration of sea fog was four orders of magnitude higher than those in the North Pacific and other sea areas of China. The dominant anion and cation in all sea fog water samples were Cl- and Na+, respectively. From backward trajectory analysis and ion loading computation, it can be concluded that the ions in the samples were transported either from pollutants in distant industrial cities or from local ion deposition processes. The concentration of Ca2+ in the sea fog water samples in Case 2 suggested that a dust storm in the Inner Mongolia, a northern region of China several thousand kilometers away, could reach the South China Sea. The data also showed that the sea fog droplet spectrum over the South China Sea is unimodal. Through relationship analysis, it is illustrated that the evolution of microphysics (such as droplet concentration, diameter, and liquid water content) during fog process could affect the chemical properties of sea fog.

  8. On Study of Sea Fog over the Yellow and Bohai Seas in China

    Science.gov (United States)

    Fu, G.; Gao, S.; Yang, Y.; Xu, X.; Wang, X.; Chen, Y.; Xue, D.; Shen, J.

    2010-07-01

    A ubiquitous feature of the Yellow and Bohai Sea (YBS) in the eastern Asian region is the frequent occurrence of the sea fog in spring and summer season. The pioneer work on sea fog over YBS can be traced back to Prof. Binhua Wang as early as 1940's. He investigated sea fog systematically and published his book Sea Fog in 1985 (by China Ocean Press and Springer-Verlag). Recently, a research group in the Department of Marine Meteorology at Ocean University of China (OUC) continued sea fog research collaborated with Shandong Meteorological Bureau and Qingdao Meteorological Bureau under the financial supports of National Natural Science Foundation of China and China Meteorological Administration. Their researches involved in both observation analyses and high-resolution modeling of sea fog over YBS. In this talk, the brief history of sea fog research in China will be reviewed firstly. Then, a typical heavy sea fog event over YBS occurred in the morning of 11 April 2004 will be documented by using all available observational data and high-resolution Regional Atmospheric Modeling System (RAMS) modeling results. Finally, the applications of a quasi-operational sea fog forecasting system which was mainly based on RAMS model will be introduced.

  9. Maritime Territorial Disputes in East Asia: A Comparative Analysis of the South China Sea and the East China Sea

    Directory of Open Access Journals (Sweden)

    Andy Yee

    2011-01-01

    Full Text Available This article systematically compares maritime territorial disputes in the East and South China Seas. It draws on the bargaining model of war and hegemonic stability theory to track the record of conflicts and shifts in the relative power balances of the claimants, leading to the conclusion that certainty and stability have improved in the South China Sea, with the converse happening in the East China Sea. To enrich the models, this article also considers social factors (constructivism and arrives at the same conclusion. This calls for a differentiated methodological approach if we are to devise strategies to mediate and resolve these disputes.

  10. High resolution bathymetry of China seas and their surroundings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the oceanic lithospheric flexure and the worldwide bathymetric data ETOPO5, the high resolu tion bathymetry of the China seas and their surroundings is computed from altimeter derived gravity anomalies. The new bathymetry obtained by this study is higher resolution and accuracy than the widely used ETOPO5 data, mean while it shows clearly the seafioor, the tectonic characteristics and the geodynamical processes in the China seas.

  11. Distributions of dimethylsulfide in the Bohai Sea and Yellow Sea of China

    Institute of Scientific and Technical Information of China (English)

    HU Min; TANG Xiao-yan; LI Jin-long; MA Qi-ju

    2003-01-01

    Dimethylsulfide(DMS) measurements in the surface seawater of China eastern coastline were conducted during March 9-10, 1993 in Bohai Sea along the cruise from Dalian to Tianjin and during September 24-25, 1994 in Yellow Sea along the cruise from Shanghai to Qingdao. On the cruise in Bohai Sea DMS concentrations varied from 0. 11 to 2.63 nmol/L with an average of 1.31 nmol/L, while DMS flux Bohai Sea. DMS concentrations and fluxes had a similar spatial trend both in Bohai Sea and Yellow Sea with the correlation coefficients of 0.75 and 0.64, respectively.

  12. Japan's Energy Policy on China:In the Perspective of Oil Dispute in East China Sea

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Over recent years, the oil dispute in the East China Sea has become a new contradictory focus in Sino-Japanese relations after the issues of the Yasukuni Shrine and history text book. This article tries to take the oil dispute in the East China Sea as a penetrating point to analyze the basic line of thinking in Japan's China energy policy adjustment so as to better recognize the current situation and future of Sino-Japanese energy relations.

  13. KUROSHIO INTRUSION INTO THE SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-hua; FAN Hai-mei; QU Yuan-yuan

    2006-01-01

    In this article, the circulation of the South China Sea (SCS), which is idealized as the rectangular basin with constant depth, is studied under Kuroshio boundary forces. Starting from the linearly quasi-geostrophic vorticity equation, the solution of the SCS circulation is given in the form of corrected Fourier series under proper boundary conditions. The results show that the intruded current flows westward and separates into the northward branch and the southward branch before arriving at the western boundary. The southward branch flows out of the SCS through the southwestern passage, at the same time, the induced cyclonic (anti-clockwise) ring almost occupies the middle and southern parts, and concomitant anti-cyclonic (clockwise) vortex appears between the cyclone and the western boundary. While the northward branch outflows through the northeastern passage, the anti-cyclonic (clockwise) ring is triggered at the northern part of the SCS. The above two vortexes are both intensified if the south-entering and the north-leaving current loop intrusion are superposed. The outer flow of the northern vortex flows westward, then northward, and then eastward, and it is very similar to the configuration of the SCS Warm Current (SCSWC) at the northern part of the SCS, thus, a kind of generating mechanism of the SCSWC is presented.

  14. Interannual variations of surface winds over China marginal seas

    Institute of Scientific and Technical Information of China (English)

    SUN Che; YAN Xiaomei

    2012-01-01

    In a study of surface monsoon winds over the China marginal seas,Sun et al.(2012) use singular value decomposition method to identify regional dominant modes and analyze their interdecadal variability.This paper continues to evaluate the interannual variability of each dominant mode and its relation to various atmospheric,oceanic and land factors.The findings include:1) The intensity of the winter monsoon over the East China Sea is highly correlated with the Siberian High intensity and anti-correlated with the latitudinal position of the Aleutian Low as well as the rainfall in eastem China,Korean Peninsula and Japan; 2) The western Pacific subtropical high is significantly correlated with the summer monsoon intensity over the East China Sea and anti-correlated with the summer monsoon over the South China Sea; 3) The winter monsoon in a broad zonal belt through the Luzon Strait is dominated by the ENSO signal,strengthening in the La Ni(n)a phase and weakening in the El Ni(n)o phase.This inverse relation exhibits interdecadal shift with a period of weak correlation in the 1980s; 4) Analysis of tidal records validates the interdecadal weakening of the East Asian summer monsoon and reveals an atmospheric bridge that conveys the ENSO signal into the South China Sea via the winter monsoon.

  15. Wind energy input in coastal seas east of China

    Institute of Scientific and Technical Information of China (English)

    ZANG Nan; WU Dexing

    2013-01-01

    This study investigates the wind energy input,an important source of mechanical energy,in the coastal seas east of China.Using the wind field from the high-resolution sea surface meteorology dataset in the Bohai Sea,Yellow Sea,and East China Sea,we studied the wind energy input through surface ageostrophic currents and surface waves.Using a simple analytical formula for the Ekman Spiral with timedependent wind,the wind energy input through ageostrophic currents was estimated at ~22 GW averaged from 1960 to 2007,and through use of an empirical formula,the wind energy input through surface waves was estimated at ~169 GW.We also examined the seasonal variation and long-term tendency of mechanical energy from wind stress,and found that the wind energy input to the East China Sea decreased before the 1980s,and then subsequently increased,which is contrary to what has been found for the Bohai Sea and Yellow Sea.More complicated physical processes and varying diffusivity need to be taken into account in future studies.

  16. Zooplankton community structure in the Yellow Sea and East China Sea in autumn

    Directory of Open Access Journals (Sweden)

    Hongju Chen

    2015-12-01

    Full Text Available Abstract Study on zooplankton spatial distribution is essential for understanding food web dynamics in marine ecosystems and fishery management. Here we elucidated the composition and distribution of large mesozooplankton on the continental shelf of the Yellow Sea and East China Sea, and explored the zooplankton community structure in these water masses. Sixty vertical hauls (bottom or 200 m in deep water to surface using a ring net (diameter 0.8 m, 505-μm mesh were exploited in November 2007. The biogeographic patterns of zooplankton communities were investigated using multivariate analysis methods; copepod biodiversity was analyzed using univariate indices. Copepods and protozoans were dominate in the communities. Based on the species composition, we divided the study areas into six station groups. Significant differences in zooplankton assemblages were detected between the Yellow Sea and East China Sea. Species richness was higher in East China Sea groups than those in Yellow Sea, whereas taxonomic distinctness was higher in Yellow Sea than in East China Sea. There was a clear relationship between the species composition and water mass group.

  17. THE CLIMATE FEATURES OF THE SOUTH CHINA SEA WARM POOL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There exists a warm pool in the South China Sea (SCS). The temporal and spatial distribution and evolution of SCS warm pool is investigated using water temperatures at a depth of 20 m in the sea. The formation of the warm pool is discussed by combining water temperatures with geostrophic currents and simulated oceanic circulation. It is found that there are significant seasonal and interannual changes in the warm pool and in association with the general circulation of the atmosphere. The development of SCS warm pool is also closely related to the gyre activities in the sea and imported warm water from Indian Ocean (Java Sea) besides radiative warming.

  18. Comparative study of SEA experiences between EU and China

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    making, such as: How inclusive will the system be in relation to environmental, economic and social indicators? And how can the appropriate aggregation level for indicators be found? This paper makes a comparative study of the experiences of using indicators in SEA in two European countries and China...... SEA legislation and guidelines, this paper evaluates the different requirements related to indicator use within SEA in different national contexts. Furthermore, technical questions of how to design and use indicators in SEA are investigated. Finally, it is explored, from a political perspective, how...

  19. Status of marine biodiversity of the China seas.

    Directory of Open Access Journals (Sweden)

    J Y Liu

    Full Text Available China's seas cover nearly 5 million square kilometers extending from the tropical to the temperate climate zones and bordering on 32,000 km of coastline, including islands. Comprehensive systematic study of the marine biodiversity within this region began in the early 1950s with the establishment of the Qingdao Marine Biological Laboratory of the Chinese Academy of Sciences. Since that time scientists have carried out intensive multidisciplinary research on marine life in the China seas and have recorded 22,629 species belonging to 46 phyla. The marine flora and fauna of the China seas are characterized by high biodiversity, including tropical and subtropical elements of the Indo-West Pacific warm-water fauna in the South and East China seas, and temperate elements of North Pacific temperate fauna mainly in the Yellow Sea. The southern South China Sea fauna is characterized by typical tropical elements paralleled with the Philippine-New Guinea-Indonesia Coral triangle typical tropical faunal center. This paper summarizes advances in studies of marine biodiversity in China's seas and discusses current research mainly on characteristics and changes in marine biodiversity, including the monitoring, assessment, and conservation of endangered species and particularly the strengthening of effective management. Studies of (1 a tidal flat in a semi-enclosed embayment, (2 the impact of global climate change on a cold-water ecosystem, (3 coral reefs of Hainan Island and Xisha-Nansha atolls, (4 mangrove forests of the South China Sea, (5 a threatened seagrass field, and (6 an example of stock enhancement practices of the Chinese shrimp fishery are briefly introduced. Besides the overexploitation of living resources (more than 12.4 million tons yielded in 2007, the major threat to the biodiversity of the China seas is environmental deterioration (pollution, coastal construction, particularly in the brackish waters of estuarine environments, which are

  20. Status of marine biodiversity of the China seas.

    Science.gov (United States)

    Liu, J Y

    2013-01-01

    China's seas cover nearly 5 million square kilometers extending from the tropical to the temperate climate zones and bordering on 32,000 km of coastline, including islands. Comprehensive systematic study of the marine biodiversity within this region began in the early 1950s with the establishment of the Qingdao Marine Biological Laboratory of the Chinese Academy of Sciences. Since that time scientists have carried out intensive multidisciplinary research on marine life in the China seas and have recorded 22,629 species belonging to 46 phyla. The marine flora and fauna of the China seas are characterized by high biodiversity, including tropical and subtropical elements of the Indo-West Pacific warm-water fauna in the South and East China seas, and temperate elements of North Pacific temperate fauna mainly in the Yellow Sea. The southern South China Sea fauna is characterized by typical tropical elements paralleled with the Philippine-New Guinea-Indonesia Coral triangle typical tropical faunal center. This paper summarizes advances in studies of marine biodiversity in China's seas and discusses current research mainly on characteristics and changes in marine biodiversity, including the monitoring, assessment, and conservation of endangered species and particularly the strengthening of effective management. Studies of (1) a tidal flat in a semi-enclosed embayment, (2) the impact of global climate change on a cold-water ecosystem, (3) coral reefs of Hainan Island and Xisha-Nansha atolls, (4) mangrove forests of the South China Sea, (5) a threatened seagrass field, and (6) an example of stock enhancement practices of the Chinese shrimp fishery are briefly introduced. Besides the overexploitation of living resources (more than 12.4 million tons yielded in 2007), the major threat to the biodiversity of the China seas is environmental deterioration (pollution, coastal construction), particularly in the brackish waters of estuarine environments, which are characterized by

  1. [Nutrient distributions and their limitation on phytoplankton in the Yellow Sea and the East China Sea].

    Science.gov (United States)

    Wang, Baodong

    2003-07-01

    Based on field observations during 1997 to 1999, the distributions of micronutrients and their limitation on the growth of phytoplankton in the Yellow Sea and the East China Sea were discussed in this paper. The results showed that there were abundant nutrients in the area of the east and northern-east of the Changjiang River estuary, and the nutrients came from the extension of the Changjiang River diluted water and the transportation of the Subei Coastal water. Besides, the maximum extension range of the nutrients in the Changjiang River diluted water was observed during the catastrophic flooding period of the Changjiang River in the summer of 1998. Based on the Redfield ratio (Si:N:P = 16:16:1) in which, three essential nutrients were utilized by marine phytoplankton, the Si/N/P ratios were calculated and studied for the upper water of the Yellow Sea and the East China Sea. The results indicated that Si/N ratios were very high, which suggested that silicate was not the limiting factor for the growth of phytoplankton in the Yellow Sea and the East China Sea. However, under the influence of terrestrial runoff, especially the Changjiang River runoff which was rich in combined nitrogen and had very high N/P ratios, high N/P ratios occurred in the Changjiang River estuary and its adjacent areas such as the south and southwest of the Yellow Sea, the inshore area of the East China Sea and the area east of the Changjiang River estuary in spring and summer. As a result, in contrast to general open marine systems, the systems in these areas resembled estuarine ones rather than typical marine ones. The primary production in a considerable portion of the Yellow Sea and the East China Sea might be limited by phosphate rather than nitrogen.

  2. [Distribution and air-sea fluxes of methane in the Yellow Sea and the East China Sea in the spring].

    Science.gov (United States)

    Cao, Xing-Peng; Zhang, Gui-Ling; Ma, Xiao; Zhang, Guo-Ling; Liu, Su-Mei

    2013-07-01

    A survey was carried out in the Yellow Sea and the East China Sea from March 17 to April 06 of 2011. Dissolved CH4 in various depths were measured and sea-to-air fluxes were estimated. Methane concentrations in surface and bottom waters ranged between 2.39-29.67 nmol x L(-1) and 2.63-30.63 nmol x L(-1), respectively. Methane concentrations in bottom waters were slightly higher than those in surface waters, suggesting the existence of methane source in bottom waters or sediments. The horizontal distribution of dissolved CH4 showed a decrease from the river mouth to the open sea, and was influenced by the freshwater discharge and the Kuroshio intrusion. Surface methane saturations ranged from 93%-1 038%. Sea to air CH4 fluxes were (2.85 +/- 5.11) micromol x (m2 x d)(-1) (5.18 +/- 9.99) micromol x (m2 x d)(-1) respectively, calculated using the Liss and Merlivat (LM86), the Wanninkhof (W92) relationships and in situ wind speeds, and estimated emission rates of methane from the East China Sea and the Yellow Sea range from 7.05 x 10(-2) - 12.0 x 10(-2) Tg x a(-1) and 1.17 x 10(-2) - 2.20 x 10(-2) Tg x a(-1), respectively. The Yellow Sea and East China Sea are the net sources of atmospheric methane in the spring.

  3. Pleistocene radiolarian biostratigraphy in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    王汝建; Andrea; Abelmann

    1999-01-01

    Based on a quantitative radiolarian analysis, 5 radiolarian zones (NR1-NR5) have been defined at Core 17957-2 from the South China Sea, considering radiolarian zonations from low latitudes. The absolute age assignment of the radiolarian zones and the ranges of the six marker species is based on the direct correlation with the paleomagnetic and isotopic record, respectively. A comparison of the radiolarian stratigraphic data obtained from Core 17957-2 from the South China Sea with those from the equatorial Pacific and the tropical Indian Ocean shows a close similarity to the ages defined in the equatorial Pacific. The obtained biostratigraphic data provide an excellent tool for further dating of Pleistocene sediments in the China Sea.

  4. The Suspended Sediment Concentration Distribution in the Bohai Sea, Yellow Sea and East China Sea

    Institute of Scientific and Technical Information of China (English)

    BIAN Changwei; JIANG Wensheng; Richard J.Greatbatch; DING Hui

    2013-01-01

    The distribution of the suspended sediment eoncentration (SSC) in the Bohai Sea,Yellow Sea and East China Sea (BYECS) is studied based on the observed turbidity data and model simulation results.The observed turbidity results show that (i)the highest SSC is found in the coastal areas while in the outer shelf sea areas turbid water is much more difficult to observe,(ii) the surface layer SSC is much lower than the bottom layer SSC and (iii) the winter SSC is higher than the summer SSC.The Regional Ocean Modeling System (ROMS) is used to simulate the SSC distribution in the BYECS.A comparison between the modeled SSC and the observed SSC in the BYECS shows that the modeled SSC can reproduce the principal features of the SSC distribution in the BYECS.The dynamic mechanisms of the sediment erosion and transport processes are studied based on the modeled results.The horizontal distribution of the SSC in the BYECS is mainly determined by the current-wave induced bottom stress and the fine-grain sediment distribution.The current-induced bottom stress is much higher than the wave-induced bottom stress,which means the tidal currents play a more significant role in the sediment resuspension than the wind waves.The vertical mixing strength is studied based on the mixed layer depth and the turbulent kinetic energy distribution in the BYECS.The strong winter time vertical mixing,which is mainly caused by the strong wind stress and surface cooling,leads to high surface layer SSC in winter.High surface layer SSC in summer is restricted in the coastal areas.

  5. Restricting factors of the development of SEA in China

    Institute of Scientific and Technical Information of China (English)

    Wang Xianghua; Zhu Xiaodong; LiYangfan; Chen Shanshan

    2006-01-01

    "Environmental Impact Assessment Law of P. R. China" was promulgated on Oct. 28th, 2002 and has been put into effect on Sep 1st, 2003. This paper puts forward some important factors which restrict the development of Strategic Environmental Assessment according to the preliminary practices of SEA in China. These restricting factors are: (1) potential resistance from some departments; (2) poor cooperation between different departments; (3) limited availability of information resources; (4) lack of well-developed SEA methods; (5) difficulties in public participation. The primary thought to solve these problems were proposed at policy and technique level.

  6. Bathymetric Inversion of South China Sea from Satellite Altimetry Data

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper focuses on the study of ocean bathymetric inversion from satellite altimeter data by using FFT technique.In this study,the free-air gravity anomalies over the South China Sea are determined by the satellite altimeter data of GEOSAT,ERS-1,ERS-2 and T/P.And the 2.5′×2.5′ bathymetry model in South China Sea is calculated from the gravity anomalies with the inversion model given.After the analysis of the inversion and the comparison between the results,some conclusions can be drawn.

  7. Dynamic simulations of the late MIS 3 transgressions in the East China Sea and southern Yellow Sea, China

    Institute of Scientific and Technical Information of China (English)

    YE Liangtao; YU Ge; LIAO Mengna; LI Yongfei

    2016-01-01

    Abundant evidences of higher sea levels from Jiangsu and Fujian coasts have proved a marine transgression event during 30–40 ka BP, suggesting that there was a stage with high sea level and a warm climate when ice sheets shrank in the Northern Hemisphere. The duration of 30–40 ka BP spanned a period in the late Marine Isotope Stage 3 (MIS 3) and was in nature an interstadial epoch during the Last Glacial period of the Quaternary. Different from the glacial period with a cold climate, this marine transgression considered as a penultimate higher sea level during the Quaternary remains a puzzle that why the evidence is contrary to the Quaternary glacial theory. It is important to understand sea level rise for these areas sensitively responding to the global changes in the future. To recognize the key issues on sea level changes, the eustatic sea level (HS) was defined as the glaciation-climate-forced sea levels, and the relative sea level change (HR) was defined as that a sea level record was preserved in sediment that experienced multiple secondary actions of land and sea effects. On the basis as defined above, we constructed multi-level models of climate-driven glacio-eustatic changes and land-sea systems. By integrating data sets from eight borehole cores and prescribing the boundary conditions, we simulated the changes of HS and HR in the East China Sea and southern Yellow Sea areas in the late MIS 3. The marine transgression strata from the borehole core data was identified at ca. 30 m below present sea level as a result of the collective influence of ice melting water, neotectonic subsidence, sediment compaction and terrestrial sediment filling since ca. 35 ka ago, whereas the simulated relative sea-levels turned out to be –26.3––29.9 m a.s.l. The small error involved in the simulation results of ±(2.5–4.5) m demonstrated the credibility of the results. Our results indicated that sea level change in the late MIS 3 was dominated by glacial effects

  8. Scientific questions about South China Sea ocean dynamics

    Institute of Scientific and Technical Information of China (English)

    HUANG Rui Xin; DU Yan

    2015-01-01

    South China Sea, its circulation and connection with other parts of the world oceans, poses important scientific questions. From the prospective view, we postulate ten key research directions to be pursued in the coming future, including ventilation of a monsoon dominated sea, water mass formation/transformation, heat/salt and water mass balance, energetics and mixing, mesoscale eddies, the role of typhoon, deep circulation and paleoclimate records, interaction with adjacent oceans, upwelling and ecology system, and response to climate changes.

  9. Long Term Sea Level Change and Water Mass Balance in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    RONG Zengrui; LIU Yuguang; ZONG Haibo; XIU Peng

    2009-01-01

    Sea level anomalies observed by altimeter during the 1993-2006 period, thermosterie sea level anomalies estimated by using subsurface temperature data produced by Ishii and SODA reanalysis data, tide gauge records and HOAPS freshwater flux data were analyzed to investigate the long term sea level change and the water mass balance in the South China Sea. The altimeter-observed sea level showed a rising rate of (3.5±0.9)mm yr-1 during the period 1993-2006, but this figure was considered to have been highly distorted by the relatively short time interval and the large inter-decadal variability, which apparently exists in both the thermosteric sea level and the observed sea level. Long term thermosteric sea level from 1945 to 2004 gave a rising rate of 0.15±0.06 mmyr-1. Tide gauge data revealed this discrepancy and the regional distributions of the sea-level trends. Both the 'real' and the thermosteric sea level showed a good correspondence to ENSO: decreasing during E1 Nifio years and increasing during La Nina years. Amplitude and phase differences between the 'real' sea level and the thermosteic sea level were substantially revealed on both seasonal and interannual time scales. As one of the possible factors, the freshwater flux might play an important role in balancing the water mass.

  10. Navigating the Security Dilemma: China, Vietnam, and the South China Sea

    Directory of Open Access Journals (Sweden)

    Jason J. Blazevic

    2012-01-01

    Full Text Available Competition and conflict in the South China Sea involves many nations due to its resources and vital sea lanes. However, it is China which increasingly serves as a common denominator of intensifying anxiety for its South China Sea maritime neighbours due to the aggressive scope of its claims to the sea and its islands. Among those states, Vietnam is most affected as it is first in the path of Chinese ambitions – ambitions which authorities fear would give China significant tactical military and economic advantage. For China, there are similar fears over threats to the sea lanes and sea bed resources. Leaders of both states also perceive their diplomatic and martial actions in the sea in historical terms as well. However, enforcement actions taken by either state may lead to a worsening security dilemma in which reactive security strategies could dangerously destabilise relations. This article discusses the motivations and strategies of both states as well as the consequences of such and applies realism, its tenets of defensive and offensive realism, and neoliberalism to examine their security concerns and perceptions. The article further proposes that the most valuable insights can be provided by defensive realism and neoliberalism, which together can encourage security, cooperation and conciliation in order to best promote the improvement of relations.

  11. Satellite based wind resource assessment over the South China Sea

    DEFF Research Database (Denmark)

    Badger, Merete; Astrup, Poul; Hasager, Charlotte Bay

    2014-01-01

    modeling to develop procedures and best practices for satellite based wind resource assessment offshore. All existing satellite images from the Envisat Advanced SAR sensor by the European Space Agency (2002-12) have been collected over a domain in the South China Sea. Wind speed is first retrieved from...

  12. The complexity of South China Sea kinematics

    Science.gov (United States)

    Sibuet, Jean-Claude; Gao, Jinyao; Zhao, Minghui; Wu, Jonny; Ding, Weiwei; Yeh, Yi-Ching; Lee, Chao-Shing

    2016-04-01

    Magnetic modeling shows that the age of the youngest South China Sea (SCS) oceanic crust is controversial (e.g. 15.5 Ma, Briais et al., JGR 1993 and 20.5 Ma, Barckhausen et al., MPG 2014). Close to the rift axis of the East sub-basin, Ar-Ar age dating of oceanic crustal rocks collected during IODP Leg 349 gives ages of 15 and 15.2 +/- 0.2 Ma (Koppers, Fall AGU meeting, 2014), which seems to favor the 15.5 Ma age given by Briais et al. modeling. However, basaltic samples might belong to a sill and not to the typical oceanic crust. As post-spreading magmatic activity (~8-13 Ma) largely masks the spreading fabric, in particular near the previously identified E-W portion of the extinct ridge axis of the East sub-basin, the published locations of the axial magnetic anomaly and spreading rates are incorrect. The compilation of available swath bathymetric data shows that if post-spreading volcanics hide the seafloor spreading magnetic fabric mostly along and near the extinct spreading axis, the whole SCS is globally characterized by rift directions following three directions: N055°in the youngest portion of the SCS, N065° and N085° in the oldest portions of the SCS (Sibuet et al., Tectonophysics 2016) suggesting the extinct ridge axis is N055° trending instead of E-W. We present an updated version of the whole SCS structural sketch based on previously published swath bathymetric trends and new detailed magnetic lineations trends compiled from an extremely dense set of magnetic data. The new structural sketch shows: - The distribution of conjugate kinematic domains, - The early opening of the NW and East sub-basins, before a jump of the rift axis, - A second ridge jump in the East basin, - The different expressions of the post-spreading magmatism in the East and SW sub-basins. In the East sub-basin, crustal magmatic intrusions led to the formation of extrusive basalts associated with the presence of numerous volcanoes (Wang et al., Geological Journal 2016). In the SW

  13. Pyrite Genesis During Early Diagenesis in Yellow Sea and East China Sea

    Institute of Scientific and Technical Information of China (English)

    段伟民; 陈丽蓉

    1994-01-01

    The content and isotopic compositions of different sulphur species in pore-water and solid phases have been examined on five sediment cores taken from muddy sediment region in the Yellow Sea and the East China Sea. Relationships among these data have been investigated with the combination of morphology of mineral pyrite and organic matter so as to role out the diagenetic behaviour of sulphur species at the early stage of diagenesis in modern marine sediment and the origin of pyrite formation.

  14. Spatial-temporal analysis of sea level changes in China seas and neighboring oceans by merged altimeter data

    Science.gov (United States)

    Xu, Yao; Zhou, Bin; Yu, Zhifeng; Lei, Hui; Sun, Jiamin; Zhu, Xingrui; Liu, Congjin

    2017-01-01

    The knowledge of sea level changes is critical important for social, economic and scientific development in coastal areas. Satellite altimeter makes it possible to observe long term and large scale dynamic changes in the ocean, contiguous shelf seas and coastal zone. In this paper, 1993-2015 altimeter data of Topex/Poseidon and its follow-on missions is used to get a time serious of continuous and homogeneous sea level anomaly gridding product. The sea level rising rate is 0.39 cm/yr in China Seas and the neighboring oceans, 0.37 cm/yr in the Bo and Yellow Sea, 0.29 cm/yr in the East China Sea and 0.40 cm/yr in the South China Sea. The mean sea level and its rising rate are spatial-temporal non-homogeneous. The mean sea level shows opposite characteristics in coastal seas versus open oceans. The Bo and Yellow Sea has the most significant seasonal variability. The results are consistent with in situ data observation by the Nation Ocean Agency of China. The coefficient of variability model is introduced to describe the spatial-temporal variability. Results show that the variability in coastal seas is stronger than that in open oceans, especially the seas off the entrance area of the river, indicating that the validation of altimeter data is less reasonable in these seas.

  15. Deepwater oil and gas field development in South China Sea

    Institute of Scientific and Technical Information of China (English)

    Zhang Dagang; Wybro Pieter; Kang Yongtian

    2013-01-01

    This paper focuses on potential development models of future oil and gas exploration in South China Sea.A detailed study of current development models worldwide is performed through some examples of industry installed/ongoing projects and major technical issues encountered during these practice.Key technologies are discussed for the success of field development.Some of the technologies and field development experience can be used for South China Sea project.Several models are studied in field development for different scenarios,including marginal field,large oil field and gas field.With the massive investment activities,continued improved technologies,and rapidly growing pool of professionals,the offshore industry in China will soon encounter a golden period.

  16. Western fault zone of South China Sea and its physical simulation evidences

    Institute of Scientific and Technical Information of China (English)

    SUN Longtao; SUN Zhen; ZHAN Wenhuan; SUN Zongxun; ZHAO Minghui; XIA Shaohong

    2006-01-01

    The western fault zone of the South China Sea is a strike-slip fault system and consists of four typical strike-slip faults. It is the western border of the South China Sea. The formation of the system is due to the extrusion of Indo - China Peninsula caused by the collision of India with Tibet and the spreading of the South China Sea in Cenozoic. There are five episodes of tectonic movement along this fault zone, which plays an important role in the Cenozoic evolution of the South China Sea. By the physical modeling experiments, it can be seen the strike-slip fault undergoes the sinistral and dextral movement due to the relative movement velocity change between the South China Sea block and the Indo - China block. The fault zone controls the evolution of the pull basins locating in the west of the South China Sea.

  17. Mercury Export from Mainland China to Adjacent Seas and Its Influence on the Marine Mercury Balance.

    Science.gov (United States)

    Liu, Maodian; Chen, Long; Wang, Xuejun; Zhang, Wei; Tong, Yindong; Ou, Langbo; Xie, Han; Shen, Huizhong; Ye, Xuejie; Deng, Chunyan; Wang, Huanhuan

    2016-06-21

    Exports from mainland China are a significant source of mercury (Hg) in the adjacent seas (Bohai Sea, Yellow Sea, East China Sea, and South China Sea) near China. A total of 240 ± 23 Mg was contributed in 2012 (30% from natural sources and 70% from anthropogenic sources), including Hg from rivers, industrial wastewater, domestic sewage, groundwater, nonpoint sources, and coastal erosion. Among the various sources, the Hg from rivers amounts to 160 ± 21 Mg and plays a dominant role. The Hg that is exported from mainland China increased from 1984 to 2013; the contributions from rivers, industrial wastewater, domestic sewage and groundwater increased, and the contributions from nonpoint sources and coastal erosion remained stable. A box model is constructed to simulate the mass balance of Hg in these seas and quantify the sources, sinks and Hg biogeochemical cycle in the seas. In total, 160 Mg of Hg was transported to the Pacific Ocean and other oceans from these seas through oceanic currents in 2012, which could have negative impacts on the marine ecosystem. A prediction of the changes in Hg exportation through 2030 shows that the impacts of terrestrial export might worsen without effective pollution reduction measures and that the Hg load in these seas will increase, especially in the seawater of the Bohai Sea, Yellow Sea, and East China Sea and in the sea margin sediments of the Bohai Sea and East China Sea.

  18. A study of long-term sea level variability in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Ying; LIN Mingsen; ZHENG Quanan; YE Xiaomin; LI Junyi; ZHU Benlu

    2015-01-01

    From the analyses of the satellite altimeter Maps of Sea Level Anomaly (MSLA) data, tidal gauge sea level data and historical sea level data, this paper investigates the long-term sea level variability in the East China Sea (ECS). Based on the correlation analysis, we calculate the correlation coefficient between tidal gauge and the closest MSLA grid point, then generate the map of correlation coefficient of the entire ECS. The results show that the satellite altimeter MSLA data is effective to observe coastal sea level variability. An important finding is that from map of correlation coefficient we can identify the Kuroshio. The existence of Kuroshio decreases the correlation between coastal and the Pacific sea level. Kurishio likes a barrier or a wall, which blocks the effect of the Pacific and the global change. Moreover, coastal sea level in the ECS is mainly associated with local systems rather than global change. In order to calculate the long-term sea level variability trend, the empirical mode decomposition (EMD) method is applied to derive the trend on each MSLA grid point in the entire ECS. According to the 2-D distribution of the trend and rising rate, the sea level on the right side of the axis of Kuroshio rise faster than in its left side. This result supports the barrier effect of Kuroshio in the ECS. For the entire ECS, the average sea level rose 45.0 mm between 1993 and 2010, with a rising rate of (2.5±0.4) mm/a which is slower than global average. The relatively slower sea level rising rate further proves that sea level rise in the ECS has less response to global change due to its own local system effect.

  19. Distribution of Bottom Trawling Effort in the Yellow Sea and East China Sea

    Science.gov (United States)

    Zhang, Shengmao; Jin, Shaofei; Zhang, Heng; Fan, Wei; Tang, Fenghua; Yang, Shenglong

    2016-01-01

    Bottom trawling is one of the most efficient fishing activities, but serious and persistent ecological issues have been observed by fishers, scientists and fishery managers. Although China has applied the Beidou fishing vessel position monitoring system (VMS) to manage trawlers since 2006, little is known regarding the impacts of trawling on the sea bottom environments. In this study, continuous VMS data of the 1403 single-rig otter trawlers registered in the Xiangshan Port, 3.9% of the total trawlers in China, were used to map the trawling effort in 2013. We used the accumulated distance (AD), accumulated power distance (APD), and trawling intensity as indexes to express the trawling efforts in the Yellow Sea (YS) and East China Sea (ECS). Our results show that all three indexes had similar patterns in the YS and ECS, and indicated a higher fishing effort of fishing grounds that were near the port. On average, the seabed was trawled 0.73 times in 2013 over the entire fishing region, and 51.38% of the total fishing grounds were with no fishing activities. Because of VMS data from only a small proportion of Chinese trawlers was calculated fishing intensity, more VMS data is required to illustrate the overall trawling effort in China seas. Our results enable fishery managers to identify the distribution of bottom trawling activities in the YS and ECS, and hence to make effective fishery policy. PMID:27855215

  20. Mass-balance ecosystem model of the East China Sea

    Institute of Scientific and Technical Information of China (English)

    Jiahua Cheng; William W.L. Cheung; Tony J. Pitcher

    2009-01-01

    Using the Ecopath mass-balance trophodynamic model, this paper analyzed the trophic levels, flows, food web structure and ecosys-tem maturity of the East China Sea, and identified ecologically important functional groups in the ecosystem. The model is based on fishery resource surveys of the East China Sea in 2000, studies on diet composition and global databases such as FishBase and the Sea Around Us Project Database. The results showed that trophic levels of the functional groups are between 2.86 and 4.37, with an average of 3.32. Anchocy (Engraulis japonicus), small fishes and benthic crustaceans such as shrimps and crabs are important groups in terms of the trophic structure and flow dynamics in the East China Sea. Energy flows of most groups are between specific trophic levels, except file fish (Thamnaconus spp.), pomfret (Pampus spp.) and cephalopods. Trophic transfer efficiency of levels Ⅱ,Ⅲ,Ⅳ and more than Ⅴ are 11.8%, 21.1%, 17.4% and 22.1-22.5%, respectively. Effects of fishery-the largest 'consumer' of the ecosystem -are much stronger than those exerted by biological groups in the system. The model suggests that the current fishery can further reduce the complexity of the ecosystem. Evaluations of the system indices suggest that maturity of the ecosystem is low. The conclusion of this model indicates that it was the overfishing that caused the ecosystem of the East China Sea declined, which should be taken into account as a critical reference for fisheries management in the future.

  1. Preliminary validation of SMOS sea surface salinity measurements in the South China Sea

    Science.gov (United States)

    Ren, Yongzheng; Dong, Qing; He, Mingxia

    2015-01-01

    The SMOS (soil moisture and ocean salinity) mission undertaken by the European Space Agency (ESA) has provided sea surface salinity (SSS) measurements at global scale since 2009. Validation of SSS values retrieved from SMOS data has been done globally and regionally. However, the accuracy of SSS measurements by SMOS in the China seas has not been examined in detail. In this study, we compared retrieved SSS values from SMOS data with in situ measurements from a South China Sea (SCS) expedition during autumn 2011. The comparison shows that the retrieved SSS values using ascending pass data have much better agreement with in situ measurements than the result derived from descending pass data. Accuracy in terms of bias and root mean square error (RMS) of the SSS retrieved using three different sea surface roughness models is very consistent, regardless of ascending or descending orbits. When ascending and descending measurements are combined for comparison, the retrieved SSS using a semi-empirical model shows the best agreement with in situ measurements, with bias -0.33 practical salinity units and RMS 0.74. We also investigated the impact of environmental conditions of sea surface wind and sea surface temperature on accuracy of the retrieved SSS. The SCS is a semi-closed basin where radio frequencies transmitted from the mainland strongly interfere with SMOS measurements. Therefore, accuracy of retrieved SSS shows a relationship with distance between the validation sites and land.

  2. Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Astrup, Poul; Zhu, Rong;

    2016-01-01

    We study the wind climate and its long-term variability in the North Sea and South China Sea, areas relevant for offshore wind energy development, using satellite-based wind data, because very few reliable long-term in-situ sea surface wind observations are available. The Special Sensor Microwave...

  3. Gunboat Diplomacy in the South China Sea

    Science.gov (United States)

    2012-01-01

    a Chinese presence in islands in Southeast Asia before 1000 CE is scant, consisting of a small amount of pottery found in southern Sumatra and the...Twenty-one vessels were boarded, seven attacks attempted, two vessels were fired upon and one was hijacked.” 53 In fact, “Since the 1990s, about half...without firing .” 124 China’s sea mine warfare is an often overlooked asymmetric capability that poses a threat not just to U.S. shipping interests

  4. Climate analysis of evaporation ducts in the South China Sea

    OpenAIRE

    McKeon, Brian D.

    2013-01-01

    Approved for public release; distribution is unlimited. Evaporation ducts have important implications for U.S. Naval activities involving electromagnetic propagation. The presence of an evaporation duct can affect naval operations involving communications, surveillance, electronic warfare, and detection of low-flying missiles, surface ships, or submarine periscopes. We conducted a climate scale analysis of evaporation duct heights (EDH) in the northern South China Sea (SCS), including how ...

  5. The South China Sea: Every Nation for Itself

    Science.gov (United States)

    2013-05-23

    the dispute desires one. 15. SUBJECT TERMS South China Sea, ASEAN, 1982 UNCLOS, 2002 ASEAN Declaration, Mancur Olson , Alan Lamborn 16. SECURITY...using international relations theories concerning the behavior of groups. Mancur Olson and Alan Lamborn have written theories that helped interpret... Mancur Olson and Alan Lamborn both provided theories that help explain why the actors in the dispute disregard a common solution in favor of their

  6. Heavy metals in sea cucumber juveniles from coastal areas of Bohai and Yellow seas, north China.

    Science.gov (United States)

    Jiang, Haifeng; Tang, Shizhan; Qin, Dongli; Chen, Zhongxiang; Wang, Jinlong; Bai, Shuyan; Mou, Zhenbo

    2015-05-01

    The study was undertaken to assess the contents of heavy metals (Cu, Zn, Cr, Pb, Cd, As and Hg) in sea cucumber (Apostichopus japonicus) juveniles from coastal areas of Bohai and Yellow seas in northern China. Sea cucumber juveniles were collected from twenty commercial hatcheries distributed in five coastal cities. The mean concentrations obtained for heavy metals in mg/kg were as follows: Cu (0.179), Zn (2.634), Cr (0.108), Pb (0.065), Cd (0.161), As (0.372), Hg (0.034). All the mean concentrations were below the maximum residual limits set by Chinese legislation, but As in 10 % samples exceeded the safety threshold. Significant differences in contents of Cr, Pb and Hg were found among the five investigated areas. Overall, the heavy metal levels in sea cucumber juveniles were relatively low and more attention should be paid to toxic metals Pb, Cd, As and Hg in future routine monitoring program.

  7. Long-term Variability of Sea Surface Temperature in the East China Sea: A Review

    Directory of Open Access Journals (Sweden)

    Jae Hak Lee

    2013-06-01

    Full Text Available The long-term variability of sea surface temperature in the East China Sea was reviewed based mainly on published literatures. Though the quantitative results are not the same, it is generally shown that sea surface temperature is increasing especially in recent years with the rate of increase about 0.03oC/year. Other meaningful results presented in the literatures is that the difference of water properties between layers upper and lower than the thermocline in summer shows an increasing trend both in temperature and salinity, suggesting that the stratification has been intensified. As a mechanism by which to evaluate the wintertime warming trend in the region, the weakening of wind strength, which is related to the variation of sea level pressure and atmospheric circulation in the western North Pacific and northern Asian continent, is suggested in the most of related studies.

  8. Heat exchange at air-sea interface in the South China Sea during monsoon periods in 1986

    Institute of Scientific and Technical Information of China (English)

    WU Disheng; LU Boming; FENG Weizhong; XU Jianping; YAN Jinghua; ZHAO Xue; ZHOU Shuihua; ZHANG Jiwei; QIAO Guanyu; LIN Fu

    2006-01-01

    In order to explore the interaction between the sea and monsoon in the South China Sea, the heat exchanges at air-sea interface during monsoon periods in 1986 were calculated using observational data. It shows that when the summer monsoon bursts and prevails over the South China Sea, the air-sea interface heat exchange is strong and the latent heat rises rapidly in the intertropical convergence zone and the tropic cyclone system near 20.49°N, 114.14°E. On May 24, 1986, the sensible heat became positive in the typhoon system. The heating exchange indicates that heat is transported from ocean to atmosphere, with major contribution of latent heat. When the summer monsoon prevails over the South China Sea and the weather is fine, even SST (sea surface temperature) is high, but sensible heat appears to be negative. The heat exchange indicates that heat is transported from atmosphere to ocean, with major contribution of short-wave radiation absorbed by sea surface and sensible heat. When summer monsoon is over and the northeast monsoon prevails over the South China Sea, the heat exchange at air-sea interface is very strong. The heating exchange shows that the ocean heats the atmosphere, with major contribution of latent heat when cold air arrives at the sea surface and the sensible heat rises to positive rapidly. Therefore it can be concluded that the heat exchange at air-sea interface is different from the SST in South China Sea. When the summer monsoon prevails over the South China Sea, the main trend is the ocean responding to the atmosphere.

  9. Modal Wave Number Tomography for South China Sea Front

    Institute of Scientific and Technical Information of China (English)

    彭临慧; 王宁; 邱晓芳; 田纪伟

    2003-01-01

    Monitoring of the South China Sea is always one of the focuses in the field of ocean engineering for its particular geographic position. The modal wave number tomography is proposed for monitoring the front and numerical simulation is performed for the front of the South China Sea. With the empirical orthonormal function (EOF) applied to reduce the parameter search space, the perturbation inversion method is used for inversing sound speed profiles. The 2-D ocean environment used for numerical simulation is selected from the ocean area, located in 20°N, 118°E~20°N, 125°E, near the Luzon Strait in the South China Sea. The ocean environment sound speed distribution in the ocean area under study is obtained from the assimilation of multi-source remote sensing data. The numerical simulation shows that the modal wave number tomography can inverse the average sound speed profile, therefore,it can be used to monitor ocean internal structures such as ocean fronts and eddies which affect sound speed distribution.

  10. Mitochondrial DNA variation in the East China Sea and Yellow Sea populations of swimming crab Ovalipes punctatus.

    Science.gov (United States)

    Zheng, Wei; Han, Zhiqiang; Chen, Guobao; Yu, Cungen; Gao, Tianxiang

    2015-08-01

    Swimming crab Ovalipes punctatus is a commercially important species in the East China Sea and Yellow Sea, but there is limited knowledge of its genetic population structure. The population genetic structure of O. punctatus in East China Sea and Yellow Sea was examined with a 658-bp segment of the mtDNA COI gene. A total of 60 individuals were collected from five locations and 48 haplotypes were obtained. Mean haplotype diversity and nucleotide diversity for the five populations were 0.9876 ± 0.0068 and 0.0074 ± 0.0041, respectively. Analysis of molecular variance (AMOVA) detected no significant differences at all hierarchical levels, and all FST values were non-significant, indicating that no significant population genetic structure exists in the East China Sea and Yellow Sea. These results supported the null hypothesis that O. punctatus within the East China Sea and Yellow Sea constitutes a panmictic mtDNA gene pool. Neutrality tests and mismatch distribution supported population expansion in this species, indicating that climate change could play an important role in affecting the demographic history of marine species. Strong dispersal capacity of larvae and adults, and ocean currents in the studied area could be the reasons for genetic homogeneity in this species in the East China Sea and Yellow Sea. Another explanation for the lack of phylogeographic structure in O. punctatus might reflect a recent range expansion after the last glacial maximum and insufficient time to attain migration-drift equilibrium.

  11. Relationship between Antarctic sea ice and the climate in summer of China

    Institute of Scientific and Technical Information of China (English)

    Ma Lijuan; Lu Longhua; Bian Lingen

    2006-01-01

    The variations of sea ice are different in different regions in Antarctica,thus have different impacts on local atmospheric circulation and global climatic system. The relationships between the sea ice in Ross Sea and Weddell Sea regions and the synoptic climate in summer of China are investigated in this paper via diagnostic analysis methods by using global sea ice concentration gridded data covering Jan. 1968through Dec. 2002 obtained from Hadley Center, combined with Geopotential Height on 500hPa and 100hPa over North Hemisphere and monthly precipitation and air temperatures data covering the corresponding period over 160 meteorological stations in China obtained from CMA (China Meteorological Administration). Results disclose that both these two regions are of indicative meanings to the climate in summer of China. The Ross Sea Region is the key sea ice region to the precipitation in Northeast China in summer. More sea ice in this region in September will result in less precipitation in Northeast China in the following June. Weddell Sea Region is the key sea ice region to the air temperature in Northeast China in summer. More sea ice in this region in September will contribute to lower air temperature in Northeast China in the following June.

  12. The Kuroshio exchange with the South and East China Seas

    Directory of Open Access Journals (Sweden)

    T. Matsuno

    2009-08-01

    Full Text Available The Kuroshio flows along the edges of the marginal East Asian seas such as the South China Sea (SCS and East China Sea (ECS. Exchanges of materials and energy between the Kuroshio and the marginal seas partly control the environments of the marginal seas. In particular, saline water from the Kuroshio maintains certain salinity in the shelf water in the ECS. Nutrients from the subsurface of the Kuroshio may influence primary production on the shelf. We summarize how the Kuroshio comes into contact with the shelf water or marginal seas, describing phenomena related to the exchange between the Kuroshio and the ECS along with the SCS, using reports in the literature along with original data. The Kuroshio tends to intrude into the SCS through the Luzon Strait in various manners such as direct intrusion, associated with eddies and as a loop current. The Kuroshio intrusion into the shelf region of the ECS has distinct seasonal variation and the Taiwan Warm Current plays a significant role in the determination of water properties in the outer shelf associated with the Kuroshio intrusion. We then examine physical processes related to the interaction between the Kuroshio and shelf water. Interaction between the Kuroshio and the bottom topography is an important process in the control of the exchange around the shelf break. Vertical mixing and frontal eddies are also important factors that control the water exchange and formation of water masses in the outer shelf. Wind stress plays a significant role in the exchange with a rather event-like manner. To determine the source of the water masses, chemical tracers could be powerful tools and it is suggested that a significant part of the shelf water consists of Kuroshio intermediate water.

  13. Modern sedimentation and extreme event in the South China Sea

    Science.gov (United States)

    Chen, Yu-Huang; Su, Chih-Chieh

    2016-04-01

    The South China Sea is the largest marginal sea of the northwest Pacific. It is situated at the plate boundary of the Eurasian, Philippine Sea, and Indian plates and also on the North Western Pacific corridor of typhoons. The unique tectonic and climatic environment makes it has to face the potential of seafloor destructions, like submarine landslides and slumps, and high sediment discharges which induced by typhoon from Philippine. In this study, we analysis the sediment properties of modern extreme event records in cores and attempt to evaluate the history of extreme events in the South China Sea. Twelve gravity cores were collected in the central South China Sea basin and around Taiping island by using R/V Ocean Research 1 from 2014 to 2015 and a series of analysis including multi-sensor core logger, XRF core scanner (Itrax), core surface images, X-radiographs, bulk density, grain size, Pb-210 chronology and X-ray diffractometer were conducted in this study. On core surface images, an obvious brownish oxidized layer exist in core top with higher Pb-210 activity beneath this oxidized layer, and we speculate this layer is caused by nature hazard. According to the sampling time, we conjecture the oxidized layer might formed by typhoon Haiyan in 2013. In addition, the Itrax data shows high manganese content only exist in this layer which might related to the modern industrial pollution delivered by typhoon induced flooding from Philippine. The sedimentation rate of the non-event years in these cores which derived from Pb-210 chronology method is about 0.02 ~0.03 cm/yr. On contrary, the event layer caused by Haiyan with a recorded maximum 87cm deposits in the South China Sea. This study aims to characterize the typhoon induced deposits in the turbidite layer and use it to identify whether the other event layers recorded in these cores were related to typhoon activities and to reconstruct the strong tropical cyclone history in the western Pacific.

  14. The Current Situation in the South China Sea Dispute and Suggested Responses

    Institute of Scientific and Technical Information of China (English)

    Li Jinming

    2012-01-01

    Tensions have been rising over the South China Sea issue in the last year. The return of the U.S. to the Asia-Pacific region has exacerbated the South China Sea dispute. This shift in U.S. strategy has seen concentrations of its land, sea and air forces in the region, in order to strengthen military ties with allies such as Japan, South Korea, Australia and the Philippines, with the clear purpose of containing China.

  15. Effect of Sea Level Variation on Tidal Characteristic Values for the East China Sea

    Institute of Scientific and Technical Information of China (English)

    于宜法; 俞聿修; 左军成; 万振文; 陈宗镛

    2003-01-01

    Tidal waves in the East China Sea are simulated numerically with POM(Princeton Ocean Model) model for normal mean sea level, 30 cm higher, 60 cm higher, and 100 cm higher, respectively, and the simulated result is compared with the harmonic analysis result of hourly sea level data from 19 tide gauges for more than 19 years. It is indicated that the long-term mean sea level variation affects notably tidal waves in this region. Generally, the tidal amplitude increases when the mean sea level rises, but this relationship may be inverse for some sea areas. The maximal variation of tidal amplitude takes place in the zones near the Fujian coast and the Zhejiang coast, rather than the shallowest Bohai Sea. The maximum increase of M2 amplitude can exceed about 15 cm corresponding to the 60 cm rise of the mean sea level along the Fujian coast. The other regions with large variations of tidal amplitude are those along the Jiangsu coast, the south-east coast of Shandong, and the south-east coast of Dalian. The propagation of tidal waves is also related to mean sea level variation, and the tidal phase-lag decreases generally when the mean sea level rises. Almost all the regions where the tidal phase-lag increases with rising mean sea level are close to amphidromic points, meanwhile the spatial area of such regions is very small. Because the influence of mean sea level variation upon tidal waves is spatially marked, such spatial effect should be considered in calculation of the tidal characteristic value and engineering water level. In the region where the amplitudes of the major tidal constituents increase, the probable maximum high water level becomes higher, the probable maximum low water level becomes lower, and both design water level andcheck water level increase obviously. For example, the design water level at Xiamen increases by 13.5 cm due to the variation of tidal waves when the mean sea level rises 60 cm, the total increase of design water level being 73.5 cm.

  16. Pigment signatures of some diatoms isolated from China seas

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The photosynthetic pigments of 12 species (14 strains) of cultured diatoms from six genera under specific conditions were examined by the HPLC. The diatom genera were Skeletonema, Thalassiosira, Chaetoceros, Nitzschia, Phaeodactylum and Meuniera. All strains were isolated from China seas and most of them were from the Jiaozhou Bay, China. Fifteen pigments were identified and eight of them were various chlorophyll a derivatives. Chlorophyll a, c2 and c1 and the carotenoids fucoxanthin, diadinoxanthin, diatoxanthin and β,β-carotene existed in all species. The ratios of each pigment to chlorophyll a were compared with the results in literatures. The pigment ratios of this study generally fall within the ranges reported by the literatures although the maximum ratio of fucoxanthin to chlorophyll a was higher and the ratios of chlorophyll c and diatoxanthin to chlorophyll a were low. The pigment ratios are useful to understanding the pigment signatures of diatoms in the Jiaozhou Bay, China, and to setting up the chemotaxonomic method ofphytoplankton in these sea areas.

  17. Holocene hydrological and sea surface temperature changes in the northern coast of the South China Sea

    Science.gov (United States)

    Wu, Mong-Sin; Zong, Yongqiang; Mok, Ka-Man; Cheung, Ka-Ming; Xiong, Haixian; Huang, Guangqing

    2017-03-01

    In order to reconstruct the Holocene environmental history of a coastal site in the northern South China Sea, this study analysed the organic carbon isotope ratios (δ13Corg) and alkenone unsaturation ratios (UK‧37) from a 36.5 m-long sediment core drilled at seabed in the mouth region of the Pearl River estuary and generated a coupled hydrological and temperature record. This record reveals changes of monsoon-induced sediment discharge and sea surface temperature of the Holocene in four stages. In Stage I, the site was under fluvial conditions prior to postglacial marine transgression. Stage II saw an increase of sea surface temperature from c. 23.0 °C to 27.0 °C, associated with a strengthened summer monsoon from c. 10,350 to 8900 cal. years BP. This was also a period of rapid sea-level rise and marine transgression, during which the sea inundated the palaeo-incised channel, i.e. the lower part of the T-shape accommodation space created by the rising sea. In these 1500 years, fluvial discharge was strong and concentrated within the channel, and the high sedimentation rate (11.8 mm/year) was very close to the rate of sea-level rise. In the subsequent 2000 years (Stage III) sea level continued to rise and the sea flooded the broad seabed above the palaeo-incised channel, resulted in fluvial discharge spreading thinly across the wide accommodation space and a much reduced sedimentation rate (1.8 mm/year). Sea surface temperature in this stage reached 27.3 °C initially, but dropped sharply to 26.1 °C towards c. 8200 cal. years BP. The final stage covers the last 7000 years, and the site was under a stable sea level. Sedimentation in this stage varied a little, but averaged at 1.8 mm/year. Whilst fluvial discharge and sea surface temperature didn't change much, two short periods of hydrological and temperature change were observed, which are related to the climatic cooling events of c. 4200 cal. years ago and the Little Ice Age.

  18. Association between Arctic autumn sea ice concentration and early winter precipitation in China

    Institute of Scientific and Technical Information of China (English)

    LIU Na; LIN Lina; KONG Bin; WANG Yingjie; ZHANG Zhanhai; CHEN Hongxia

    2016-01-01

    Associations between autumn Arctic sea ice concentration (SIC) and early winter precipitation in China are studied using singular value decomposition analysis. The results show that a reduced SIC almost everywhere in the Arctic Ocean, except the northern Greenland Sea and Canadian Basin, are accompanied by dry conditions over central China, extending northeast from the Tibetan Plateau toward the Japan Sea, the Bohai Sea and the Yellow Sea, and wet conditions over South China and North China. Atmospheric circulation anomalies associated with SIC variability show two wave-train structures, which are persistent from autumn to winter, leading to the identified relationship between autumn Arctic SIC and early winter precipitation in China. Given that the decline in autumn SIC in the Arctic Ocean is expected to continue as the climate warms, this relationship provides a possible long-term outlook for early winter precipitation in China.

  19. Numerical Study of Water and Suspended Matter Exchange Between the Yellow Sea and the East China Sea

    Institute of Scientific and Technical Information of China (English)

    庞重光; 白学志; 胡敦欣

    2003-01-01

    POM was used to study the monthly mean circulation in the Yellow Sea and East China Sea. The calculated results showed almost all major characteristics of the circulation system. The calculated circulation system and observational data were used to determine the sediment concentration, volume transport, heat flux and suspended matter flux between the Yellow Sea and the East China Sea. The conclusions obtained were that the volume and heat are transported northward through the 32°N section during each season; that in winter and autumn, total suspended matter is transported southward, and is larger in winter than in autumn. The reason is that the Yellow Sea Coastal Current is strong and always contains more suspend matter in winter and autumn. The seasonal suspended matter exchange between the Yellow Sea and the East China Sea are 0.58 x 107 tons in spring, 2.81 x 107 tons in summer, - 2.60 x 107 tons in autumn and - 3.40 x 107 tons in winter. Net flux of suspended matter from the Yellow Sea to the East China Sea is 2.61 x 107 tons every year.

  20. Distribution characteristics of zooplankton biomass in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Zhaoli; CHAO Min; CHEN Yaqu

    2004-01-01

    On the basis of the data of oceanographic survey in the East China Sea in four seasons during 1997~2000 (23°30′~33°00′N,118°30′~ 128°E), the variation of total biomass and diet biomass of zooplankton and their spatial-temporal distribution and relationship with the fishing ground of Engraulisjaponicus are approached and analyzed. The results show that the average biomass is 65.32 mg/m3 in four seasons, autumn (86.18 mg/m3) being greater than summer (69.18 mg/m3) greater than s pring ( 55.67 mg/m3) greater than winter (50.33 mg/m3). The average value of diet zooplankton biomass is 40.9 mg/m3.The trends of horizontal distribution both in the total biomass and the diet biomass of zooplankton are similar. The high biomass region (250~500 mg/m3) is very limited, only accounting for 1% of the investigation area. Seasonal variation of the biomass is very remarkable in the west and north parts of East China Sea coastal waters ( 29°30′N, 125°E). The horizontal distribution of diet zooplankton depends on the abundance distribution of crustacean. The distribution of diet zooplankton is related to the fishing ground of Engraulis japonicus and the high-density area of young fish and larval. In spring, the central fishing ground of Engraulis japonicus (>100 kg/h) and the high-density area of young fish and larval (>100 individuals per net) are located at the same place of high-density (100~250 mg/m3)area of diet zooplankton in the middle-southern part of East China Sea or the edge of its waters.

  1. Distribution characteristics of zooplankton biomass in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Zhaoli; CHAO Min; CHEN Yaqu

    2004-01-01

    On the basis of the data of oceanographic survey in the East China Sea in four seasons during 1997~2000 (23°30′~33°00′N,118°30′~ 128°E), the variation of total biomass and diet biomass of zooplankton and their spatial-temporal distribution and relationship with the fishing ground of Engraulis japonicus are approached and analyzed. The results show that the average biomass is 65.32 mg/m3 in four seasons, autumn (86.18 mg/m3) being greater than summer (69.18 mg/m3) greater than spring (55.67 mg/m3) greater than winter (50.33 mg/m3). The average value of diet zooplankton hiomass is 40.9 mg/m3.The trends of horizontal distribution both in the total biomass and the diet biomass of zooplankton are similar. The high biomass region (250~500 mg/m3) is very limited, only accounting for 1% of the investigation area. Seasonal variation of the biomass is very remarkable in the west and north parts of East China Sea coastal waters (29°30'N,125°E). The horizontal distribution of diet zooplankton depends on the abundance distribution of crustacean. The distribution of diet zooplankton is related to the fishing ground of Engraulis japonicus and the high-density area of young fish and larval. In spring, the central fishing ground of Engraulis japonicus (>100 kg/h) and the high-density area of young fish and larval (>100 individuals per net) are located at the same place of high-density (100~250 mg/m3)area of diet zooplankton in the middle-southern part of East China Sea or the edge of its waters.

  2. Sea level rise projection in the South China Sea from CMIP5 models

    Institute of Scientific and Technical Information of China (English)

    HUANG Chuanjiang; QIAO Fangli

    2015-01-01

    Future potential sea level change in the South China Sea (SCS) is estimated by using 24 CMIP5 models under different representative concentration pathway (RCP) scenarios. By the end of the 21st century (2081–2100 relative to 1986–2005), the multimodel ensemble mean dynamic sea level (DSL) is projected to rise 0.9, 1.6, and 1.1 cm under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively, resulting in a total sea level rise (SLR) of 40.9, 48.6, and 64.1 cm in the SCS. It indicates that the SCS will experience a substantial SLR over the 21st century, and the rise is only marginal larger than the global mean SLR. During the same period, the steric sea level (SSL) rise is estimated to be 6.7, 10.0, and 15.3 cm under the three scenarios, respectively, which accounts only for 16%, 21% and 24% of the total SLR in this region. The changes of the SSL in the SCS are almost out of phase with those of the DSL for the three scenarios. The central deep basin has a slightly weak DSL rise, but a strong SSL rise during the 21st century, compared with the north and southwest shelves.

  3. Records of Toba eruptions in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LlANG; Xirong

    2001-01-01

    [1]Rose,W. I., Chesner, C. A., Dispersal of ash in the great Toba eruption, 75 ka, Geology, 1987, 15: 913-917.[2]Acharyya, S. K., Basu, P. K. ,Toba ash on the Indian subcontinent and its implications for correlation of late Pleistocene alluvium, Quaternary Research, 1993, 40: 10-19.[3]Shane, P., Westgate, J., Williams, M. et al., New geochemical evidence for the youngest Toba Tuff in India, Quaternary Research, 1995, 44: 200-204.[4]Westgate, J. A., Sha ne, P. A. R., Pearce, N. J. G. et al., All Toba occurrences across Peninsular India belong to the 75000yr B. P. eruption, Quaternary Research, 1998, 50:107-112.[5]Pattan, J. N., Shane, P., Banakar, V. K., New occurrences of youngest Toba Tuff in abyssal sediments of the Central Indian Basin, Marine Geology, 1999, 155: 243-248.[6]Gasparotto, G., Spadafora, E,, Summa, V. et al., Contribution of grain size and compositional data from the Bengal Fan sediment to the understanding of Toba volcanic event, Marine Geology, 2000, 162: 561-572.[7]Dehn, J., Farrell, J. W., Schmincke, H. U., Neogene tephrochronology from Site 758 on northern Ninetyeast Ridge: Indon isian arc volcanism of the Past 5 Ma, Proceedings of the Ocean Drilling Program, Scientific Results (eds. Weissel, J. P.,Taylor, E., Alt, J. et al.), College Station, Texas, Ocean Drilling Program, 1991, 121: 273-295.[8]Lee M. Y., Wet, K. Y., Chen, Y. G., High-resolution oxygen isotope stratigraphy for the last 150000 years in the southern South China Sea, Terrestrial, Atmospheric and Oceanic Sciences TAO, 1999, 10: 239-254.[9]Biihring, C., Sarnthein, Toba ash layers in the South China Sea: Evidence of contrasting wind directions during eruption ca.74 ka, Geology, 2000, 28: 275-278.[10]Chesner, C. A., Petrogenesis of the Toba tuffs, Sumatra, Indonesia, Journal of Petrology, 1998, 39: 397-438.[11]Rampino, M. R., Self. S., Volcanic winter and accelerated glaciation follow ing the Toba super-eruption, Nature, 1992, 359:50-52.

  4. SEASONAL AND INTER-ANNUAL VARIABILITY OF THE SOUTH CHINA SEA WARM POOL AND ITS RELATION TO THE SOUTH CHINA SEA MONSOON ONSET

    Institute of Scientific and Technical Information of China (English)

    赵永平; 陈永利

    2001-01-01

    The South China Sea warm pool interacts vigorously with the summer monsoon which is active in the region. However, there has not been a definition concerning the former warm pool which is as specific as that for the latter. The seasonal and inter-annual variability of the South China Sea warm pool and its relations to the South China Sea monsoon onset were analyzed using Levitus and NCEP/NCAR OISST data. The results show that, the seasonal variability of the South China Sea warm pool is obvious, which is weak in winter, develops rapidly in spring, becomes strong and extensive in summer and early autumn, and quickly decays from mid-autumn. The South China Sea warm pool is 55 m in thickness in the strongest period and its axis is oriented from southwest to northeast with the main section locating along the western offshore steep slope of northern Kalimantan-Palawan Island. For the warm pools in the South China Sea, west Pacific and Indian Ocean, the oscillation, which is within the same large scale air-sea coupling system, is periodic around 5 years. There are additional oscillations of about 2.5 years and simultaneous inter-annual variations for the latter two warm pools. The intensity of the South China Sea warm pool varies by a lag of about 5 months as compared to the west Pacific one. The result also indicates that the inter-annual variation of the intensity index is closely related with the onset time of the South China Sea monsoon. When the former is persistently warmer (colder) in preceding winter and spring, the monsoon in the South China Sea usually sets in on a later (earlier) date in early summer. The relation is associated with the activity of the high pressure over the sea in early summer. An oceanic background is given for the prediction of the South China Sea summer monsoon, though the mechanism through which the warm pool and eventually the monsoon are affected remains unclear.

  5. Brief Understanding of the South China Sea Intermittent Line and China’s Relations With Its Neighbors Surrounding the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Hou; Yi

    2014-01-01

    <正>I,Formation of the South China Sea"Intermittent Line"According to historical records,as early as the Qin and Han dynasties,Chinese people began sailing activities onto the Oceans.With the ongoing maritime activities,and improved shipbuilding technology and expanded fishing,the Chinese people in the Han Dynasty first discovered the islands in the South China Sea,

  6. An oil slick spectral experiment of nearshore sea water in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Difeng; PAN Delu; GONG Fang; WANG Tianyu; ZHAN Yuanzeng

    2013-01-01

    Along with the rapid advance in global industrialization, oil spill events caused by offshore operations, trans-portation and accidents are increasing. Compared with ship surveys, monitoring oil spills through remote sensing has real-time, comprehensive, low-cost advantages, which can effectively guide cleaning and evalu-ation, and reduce the marine ecological destruction resulting from oil spills. Therefore, studying the remote sensing mechanism used to monitor marine oil spills is of great significance for ecological environmen-tal protection. This paper describes an experiment and corresponding analysis based on the above-water method, using the East China Sea coastal turbid water. The analysis shows that“upward short-wave”in ultraviolet and blue-purple bands and its displacement, along with the changing thickness, are important characteristics for distinguishing between the oil slick and the sea water, and also to differentiate oil slicks of different thicknesses. From blue to near-infrared bands, the spectrum of lube oil is flatter than that of diesel, and the diesel spectrum rises faster than the lube spectrum on the right side of the trough at 400 nm. These two features form an important basis for differentiating diesel from lube oil. These analyses will further the development of oil spill remote sensing in the East China Sea.

  7. Seasonal Variability of the Yellow Sea/East China Sea Surface Fluxes and Thermohaline Structure

    Institute of Scientific and Technical Information of China (English)

    Peter CHU; CHEN Yuchun; Akira KUNINAKA

    2005-01-01

    We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) for the Yellow Sea/East China Sea (YES) to investigate the climatological water mass features and the seasonal and non-seasonal variabilities of the thermohaline structure, and use the Comprehensive Ocean-Atmosphere Data Set (COADS) from 1945 to 1989 to investigate the linkage between the fluxes (momentum, heat, and moisture) across the air-ocean interface and the formation of the water mass features. After examining the major current systems and considering the local bathymetry and water mass properties, we divide YES into five regions: East China Sea (ECS) shelf, Yellow Sea (YS) Basin, Cheju bifurcation (CB) zone, Taiwan Warm Current (TWC) region, Kuroshio Current (KG) region. The long term mean surface heat balance corresponds to a heat loss of 30 W m-2 in the ESC and CB regions, a heat loss of 65 W m-2 in the KG and TWC regions, and a heat gain of 15 W m-2 in the YS region. The surface freshwater balance is defined by precipitation minus evaporation. The annual water loss from the surface for the five subareas ranges from 1.8 to 4 cm month-1. The fresh water loss from the surface should be compensated for from the river run-off. The entire water column of the shelf region (ECS, YS, and CB) undergoes an evident seasonal thermal cycle with maximum values of temperature during summer and maximum mixed layer depths during winter. However, only the surface waters of the TWC and KG regions exhibit a seasonal thermal cycle.We also found two different relations between surface salinity and the Yangtze River run-off, namely, out-of-phase in the East China Sea shelf and in-phase in the Yellow Sea. This may confirm an earlier study that the summer fresh water discharge from the Yangtze River forms a relatively shallow, low salinity plume-like structure extending offshore on average towards the northeast.

  8. Internal solitary waves in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    LI Xiaofeng; ZHAO Zhongxiang; HAN Zhen; XU Liuxiong

    2008-01-01

    A European Space Agency's ENVISAT advanced synthetic aperture radar (ASAR) image covering Zhejiang coastal water in the East China Sea (ECS) was acquired on 1 August 2007. This image shows that there are about 20 coherent internal solitary wave (ISW) packets propagating southwestward toward Zhejiang coast. These ISW packets are separated by about 10 kin, suggesting that these ISWs are tide-generated waves. Each ISW packet contains 5--15 wave crests. The wavelengths of the wave crests with-in the ISW packets are about 300 m. The lengths of the leading wave crests are about 50 km. The ISW amplitude is estimated from solving KdV equation in an ideal two-layer ocean model. It is found that the ISW amplitudes is about 8 m. Further analysis of the ASAR image and ocean stratification profiles show that the observed ISWs are depression waves. Analyzing the tidal current finds that these waves are locally generated. The wavelength and amplitude of the ECS ISW are much smaller than their counter-parts in the South China Sea (SCS). The propagation speed of the ECS ISW is also an order of magnitude smaller than that of the SCS ISW. The observed ISWs in the ECS happened during a spring tide period.

  9. Ocean primary productivity estimation of China Sea by remote sensing

    Institute of Scientific and Technical Information of China (English)

    PAN Delu; GUAN Wenjiang; BAI Yan; HUANG Haiqing

    2005-01-01

    Ocean primary productivity is a key parameter in the research of global carbon cycle, ocean biological resources, and in evaluation of the feature and quality of ocean biological environment. Traditional shipboard measurement which is costly and time-consuming is impossible to obtain the spatial and temporal information on primary productivity on a large scale in a short period of time. Satellite remote sensing is an effective strategy to acquire the ocean information in near real time. Here we propose a model special for China Sea based on the concept of primary productivity using in situ primary productivity and environmental data from 1984 to 1990, and discuss every modeling parameter which can be retrieved by remote sensing in detail. The reliability of this model is tested by in situ data, and the comparison of other primary productivity models is made. We also analyze the temporal and spatial distribution of China Sea primary productivity in 2000. From our analysis the satellite remote sensing data have been proved very useful for ocean primary productivity study.

  10. Evolution of Nonlinear Internal Waves in China Seas

    Science.gov (United States)

    Liu, Antony K.; Hsu, Ming-K.; Liang, Nai K.

    1997-01-01

    Synthetic Aperture Radar (SAR) images from ERS-I have been used to study the characteristics of internal waves of Taiwan in the East China Sea, and east of Hainan Island in the South China Sea. Rank-ordered packets of internal solitons propagating shoreward from the edge of the continental shelf were observed in the SAR images. Based on the assumption of a semidiurnal tidal origin, the wave speed can be estimated and is consistent with the internal wave theory. By using the SAR images and hydrographic data, internal waves of elevation have been identified in shallow water due to a thicker mixed layer as compared with the bottom layer on the continental shelf. The generation mechanism includes the influences of the tide and the Kuroshio intrusion across the continental shelf for the formations of elevation internal waves. The effects of water depth on the evolution of solitons and wave packets are modeled by nonlinear Kortweg-deVries (KdV) type equation and linked to satellite image observations. The numerical calculations of internal wave evolution on the continental shelf have been performed and compared with the SAR observations. For a case of depression waves in deep water, the solitons first disintegrate into dispersive wave trains and then evolve to a packet of elevation waves in the shallow water area after they pass through a turning point of approximately equal layer depths has been observed in the SAR image and simulated by numerical model.

  11. Deep-water Oligocene pollen record from South China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Guoxuan; QIN Jungan; MAO Shaozhi

    2003-01-01

    Leg 184 of ODP recovered a record of deep- water sediments spanning the past 32.8 Ma from the South China Sea (SCS). The sediments of the Oligocene (32.8 - 23.8 Ma) at Site 1148 contain relatively abundant fossil pollen. The pollen analysis at Site 1148 has established the first pollen assemblage sequence of deep-water Oligocene in the China Sea. The pollen assemblages of the Oligocene are dominated by montane conifer tree pollen. The abundances of broad-leaved tree pollen are lower in the assemblages. Both of the montane conifer and broad-leaved tree pollen groups include mainly tropical-subtropical components. The pollen of cold and drought-enduring plants is present in lower content. The distinct change in pollen assemblage sequence of deep-water Oligocene of the SCS occurred at 32.0 Ma, indicative of an important shift of the Oligocene climate in the SCS region. The characteristics of the pollen flora of the deep-water Oligocene indicate the tropical montane rainforest and lowland rainforest developed on the areas around the SCS before 32.0 Ma, reflecting the warm and wet climatic condition. In the pollen flora of the Oligocene after 32.0 Ma, the temperate montane conifer and cool and drought-en- during deciduous tree taxa remarkably increased, indicating that the climate in the SCS region became comparatively cool and dry.

  12. A potential submarine landslide tsunami in South China Sea

    Science.gov (United States)

    Huang, Z.; Zhang, Y.; Switzer, A. D.

    2010-12-01

    Submarine earthquakes and submarine landslides are two main sources of tsunamis. Tsunami hazard modeling in the South China Sea has been primarily concerned with the potential large submarine earthquakes in the Manila trench. In contrast, evaluating the regional risk posed by tsunamis generated from submarine landslide is a new endeavor. At offshore south central Vietnam, bathymetric and seismic surveys show evidence of potentially tsunamigenic submarine landslides although their ages remain uncertain. We model two hypothetical submarine landslide events at a potential site on the heavily sediment laden, seismically active, steep continental slope offshore southeast Vietnam. Water level rises along the coast of Vietnam are presented for the potential scenarios, which indicate that the southeast coastal areas of Vietnam are at considerable risk of tsunami generated offshore submarine landslides. Key references: Kusnowidjaja Megawati, Felicia Shaw, Kerry Sieh, Zhenhua Huang, Tso-Ren Wu, Y. Lin, Soon Keat Tan and Tso-Chien Pan.(2009). Tsunami hazard from the subduction megathrust of the South China Sea, Part I, Source characterization and the resulting tsunami, Journal of Asian Earth Sciences, Vol. 36(1), pp. 13-20. Enet, F., Grilli, S.T. and Watts, P. (2003). Laboratory experiments for tsunami generated by underwater landslides: comparison with numerical modeling, In: Proceedings of 13th International Conference on Offshore and Polar Engineering, Honolulu, Hawaii, USA, pp. 372-379.

  13. PRELIMINARY STUDY OF RELATIONSHIP BETWEEN INTERANNUAL VARIATIONS OF SST IN SOUTH CHINA SEA AND TROPICAL INDIAN OCEAN AND SOUTH CHINA SEA MONSOON OUTBREAK

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Conclusions are divided regarding the role of the variations of thermodynamics in the monsoon activity for the South China Sea region. In this study, primary eigenvectors are studied for the SSTA from East Asia to the tropical eastern Indian Ocean in May. The results show that temperature anomalies that center on Sumatra are closely related with the outbreak of the South China Sea monsoon. When the SST is warmer (cooler) than average year, it is likely that the monsoon set in late (early). It may be caused by the changes in meridional difference in thermodynamics between the Indochina Peninsula and its southern tropical oceans. Studying the temporal and spatial evolution of primary eigenvector distribution of the SSTA in the South China Sea-tropical eastern Indian Ocean from winter to summer, we find that the temperature anomalies that center around Sumatra in late spring and early summer can be traced back to the variations of the SST fields in the South China Sea in the preceding winter. Being well associated with the outbreak of the South China Sea monsoon, the latter is a significant index for it. The work helps understanding the atmospheric and oceanic background against which the South China Sea monsoon breaks out and behaves.

  14. Model study of the upper circulation in the Sulu Sea and its relation to the South China Sea circulation

    Institute of Scientific and Technical Information of China (English)

    CAI Shuqun; HE Yinghui; LONG Xiaomin; WANG Shengan

    2008-01-01

    According to the satellite remote sensing monthly mean sea surface temperature data from 1998 to 2002, it is shown that, the Sulu Sea is dominated by a cold eddy both in summer and winter. A coupled single-layer/two-layer model is employed here to study the summery and wintry characteristics and dynamic mechanism of the upper circulation in the Sulu Sea. According to the numerical experiments, it is found that, due to the local monsoon stress cud, the upper circulation in the Sulu Sea is dominated by a weak anticyclonic eddy in summer and a strong cyclonic eddy in winter. Once there is a large outflow via the Sibutu Passage flowing out of the Sulu Sea in summer, the upper circulation in the Sulu Sea may be dominated by a cyclonic eddy instead of the normal anti- cyclonic one. Moreover, in summer, the water exchange between the Sulu Sea and South China Sea via the Mindoro and Balabac Straits might have some effect on the separation position and strength of the northward western boundary current next to the Indo - China Peninsula in the southern South China Sea.

  15. Analysis of Results from ASIAEX East China Sea: Mid to High Frequency Bottom Loss

    Science.gov (United States)

    2016-06-07

    Analysis of Results from ASIAEX East China Sea : Mid to High Frequency Bottom Loss Peter H. Dahl phone: (206) 543-2667 fax: (206) 543-6785...during the Asian Seas International Acoustics Experiment (ASIAEX) conducted in the East China Sea (May-June 2001). APPROACH The bottom loss...measurements are interpreted as estimates of the modulus of the plane wave reflection coefficient, and data are compared to predicted values using a

  16. Four new recorded species of marine nanoplanktonic diatoms found in the East China Sea and Huanghai Sea

    Institute of Scientific and Technical Information of China (English)

    Yang Li; Yahui Gao

    2003-01-01

    In a study of species composition of marine nanoplanktonic diatoms (< 20 μm) in watersamples from the East China Sea and Huanghai Sea (Yellow Sea), four diatom species were identifiedby TEM as new records for China. They were Thalassiosira oceanica Hasle, Navicula britannicaHustedt et Aleem, Nitzschia leehyi Fryxell and Synedra indica Taylor. Detailed description of the taxo-nomic characteristics with TEM photographs of the four species and their ecological behavior and distri-bution is given in this paper.

  17. Study on numerical simulation and dynamic mechanism of winter- time circulation in the eastern China seas

    Institute of Scientific and Technical Information of China (English)

    HAN Dong; HOU Yijun; WEI Zexun; LIU Xingquan; ZHAO Xixi

    2004-01-01

    An MOM2 based 3-dimentional prognostic baroclinic Z-ordinate model was established to study the circulation in eastern China seas, considering the topography, inflow and outflow on the open boundary, wind stress, temperature and salinity exchange on the sea surface. The results were consistent with observation and showed that the Kuroshio intrudes in large scale into the East China Sea continental shelf East China, during which its water is exchanged ceaselessly with outer sea water along Ryukyu Island. The Tsushima Warm Current is derived from several sources, a branch of the Kuroshio, part of the Taiwan Warm Current, and Yellow Sea mixed water coming from the west of Cheju Island. The water from the west of Cheju Island contributes approximately 13% of the Isushima Warm Current total transport through the Korea Strait. The circulation in the Bohai Sea and Yellow Sea is basically cyclonic circulation, and is comprised of coastal currents and the Yellow Sea Warm Current. Besides simulation of the real circulation, numerical experiments were conducted to study the dynamic mechanism. The numerical experiments indicated that wind directly drives the East China Sea and Yellow Sea Coastal Currents, and strengthens the Korea Coastal Current and Yellow Sea Warm Current. In the no wind case, the kinetic energy of the coastal current area and main YSWC area is only 1% of that of the wind case. Numerical experiments also showed that the Tsushima Warm Current is of great importance to the formation of the Korea Coastal Current and Yellow Sea Warm Current.

  18. Mitigating the Security Risks in the South China Sea Island Disputes

    Science.gov (United States)

    2014-02-13

    South China Sea. The Association of Southeast Nations ( ASEAN ) is disunited and has been largely ineffective in moving the dispute forward. However... ASEAN ). While it has declared an Air Defense Identification Zone in the East China Sea, China has publicly 5 dismissed any rumors that it would do...with ASEAN . Thus, China’s use ambiguity to avoid conflict with ASEAN , maintain the status quo and delay the settlement of the dispute. Strategy of

  19. Interannual to decadal variation of spring sea level anomaly in the western South China Sea

    Science.gov (United States)

    Qiu, Fuwen; Fang, Wendong; Pan, Aijun; Cha, Jing; Zhang, Shanwu; Huang, Jiang

    2017-01-01

    Satellite observations of sea level anomalies (SLA) from January 1993 to December 2012 are used to investigate the interannual to decadal changes of the boreal spring high SLA in the western South China Sea (SCS) using the Empirical Orthogonal Function (EOF) method. We find that the SLA variability has two dominant modes. The Sea Level Changing Mode (SLCM) occurs mainly during La Niña years, with high SLA extension from west of Luzon to the eastern coast of Vietnam along the central basin of the SCS, and is likely induced by the increment of the ocean heat content. The Anticyclonic Eddy Mode (AEM) occurs mainly during El Niño years and appears to be triggered by the negative wind curl anomalies within the central SCS. In addition, the spring high SLA in the western SCS experienced a quasi-decadal change during 1993-2012; in other words, the AEM predominated during 1993-1998 and 2002-2005, while the La Niña-related SLCM prevailed during 1999-2001 and 2006-2012. Moreover, we suggest that the accelerated sea level rise in the SCS during 2005-2012 makes the SLCM the leading mode over the past two decades.

  20. Sea level change under IPCC-A2 scenario in Bohai, Yellow, and East China Seas

    Directory of Open Access Journals (Sweden)

    Chang-lin CHEN

    2015-10-01

    Full Text Available Because of the environmental and socioeconomic impacts of anthropogenic sea level rise (SLR, it is very important to understand the processes leading to past and present SLRs towards more reliable future SLR projections. A regional ocean general circulation model (ROGCM, with a grid refinement in the Bohai, Yellow, and East China Seas (BYECSs, was set up to project SLR induced by the ocean dynamic change in the 21st century. The model does not consider the contributions from ice sheets and glacier melting. Data of all forcing terms required in the model came from the simulation of the Community Climate System Model version 3.0 (CCSM3 under the International Panel on Climate Change (IPCC-A2 scenario. Simulation results show that at the end of the 21st century, the sea level in the BYECSs will rise about 0.12 to 0.20 m. The SLR in the BYECSs during the 21st century is mainly caused by the ocean mass redistribution due to the ocean dynamic change of the Pacific Ocean, which means that water in the Pacific Ocean tends to move to the continental shelves of the BYECSs, although the local steric sea level change is another factor.

  1. Sea level change under IPCC-A2 scenario in Bohai, Yellow, and East China Seas

    Institute of Scientific and Technical Information of China (English)

    Chang-lin CHEN; Jun-cheng ZUO; Mei-xiang CHEN; Zhi-gang GAO; C-K SHUM

    2014-01-01

    Because of the environmental and socioeconomic impacts of anthropogenic sea level rise (SLR), it is very important to understand the processes leading to past and present SLRs towards more reliable future SLR projections. A regional ocean general circulation model (ROGCM), with a grid refinement in the Bohai, Yellow, and East China Seas (BYECSs), was set up to project SLR induced by the ocean dynamic change in the 21st century. The model does not consider the contributions from ice sheets and glacier melting. Data of all forcing terms required in the model came from the simulation of the Community Climate System Model version 3.0 (CCSM3) under the International Panel on Climate Change (IPCC)-A2 scenario. Simulation results show that at the end of the 21st century, the sea level in the BYECSs will rise about 0.12 to 0.20 m. The SLR in the BYECSs during the 21st century is mainly caused by the ocean mass redistribution due to the ocean dynamic change of the Pacific Ocean, which means that water in the Pacific Ocean tends to move to the continental shelves of the BYECSs, although the local steric sea level change is another factor.

  2. Maritime Territorialisation as Performance of Sovereignty and Nationhood in the South China Sea

    DEFF Research Database (Denmark)

    Roszko, Edyta

    2015-01-01

    The South China Sea (SCS) is a conflict-ridden international arena of rivalry between China, the US, India, and the other ASEAN countries over sovereignty, resources and security. In this geo-political clash China is the dominant force and Vietnam its main challenger. While most analysts assume...

  3. Distributions of Inorganic Nutrients in the Bohai Sea of China

    Institute of Scientific and Technical Information of China (English)

    LI Zhengyan; BAI Jie; SHI Jinhui; GAO Huiwang

    2003-01-01

    To study the contents and distribution of inorganic nutrients in the Bohai Sea of China, two cruise surveys were undertaken in August (summer) 2000 and January (winter) 2001, respectively. A total of 595 water samples were collected from 91 stations and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed for each sample. The results show that the average concentration of dissolved inorganic nitrogen (DIN) in the Bohai Sea in winter (6.529μmol L-1) is significantly higher than that in summer (3.717μmolL-1 ). The phosphorus concentration in winter (0.660μmolL-1) is also significantly higher than that in summer (0.329μmol L-1). Mean silicate concentration in winter (7.858μmolL-1) is, however, not significantly different from that in summer (7.200 μmol L-1 ). Nutrients also vary considerably in different areas in Bohai Sea. DIN concentration in the Laizhou Bay (4.444μmolL-1 ), for example, is significantly higher than those in the Bohai Bay (2.270μmol L-1 ) and Bohai Strait (2.431μmol L-1 ), which is caused by the discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients show different vertical distribution patterns. In summer, nutrients in bottom layer are generally richer than those in surface and middle layers. In winter, however, nutrients are not significantly different in different layers. Compared with historic data, DIN contents have increased continually since the early 1980 s. Based on atomic ratios of different nutrients, nitrogen is still the limiting factor for algal growth in the Bohai Sea.

  4. Trends of sea level rise in the South China Sea during the 1990s: An altimetry result

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Using 7 years of TOPEX/POSEIDON satellite altimetry data, we have identified a general trend of sea level rising in the South China Sea between January 1993 and December 1999. The estimated bulk rising rate of the entire basin is ~1 cm/a. The rise of sea level appears to be spatially non-homogeneous, which shows a highest rate of 2.7 cm/a in the deep basin west of Luzon and generally Iow (even negafive) rates over the shallow continental shelves. It is believed that the observed rapid rising of sea level is a regional phenomenon and is mainly caused by warming of the upper layer of the South China Sea, which showed a bulk warming rate of 0.15℃/a in the same period. It is also suggested that the observed rising trend is mainly a decadal signal, which is possibly associated with decadal variation of the Pacific warm pool region.

  5. Water-transparency (Secchi Depth) monitoring in the China Sea with the SeaWiFS satellite sensor

    Science.gov (United States)

    He, Xianqiang; Pan, Delu; Mao, Zhihua

    2004-10-01

    Water transparency (Secchi depth) is a basic parameter that describes the optical property of water, and it is a traditional item measured in situ. The traditional method of monitoring water transparency is the in-situ measurement by ship. However, because of its inherent shortcoming, this in situ method can not satisfy the requirement of the large-scale, quick and real-time monitoring of the water transparency. Therefore, it must be combined with the remote sensing technology to fulfill the monitoring of the water transparency. This paper studies the water transparency monitoring in China Sea by using SeaWiFS satellite sensor. First, the inversing algorithm of water transparency is introduced briefly, which based on the radiative transfer theory and bio-optical model of water. Second, the accuracy of the algorithm is validated by using the large-scale in-situ data from the Japan Meteorological Agency (JMA), which covered most of the Northwest Pacific ocean. The result shows the inversing relative error of water transparency is 22.6% by using the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data, and it is even better in the open sea. Third, using this algorithm and SeaWiFS data, a remote sensing product data set of water transparency in China Sea was generated. Finally, we present the analysis of seasonal distribution and fluctuation patterns of water transparency in China Sea by using the generated remote sensing product collection of water transparency.

  6. Potential impacts of Three Gorges Dam in China on the ecosystem of East China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Baodong; BROCKMANN Uwe

    2008-01-01

    The Changjiang River in China was dammed in 2003.The possible changes in matters fluxes from the river downstream after the completion of Three Gorges Dam and their potential impacts on the ecosystem of the East China Sea are discussed.The estuarine and coastal waters in the East China Sea were heavily fertilized by the inflow of nutrient-rich freshwater from the Changjiang River, which has led to severe eutrophication and frequent harmful algal blooms,thus worsening the ecosystem health in this area.Analy- sis showed that the nutrient loadings are very likely to be reduced in the lower Changjiang River due to the construction of Three Gorges Dam.Especially for the total phosphorus,the discharges to the East China Sea will be reduced by one-third,which would relieve the severe eutrophication in this area.However,the expected decrease in the riverine silicate discharge would lead the ra- tio of silicon to nitrogen to be much less than 1 in the estuarine and coastal waters and thus may cause an elevation of flagellate growth.The changes in the annual water discharges and their seasonal distributions below the dam will be minor.Reduction of suspended particulate matter loading,due to the sedimentation behind the dam,will reduce the nutrient loadings of the particulate form especially for phosphorus,and decrease the turbidity of estuarine and coastal waters.On the other hand,this may enhance the erosion of the delta and the coasts as well as modifythe benthic ecosystem.

  7. Comparison of TOPEX/POSEIDON altimeter derived wave period with ocean buoy data in the East China Sea and South China Sea

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Altimeter wave period data obtained from continental shelf seas are analyzed in this paper.Empirical models are introduced for zero up-crossing and peak wave period calculation with TOPEX/POSEIDON data. Their performances are assessed using independent validation dataset in four sites in the open ocean of China. To provide more accurate wave period estimation, new coefficients are applied to reliable in situ data. Comparison of our estimated the wave periods with new linear calibrations based on independent data of Seapac 2100 deployed in the East China Sea and South China Sea showed that the accuracy was improved over estimates determined from earlier empirical models. Regional analysis indicated that the wave period model works better under wind sea condition.

  8. The circulation in the southern Huanghai Sea and northern East China Sea in June 1999

    Institute of Scientific and Technical Information of China (English)

    Yaochu Yuan; Yonggang Liu; Mingyu Zhou; Arata Kaneko; Zhou Yuan; Noriaki Gohda

    2003-01-01

    On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method.The Kuroshio flows northeastward through eastern part of the investigated region and has the main coreat Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy be-tween these two northward flows, and a weak cyclonic eddy at the western part of Section PN. Theabove current structure is one type of the current structures at Section PN in ECS. The net northwardvolume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB)through Section PN is about 26.2× 106 m3/s in June 1999. The VT of the inshore branch of TaiwanWarm CArrent (TWCIB) through the investigated region is about 0.4 × 106 m3/s. The Taiwan WarmCurrent (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea CoastalCurrent (HSCC) flows southeastward and enters into the northwestern part of investigated region, andflows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan WarmCurrent and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea CoastalCurrent flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and coldwater is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 atthe northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).

  9. The Changing Faces of the South China Sea

    Science.gov (United States)

    Pubellier, M. F.; Savva, D.; Franke, D.; Meresse, F.; Steuer, S.; Auxietre, J. L.; Aurelio, M.; Chamot-Rooke, N. R. A.; Chan, L. S.

    2014-12-01

    The South China Sea (SCS) region was situated during Mesozoic on the upper plate of a subduction zone. It later evolved as a collapsed continental basin on the edge of the Yenshanian Andean-type orogeny which has been since then considerably eroded, exposing only granites and relicts of Cretaceous molasse basins. The continental crust rifted from the Paleocene to the Mid Oligocene in the eastern part, and the rifting continued until the Middle Miocene in the SW, in an environment of marginal basin opened in the midst of the lower plate. Both spreading and rifting ceased when the subduction of the Proto South China Sea (PSCS) was blocked. Finally the SCS basin which was previously always open to the NE, became isolated by the docking of the northern Philippine Mobile Belt in Luzon, Mindoro and Taiwan islands, during the Late Miocene. Since then the basin subsided whereas the margins observed various amount of uplift, and subsequent gravity tectonics. We illustrate how these event are interdependent, the Cretaceous active margin opening the PSCS by rifting and oceanic crust developed from magma-poor rifting to subsequent seafloor spreading in the Paleogene. It is not clear how the inherited sub continental mantle played a role in the unusual rifting style of the SCS, whose upper crust was extremely stretched for a large time span and was sustained near sea level during the entire duration of the rifting process. The large Jurassic and Cretaceous granitic bodies conditioned the location of the extension via large detachments and normal faults; so that the present day morphology of the sea floor still reflects the location of the granites on which large reefal platforms developed. The mid Miocene cessation of subduction in the PSCS created shortening which jammed its sediments on the NE margin of Borneo, thus generating sub-aerial conditions for the NW Borneo wedge. The resulting erosion created the large deltas starting from the end of the Early Miocene. Excess of

  10. Temperature profile and water depth data collected from USS COCHRANE using BT and XBT casts in the East China sea and other seas from 07 March 1987 to 19 March 1987 (NODC Accession 8700263)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS COCHRANE in the South China sea, East China Sea, and Philippine Sea. Data...

  11. Impact of Sea Surface Temperature Front on Stratus-Sea Fog over the Yellow and East China Seas-A Case Study with Implications for Climatology

    Institute of Scientific and Technical Information of China (English)

    LI Man; ZHANG Suping

    2013-01-01

    A stratus-sea fog event that occurred over the Yellow and East China Seas on 3 June 2011 is investigated using observations and a numerical model,with a focus on the effects of background circulation and Sea Surface Temperature Front (SSTF) on the transition of stratus into sea fog.Southerly winds of a synoptic high-pressure circulation transport water vapor to the Yellow Sea,creating conditions favorable for sea fog/stratus formation.The subsidence from the high-pressure contributes to the temperature inversion at the top of the stratus.The SSTF forces a secondary circulation within the ABL (Atmospheric Boundary Layer),the sinking branch of which on the cold flank of SSTF helps lower the stratus layer further to reach the sea surface.The cooling effect over the cold sea surface counteracts the adiabatic warming induced by subsidence.The secondary circulation becomes weak and the fog patches are shrunk heavily with the smoothed SSTF.A conceptual model is proposed for the transition of stratus into sea fog over the Yellow and East China Seas.Finally,the analyses suggest that sea fog frequency will probably decrease due to the weakened SSTF and the reduced subsidence of secondary circulation under global warming.

  12. Distribution and chemical speciation of dissolved inorganic arsenic in the Yellow Sea and East China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Bin; SONG Jinming; LI Xuegang

    2015-01-01

    Distribution and chemical speciation of dissolved inorganic arsenic were examined in Yellow Sea and East China Sea. Results demonstrated that: (1) both As(III) and As(V) were detected, with As(V) dominated at 40% stations of surface water and 51% stations of bottom water; (2) influenced by the exchange of fresh and sea water, the type of surface sediment and the transport of various water masses, large values in surface water were observed along the coastal region and in the same latitude of Changjiang River Estuary and Hangzhou Bay, and in bottom water found in the southern area where the Taiwan Warm Current and Kuroshio Current influenced; (3) As(III) behaved non-conservatively in Changjiang River Estuary. Man-derived inputs cause substantial positive deviation from the theoretical dilution. The negative correlation of As(V) to salinity in surface water suggested that it behaved conservatively during the transportation along Changjiang River Estuary. While, the occurrence of As(V) up to the linear fit in bottom water indicated the eventual transfer from dissolved phase to particulate phase, which was impossible to be determined without the knowledge of arsenic level and speciation in suspended particulate matter. Further study is needed on the arsenic source/sink relationships based on the distribution profiles.

  13. Dissolved Black Carbon in the South China Sea

    Science.gov (United States)

    Fang, Z.; Yang, W.; Chen, M.; Ma, H.

    2015-12-01

    Dissolved black carbon (DBC) has been ubiquitously reported in dissolved organic matter (DOM). However, the abundance and provenance of DBC in the ocean are not well understood. Here, DBC in the South China Sea (SCS) was determined at molecular level using the benzenepolycarboxylic acids (BPCAs) method. DBC showed high concentrations in the upper 100 m seawater with the average of 1.13 μmol l-1 (n=55). In the intermediate seawater (200-1500 m), DBC ranged from 0.67 to 0.89 μmol l-1 with the average of 0.78 μmol l-1 (n=9), exhibiting nearly homogeneous distributions. The vertical distribution pattern indicated that DBC significantly degraded in the photic zone, corresponding to an attenuate constant of 12.5±4.9 km-1. The ratios of B6CA/B3CAs increased downward, implying that aromatic condensation degree of DBC increase during transport from surface to deep water. Using the standing crops of DBC in the upper 200 m and the residence time of seawater, atmospheric deposition of DBC was estimated to be 1.94 TgC yr-1, accounting for around 16% of the global BC deposition. Our study highlights that DBC could be an important component of ocean carbon cycling in Pacific Asia Marginal Seas.

  14. Regulation of South China Sea throughflow by pressure difference

    Science.gov (United States)

    Qin, Huiling; Huang, Rui Xin; Wang, Weiqiang; Xue, Huijie

    2016-06-01

    Sea Surface Height (SSH) data from the European Centre for Medium-Range Weather Forecasts-Ocean Reanalysis System 4 (ECMWF-ORAS4) are used to determine the pressure difference in connection with variability of the South China Sea ThroughFlow (SCSTF) from 1958 to 2007. Two branches of SCSTF, the Karimata-Sunda Strait ThroughFlow (KSSTF) and the Mindoro Strait ThroughFlow (MSTF), are examined. Using the ensemble empirical mode decomposition method (EEMD), time series of pressure difference and volume transport are decomposed into intrinsic mode functions and trend functions, with the corresponding variability on different time scales. Pressure difference agrees with the KSSTF volume transport on decadal time scale; while for the MSTF, pressure difference varies similarly with volume transport on interannual time scale. Separating the dynamic height difference into the thermal and haline terms, for the KSSTF more than half of the dynamic height difference (32 cm) is due to the thermal contributions; while the remaining dynamic height difference (23 cm) is due to the haline contributions. For the MSTF, the dynamic height difference (29 cm) is primarily due to the thermal contribution (26 cm).

  15. The Delimitation of East China Sea Continental Shelf:Sino-Japanese Disputes from the Perspective of International Law

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The East China Sea which covers a total area of 750,000 square kilometers is a semi-closed sea lying between the eastern coast of China’s mainland and the Pacific Ocean, bounded on the west by China, on the east by the Kyushu and the Ryukyu Islands of Japan, and on the north by Jichu Island of the Republic of Korea (ROK) and the Yellow Sea, and connected with the South China Sea by the Taiwan Strait on

  16. Chemical and temperature profile data from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean (NODC Accession 9700022)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical and temperature profile data were collected from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean. Data were submitted by the Japan...

  17. Intercomparison of three South China Sea circulation models

    Institute of Scientific and Technical Information of China (English)

    DU Yan; WANG Dongxiao; ZHOU Weidong; WANG Weiqiang; LIU Xiongbin

    2004-01-01

    Three numerical oceanic circulation models: POM(Princeton ocean model), MICOM(Miami isopycnal coordinates ocean model) and GFDL model, which adopt sigma coordinate, isopycnal coordinate and depth coordinate respectively,are used in the South China Sea(SCS) circulation modeling. Model domain has the same topography, grid resolution,initial conditions and surface boundary conditions. The maximum ocean depth is set as 1000 m. Grid resolution is 0.5°×0.5°.Initial conditions are supplied by climatological temperature and salinity data in January. Climatological wind stress, surface temperature and salinity are used as surface forcing. Lateral boundaries take enclosed boundary conditions artificially. Focusing on the common point of different ocean circulation models, the circulation pattern in winter and summer, sea surface height in the northern SCS, seasonal cycle of the mixed layer thickness in the southem SCS,barotropic stream function in winter are selected to carry out intercomparison. In winter, a strong cyclonic gyre occupies the whole SCS. In summer, a strong anticyclonic gyre occupies the southern SCS and a weak cyclonic gyre occupies the northern SCS. The thickness of the mixed layer shows bimodal features in the southern SCS. Sea surface height anomaly(SSHA) in the northern SCS has an eastward propagating feature, in agreement with the remote sensing observation. Barotropic stream functions indicate that the circulation of the upper ocean is mainly forced by inputting of wind stress curl under closed boundary conditions. In addition, three models also show distinct differences. The basinscale circulation fiom MICOM is distinct. Output of POM has more mesoscale eddies than others. GFDL model seems good at simulating westward intensification.

  18. Limit analysis of extended reach drilling in South China Sea

    Institute of Scientific and Technical Information of China (English)

    Gao Deli; Tan Chengjin; Tang Haixiong

    2009-01-01

    Extended reach wells (ERWs), especially horizontal extended reach well with a high HD (horizontal displacement) to TVD (true vertical depth) ratio, represent a frontier technology and challenge the drilling limitations.Oil and gas reservoir in beaches or lakes and offshore can be effectively exploited by using extended reach drilling (ERD) technology.This paper focuses on the difficult technological problems encountered during exploiting the Liuhua 11-1 oil field in the South China Sea, China.Emphasis is on investigating the key subjects including prediction and control of open hole limit extension in offshore ERD, prediction of casing wear and its prevention and torque reduction, φ244.5mm casing running with floating collars to control drag force, and steerable drilling modes.The basic concept of limit extension in ERD is presented and the prediction method for open hole limit extension is given in this paper.A set of advanced drilling mechanics and control technology has been established and its practical results are verified by field cases.All those efforts may be significant for further investigating and practicing ERD limit theory and control technology in the future.

  19. South China Sea Territorial Disputes and Sino-Philippine Trade

    Institute of Scientific and Technical Information of China (English)

    FANG; WANG

    2015-01-01

    As political factors affect trade activities greatly, this paper considers whether a series of political events have had a negative impact on Sino-Philippine trade relations. Of particular concern is the influence on bilateral relations and the Philippines’ domestic economy from political and diplomatic tensions between China and the Philippines caused by territorial disputes in the South China Sea. Political events are divided into two levels, general conflicts and serious conflicts, which are analyzed from the perspectives of both overall level and product level to present their final impact on trade. This research finds that territorial disputes between the two countries deteriorated trade, as the volume of trade usually decreased distinctly after conflicts. The negative impact on trade generated by serious conflicts usually occurred more rapidly and on a larger scale. The effect of trade deterioration caused by political events weakened over time. Furthermore, after serious conflicts, although the volume of trade of certain products decreased temporarily, it rebounded quickly or even increased soon. However, industrial equipment or industrial raw materials trade activities between the two countries were basically independent of the conflicts’ impact.

  20. Introducing Seawater China for Sustainablefrom Bohai Sea to WestDevelopment in the Area

    Institute of Scientific and Technical Information of China (English)

    ChenChangli

    2004-01-01

    Sustained and profound aridization process in north-west China in Tertiary and Quaternary period and time of mankind history are discussed. The rain-creased function of 3 set high mountain condensation systems in north-west China is recognized once more. A sandstorm happened on 20th March 2002 in Alasan and Ejinaqi areas was very strong and arrived in Japan and Korea. For saving Alasan area from sandstorm a way of introducing sea water from Bohai to Alasan has been proposed. Four problems are replied in this paper. It is concluded that introducing sea water from Bohai to west China is the best way for sustainable development of west China.

  1. Transition of Quaternary glacial cyclicity in deep-sea records at Nansha, the South China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG; Pinxian

    2001-01-01

    [1]Shackleton. N. J., Opdyke, N. D., Oxygen isotope and paleomagnetic stratigraphy of Pacific core V28-239: Late Plio cene to Latest Pleistocene, Mem. Geol. Soc. Am., 1976, 145: 449-464.[2]Ding, Z., Liu, D., New Development of China Loess Research (1) Loess Stratigraphy, Quaternary Research (in Chinese),1989, 1: 24-35.[3]Raymo, M. E., Oppo, D. W., Curry. W., The mid-Pleistocene climate transition: A deep sea carbon isotopic perspective,Paleoceanography, 1997, 12(4): 546-559.[4]PrellW. L., Oxygen and carbon isotope stratigraphy for the Quaternary of Hole 502B: Evidence for two modes of isotopic variability, in Init. Repts. DSDP (eds. Prell and W. L., Gardner, J. V.), 1982, 68: 455-464.[5]Shackleton. N. J., The 100,000-year ice-age cycle identified and found to lag temperature, carbon dioxide, and orbital eccentricity, Science, 2000, 289: 1897-1902.[6]Rutherford, S., D'Hondt, S., Early onset and tropical forcing of 100,000-year Pleistocene glacial cycles, Nature, 2000, 408:72-75.[7]Berger, W. H., Bickert, T., Jansen, E. et al., The central mystery of the Quaternary Ice Age, Oceanus, 1993, 36(4): 53-56.[8]Raymo, M. E., The timing of major climate terminations, Paleoceanography, 1997, 12(4): 577-585.[9]Berger, W. H., Jansen, E., Mid-Pleistocene climate shift: The Nansen connection, Geophysical Monograph, 1994, 84:295-311.[10]Clark, P. C., Pollanrd, D., Origin of the middle Pleistocene transition by ice sheet erosion of regolith, Paleoceanography,1998, 13: 1-19.[11]Wang, P., Prell, W., Blum, P. et al. Initial Reports 184, Ocean Drilling Program in Proceedings of the ODP [CD-ROM].Texas: Texas A&M University, College Station, 2000, 1-103.[12]Zhao, Q., Jian, Z., Liang, J. et al., Neogene Oxygen Isotopic Stratigraphy, ODP Site 1148, northern South China Sea, Sci ence in China, Ser. D,2001, 44(10): 934-942.[13]Zhao, Q., Jian, Z., Li, B. et al., Microtektites in the Middle Pleistocene deep-sea sediments of the South China

  2. Distributions and sea-to-air fluxes of nitrous oxide in the South China Sea and the West Philippines Sea

    Science.gov (United States)

    Tseng, Hsiao-Chun; Chen, Chen-Tung Arthur; Borges, Alberto V.; DelValls, T. Angel; Lai, Chao-Ming; Chen, Ting-Yu

    2016-09-01

    Approximately 600 water samples from the South China Sea (SCS) and 250 water samples from the West Philippines Sea (WPS) were collected during seven cruises from August 2003 to July 2007 to determine nitrous oxide (N2O) distributions between the surface and a maximum depth of 4250 m. In the SCS, the average surface N2O concentration exceeded the atmospheric equilibrium concentration (on average 132±23%); however in the WPS, the surface N2O concentration was lower than the atmospheric equilibrium concentration (on average 90±22%). The N2O concentration reached a maximum (~23 nmol L-1) in the WPS at 800-1000 m, and (~28 nmol L-1) at a shallower depth of around 600-800 m in the SCS, owing to vertical mixing and intensive upwelling in the SCS. In the SCS, the surface N2O concentration was 7.59±1.32 nmol L-1 and the calculated sea-to-air flux was 5.5±3.9 μmol m-2 d-1. The surface N2O concentration in the WPS, 5.19±1.26 nmol L-1, was lower than that in the SCS. The WPS is a sink for N2O and the calculated sea-to-air flux was -1.7±3.9 μmol m-2 d-1. The SCS emitted 19.3×106 mol d-1 N2O to the atmosphere and exported 8.5×106 mol d-1 N2O to the WPS during the wet season.

  3. Reanalysis of the Atmospheric Flux of Nutrient Elements to the Southern Yellow Sea and the East China Sea

    Institute of Scientific and Technical Information of China (English)

    Wan Xiaofang; Wu Zengmao; Chang Zhiqing

    2003-01-01

    Based on the recent research results on dry and wet deposition of nutrient elements and sulphate, we estimate the atmospheric flux of nutrient elements and sulphate to the southern Yellow Sea and the East China Sea in each season. The results suggest that the concentrations of nutrient elements and sulphate in aerosol and precipitation show an apparent seasonal cycle with the maximum values in winter and the minimum values in summer. Depositions of nitrate and sulphate are dominated by wet deposition, while the deposition for phosphate is mainly dry deposition. Moreover, compared with the riverine inputs, the atmospheric deposition may be the main source of dissolved inorganic nutrients in the southern Yellow Sea and the East China Sea.

  4. From Source to Sink of Polycyclic Aromatic Hydrocarbons in Sediments in the East China Seas

    Science.gov (United States)

    Guo, Z.; Lin, T.; Hu, L.

    2014-12-01

    The East China Seas (ECSs), including Bohai Sea (77,000 km2), Yellow Sea (400,000 km2) and East China Sea (770,000 km2) have experienced a great variety of demographic and economic conditions which have a profound influence on the source composition of land-based polycyclic aromatic hydrocarbons (PAHs) in the sediments since ECSs's coasts support about 420 million peoples, provide more than half of the national GDP in China in 2007, and are major emission regions of PAHs in China. Furthermore, the ECSs are downwind of the Asian continental outflow in spring and winter driven by the East Asian monsoon. The sources of 16 USEPA priority PAHs in strategically selected surface sediment samples from the ECSs were apportioned using positive matrix factorization model, and the input pathways of PAHs were also revealed in the regions. Four sources were identified: petroleum residue, vehicular emissions, coal combustion and biomass burning. Petroleum residue was the dominant contributor of PAHs in the coast of the Bohai Bay probably due to Haihe River runoff, oil leakage from ships and offshore oil fields. The PAHs in sediments of the coastal East China Sea were mainly sourced from the Yangtze River discharge into the sea. The combined results of PMF, PCA and composition of PAHs suggest that the atmospheric deposition is the dominate input of PAHs for the open seas of Bohai Sea, East China Sea and Yellow Sea; while river input is the major pathway of PAHs in the estuarine and neighborhood coastal areas. The demographic and economic conditions around the ECSs have profound influence on the origins of the land-based PAHs in the sediments of the open seas.

  5. TIDAL FEATURES IN THE CHINA SEAS AND THEIR ADJACENT SEA AREAS AS DERIVED FROM TOPEX/POSEIDON ALTIMETER DATA

    Institute of Scientific and Technical Information of China (English)

    胡建宇; HiroshiKAWAMURA; 洪华生; FumiakiKOBASHI; 谢强

    2001-01-01

    Some important tidal features of 8 major tidal constituents (M2, S2, K1, O1, P1,Sa, N2 and K2 ) in the china Seas and their adjacent sea areas were obtained using six years' TOPEX/POSEIDON altimeter data. The results showed that the obtained co-tidal and co-range charts for these major tidal constituents agreed well with those of previous researches using observational data from coastal tidal gauge stations and numerical models.

  6. Advances in Studying Oceanic Circulation from Hydrographic Data with Applications in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    王桂华; 李荣凤; 闫长香

    2003-01-01

    Methods for studying oceanic circulation from hydrographic data are reviewed in the context of their applications in the South China Sea. These methods can be classified into three types according to their different dynamics as follows: (1) descriptive methods, (2) diagnostic methods without surface and bottom forcing, and (3) diagnostic methods with the above boundary forcing. The paper discusses the progress made in the above methods together with the advancement of study in the South China Sea circulation.

  7. Spatial distributions of floating seaweeds in the East China Sea from late winter to early spring

    OpenAIRE

    Mizuno, S.; Ajisaka, T.; Lahbib, S.; Kokubu, Y.; Alabsi, M. N.; Komatsu, T

    2013-01-01

    Floating seaweeds play an important role as a habitat for many animals accompanying or attaching to them in offshore waters. It was in 2000 that the first report described abundant distributions of floating seaweeds in offshore waters in the East China Sea in spring. Young individuals of the yellowtail Seriola quinqueradiata are captured for aquaculture purposes from floating seaweeds in the East China Sea. Therefore, a sound understanding of the distributions of floating seaweeds in the East...

  8. The assimilation experiment in the southwestern South China Sea in summer 2000

    Institute of Scientific and Technical Information of China (English)

    XIAO Xianjun; WANG Dongxiao; XU Jianjun

    2006-01-01

    We performed an assimilation experiment of the southern South China Sea in summer 2000, and the altimeter data were assimilated into Princeton Ocean Model (POM). The result was evaluated with the in situ data. There were obvious improvements of the currents in the southern South China Sea, and the modeling uncertainty coming from the error of wind stress forcing was reduced.This experiment provides us a new idea about improving the modeling of the ocean currents.

  9. Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

    Directory of Open Access Journals (Sweden)

    Charlotte Bay Hasager

    2016-09-01

    Full Text Available We study the wind climate and its long-term variability in the North Sea and South China Sea, areas relevant for offshore wind energy development, using satellite-based wind data, because very few reliable long-term in-situ sea surface wind observations are available. The Special Sensor Microwave Imager (SSM/I ocean winds extrapolated from 10 m to 100 m using the Charnock relationship and the logarithmic profile method are compared to Weather Research and Forecasting (WRF model results in both seas and to in-situ observations in the North Sea. The mean wind speed from SSM/I and WRF differ only by 0.1 m/s at Fino1 in the North Sea, while west of Hainan in the South China Sea the difference is 1.0 m/s. Linear regression between SSM/I and WRF winds at 100 m show correlation coefficients squared of 0.75 and 0.67, standard deviation of 1.67 m/s and 1.41 m/s, and mean difference of −0.12 m/s and 0.83 m/s for Fino1 and Hainan, respectively. The WRF-derived winds overestimate the values in the South China Sea. The inter-annual wind speed variability is estimated as 4.6% and 4.4% based on SSM/I at Fino1 and Hainan, respectively. We find significant changes in the seasonal wind pattern at Fino1 with springtime winds arriving one month earlier from 1988 to 2013 and higher winds in June; no yearly trend in wind speed is observed in the two seas.

  10. Mud Volcanoes from the Beaufort Sea to the South China Sea

    Science.gov (United States)

    Lundsten, E. M.; Paull, C. K.; Caress, D. W.; Dallimore, S.; Melling, H.; Liu, C. S.; Anderson, K.; Gwiazda, R.

    2015-12-01

    The detailed morphology of five submarine mud volcanoes were surveyed using an Autonomous Underwater Vehicle (AUV) developed at the Monterey Bay Aquarium Research Institute. Mud volcanoes are constructional features built by extrusion of gas, subsurface fluids and fine-grained sediment. Two surveys covering four submarine mud volcanoes were conducted on the CCGS Sir Wilfred Laurier in the Beaufort Sea in the Canadian Arctic. A survey of one mud volcano was conducted on the Taiwanese Ocean Research V in the South China Sea, SE of Taiwan. The AUV carried a multibeam sonar, a 1-6 kHz chirp sub-bottom profiler, and a110 kHz sidescan, and obtained overlapping multibeam bathymetric coverage at a vertical resolution of 0.15 m with a horizontal footprint of 0.9 m and chirp seismic-reflection profiles with a vertical resolution of 0.11 m. Mud volcanoes were either flat topped or conical. The conical mud volcano off Taiwan had a diameter of ~2 km and 10° side slopes; the conical feature in the Beaufort Sea had a diameter of ~1.5 km and 4° side slopes. The sides of the conical mud volcanoes were smooth, suggesting they were formed by sediment flows that emanate from a vent on their crests. The flanks of the conical mud volcanoes characteristically had very low acoustic reflectivity, but one single high reflectivity trail from the crest of the Beaufort Sea mud volcano indicates a recent flow. Three mud volcanoes in the Beaufort Sea formed circular, flat-topped plateaus that are up to ~1.1 km in diameter and elevated up to 30 m from the surrounding seafloor. The fine scale morphology and reflectivity on these plateaus show low relief, concentric, and ovoid circles that appear to be mud boils probably associated with eruptive events of varying ages at shifting vent sites. The different mud volcano shapes are attributed to variations in the viscosity of the erupting sediment slurries and may represent a sequential morphology, which is altered by shifts in venting position over

  11. GRAIN SIZE DISTRIBUTION OF SEDIMENT IN THE NORTHERN EAST CHINA SEA AND THE RELATIONSHIP WITH THE SEA CURRENTS

    Institute of Scientific and Technical Information of China (English)

    LEI Kun; YANG Zuosheng; GUO Zhigang

    2002-01-01

    This paper discusses the relationship between the grain size distribution of sediment and currents in the northern East China Sea on the basis of the grain size analysis. The results show that grain size distribution of suspended sediment is controlled by the currents. Suspended sediment in the littoral water is finer than those in the open sea currents. Grain size distribution of surface sediment is affected by the sea currents to some extent. And the grain size of suspended sediment and surface sediment do not agree with each other in positions.

  12. Comparison of different Geostatistical Approaches to map Sea Surface Temperature (SST) of Southern South China Sea

    Science.gov (United States)

    Ali, Azizi; Mohd Muslim, Aidy; Lokman Husain, Mohd; Fadzil Akhir, Mohd

    2013-04-01

    Sea surface temperature (SST) variation provides vital information for weather and ocean forecasting especially when studying climate change. Conventional methods of collecting ocean parameters such as SST, remains expensive and labor intensive due to the large area coverage and complex analytical procedure required. Therefore, some studies need to be conducted on the spatial and temporal distribution of ocean parameters. This study looks at Geo-statisctical methods in interpolating SST values and its impact on accuracy. Two spatial Geo-statistical techniques, mainly kriging and inverse distance functions (IDW) were applied to create variability distribution maps of SST for the Southern South China Sea (SCS). Data from 72 sampling station was collected in July 2012 covering an area of 270 km x 100 km and 263 km away from shore. This data provide the basis for the interpolation and accuracy analysis. After normalization, variograms were computed to fit the data sets producing models with the least RSS value. The accuracy were later evaluated based on on root mean squared error (RMSE) and root mean kriging variance (RMKV). Results show that Kriging with exponential model produced most accuracy estimates, reducing error in 17.3% compared with inverse distance functions.

  13. Methane in the South China Sea and the Western Philippine Sea

    Science.gov (United States)

    Tseng, Hsiao-Chun; Chen, Chen-Tung Arthur; Borges, Alberto V.; DelValls, T. Angel; Chang, Yu-Chang

    2017-03-01

    Approximately 700 water samples from the South China Sea (SCS) and 300 water samples from the western Philippine Sea (wPS) were collected during eight cruises from August 2003 to July 2007 to determine methane (CH4) distributions from the surface to a depth of 4250 m. The surface CH4 concentrations exceeded atmospheric equilibrium, both in the SCS and the wPS, and the concentrations were 4.5±3.6 and 3.0±1.2 nmol L-1, respectively. The sea-to-air fluxes were calculated, and the SCS and the wPS were found to emit CH4 to the atmosphere at 8.6±6.4 μmol m-2 d-1 and 4.9±4.9 μmol m-2 d-1, respectively. In the SCS, CH4 emissions were higher over the continental shelf (11.0±7.4 μmol m-2 d-1) than over the deep ocean (6.1±6.0 μmol m-2 d-1), owing to greater biological productivity and closer coupling with the sediments on the continental shelf. The SCS emitted 30.1×106 mol d-1 CH4 to the atmosphere and exported 1.82×106 mol d-1 CH4 to the wPS. The concentrations of both CH4 and chlorophyll a were high in the 150 m surface layer of the wPS, but were not significantly correlated with each other. CH4 concentrations generally declined with increasing depth below the euphotic zone but remained constant below 1,000 m, both in the SCS and the wPS. Some high CH4 concentrations were observed at mid-depths and bottom waters in the SCS, and were most likely caused by the release of CH4 from gas hydrates or gas seepage.

  14. In situ study on photosynthetic characteristics of phytoplankton in the Yellow Sea and East China Sea in summer 2013

    Science.gov (United States)

    Li, Junlei; Sun, Xiaoxia; Zheng, Shan

    2016-08-01

    In situ studies on photosynthetic characteristics of phytoplankton were important for the analysis of changes in community structure and for the prediction and control of algal blooms, but such studies of phytoplankton in offshore China were few. In this study, the detailed distribution of photosynthetic characteristics of phytoplankton in the summer of 2013 in the Yellow Sea and East China Sea was measured using Phyto-PAM (Pulse Amplitude Modulation). The phytoplankton community structure and the environmental parameters were also investigated to estimate the relationship between the distribution of the photochemical competence of phytoplankton and ecological factors. The total average Fv/Fm (the potential maximum quantum yield) value of phytoplankton in the Yellow Sea and East China Sea in summer 2013 was less than 0.5, reflecting that the photosynthetic activity of phytoplankton was relatively low. Fv/Fm of phytoplankton in summer was significantly positively associated with nitrate content (NO2-), which reflects relationship between metabolism and photosynthesis of phytoplankton: accompanied by NO2- metabolism, photosynthesis and photosynthetic capacity may be enhanced simultaneously, so the Fv/Fm value would increase with the NO2- released by phytoplankton. Through the in situ study on photosynthetic characteristics of phytoplankton in the Yellow Sea and East China Sea, we come to the conclusion that photosynthetic characteristics and activity of phytoplankton are influenced by its biological characteristics and surrounding ecological factors, such as irradiance, nutrients and phytoplankton community. Meanwhile, the thermally stratified structure and the movement of water masses, such as the Yangtze River diluted water, the Yellow Sea cold water mass and other different water system, also have an important impact on phytoplankton photosynthetic activity and characteristics. Greater understanding of the detailed photosynthetic characteristics of phytoplankton

  15. Linking Tarim Basin sea retreat (west China) and Asian aridification in the late Eocene

    NARCIS (Netherlands)

    Bosboom, R.; Dupont-Nivet, G.; Grothe, A.; Brinkhuis, H.; Villa, G.; Mandic, O.; Stoica, M.; Huang, W.; Yang, W.; Guo, Z.; Krijgsman, W.

    2014-01-01

    The Tarim Basin in western China formed the easternmost margin of a shallow epicontinental sea that extended across Eurasia and was well connected to the western Tethys during the Paleogene. Climate modelling studies suggest that the westward retreat of this sea from Central Asia may have been as im

  16. Some Results from SAR and Optical Sensor Monitoring of China Seas

    Science.gov (United States)

    Yang, Jingsong; Lou, Xiulin; Chen, Peng; Wang, Juan; Ren, Lin; Chang, Junfang; Pan, Yufang

    2013-01-01

    As part of the final results of Dragon 2 Project Id. 5316 “Demonstrating SAR and optical sensor monitoring of Chinese Seas”, some results from SAR and optical sensor monitoring of China Seas including sea surface winds, ocean surface waves, typhoon and typhoon waves, ocean internal waves, red tides, and ships are given in this paper.

  17. Carbon budget in East China Sea in spring

    Energy Technology Data Exchange (ETDEWEB)

    Peng Tsunghung; Wanninkhof, R. [National Oceanic and Atmospheric Administration, Miami, FL (United States). Atlantic Oceanographic and Meteorological Labs.; Hung, Jiajang [NSYSU, Kaohsiung (Taiwan, Province of China); Millero, F.J. [Miami Univ., FL (United States). Dept. of Marine and Atmospheric Chemistry]|[Rosenstiel School of Marine and Atmospheric Sciences

    1999-04-01

    Results of total dissolved inorganic carbon (DIC) and total alkalinity (TA) measurements made in the East China Sea (ECS) during a geochemical expedition of KEEP (Kuroshio Edge Exchange Processes) program in May of 1996 show that ECS is a CO{sub 2} sink during the spring season. The mean difference of fCO{sub 2} (fugacity of CO{sub 2}) between the atmosphere and surface water is calculated to be 28 {mu}atm, and the resulting net CO{sub 2} invasion flux is 2.1 mol m{sup -2} yr{sup -1}, which gives about 0.03 GtC/yr of CO{sub 2} uptake in this continental shelf in spring. This study supports the notion that the shelf regions can be a significant CO{sub 2} sink. The riverine alkalinity, which discharges into ECS, is estimated to be 1,743 {mu}mol kg{sup -1} on the basis of a linear relationship between TA and salinity. The observed salinity-normalized alkalinity in ECS is higher than that in the open sea, and this excess alkalinity is estimated to be 42 {mu}mol kg{sup -1}. With the known rate of the Changjiang discharge, this excess TA gives a mean residence time of 1.2 years for the continental shelf water in the ECS. The DIC in the ECS is also found to be higher than that in the open sea. This excess DIC is estimated to be about 76 {+-} 70 {mu}mol kg{sup -1}, which is equal to a net carbon input to ECS of 3.9 {+-} 3.6 mol m{sup -2} yr{sup -1}. Based on the riverine alkalinity input, the equivalent riverine carbon flux from Changjiang discharge is estimated to be about 1.8 mol m{sup -2} yr{sup -1}. With net CO{sub 2} invasion flux of 2.1 {+-} 2.8 mol m{sup -2} yr{sup -1}, the remaining 0 {+-} 4.6 mol m{sup -2} yr{sup -1} could come from remineralization of organic matter derived from biological pump in the shelf or terrestrial sources. Although this preliminary carbon budget implies that gas exchange and riverine input are the main sources of excess carbon in ECS, the contribution of biological carbon flux can not be ruled out because of the large uncertainty

  18. Pollen record of the last 280 ka from deep sea sediments of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    SUN; Xiangjun

    2001-01-01

    [1]Wang, P., West Pacific in glacial cycles: Seasonality in marginal sea and variability of Warm Pool, Science in China, Ser.D, 1998, 41 (1): 35.[2]Jian, Z., Li, B., Pflaumann, U. et al., Late Holocene cooling event in the West Pacific, Science in China, Ser. D, 1996,39(5): 543.[3]Jian, Z., Chen, M., Lin, H. et al., Stepwise paleoceanographic changes during the last deglaciation in the southern South China Sea: Records of stable isotope and microfossils, Science in China, Ser. D, 1998, 41(2): 187.[4]Sun, X., Li, X., A pollen record of the last 37 ka in deep sea core 17940 from the northern slope of the South China Sea,Marine Geology, 1999, 156: 224-227.[5]Sun, X, Li, X., Luo, Y. et al., The vegetation and climate at the last glaciation on the emerged continental shelf of the South China Sea, Palaeogeogr. Palaeoclimatol. Palaeoecol., 2000, 160:301-316.[6]Department of Tectonics, Institute of Oceanography, Chinese Academy of Sciences, Geological Tectonics of the South China Sea and Spreading of the Continental Margin (in Chinese), Beijing: Science Press, 1988, 339-379.[7]Zhao Huanting, Zhang Qiaomin, Song Chaojing et al., Geomorphology and environment of the South China Sea islands (in Chinese), Beijing: Science Press, 1999, 1-528.[8]Wang, P., Prell, W. L., Blum, P. et al., Proc, ODP, Init. Repts. 184, College Station TX (Ocean Drilling Program), 2000,1-77.[9]Florin, R., The distribution of conifer and taxad genera in time and space, Acta Horti Bergiani., 1963, 20 (4): 121-312.[10]Cooling, E. N. G., Pinus Mercusii Fast Growing Timber Tree of Lowland Tropics, Oxford: Dep. Forestry, Oxford, 1968.[11]Sun, X., Li, X., Beug, H. J., Pollen distribution in hemipelagic surface sediments of the South China Sea and its relation to modem vegetation distribution, Mar. Geol., 1999, 156:211226.[12]Sun Xiangjun, Song Changqing, Wang Fengyu, Pollen-climate response surface of selected taxa from northern China, Sci ence in China, Ser. D

  19. Research on the dynamics of the South China Sea opening: Evidence from analogue modeling

    Institute of Scientific and Technical Information of China (English)

    SUN; Zhen; ZHOU; Di; ZHONG; Zhihong; XIA; Bin; QIU; Xuelin; ZENG; Zuoxun

    2006-01-01

    Independent of Indochina extrusion, the South China Sea experienced a process from passive continental rifting to marginal sea drifting. According to the fault patterns in the Beibu Gulf basin and the Pearl River Mouth basin, the continental rifting and early spreading stage from 32 to 26 Ma were controlled by extensional stress field, which shifted clockwise from southeastward to south southeastward. From 24 Ma on, the sea spread in NW-SE direction and ceased spreading at around 15.5 Ma. Integrated geological information with the assumption that the South China Sea developed along a pre-Cenozoic weakness zone, we did analogue experiments on the South China Sea evolution. Experiments revealed that the pre-existing weakness zone goes roughly along the uplift zone between the present Zhu-1 and Zhu-2 depression. The pre-existing weakness zone is composed of three segments trending NNE, roughly EW and NEE, respectively. The early opening of the South China Sea is accompanied with roughly 15° clockwise rotation, while the SE sub-sea basin opened with SE extension. Tinjar fault was the western boundary of the Nansha block (Dangerous Ground),while Lupar fault was the eastern boundary of the Indochina, NW-trending rift belt known as Zengmu basin developed between above two faults due to block divergent of Indochina from Nansha. In the experiment, transtensional flower structures along NW-trending faults are seen, and slight inversion occurs along some NE-dipping faults. The existence of rigid massifs changed the orientations of some faults and rift belt, and also led to deformation concentrate around the massifs. The rifting and drifting of the South China Sea might be caused by slab pull from the proto South China Sea subducting toward Borneo and/or mantle flow caused by India-Asia collision.

  20. Orographic effects on South China Sea summer climate

    Science.gov (United States)

    Xu, H.; Xie, S.-P.; Wang, Y.; Zhuang, W.; Wang, D.

    2008-08-01

    New satellite observations reveal several distinct features of the South China Sea (SCS) summer climate: an intense low-level southwesterly wind jet off the coast of South Vietnam, a precipitation band on the western flank of the north south running Annam mountain range, and a rainfall shadow to the east in the western SCS off the east coast of Vietnam. A high-resolution full-physics regional atmospheric model is used to investigate the mechanism for the formation of SCS summer climate. A comparison of the control model simulation with a sensitivity experiment with the mountain range artificially removed demonstrates that the aforementioned features form due to orographic effects of the Annam mountains. Under the prevailing southwesterly monsoon, the mountain range forces the ascending motion on the windward and subsidence on the lee side, giving rise to bands of active and suppressed convection, respectively. On the south edge of the mountain range, the southwesterlies are accelerated to form an offshore low-level wind jet. The mid-summer cooling in the SCS induced by this wind jet further helps reduce precipitation over the central SCS. A reduced-gravity ocean model is used to investigate the ocean response to the orographically induced wind forcing, which is found to be important for the formation of the double-gyre circulation observed in the summer in SCS, in particular for the northern cyclonic circulation. Thus, orography is a key to shaping the SCS summer climate both in the atmosphere and in the ocean.

  1. Circulation in the South China Sea in summer of 1998

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the CTD and meteorological data obtained by R/V Xiangyanghong No.14 in the South China Sea (SCS) in the summer of 1998, both current velocity and volume transport are calculated by using a modified inverse model. Circulation in the SCS is analyzed by combining the calculated results with ADCP data. The following results are obtained. (i) The most important feature of the circulation in the northeastern SCS is that a branch of the Kuroshio intrudes into the SCS with a small volume transport. It flows anticyclonically through the Bashi Strait and towards the southwest off the Taiwan Island, and it does not intrude into the inner SCS. (ii) The northern SCS is dominated mainly by a cyclonic circulation system with two cold eddies. (iii) The central and southwestern SCSs are mainly occupied by anticyclonic circulation systems, including three anticyclonic and one stronger cyclonic eddies. (iv) In the southeastern SCS, there is a large scope of cyclonic circulation extending in the SW-NE direction. (v) There is a "multi-eddy phenomenon" in the SCS, and a larger eddy contains several small eddies. (vi) There is western intensifying of the currents and eddies in the SCS.

  2. ESTIMATION OF SOUNDING ABILITY OF A BRILLOUIN LIDAR IN THE EAST CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Vertical profiles of sound speed in the sea can be measured by using laser excited Brillouin scattering. In this paper the dependence of the accuracy of sound speed measurement on the accuracy of the Brillouin shift measurement is analyzed. We calculated the maximum detecting depths of sound speed to an accuracy of 1 m/s by lidar with different laser pulse energy, platform altitude, telescope aperture and lidar effective attenuation coefficient. The estimation of sounding ability in the East China Sea is made in some stations. These data can be used in the design of Brillouin Lidar for the China Sea.

  3. Spacebased Observations of the Oceanic Responses to Monsoons in South China Sea and Arabian Sea

    Science.gov (United States)

    Xie, Xiao-Su; Liu, W. Timothy

    2000-01-01

    A large percentage of the world's population and their agrarian economy must endure the vagaries of the monsoons over the tropical oceans between Africa and the Philippines. We know very little about the oceanic responses to changes of the monsoon in the South China Sea (SCS), which is under the influence of the East Asian Monsoon System, and the Arabian Sea (AS), which is dominated by the Indian Monsoon System; oceanic observations are sparse in both regions. Data from spaceborne microwave scatterometers and radiometers have been used to estimate the two major atmospheric forcing, momentum flux and latent heat flux (LHF), which change with the monsoon winds. Spaceborne sensors also observed the surface signatures of the oceanic response: SST and sea level changes (SLC. Sufficient durations of these data have recently become available to allow the meaningful studies of the annual cycles and interannual anomalies. In SCS, the winter monsoon is strong and steady but the summer monsoon is weak and has large intraseasonal fluctuations. In AS, the summer monsoon is much stronger than the winter monsoon. Significant correlations between LHF and SST tendency, and between curl of wind stress and SLC are found in both oceans. In the north SCS, winds are strong and dry, LHF is high, and ocean cooling is also large in fall; LHF is low and the ocean warms up in spring. In AS, LHF and SST tendency have a semi annual period; LHF is high in summer when the wind is strong and in winter when the wind is dry. Along the coast of Oman, the strong summer southwest monsoon causes intense upwelling, low SST and LHF in summer; such wind-driven SST changes is not as obvious along the Vietnam coast because of the weaker summer monsoon. The negative correlation between curl of wind stress and SLC found in the central basins of both SCS and AS agrees with a simple Ekman pumping scenario. Cyclonic winds drive surface divergence and upwelling in the ocean; the rise of the thermocline causes

  4. Vertical characteristics revealed by biweekly and synoptic variability of upper sea temperature in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yani; ZHOU Faxiu; HUANG Fei

    2005-01-01

    On the basis of the analysis of the sea temperature data that are observed from the three automatic temperature line acquisition sysem mooring buoys deployed in the central South China Sea (SCS) during South China Sea monsoon experiment, vertical features of biweekly and synoptic variability are discussed. There are five vertical modes, that is, subsurface temperature variability is in phase with,out of phase with, leads to, lags the surface temperature variability, and at depths within the subsurface layer the upper and lower temperature variations are out of phase. The formation of these vertical modes is related to the property of low-level atmospheric forcing and to the background in atmosphere and ocean. Wind stress curl is the main driving factor in forming Modes 1 and 3, and wind stresses in forming Modes 2 and 4.

  5. Geopolitical Implications of the Sino-Japanese East China Sea Dispute for the U.S.

    OpenAIRE

    Chapman, Bert

    2016-01-01

    Much analysis on Asian strategic challenges facing the U.S. has justifiably emphasized the South China Sea (SCS). This has also been reflected in 2016 presidential campaign debate on the SCS as an emerging area of U.S. foreign and national security policy concern. The East China Sea (ECS) is at least as important for the strategic interests of the U.S. and its allies given the tension between China and Japan over the Senkaku/Diaoyu islands, potential energy resources in this body of water, in...

  6. Distributions and sea-to-air fluxes of volatile halocarbons in the southern Yellow Sea and the East China Sea

    Institute of Scientific and Technical Information of China (English)

    YANG Guipeng; LI Li; LU Xiaolan; ZHANG Liang

    2015-01-01

    Distributions and sea-to-air fluxes of five kinds of volatile halocarbons (VHCs) were studied in the southern Yellow Sea (SYS) and the East China Sea (ECS) in November 2007. The results showed that the concentrations of 1,1,1- trichloroethane (C2H3Cl3), 1,1-dichloroethene (C2H2Cl2), 1,1,2-trichloroethene (C2HCl3), trichloromethane (CHCl3) and tetrachloromethane (CCl4) in the surface water were 0.31–4.81, 2.75–21.3, 1.21–17.1, 5.02–233 and 0.045–4.47 pmol/L, respectively, with the average values of 1.89, 12.20, 6.93, 60.90 and 0.33 pmol/L. On the whole, the horizontal distributions of C2H3Cl3, C2H2Cl2 and CCl4 were affected mainly by anthropogenic activities, while C2HCl3 and CHCl3 were influenced by biological factors as well as anthropogenic activities. In the study area, the concentrations of VHCs (except C2HCl3) exhibited a decreasing trend from inshore to offshore sites, with the higher values occurring in the coastal waters. The sea-to-air fluxes of C2H3Cl3, C2HCl3, CHCl3 and CCl4 were calculated to be -56.00–(-5.68),-7.31–123.42, 148.00–1 309.31 and -83.32–(-1.53) nmol/(m2·d), respectively, with the average values of -6.77, 17.14, 183.38 and -21.27 nmol/(m2·d). Our data showed that the SYS and ECS in autumn was a sink for C2H3Cl3 and CCl4, while it was a source for C2HCl3 and CHCl3 in the atmosphere.

  7. The barrier layer in the southern region of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By analysing the CTD data in the southernregion of the South China Sea gathered during six cruises between 1989 and 1999, a barrier layer with seasonal variation just like what exists in the equatorial oceans is found in this region. It is the first discovery in such a marginal sea yet.It is strong in autunm and a little weak in summer and winter. The thicker the barrier layer, the higher the average temperature of the upper mixed layer. The region with the thicker barrier layer overlaps the region with the higher average temperature of the upper mixed layer, and accords with the thicker region of the warm pool in the South China Sea got from the Levitus data. The barrier layer in the southern region of the South China Sea has significant influence on the heat storage of the upper ocean there.``

  8. Chemical, optical and other data collected aboard the MELVILLE during cruise MV0902 in the Philippine Sea, South China Sea (Nan Hai) and Sulu Sea from 2009-02-06 to 2009-02-23 (NODC Accession 0116957)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116957 includes chemical, optical and other data collected aboard the MELVILLE during cruise MV0902 in the Philippine Sea, South China Sea (Nan Hai)...

  9. Physical and underway data collected aboard the MELVILLE during cruise MGLN30MV in the Philippine Sea, South China Sea (Nan Hai) and Sulu Sea from 2007-11-30 to 2008-01-04 (NODC Accession 0098586)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0098586 includes physical and underway data collected aboard the MELVILLE during cruise MGLN30MV in the Philippine Sea, South China Sea (Nan Hai) and...

  10. Physical and underway data collected aboard the MELVILLE during cruise MGLN32MV in the Philippine Sea, South China Sea (Nan Hai) and Sulu Sea from 2008-02-07 to 2008-02-28 (NCEI Accession 0155954)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155954 includes physical and underway data collected aboard the MELVILLE during cruise MGLN32MV in the Philippine Sea, South China Sea (Nan Hai) and...

  11. Dynamics of the water circulations in the southern South China Sea and its seasonal transports

    DEFF Research Database (Denmark)

    Daryabor, Farshid; Ooi, See Hai Ooi; Samah, Azizan Abu

    2016-01-01

    A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re......-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast...... circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China...

  12. Sea-level trend in the South China Sea observed from 20 years of along-track satellite altimetric data

    DEFF Research Database (Denmark)

    Cheng, Yongcun; Xu, Qing; Andersen, Ole Baltazar

    2014-01-01

    The sea-level trend in the South China Sea (SCS) is investigated based on 20 years of along-track data from TOPEX and Jason-1/2 satellite altimetry. The average sea-level rise over all the regions in the study area is observed to have a rate of 5.1 ± 0.8 mm year-1 for the period from 1993 to 2012....... The steric sea level contributes 45% to the observed sea-level trend. These results are consistent with previous studies. In addition, the results demonstrate that the maximum sea-level rise rate of 8.4 mm year-1 is occurring off the east coast of Vietnam and eastern part of SCS. During 2010-2011, the La...... Niña event was highly correlated with the dramatic sea-level rise in the SCS; La Niña events were also associated with the maximum rate of sea rise off the east coast of Vietnam, which occurred during 1993 and 2012. We also evaluated the trends in the geophysical (e.g. dynamical atmospheric correction...

  13. On the recurrent Ulva prolifera blooms in the Yellow Sea and East China Sea

    Science.gov (United States)

    Hu, Chuanmin; Li, Daqiu; Chen, Changsheng; Ge, Jianzhong; Muller-Karger, Frank E.; Liu, Junpeng; Yu, Feng; He, Ming-Xia

    2010-05-01

    A massive bloom of the green macroalgae Ulva prolifera (previously known as Enteromorpha prolifera) occurred in June 2008 in the Yellow Sea (YS), resulting in perhaps the largest "green tide" event in history. Using a novel index (Floating Algae Index) and multiresolution remote sensing data from MODIS and Landsat, we show that U. prolifera patches appeared nearly every year between April and July 2000-2009 in the YS and/or East China Sea (ECS), which all originated from the nearshore Subei Bank. A finite volume numerical circulation model, driven by realistic forcing and boundary conditions, confirmed this finding. Analysis of meteorological/environmental data and information related to local aquaculture activities strongly supports the hypothesis that the recurrent U. prolifera in the YS and ECS resulted from aquaculture of the seaweed Porphyra yezoensis (or nori) conducted along the 200 km shoreline of the Subei Bank north of the Changjiang (Yangtze) River mouth. Given the continuous growth in aquaculture efforts in the region, similar macroalgae bloom events, such as the summer 2008 event, are likely to occur in the future, particularly between May and July. This was confirmed by the 2009 bloom event in the same regions and the same period. The profit of the local P. yezoensis aquaculture industry (˜16,000 Ha in 2007) is estimated as U.S. 53 million, yet the cost to manage the impact of the summer 2008 U. prolifera bloom exceeded U.S. 100 million. Therefore, better strategies are required to balance the economic benefit of seaweed aquaculture and the costs of environmental impacts.

  14. Hydrodynamic condition and suspended sediment diffusion in the Yellow Sea and East China Sea

    Science.gov (United States)

    Li, Guangxue; Qiao, Lulu; Dong, Ping; Ma, Yanyan; Xu, Jishang; Liu, Shidong; Liu, Yong; Li, Jianchao; Li, Pin; Ding, Dong; Wang, Nan; Olusegun A, Dada; Liu, Ling

    2016-08-01

    Based on monthly averaged current, temperature, and salinity, we analyzed the changes of suspended sediment concentration (SSC) and the relationship with the warm current, coastal current, and cold water mass (CWM) in the East China Seas (ECSs). The result shows that the coastal current and surface diluted water are the route for transporting suspended sediment. The Kuroshio and its derived warm current branches play the important role of the continental shelf circulation system and control the diffusion of suspended sediment. High SSC has been mainly concentrated in coastal current and CWM. Two sedimentary dynamic patterns have been identified. The winter-half-year pattern lasts almost 7 months. The coastal currents off the Shandong Peninsula, northern Jiangsu, Zhejiang-Fujian coast are the main routes for diffusion and deposition of the suspended sediment from the Yellow River and Changjiang River. The summer-half-year pattern is characterized by the well-developed CWM. All CWMs have a unique function to trap suspended sediment under the thermocline due to weakening tidal current and residual current there. These CWMs in the Yellow Sea (YS) and north ECS are connected together. The layer above the thermocline is characterized by diluted water with low salinity, high temperature. Suspended sediment can be transported into the Okinawa Trough and the South Korea coast during this period. A strong eddy always occur nearby the Kuroshio bend at northeast Taiwan, which has promoted the exchange between the ECS shelf and Okinawa Trough, and the development of the shelf edge current and Taiwan warm current (TWC).

  15. Maritime Territorialisation as Performance of Sovereignty and Nationhood in the South China Sea

    DEFF Research Database (Denmark)

    Roszko, Edyta

    2015-01-01

    The South China Sea (SCS) is a conflict-ridden international arena of rivalry between China, the US, India, and the other ASEAN countries over sovereignty, resources and security. In this geo-political clash China is the dominant force and Vietnam its main challenger. While most analysts assume...... that the various claims to the mostly uninhabited islands are motivated by the presence of submarine mineral resources, the conflicts evoke strong nationalist feelings in Vietnam and China, fuelled by narratives of the historical presence of fisheries and navies. By analyzing the tension between complex...... is a paradox of treating the sea as ‘land’ produced by the performance of a socially constructed image of the state geo-body capitalizing on strong nationalistic sentiments in China and Vietnam....

  16. Air-sea exchange of gaseous mercury in the East China Sea.

    Science.gov (United States)

    Wang, Chunjie; Ci, Zhijia; Wang, Zhangwei; Zhang, Xiaoshan

    2016-05-01

    Two oceanographic cruises were carried out in the East China Sea (ECS) during the summer and fall of 2013. The main objectives of this study are to identify the spatial-temporal distributions of gaseous elemental mercury (GEM) in air and dissolved gaseous mercury (DGM) in surface seawater, and then to estimate the Hg(0) flux. The GEM concentration was lower in summer (1.61 ± 0.32 ng m(-3)) than in fall (2.20 ± 0.58 ng m(-3)). The back-trajectory analysis revealed that the air masses with high GEM levels during fall largely originated from the land, while the air masses with low GEM levels during summer primarily originated from ocean. The spatial distribution patterns of total Hg (THg), fluorescence, and turbidity were consistent with the pattern of DGM with high levels in the nearshore area and low levels in the open sea. Additionally, the levels of percentage of DGM to THg (%DGM) were higher in the open sea than in the nearshore area, which was consistent with the previous studies. The THg concentration in fall was higher (1.47 ± 0.51 ng l(-1)) than those of other open oceans. The DGM concentration (60.1 ± 17.6 pg l(-1)) and Hg(0) flux (4.6 ± 3.6 ng m(-2) h(-1)) in summer were higher than those in fall (DGM: 49.6 ± 12.5 pg l(-1) and Hg(0) flux: 3.6 ± 2.8 ng m(-2) h(-1)). The emission flux of Hg(0) from the ECS was estimated to be 27.6 tons yr(-1), accounting for ∼0.98% of the global Hg oceanic evasion though the ECS only accounts for ∼0.21% of global ocean area, indicating that the ECS plays an important role in the oceanic Hg cycle.

  17. Modelling sea level data from China and Malay-Thailand to estimate Holocene ice-volume equivalent sea level change

    Science.gov (United States)

    Bradley, Sarah L.; Milne, Glenn A.; Horton, Benjamin P.; Zong, Yongqiang

    2016-04-01

    This study presents a new model of Holocene ice-volume equivalent sea level (ESL), extending a previously published global ice sheet model (Bassett et al., 2005), which was unconstrained from 10 kyr BP to present. This new model was developed by comparing relative sea level (RSL) predictions from a glacial isostatic adjustment (GIA) model to a suite of Holocene sea level index points from China and Malay-Thailand. Three consistent data-model misfits were found using the Bassett et al. (2005) model: an over-prediction in the height of maximum sea level, the timing of this maximum, and the temporal variation of sea level from the time of the highstand to present. The data-model misfits were examined for a large suite of ESL scenarios and a range of earth model parameters to determine an optimum model of Holocene ESL. This model is characterised by a slowdown in melting at ∼7 kyr BP, associated with the final deglaciation of the Laurentide Ice Sheet, followed by a continued rise in ESL until ∼1 kyr BP of ∼5.8 m associated with melting from the Antarctic Ice Sheet. It was not possible to identify an earth viscosity model that provided good fits for both regions; with the China data preferring viscosity values in the upper mantle of less than 1.5 × 1020 Pa s and the Malay-Thailand data preferring greater values. We suggest that this inference of a very weak upper mantle for the China data originates from the nearby subduction zone and Hainan Plume. The low viscosity values may also account for the lack of a well-defined highstand at the China sites.

  18. A Preliminary Study of the Microbial Resources and Their Biological Activities of the East China Sea

    Directory of Open Access Journals (Sweden)

    Xiaoling Lu

    2011-01-01

    Full Text Available East China Sea is one of the four sea areas in China, which possesses peculiar ecological environment and many kinds of living creatures, especially the microorganisms. We established the East China Sea microorganism library (during 2006–2010 for the first time, which stored about 30000 strains that covered most kinds of the species. In this paper, 395 pure strains of East China Sea microorganism library which belong to 33 different genera were mainly introduced. Sulfitobacter, Halomonas, Bacillus, Pseudoalteromonas, and Idiomarina were the most dominant species. On the large-scale biological activity screening of the 395 strains, 100 strains possess different biological activities based on different screening models, of which 11.4% strains have antibacterial activities, 15.9% have cytotoxicity activities, and 6.1% have antioxidation activities. Besides, the secondary metabolites of 6 strains with strong biological activities were studied systematically; diketopiperazines and macrocyclic lactones are the active secondary metabolites. The species and the biological activity of microorganisms diversity, the abundant structure type of the secondary metabolites, and their bioactivities all indicate that East China Sea is a potent marine microorganisms-derived developing resource for drug discovery.

  19. Deepwater Ventilation and Stratification in the Neogene South China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Combined data of physical property, benthic foraminifera, and stable isotopes from ODP Sites 1148, 1146, and 1143 are used to discuss deep water evolution in the South China Sea (SCS) since the Early Miocene. The results indicate that 3 lithostratigraphic units, respectively corresponding to 21-17 Ma, 15-10 Ma, and 10-5 Ma with positive red parameter (a*) marking the red brown sediment color represent 3 periods of deep water ventilation. The first 2 periods show a closer link to contemporary production of the Antarctic Bottom Water (AABW) and Northern Component Water(NCW), indicating a free connection of deep waters between the SCS and the open ocean before 10 Ma.After 10 Ma, red parameter dropped but stayed higher than the modern value (a*=0), the CaCO3 percentage difference between Site 1148 from a lower deepwater setting and Site 1146 from an upper deepwater setting enlarged significantly, and benthic species which prefer oxygen-rich bottom conditions dramatically decreased. Coupled with a major negative excursion of benthic δ13C at ~10 Ma,these parameters may denote a weakening in the control of the SCS deep water by the open ocean.Probably they mark the birth of a local deep water due to shallow waterways or rise of sill depths during the course of sea basin closing from south to east by the west-moving Philippine Arc after the end of SCS seafloor spreading at 16-15 Ma. However, it took another 5 Ma before the dissolved oxygen approached close to the modern level. Although the oxygen level continued to stabilize, several Pacific Bottom Water (PBW) and Pacific Deep Water (PDW) marker species rapidly increased since ~6 Ma,followed by a dramatic escalation in planktonic fragmentation which indicates high dissolution especially after ~5 Ma. The period of 5-3 Ma saw the strongest stratified deepwater in the then SCS, as indicated by up to 40% CaCO3 difference between Sites 1148 and 1146. Apart from a strengthening PDW as a result of global cooling and ice

  20. Reconstruction of paleocoastlines for the northwestern South China Sea since the Last Glacial Maximum

    Institute of Scientific and Technical Information of China (English)

    YAO YanTao; HARFF Jan; MEYER Michael; ZHAN WenHuan

    2009-01-01

    The range of relative sea level rise in the northwestern South China Sea since the Last Glacial Maximum was over 100 m. As a result, lowland regions including the Northeast Vietnam coast, Beibu Gulf, and South China coast experienced an evolution from land to sea. Based on the principle of recon structing paleogeography and using recent digital elevation model, relative sea level curves, and sediment accumulation data, this paper presents a series of paleogeographic scenarios back to 20 cal. ka BP for the northwestern South China Sea. The scenarios demonstrate the entire process of coastline changes for the area of interest. During the late glacial period from 20 to 15 cal. ka BP, coastline slowly retreated, causing a land loss of only 1 ×104 km2, and thus the land-sea distribution remained nearly unchanged. Later in 15--10 cal. ka BP coastline rapidly retreated and area of land loss was up to 24×104 km2, causing lowlands around Northeast Vietnam and South China soon to be underwater. Coastline retreat continued quite rapidly during the early Holocene. From 10 to 6 cal. ka BP land area had decreased by 9×104 km2, and during that process the Qiongzhou Strait completely opened up. Since the mid Holocene, main controls on coastline change are from vertical crustal movements and sedimentation. Transgression was surpassed by regression, resulting in a land accretion of about 10×104 km2.

  1. Reconstruction of paleocoastlines for the northwestern South China Sea since the Last Glacial Maximum

    Institute of Scientific and Technical Information of China (English)

    HARFF; Jan; MEYER; Michael

    2009-01-01

    The range of relative sea level rise in the northwestern South China Sea since the Last Glacial Maximum was over 100 m. As a result, lowland regions including the Northeast Vietnam coast, Beibu Gulf, and South China coast experienced an evolution from land to sea. Based on the principle of reconstructing paleogeography and using recent digital elevation model, relative sea level curves, and sediment accumulation data, this paper presents a series of paleogeographic scenarios back to 20 cal. ka BP for the northwestern South China Sea. The scenarios demonstrate the entire process of coastline changes for the area of interest. During the late glacial period from 20 to 15 cal. ka BP, coastline slowly retreated, causing a land loss of only 1×104 km2, and thus the land-sea distribution remained nearly unchanged. Later in 15-10 cal. ka BP coastline rapidly retreated and area of land loss was up to 24×104 km2, causing lowlands around Northeast Vietnam and South China soon to be underwater. Coastline retreat continued quite rapidly during the early Holocene. From 10 to 6 cal. ka BP land area had decreased by 9×104 km2, and during that process the Qiongzhou Strait completely opened up. Since the mid Holocene, main controls on coastline change are from vertical crustal movements and sedimentation. Transgression was surpassed by regression, resulting in a land accretion of about 10×104 km2.

  2. Assessment of marine debris in beaches or seawaters around the China Seas and coastal provinces.

    Science.gov (United States)

    Zhou, Changchun; Liu, Xu; Wang, Zhengwen; Yang, Tiantian; Shi, Linna; Wang, Linlin; You, Suwen; Li, Min; Zhang, Cuicui

    2016-02-01

    Compared with United States of America (USA), Brazil, Chile, Australia, limited attention has been paid to marine debris research in China and few studies have attempted to quantify the abundance and mass of marine debris. In this study, firstly the general status and sources of marine debris in China were assessed in the time period between 2007 and 2014, and secondly marine debris situation was evaluated in three China Sea Areas (the North China Sea, the East China Sea and the South China Sea) from 2009 to 2013, and finally marine debris conditions and sources were analyzed in beaches or seawaters around some coastal provinces of China during 2007-2013. Based on above analysis, the primary conclusions were as follows: (1) The mean number and weight densities of beached marine debris (BMD) and submerged marine debris (SMD) were 4.30, 0.13items/100m(2) and 133.80, 22.60g/100m(2) in China from 2007 to 2014, respectively. The average number density of the large size FMD (LOSFMD) was 0.0024items/100m(2) and that of the small and medium size FMD (SMSFMD) was 0.30items/100m(2), and the mean weight density of the SMSFMD was 1.40g/100m(2) from 2008 to 2014. The SMD and FMD densities were at the low level and the BMD density was at the high level in China. (2) The marine debris primarily was comprised of plastic, Styrofoam, wood, glass, rubber, fabric/fiber and metal, which included almost all major categories of marine debris. (3) Sources of BMD and FMD were as follows: the first source was coastal/recreational activities, followed by other disposal sources, navigation/fishing activities and the activities related smoking, and the least source being those associated with medical/sanitary activities, while the source of SMD remained unknown. (4) The mean number and weight densities of BMD were the biggest in the North China Sea, while those of FMD and SMD were the highest in the northern South China Sea. The results of this study were beneficial to the establishment of

  3. Exploitable wave energy assessment based on ERA-Interim reanalysis data-A case study in the East China Sea and the South China Sea

    Institute of Scientific and Technical Information of China (English)

    WAN Yong; ZHANG Jie; MENG Junmin; WANG Jing

    2015-01-01

    Wave energy resources assessment is a very important process before the exploitation and utilization of the wave energy. At present, the existing wave energy assessment is focused on theoretical wave energy conditions for interesting areas. While the evaluation for exploitable wave energy conditions is scarcely ever performed. Generally speaking, the wave energy are non-exploitable under a high sea state and a lower sea state which must be ignored when assessing wave energy. Aiming at this situation, a case study of the East China Sea and the South China Sea is performed. First, a division basis between the theoretical wave energy and the exploitable wave energy is studied. Next, based on recent 20 a ERA-Interim wave field data, some indexes including the spatial and temporal distribution of wave power density, a wave energy exploitable ratio, a wave energy level, a wave energy stability, a total wave energy density, the seasonal variation of the total wave energy and a high sea condition frequency are calculated. And then the theoretical wave energy and the exploitable wave energy are compared each other;the distributions of the exploitable wave energy are assessed and a regional division for exploitable wave energy resources is carried out;the influence of the high sea state is evaluated. The results show that considering collapsing force of the high sea state and the utilization efficiency for wave energy, it is determined that the energy by wave with a significant wave height being not less 1 m or not greater than 4 m is the exploitable wave energy. Compared with the theoretical wave energy, the average wave power density, energy level, total wave energy density and total wave energy of the exploitable wave energy decrease obviously and the stability enhances somewhat. Pronounced differences between the theoretical wave energy and the exploitable wave energy are present. In the East China Sea and the South China Sea, the areas of an abundant and stable

  4. Analysis of sea use landscape pattern based on GIS: a case study in Huludao, China.

    Science.gov (United States)

    Suo, Anning; Wang, Chen; Zhang, Minghui

    2016-01-01

    This study aims to analyse sea use landscape patterns on a regional scale based on methods of landscape ecology integrated with sea use spatial characteristics. Several landscape-level analysis indices, such as the dominance index, complex index, intensivity index, diversity index and sea congruency index, were established using Geographic Information System (GIS) and applied in Huludao, China. The results indicated that sea use landscape analysis indices, which were created based on the characteristics of sea use spatial patterns using GIS, are suitable to quantitatively describe the landscape patterns of sea use. They are operable tools for the landscape analysis of sea use. The sea use landscape in Huludao was dominated by fishing use with a landscape dominance index of 0.724. The sea use landscape is a complex mosaic with high diversity and plenty of fishing areas, as shown by the landscape complex index of 27.21 and the landscape diversity index of 1.25. Most sea use patches correspond to the marine functional zonation plan and the sea use congruency index is 0.89 in the fishing zone and 0.92 in the transportation zone.

  5. A New model to forecast fishing ground ofScomber japonicus in the Yellow Sea and East China Sea

    Institute of Scientific and Technical Information of China (English)

    GAO Feng; CHEN Xinjun; GUAN Wenjiang; LI Gang

    2016-01-01

    The pelagic species is closely related to the marine environmental factors, and establishment of forecasting model of fishing ground with high accuracy is an important content for pelagic fishery. The chub mackerel (Scomber japonicus) in the Yellow Sea and East China Sea is an important fishing target for Chinese lighting purse seine fishery. Based on the fishery data from China’s mainland large-type lighting purse seine fishery for chub mackerel during the period of 2003 to 2010 and the environmental data including sea surface temperature (SST), gradient of the sea surface temperature (GSST), sea surface height (SSH) and geostrophic velocity (GV), we attempt to establish one new forecasting model of fishing ground based on boosted regression trees. In this study, the fishing areas with fishing effort is considered as one fishing ground, and the areas with no fishing ground are randomly selected from a background field, in which the fishing areas have no records in the logbooks. The performance of the forecasting model of fishing ground is evaluated with the testing data from the actual fishing data in 2011. The results show that the forecasting model of fishing ground has a high prediction performance, and the area under receiver operating curve (AUC) attains 0.897. The predicted fishing grounds are coincided with the actual fishing locations in 2011, and the movement route is also the same as the shift of fishing vessels, which indicates that this forecasting model based on the boosted regression trees can be used to effectively forecast the fishing ground of chub mackerel in the Yellow Sea and East China Sea.

  6. Estimating peak response frequencies in a tidal band in the seas adjacent to China with a numerical model

    Institute of Scientific and Technical Information of China (English)

    CUI Xinmei; FANG Guohong; TENG Fei; WU Di

    2015-01-01

    A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China's adjacent seas shows that the Bohai Sea has a highest peak response frequency (PRF) of 1.52 d−1; the northern Yellow Sea has a PRF of 1.69 d−1; the Gyeonggi Bay has a high amplitude gain plateau in the frequency band roughly from 1.7 to 2.7 d−1; the Yellow Sea (includ-ing the Gyeonggi Bay), the East China Sea shelf and the Taiwan Strait have a common high amplitude gain band with frequencies around 1.76 to 1.78 d−1 and are shown to be a system that responds to the open ocean forcing in favor of amplifying the waves with frequencies in this band; the Beibu Gulf, the Gulf of Thailand and the South China Sea deep basin have PRFs of 0.91, 1.01 and 0.98 d−1 respectively. In addition, the East China Sea has a Poincare mode PRF of 3.91 d−1. The PRFs of the Bohai Sea, the northern Yellow Sea, the Bei-bu Gulf and the South China Sea can be explained by a classical quarter (half for the Bohai Sea) wavelength resonance theory. The results show that further investigations are needed for the response dynamics of the Yellow Sea-East China Sea-Taiwan Strait system, the East China Sea Poincare mode, the Taiwan Strait, and the Gulf of Thailand.

  7. Data from renewable energy assessments for resort islands in the South China Sea.

    Science.gov (United States)

    Basir Khan, M Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

    2016-03-01

    Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article "Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea" published in Energy (Khan et al., 2015) [1].

  8. Measurement of single-fish target strength in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    CHEN Guobao; LI Yongzhen; CHEN Pimao; ZHANG Jun; FANG Lichen; LI Nana

    2012-01-01

    We measured the target strength (TS) of three commercial fish species:whitespotted spinefoot (Siganus canaliculatus),black porgy (Acanthopagrus schlegelii),and creek red bream (Lutjanus argentimaculatus),in the South China Sea.The TS of caged or tethered fish (n=76 total) was measured using a Simrad EY60 portable scientific echosounder at 120 kHz.We evaluated the relationship between TS and total length (TL,cm) for the three species.This is the first attempt to use split-beam acoustics to measure single-fish TS in the South China Sea by Chinese researchers.Our results will improve the accuracy and precision of acoustic abundance estimates of commercially important species and further the development of underwater acoustic survey techniques in fisheries in the South China Sea.

  9. Taxonomic study on the family Mitridae (Mollusca: Gastropoda: Neogastropoda) from the China's seas. Subfamilies: Imbricariinae and Cylindromitrinae

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Ninteen species of subfamilies Imbricariinae and Cylindromitrinae, family Mitridae, are recorded from the China's seas. Of which, one genus and six species are recorded for the first time from China' s seas, i.e., genus Ziba Adams H and Adams A, Cancilla (Cancilla)carnicolor, Ziba duplilirata, Z. insculpta, Neocancilla circula, Scabricola (Scabricola) desetangsii, Scabricola (Swainsonia) ocellata ocellata.

  10. THE EFFECT OF KUROSHIO ON THE CIRCULATION IN CHINA SEAS-FROM SATELLITE-TRACKED DRIFTER DATA

    Institute of Scientific and Technical Information of China (English)

    Hou Yi-jun; Su Jing-zhi; Fang Guo-hong; Yin Bao-shu; Cheng Ming-hua

    2003-01-01

    A dataset derived from satellite-tracked drifting buoy archived at the Marine Envimoment Data Service (MEDS) in Canada are analyzed to study the effect of the Kuroshio on the China Seas, and the results can exhibit the spacial difference and temporal difference of the effect of Kuroshio on the circulation in the China Seas.

  11. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports

    Science.gov (United States)

    Ooi, See Hai; Samah, Azizan Abu; Akbari, Abolghasem

    2016-01-01

    A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea. PMID:27410682

  12. Photophysiological state of natural phytoplankton communities in the South China Sea and Sulu Sea

    Directory of Open Access Journals (Sweden)

    W. Cheah

    2013-07-01

    Full Text Available In recent years, an increasing number of studies on phytoplankton in the tropical South China Sea (SCS and Sulu Sea (SS have been conducted. However, still little is known about the photophysiological state of natural phytoplankton communities under varying environmental conditions. This study investigates the photophysiological state of natural phytoplankton communities in the southern SCS and SS based on high horizontal and vertical resolution field observations collected during the SHIVA (Stratosphere ozone: Halogens in a Varying Atmosphere cruise (SO 218 in November 2011 on board RV Sonne. At the surface, pigment results revealed that total chlorophyll a (TChl a concentrations at all offshore stations were low at the surface and were generally dominated by cyanobacteria. Enhanced concentrations of TChl a were only observed below the upper mixed layer and above the euphotic depth with haptophytes, prochlorophytes and prasinophytes contributing most of the biomass. At stations close to the coast and river outflows, surface phytoplankton blooms (between 1 to 2.2 mg m−3 dominated by diatoms were observed. Overall, the study region exhibited strong nitrate + nitrite (NOx, −1, and phosphate (PO4, −1 depletion from surface down to about 50–60 m. Silicate (Si exhibited similar trends with the exception of some near shore stations in which high Si concentrations (> 2 μmol L−1 were observed in conjunction with increased TChl a and diatoms concentrations. Surface NOx concentrations were observed to correlate positively with temperature (τ = 0.22, p n = 108, whereas negative correlations were reported between surface NOx (τ = −0.27, p n = 108, Si (τ = −0.68, p n = 108 and salinity indicating that the enhancement in nutrients at the surface was probably supplied through fresher and warmer river waters near the coast. In contrast, the opposite was observed between temperature, salinity and all nutrients in the water column suggesting

  13. Nitrate dual isotopic composition in the northern South China Sea and neighboring West Philippine Sea

    Science.gov (United States)

    Yang, J.; Xu, M.; Wu, Y.; Dai, M.; Kao, S.

    2013-12-01

    Nitrate nitrogen and oxygen isotopic compositions (δ15NNO3 and δ18ONO3) were used to diagnose nitrate dynamics and the origins of water masses in the northern South China Sea (SCS) and West Philippine Sea (WPS) where water exchanges via the Luzon Strait at different depths. In the SCS, 1-3‰ greater upward increase in δ18ONO3 relative to corresponding δ15NNO3 was just observed in the lower euphotic zone (EZ), indicating a rapid internal cycle of nitrate assimilation and remineralization. Much lower nitrate concentration in the EZ of WPS does not allow us to measure its dual isotopes. From 500 m deep to the base of EZ in the WPS, non-proportional decreases in δ15NNO3 (from 6.4‰ to 2.1-2.6‰) and δ18ONO3 (from 3.0‰ to 1.1‰) accompanying with elevated N:P ratio anomalies (N* from -1.2 μM up to 2 μM), suggest the accumulation of atmospheric-derived N (e.g. N2 fixation and/or N deposition). This allochthonous N signal cumulated in the subsurface of WPS may regulate the δ15NNO3 in the SCS subsurface due to seasonal Kuroshio intrusion, which could supply isotopically light nitrate as newly fixed N source to the SCS. The higher (~0.5‰) δ15NNO3 and δ18ONO3 values, associated with lower N* were detected in the WPS intermediate water (WPS-IW, σθ = 26.5~27.1 kg m-3) around depth of 600-800 m (especially at a southern site) when compared to those of the conventional water source coming from North Pacific Intermediate Water (NPIW). By combining nitrate concentration, N* and δ15NNO3 as constraints, we propose that an additional southerly source other than NPIW may feed into the WPS-IW. On the other hand, the SCS intermediate water (SCS-IW, ~400-700 m), which supposedly sourced from WPS-IW along similar isopycnal levels, showed ~1‰ lower δ15NNO3 and δ18ONO3 values. This reduction in nitrate duel isotopes indicates intense diapycnal mixing primarily due to basin-wide upwelling in the SCS interior. This is the first hand data in the SCS for deep profiles

  14. Tidal changes in the Yellow/East China Sea caused by the rapid sea-level rise during the Holocene

    Institute of Scientific and Technical Information of China (English)

    KatsutoUehara

    2001-01-01

    Two-dimensional numerical simulations of M2 and K1 tides were performed in order to assess the effect of the rapid sea level change occurring during the last 20000 years in the Yellow/East China Sea (YECS). Results were interpreted by utilizing the difference of the dynamical nature inherited in diurnal and semi-diurnal tides. M2 tides at the coastal region south of Korea exceeded 2 m in amplitude when the sea-level was low, and decreased as the water depth become larger. In the Yellow Sea, on the other hand, tidal amplitudes were small at the low sea-level stages and increased along with the sea-level rise. The way of the increase was not monotonic but with fluctuations, which was due to the movement of the standing wave nodes. An additional experiment with closing the Taiwan Strait revealed that changing the sill depth of the strait not only affects the M2 tides around the southeastern Chinese coast, but also modifies the tides around the southwestern coast of Korea. This result recall us the significa

  15. A study of sea level variability and its long-term trend in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Ying; LIN Mingsen; ZHENG Quanan; SONG Qingtao; YE Xiaomin

    2016-01-01

    On the basis of the satellite maps of sea level anomaly (MSLA) data andin situ tidal gauge sea level data, correlation analysis and empirical mode decomposition (EMD) are employed to investigate the applicability of MSLA data, sea level correlation, long-term sea level variability (SLV) trend, sea level rise (SLR) rate and its geographic distribution in the South China Sea (SCS). The findings show that for Dongfang Station, Haikou Station, Shanwei Station and Zhapo Station, the minimum correlation coefficient between the closest MSLA grid point and tidal station is 0.61. This suggests that the satellite altimeter MSLA data are effective to observe the coastal SLV in the SCS. On the monthly scale, coastal SLV in the western and northern part of SCS are highly associated with coastal currents. On the seasonal scale, SLV of the coastal area in the western part of the SCS is still strongly influenced by the coastal current system in summer and winter. The Pacific change can affect the SCS mainly in winter rather than summer and the affected area mostly concentrated in the northeastern and eastern parts of the SCS. Overall, the average SLR in the SCS is 90.8 mm with a rising rate of (5.0±0.4) mm/a during 1993–2010. The SLR rate from the southern Luzon Strait through the Huangyan Seamount area to the Xisha Islands area is higher than that of other areas of the SCS.

  16. Evaluation of an ocean data assimilation system for Chinese marginal seas with a focus on the South China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Dazhi; LI Xichen; ZHU Jiang; QI Yiquan

    2011-01-01

    Data assimilation is a powerful tool to improve ocean forecasting by reducing uncertainties in forecast initial conditions. Recently, an ocean data assimilation system based on the ensemble optimal interpolation (EnOI) scheme and HYbrid Coordinate Ocean Model (HYCOM) for marginal seas around China was developed. This system can assimilate both satellite observations of sea surface temperature (SST) and along-track sea level anomaly (SLA) data. The purpose of this study was to evaluate the performance of the system. Two experiments were performed, which spanned a 3-year period from January 1, 2004 to December 30, 2006, with and without data assimilation. The data assimilation results were promising, with a positive impact on the modeled fields. The SST and SLA were clearly improved in terms of bias and root mean square error over the whole domain. In addition, the assimilations provided improvements in some regions to the surface field where mesoscale processes are not well simulated by the model. Comparisons with surface drifter trajectories showed that assimilated SST and SLA also better represent surface currents, with drifter trajectories fitting better to the contours of SLA field than that without assimilation. The forecasting capacity of this assimilation system was also evaluated through a case study of a birth-and-death process of an anticyclone eddy in the Northern South China Sea (NSCS), in which the anticyclone eddy was successfully hindcasted by the assimilation system. This study suggests the data assimilation system gives reasonable descriptions of the near-surface ocean state and can be applied to forecast mesoscale ocean processes in the marginal seas around China.

  17. Tectonics and Petroleum Potential of the East China Sea Shelf Rift Basin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There are two Cenozoic sedimentary basins in the East China Sea. They are the East China Sea shelf basin and the Okinawa Trough basin. The former can be divided into a western and an eastern rift region. The development of the shelf basin underwent continental-margin fault depression, post-rift and then tectonic inversion stages. Available exploration results show that the distribution of source rocks is controlled by the basin architecture and its tectonic evolution. In the Xihu depression, mudstones and coals are the main source rocks. The eastern rift region has good geological conditions for the formation of large oil and gas fields.

  18. Implementation and application of a nested numerical storm surge forecast model in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    于福江; 张占海

    2002-01-01

    A nested numerical storm surge forecast model for the East China Sea is developed. A one-way relaxing nest method is used to exchange the information between coarse grid and fine grid. In the inner boundary of the fine grid model a transition area is set up to relax the forecast variables. This ensures that the forecast variables of the coarse model may transit to those of fine grid gradually, which enhances the model stability. By using this model, a number of hindcasts and forecast are performed for six severe storm surges caused by tropical cyclones in the East China Sea. The results show good agreement with the observations.

  19. A new species of Lophophysema (Porifera, Hexactinellida, Hyalonematidae) from the South China Sea.

    Science.gov (United States)

    Gong, Lin; Li, Xinzheng; Qiu, Jian-Wen

    2014-11-19

    We describe Lophophysema eversa sp. nov. (Porifera, Hexactinellida, Hyalonematidae) based on a single specimen collected from the South China Sea at a depth of 3683 m. The new species can be distinguished from the three known congeners by its unusual body shape with basalia on the side of the body, the lack of macramphidiscs, the combination of the pinular pentactins having spiny tangential rays and the pinular ray of atrialia longer than dermalia and canalaria. This is the first record of the genus Lophophysema from the South China Sea. We also use a partial sequence of the 16S rRNA gene to confirm the family assignment of the new specimen.

  20. The 1997-1998 warm event in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A strong warm event happens during spring 1997 to spring 1999 in the South China Sea. Its intensity and duration show that it is the strongest event on the record over the past decades. It also corresponds with the severe flood over the valley of the Yangtze River and a couple of marine environmental events. This note addressed the evolution process by using several data sets, such as sea surface temperature, height and wind stress in addition to subsurface temperature. The onset of the warm event almost teleconnects with the El Ni?o event in the tropical Pacific Ocean. Summer monsoon is stronger and winter monsoon is weaker in 1997 so that there are persistent westerly anomalies in the South China Sea. During the development phase, the warm advection caused by southerly anomalies is the major factor while the adjustment of the thermocline is not obvious. Subsequently, the southerly anomalies decay and even northerly anomalies appear in the summer of 1998 resulting from the weaker than normal summer monsoon in 1998 in the South China Sea. The thermocline develops deeper than normal, which causes the downwelling pattern and the start of the maintaining phase of the warm event. Temperature anomalies in the southern South China Sea begin to decay in the winter of 1998-1999 and this warm event ends in the May of 1999.

  1. Historical records of eutrophication in Changjiang (Yangtze River estuary and its adjacent East China Sea

    Directory of Open Access Journals (Sweden)

    F. Cheng

    2012-06-01

    Full Text Available Two sediment cores from the Changjiang (Yangtze River estuary and its adjacent East China Sea were collected and studied for eutrophication history using paleoecological records of environmental changes over the last century. A multiproxy approach by using biological and geochemical analyses revealed changes in diatom assemblages, total organic carbon (TOC, total nitrogen (TN and biogenic silica (BSi and give an indication of nutrient in status and trends in Changjiang River estuary and its adjacent East China Sea. The diatom assemblages in the two cores generally increased gradually from the 1970s, and accelerated from the 1990s until now, reflecting the increased eutrophication and causing large algae blooms/red tides. The TOC, TN and BSi showing the similar trends, supported the interpretation of the eutrophication process indicated by diatom analyses. The two cores were located in different sea areas of the East China Sea, and we discuss their relative changes based on their environment characteristics. We also discuss the potential effect of anthropogenic influences and ongoing projects on eutrophication in the Changjiang River and its adjacent East China Sea.

  2. Distribution of Organic Matter, Iron, Mangenese in Surface Sediments in the Nansha Islands Sea Area, South China Sea

    Institute of Scientific and Technical Information of China (English)

    Zhou Weihua; Wu Yunhua; Chen Shaoyong; Yin Kedong

    2003-01-01

    Concentrations of organic matter, iron and manganese in the deep sea surface sediments in the Nansha Islands sea area, South China Sea are measured. Horizontal and vertical distributions of iron and manganese are discussed. The vertical distribution of iron and manganese in the sediments results from reduction, diffusion, and redeposition of manganese (or iron) oxide and hydroxide in the sediment. There are the maxima of iron and manganese in solid phase in the top of the sediment, which is caused by the penetration of O2 and the upward flux of Mn2+ ( or Fe2+ ). Manganese bacteria play a very important role in the cycle of solid-phase iron and manganese in the ocean environment. Manganese bacteria oxidize Mn2+ ( or Fe2+ ) in dissolved state to Mn4+ ( or Fe3+ ) in oxidized state under the aerobic condition, whereas they reduce iron and manganese in anaerobic conditions.

  3. A Regional Ocean Reanalysis System for Coastal Waters of China and Adjacent Seas

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A regional ocean reanalysis system for the coastal waters of China and adjacent seas has been developed by the National Marine Data and Information Service(NMDIS).It produces a dataset package called CORA (China ocean reanalysis).The regional ocean model used is based on the Princeton Ocean Model with a generalized coordinate system(POMgcs).The model is parallelized by NMDIS with the addition of the wave breaking and tidal mixing processes into model parameterizations.Data assimilation is a sequential three-dimensional variational(3D-Var) scheme implemented within a multigrid framework.Observations include satellite remote sensing sea surface temperature(SST),altimetry sea level anomaly(SLA),and temperature/salinity profiles.The reanalysis fields of sea surface height,temperature,salinity,and currents begin with January 1986 and are currently updated every year. Error statistics and error distributions of temperature,salinity and currents are presented as a primary evaluation of the reanalysis fields using sea level data from tidal gauges,temperature profiles,as well as the trajectories of Argo floats.Some case studies offer the opportunity to verify the evolution of certain local circulations.These evaluations show that the reanalysis data produced provide a good representation of the ocean processes and phenomena in the coastal waters of China and adjacent seas.

  4. On the relationship between convection intensity of South China Sea summer monsoon and air-sea temperature difference in the tropical oceans

    Institute of Scientific and Technical Information of China (English)

    LIN Ailan; LIANG Jianyin; GU Dejun; WANG Dongxiao

    2004-01-01

    The annual, interannual and inter-decadal variability of convection intensity of South China Sea (SCS) summer monsoon and air-sea temperature difference in the tropical ocean is analyzed, and their relationship is discussed using two data sets of 48-a SODA (simple ocean data assimilation) and NCEP/NCAR. Analyses show that in wintertime Indian Ocean (WIO), springtime central tropical Pacific (SCTP) and summertime South China Sea-West Pacific (SSCSWP), air-sea temperature difference is significantly associated with the convection intensity of South China Sea summer monsoon. Correlation of the inter-decadal time scale (above 10 a) is higher and more stable. There is interdecadal variability of correlation in scales less than 10 a and it is related with the air-sea temperature difference itself for corresponding waters. The inter-decadal variability of the convection intensity during the South China Sea summer monsoon is closely related to the inter-decadal variability of the general circulation of the atmosphere. Since the late period of the 1970s, in the lower troposphere, the cross-equatorial flow from the Southern Hemisphere has intensified. At the upper troposphere layer, the South Asian high and cross-equatorial flow from the Northern Hemisphere has intensified at the same time. Then the monsoon cell has also strengthened and resulted in the reinforcing of the convection of South China Sea summer monsoon.

  5. Sedimentary architecture of the Bohai Sea China over the last 1 Ma and implications for sea-level changes

    Science.gov (United States)

    Shi, Xuefa; Yao, Zhengquan; Liu, Qingsong; Larrasoaña, Juan Cruz; Bai, Yazhi; Liu, Yanguang; Liu, Jihua; Cao, Peng; Li, Xiaoyan; Qiao, Shuqing; Wang, Kunshan; Fang, Xisheng; Xu, Taoyu

    2016-10-01

    Sedimentary architecture dominated by transgression-regression cycles in the shallow Bohai shelf region contains information about global sea-level, climate and local tectonics. However, previous studies of transgression-regression cycles in this region at orbital timescales that extend back to the early Pleistocene are sparse, mainly because of the shortage of well-dated long cores. Although transgression-regression sedimentary cycles in the region have been interpreted in terms of local tectonics, sea-level, and climate change, the detailed structure of marine transgressions and their significance for Quaternary global sea-level variations remains to be examined. In this study, we present an integrated sedimentological, geochemical and paleontological study of a 212.4 m (∼1 Ma) core (BH08) recovered from the Bohai Sea, China, for which an astronomically-based age model is available. Correspondence between marine-terrestrial sedimentary cycles and global sea-level fluctuations suggests that stacking of marine and terrestrial sediments was driven mainly by glacio-eustatic sea-level fluctuations in a context in which tectonic subsidence was largely balanced by sediment supply over the last ∼1 Ma. We report a dominant 100-kyr cycle beginning at ∼650 ka, which reflects the worldwide influence of the mid-Pleistocene transition (MPT) in sea-level records. We find that neritic deposits after the MPT were relatively thicker than before the MPT, which indicates an important control of the MPT on sedimentary architecture through lengthening of the duration of sea-level highstands.

  6. Inter-shelf nutrient transport from the East China Sea as a major nutrient source supporting winter primary production on the northeast South China Sea shelf

    Directory of Open Access Journals (Sweden)

    A. Han

    2013-02-01

    Full Text Available The East China Sea (ECS and the South China Sea (SCS are two major marginal seas of the north Pacific with distinct seasonal primary productivity. Based upon field observation in December 2008–January 2009 covering both the ECS and the northern SCS (NSCS in wintertime, we examined southward long-range nutrient-transport from the ECS to the northeast SCS (NESCS carried by the China Coastal Current (CCC driven by the northeast prevailing monsoon. These nutrients escaped from the cold ECS shelf to refuel the primary production on the NESCS shelf where river-sourced nutrients were limited yet water temperature remained favorable. By coupling the field observation of nitrate + nitrite (DIN with the volume transport of the CCC, we derived a first order estimate of DIN flux of ~ 1430 ± 260 mol s−1. This DIN flux was ~ 7 times the wintertime DIN input from the Pearl River, a primary riverine nutrient source to the NSCS. By assuming DIN was the limiting nutrient, such southward DIN transport would have stimulated ~ 8.8 ± 1.6 × 1011 gC of new production (NP, accounting for ~ > 58 ± 10% of the total NP or ~ 38 ± 7–24 ± 4% of primary production on the NESCS shelf shallower than 100 m.

  7. An Objective Analysis Method for Surface Residual Current Field in the East China Seas

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; WANG Cizhen

    2003-01-01

    Since the volume transport across the pycnocline is much smaller than that in the mixed layer, the current in the mixed layer can be regarded as non-divergent. An objective analysis method is deduced based on this hypothesis. The linear combination method is used to solve the non-divergent component of the current field of an ocean basin containing islands,which is equivalent to a mathematical problem of solving a Poisson equation in a multi-connected domain. The method is applied to the Bohai Sea, the Yellow Sea and the East China Sea (ECS). The modeled result is consistent with the current maps constructed by other oceanographers.

  8. Numerical simulation of scatterometer assimilated wind and ocean wave in eastern China seas and adjacent waters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Using the latest version of Mesoscale Modeling System (MM5v3), we assimilated wind data from the scatterometer and built a model to assimilate the wind field over eastern China seas and adjacent waters and applied the wave model WAVEWATCH-Ⅲ to test the sea area with assimilative wind and blended wind of QSCAT and NCEP as driving forces. High precision and resolution numerical wave results were obtained.Analysis indicated that ifwe replace the model wind result with the blended wind, better sea surface wind results and wave results could be obtained.

  9. Biomass of meiobenthic in the Bohai Sea, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A grid of 22 stations, giving a broad geographic coverage of the Bohai Sea and the Bohai Strait was selected. Undisturbed sediments were collected from sampling stations during cruises in June 1997, in September/October 1998 and again in April/May 1999. Based on the results of Juario (1975),the average biornass, 0.404 g/(m2@ a) of meiofauna (including nematode, harpacticoida, bivalve larvae,polycheata and kinorhyncha) in the Bohai Sea is given and accounts for 4.5 percent of the macrofauna in the Bohai Sea. The horizontal distribution of the biomass of meiofauna showed that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruises and it decreased at the stations near to the strait mouth and increased at Station B1 in 1999 cruise. The annual average pro duction in the Bohai Sea is 3. 636 g/m2 calculated in term of the formula P = 9B. Compared with the biomass of other sea areas in the world, the biomass of the Bohai Sea is similar but slightly lower. The individual average dry weight of nematodes given by different authors is analyzed.

  10. Optical properties of sea ice in Liaodong Bay, China

    Science.gov (United States)

    Xu, Zhantang; Yang, Yuezhong; Wang, Guifen; Cao, Wenxi; Li, Zhijun; Sun, Zhaohua

    2012-03-01

    Many industrial, agricultural, and residential areas surrounding Liaodong Bay are responsible for much of the particulate matter (PM) and colored dissolved organic matter (CDOM) found in the sea ice in the bay. Understanding the optical properties of "dirty" sea ice is important for analyzing remote sensing data and calculating energy balances. We designed a hyperspectral radiation instrument to observe the optical properties of sea ice. The results show that albedo peaks ranged from 0.3 to 0.85 and that the peaks shifted to a longer wavelength for high PM and CDOM concentrations. The absorption and scattering coefficients for sea ice were obtained. The bulk absorption coefficient shows that bulk absorption is primarily determined by PM and CDOM at shorter wavelengths, while pure ice and brine pockets become more important at longer wavelengths. Scattering coefficients for sea ice ranged from 197 to 1072 m-1, and showed consistent variations with gas bubble and brine pocket concentrations. The effects of PM and CDOM on the bulk absorption coefficient of sea ice were studied. At 440 nm, particulates accounted for 55-98% and CDOM accounted for 2-37% of the bulk absorption. Ratios between particulate absorption and bulk absorption for sea ice were almost constant from 400 to 550 nm, and began to decrease sharply for wavelengths >550 nm. Ratios between CDOM and bulk absorption decreased almost linearly with increasing wavelength.

  11. Spatial distributions of floating seaweeds in the East China Sea from late winter to early spring.

    Science.gov (United States)

    Mizuno, S; Ajisaka, T; Lahbib, S; Kokubu, Y; Alabsi, M N; Komatsu, T

    2014-01-01

    Floating seaweeds play an important role as a habitat for many animals accompanying or attaching to them in offshore waters. It was in 2000 that the first report described abundant distributions of floating seaweeds in offshore waters in the East China Sea in spring. Young individuals of the yellowtail Seriola quinqueradiata are captured for aquaculture purposes from floating seaweeds in the East China Sea. Therefore, a sound understanding of the distributions of floating seaweeds in the East China Sea is needed. Detailed information is especially important during the late winter to early spring, which corresponds to the juvenile period of the yellowtail. Thus, field surveys using R/V Tansei-Maru were conducted in the Japanese Exclusive Economic Zone in the East China Sea from late winter to early spring in 2010 and 2011. We obtained positions of the vessel by GPS and transversal distances from the vessel to a raft by visual observation. Distance sampling method (Thomas et al. 2010) was applied to estimation of floating seaweed densities (rafts km(-2)). Seaweed rafts were also randomly sampled using nets during the research cruises. In the East China Sea, seaweed rafts were distributed mainly on the continental shelf west of the Kuroshio, especially in waters between 26° N and 30° N. Collected rafts consisted of only one species, Sargassum horneri (Turner) C. Agardh. Taking into account surface currents and geographical distribution of S. horneri, it is estimated that these floating seaweeds originated from natural beds along the coast between mid and south China. Considering the approximate travel times, it is suggested that floating patches are colonized by yellowtails early on during their trips, i.e., close to the Chinese coast.

  12. Monthly sea surface temperature records reconstructed by δ18O of reef-building coral in the east of Hainan Island,South China Sea

    Institute of Scientific and Technical Information of China (English)

    HE; Xuexian(何学贤); LIU; Dunyi(刘敦一); PENG; Zicheng(彭子成); LIU; Weiguo(刘卫国)

    2002-01-01

    Stable oxygen isotopic compositions of a coral colony of Porites lutea obtained on a core allowed the reconstruction of a 56-a (1943-1998) proxy record of the sea surface temperatures. This coral δ18O data are from the east of Hainan Island water (22°20′N, 110°39′E), South China Sea. The relationship between δ18O in the skeletal aragonite carbonate and the sea surface temperature (SST) is SST = -5.36 δ18OPDB-3.51 (r = 0.73, n = 470), dδ18O/d(SST) = -0.187‰/ ℃; and the thermometer was set at monthly resolution. The 56-a (1943-1998) proxy record of the sea surface temperatures reflected the same change trend in the northern part of South China Sea as the air temperature change trend in China.

  13. INTENSITY INDEX OF SOUTH CHINA SEA MONSOON AND ITS VARIATION CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    吴尚森; 梁建茵

    2002-01-01

    According to the basic characteristics of the activities of summer monsoon in the South China Sea,Standardized index,Is,has been designed that integrates a dynamic factor(southwesterly component) and a thermodynamic factor(OLR) for the indication of summer monsoon in the South China Sea,With the index determined for individual months of June,July and August and the entire summertime from 1975 to 1999,specific months and years are indicated that are either strong or weak in monsoon intensity,The variation is studied for the patterns and Is's relationship is revealed with the onset of summer monsoon and the precipitation in Guang-dong province and China.The results show that there are quasi-10 and quasi-3-4 year cycles in the interannual variation of the monsooon over the past 25 years.When it has an early(late)onset,the summer monsoon is usually strong (weak),In the strong(weak)monsoon,years,precipitation tends to be more(less)in the first raining season of the year but normal or less(normal)in the second,in the province,but it would be more(less) in northeastern China and most parts of the northern china and south of the lower reaches of the Changjiang River and less(more)in the middle and lower reaches of the river,western part of northern China and western China.

  14. INTENSITY INDEX OF SOUTH CHINA SEA MONSOON AND ITS VARIATION CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    吴尚森; 梁建茵

    2002-01-01

    According to the basic characteristics of the activities of summer monsoon in the South China Sea,a standardized index,, has been designed that integrates a dynamic factor (southwesterly component) and a thermodynamic factor (OLR) for the indication of summer monsoon in the South China Sea.With the index determined for individual months of June,July and August and the entire summertime from 1975 to 1999,specific months and years are indicated that are either strong or weak in monsoon intensity.The variation is studied for the patterns and 's relationship is revealed with the onset of summer monsoon and the precipitation in Guangdong province and China.The results show that there are quasi-10 and quasi-3-4 year cycles in the interannual variation of the monsoon over the past 25 years.When it has an early (late) onset,the summer monsoon is usually strong (weak).In the strong (weak) monsoon years,precipitation tends to be more (less) in the first raining season of the year but normal or less (normal) in the second,in the province,but it would be more (less) in northeastern China and most parts of the northern China and south of the lower reaches of the Changjiang River and less (more) in the middle and lower reaches of the river,western part of northern China and western China.

  15. Distribution of Dissolved Inorganic Phosphate in Nansha Islands Sea Area,Southern South China Sea

    Institute of Scientific and Technical Information of China (English)

    程塞伟; 林洪瑛

    2004-01-01

    Based on the survey data from the program Multidisciplinary Expedition to Nansha Islands Sea Area, the distribution of dissolved inorganic phosphate ( PO43--P ) in the sea water of Nansha Islands Sea Area is comprehensively analyzed in this paper. The results show that PO43--P concentration in the sea water of southeastern Nansha Islands Sea Area is commonly higher than that in the other sea areas; the vertical distribution of PO43--P concentration varies inconspicuously in different seasons; the concentration of PO43--P increases with water depth and changes most greatly in the layer of 50 ~ 100 m. The diurnal variation of PO43--P concentration differs in different seasons and at different observation stations. The distribution and variation of PO43--P concentration result from the physical and biological processes together.

  16. 宽鳃鮟鱇属一新种%A NEW SPECIES OF THE GENUS SLADENIA (PISCES, LOPHIIDAE) FROM THE EAST CHINA SEA AND THE SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    倪勇; 伍汉霖; 李生

    2012-01-01

    A new lophiid anglerfish of the deep water genus Sladenia is described based on four specimens collected from the East China Sea and the South China Sea during the period from 1980 to 1982.Sladenia Regan ( 1908 ) is a genus of lophiid anglerfish with rounded rather than depressed head, and compressed rather than depressed tail; nasal sacs not constricted at the base; very long pseudobranchia; humeral, subopercular, quadrate, parietal and articular spines absent; epiotic and interopercular spines low and rounded; vomerine teeth larger than palatine teeth; illicial bone and second dorsal spine inserting very close together on illicial pterygiophore; third or third and fourth dorsal spines invisible, hiding under the skin of post-cephalic portion; and smooth ridge on frontal bones anterior to eyes and lateral to illicial pterygiophore.There were only four specimens, identified as 3 species, I. E., S. Gardineri Regan, 1908, S. Remiger Smith et Radcliffe, 1912 and S. Shaefersi Caruso et Bullis 1976, belonging to the genus Sladenia in the world before 1976. During the period from 1980 to 1982, the RV "Dongfang" and the RV "Nanfeng" of the East China Sea Fisheries Institute and the South China Sea Fisheries Research Institute respectively, completed a survey of the deep water fish fauna of the East and South China Seas. Four separate Chinese specimens of the rare lophiid anglerfish genus Sladenia were collected. With detailed analysis of the four rare specimens, it was recognized that they should belong to the same species, and also a new species named as Sladenia zhui.%20世纪70年代以前,全世界已知宽鳃鮟鱇属Sladenia Regan( 1908)鱼类仅有3种.1980~1982年期间,东海水产研究所“东方”号和南海水产研究所“南锋”号调查船分别在东海和南海的大陆架渔场调查时,共采集到4尾珍稀的深海鮟鱇鱼类.经研究,认为这4尾标本是1新种,定名为朱氏宽鳃鮟鱇Sladenia zhui sp.nov..

  17. Tidal elevation, current, and energy flux in the area between the South China Sea and Java Sea

    Science.gov (United States)

    Wei, Zexun; Fang, Guohong; Dwi Susanto, R.; Rameyo Adi, Tukul; Fan, Bin; Setiawan, Agus; Li, Shujiang; Wang, Yonggang; Gao, Xiumin

    2016-04-01

    The South China Sea (SCS) and the Java Sea (JS) are connected through the Karimata Strait, Gaspar Strait, and the southern Natuna Sea, where the tides are often used as open boundary condition for tidal simulation in the SCS or Indonesian seas. Tides, tidal currents, and tidal energy fluxes of the principle constituents K1, O1, Q1, M2, S2, and N2 at five stations in this area have been analyzed using in situ observational data. The results show that the diurnal tides are the dominant constituents in the entire study area. The constituent K1 has the largest amplitude, exceeding 50 cm, whereas the amplitudes of M2 are smaller than 5 cm at all stations. The amplitudes of S2 may exceed M2 in the Karimata and Gaspar straits. Tidal currents are mostly of rectilinear type in this area. The semi-major axes lengths of the diurnal tidal current ellipses are about 10 cm s-1, and those of the semidiurnal tidal currents are smaller than 5 cm s-1. The diurnal tidal energy flows from the SCS to the JS. The semidiurnal tidal energy flows from the SCS to the JS through the Karimata Strait and the eastern part of the southern Natuna Sea but flows in the opposite direction in the Gaspar Strait and the western part of the southern Natuna Sea. Harmonic analysis of sea level and current observation also suggest that the study area is located in the antinodal band of the diurnal tidal waves, and in the nodal band of the semidiurnal tidal waves. Comparisons show that the existing models are basically consistent with the observational results, but further improvements are necessary.

  18. Dissolved Cu, Pb, Zn and Cd in the South China Sea surface waters

    Institute of Scientific and Technical Information of China (English)

    Huo Wenmian; Ji Weidong; Xu Kuncan

    2001-01-01

    A total of 106 surface water samples were collected in the South China Sea during two transects in June and December 1998. The samples were collected with strictly contamination free procedure and trace metals were measured by clean laboratory methods and GFAAS. The mean concentrations for the dissolved fractions are: Cu 0.100 μg/dm3, Pb 0.060 μg/dm3, Zn 0.086 μg/dm3, Cd 0.007 μg/dm3, which is close to the world open ocean's level. The spatial distribution of the trace heavy metals shows higher concentrations in offshore area and lower concentrations in the central in the South China Sea, and the concentrations decrease with the distance from the offshore, which suggests the existence of significant continental shelf input of the trace heavy metals. The correlationship among the elements is better in summer than that in winter. Cu is positively correlated with Cd in both seasons and it is also found for the first time that they are positively correlated with nutrients in the South China Sea surface waters which further indicate the biogeochemical cycle of these elements in the marine environment. The baseline value of Cu, Pb, Zn, Cd in the South China Sea surface waters is obtained through statistical analysis.

  19. Bioremediation efficiency of the largest scale artificial Porphyra yezoensis cultivation in the open sea in China.

    Science.gov (United States)

    Wu, Hailong; Huo, Yuanzi; Zhang, Jianheng; Liu, Yuanyuan; Zhao, Yating; He, Peimin

    2015-06-15

    The bioremediation efficiency of China's largest scale Porphyra yezoensis cultivation for removing dissolved nutrients and controlling harmful algae was studied in the radial sandbanks waters of Jiangsu Province in the year 2012-2013. Mean nutrient concentration values in the P. yezoensis cultivation area were significantly lower than those in the non-cultivation area, especially during the cultivation season (popen sea.

  20. Numerical Forecasting Experiment of the Wave Energy Resource in the China Sea

    Directory of Open Access Journals (Sweden)

    Chong Wei Zheng

    2016-01-01

    Full Text Available The short-term forecasting of wave energy is important to provide guidance for the electric power operation and power transmission system and to enhance the efficiency of energy capture and conversion. This study produced a numerical forecasting experiment of the China Sea wave energy using WAVEWATCH-III (WW3, the latest version 4.18 wave model driven by T213 (WW3-T213 and T639 (WW3-T639 wind data separately. Then the WW3-T213 and WW3-T639 were verified and compared to build a short-term wave energy forecasting structure suited for the China Sea. Considering the value of wave power density (WPD, “wave energy rose,” daily and weekly total storage and effective storage of wave energy, this study also designed a series of short-term wave energy forecasting productions. Results show that both the WW3-T213 and WW3-T639 exhibit a good skill on the numerical forecasting of the China Sea WPD, while the result of WW3-T639 is much better. Judging from WPD and daily and weekly total storage and effective storage of wave energy, great wave energy caused by cold airs was found. As there are relatively frequent cold airs in winter, early spring, and later autumn in the China Sea and the surrounding waters, abundant wave energy ensues.

  1. Critical Discourse Analysis of American News Reports on South China Sea Issue

    Institute of Scientific and Technical Information of China (English)

    黄佳琪

    2014-01-01

    Critical discourse analysis (CDA) is an influential and useful approach to comprehend a discourse, which helps reveal the embedded ideology within the discourse. According to the CDA and systemic-functional grammar, this paper tries to analyze two American news reports on South China Sea issue and to explore the hidden ideology behind them.

  2. Atmospheric transport and deposition of anthropogenic substances from the Asia to the East China Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Uematsu, M.; Hattori, H.; Nakamura, T.; Narita, Y.; Jung, J.; Matsumoto, K.; Nakaguchi, Y.; DileepKumar, M.

    deposition over the East China Sea. We determined the concentrations of trace elements Al, Mn, Pb, Se, and Zn and major ions Na sup(+), SO sub(4) sup(2-) and NO sub(3) sup(-) in aerosol particles. Aerosols were continuously collected in fine and coarse size...

  3. Descriptions of three new species of Mitridae (Mollusca: Gastropoda) from South China Sea

    Institute of Scientific and Technical Information of China (English)

    LI Baoquan; ZHANG Suping; LI Xinzheng

    2005-01-01

    Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANG, Neocancilla daidaleosa sp.nov. B. LI & X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.

  4. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    DEFF Research Database (Denmark)

    Chang, Rui; Rong, Zhu; Badger, Merete

    2015-01-01

    offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...

  5. The boat people of Vietnam. Rescue on the South China Sea.

    Science.gov (United States)

    Hayes, T J; Thomas, D; Dewar, E P

    1990-01-01

    Poor economic conditions in Vietnam have encouraged large numbers of people seeking a better life in the West to join the flow of political refugees leaving the country as "boat people". We report the events surrounding one such group of people who were rescued from the South China Sea by the Outback 88 Task Group.

  6. Distribution of nanoflagellates in five water masses of the East China Sea in autumn and winter

    Science.gov (United States)

    Lin, Shiquan; Huang, Lingfeng; Zhu, Zhisheng; Xiong, Yuan; Lu, Jiachang

    2016-02-01

    The variations of abundance, biomass and trophic structure of nanoflagellates (NF) among five typical water masses in the East China Sea were investigated in autumn (November 19-December 23, 2006) and winter (February 22-March 11, 2007). It was found that water mass had a significant impact on the distribution of NF. Either in autumn or in winter, the highest abundance and biomass of NF were recorded in the East China Sea Shelf Mixing Water (ECSSMW), and the lowest in the Kuroshio Subsurface Water (KSSW). While in the East China Sea Coastal Water (ECSCW), the abundance and biomass of both heterotrophic nanoflagellates (HNF) and pigmented phototrophic nanoflagellates (PNF) were only slightly higher than that in Taiwan Strait Water (TSW) and Kuroshio Surface Water (KSW). In respect to the seasonal variation, the abundance and biomass of NF in TSW declined in winter, while in other 4 water masses, they showed an increasing trend from autumn to winter, mainly due to the decrease (in TSW) or increase (in ECSCW, ECSSMW, KSW and KSSW) of HNF. The distribution pattern of abundance- or biomass-based PNF/HNF ratio was found to be correlated to the nutrient level of the water mass. Results of Pearson correlation analysis and principle component analysis indicated that PNF was mainly constrained by nutrient supply, and HNF was controlled by food availability in the East China Sea.

  7. Contrasting behavior of tungsten and molybdenum in the Okinawa Trough, the East China Sea and the Yellow Sea

    Energy Technology Data Exchange (ETDEWEB)

    Sohrin, Yoshiki; Matsui, Masakazu; Nakayama, Eiichiro

    1999-10-01

    By using catalytic current polarography and high-resolution inductively coupled plasma mass spectrometry, W and Mo in seawater were determined in the Okinawa Trough, a backarc rift, and in the East China Sea and the Yellow Sea. Mo was distributed conservatively throughout the study area, and its salinity-normalized concentration was 104 {+-} 6 nM (n = 105). W was also uniformly distributed south of the Kuroshio Current (56 {+-} 7 pM, n = 51). Anomalous high concentrations of W (maximum 254 pM) were found in the Iheya Graben in the middle Okinawa Trough ({gt}1,000 m depth), which were probably supplied by hydrothermal activity. The concentrations of Mo and W in the East China Sea and the Yellow Sea showed linear correlation with salinity (26 {lt} S {lt} 35). The Mo data can be explained by mixing of seawater and river water of the Changjiang (Mo = 10 nM; Qu et al., 1993). However, the values of W extrapolated to S = 0 were largely different between two cruises (1,200 pM in May-June 1987 and 540 pM in June 1994) and much higher than the reported concentrations of 160 pM for world rivers by Turekian (1969) and 30 pM for unpolluted Japanese rivers by Sohrin et al. (1989). Moreover, significantly high W was observed in the bottom water at stations near the Changjiang River estuary and the western Yellow Sea. While these data may suggest that W is released from the anoxic sediments of the continental shelf, more data are needed to elucidate the mechanism controlling the distribution of W.

  8. Chinese Assertiveness in the South China Sea and Southeast Asian Responses

    Directory of Open Access Journals (Sweden)

    Carlyle A. Thayer

    2011-01-01

    Full Text Available This article reviews Chinese assertive behaviour towards the Philippines and Vietnam over South China Sea issues in 2011. The article compares and contrasts Chinese diplomatic behaviour in the period before and after the adoption by ASEAN member states and China of Guidelines for the Implementation the Declaration on Conduct of Parties in the South China Sea in July. In the first period China aggressively asserted its claims to sovereignty by interfering with commercial fishing and oil exploration activities of vessels operating in the Exclusive Economic Zones of Vietnam and the Philippines. Both states resisted Chinese actions. The Philippines allocated increased funding for defence modernization, lobbied ASEAN states and shored up its alliance with the United States. Vietnam too protested Chinese action and undertook symbolic steps to defend national sovereignty. In the second period all states moved to contain South China Sea tensions from affecting their larger bilateral relations. It remains to be seen, however, if proposed confidence building measures will ameliorate Chinese assertiveness.

  9. Tectono-thermal modeling of the Yinggehai Basin, South China Sea

    Institute of Scientific and Technical Information of China (English)

    HE; Lijuan

    2001-01-01

    [1]Li Yuliang, Huang Zhongming, Thermal history about northern margin of South China Sea, China Offshore Oil and Gas (Geology) (in Chinese), 1990, 4(6): 31.[2]Li Yuliang, Zhang Quanxing, Zhang Qiming, Thermal abnormality of Ya13-1 gas field, China Offshore Oil and Gas (Geology) (in Chinese), 1992, 6(5): 33.[3]Gong Zaisheng, Li Sitian et al., Basin Analysis and Accumulation of Oil and Gas in Northern Margin of South China Sea (in Chinese), Beijing: Science Press, 1997.[4]He Lijuan, Xiong Liangping, Wang Jiyang et al., Calculation of stretching factors in the multi-phase modeling of sedimentary basins, Chinese Science Bulletin (in Chinese), 1995, 40(24): 2261.[5]He Lijuan, Xiong Liangping, Wang Jiyang, Effects on the tectono-thermal modeling of extensional basins, Scientia Geologica Sinica (in Chinese), 1998, 33(2): 222.[6]Pitman, W. C., Andrews, J. A., Subsidence and thermal history of small pull-apart basins, in Strike-slip Deformation, Basin Formation and Sedimentation (eds. Kevin, T. B., Nicholas, C. B.), Society of Economic Paleontologists and Mineralogists, Special Publication, 1985.[7]Zhang Qiming, Hu Zhongliang, High-temperature and high-pressure conditions and migration of hydrocarbons in Yinggehai-Qiongdongnan basin, A Collection on Petroleum Geology of Yinggehai Basin, South China Sea (in Chinese), Beijing: Seismology Press, 1993, 78-84.

  10. Application of adjoint assimilation technique in simulating tides and tidal currents of the Bohai Sea, the Yellow Sea and the East China Sea

    Institute of Scientific and Technical Information of China (English)

    Cheng Yongcun; Lu Xianqing; Liu Yuguang; Xu Qing

    2007-01-01

    Considering the interaction of different tidal waves, an adjoint numerical model is developed to simulate M2, S2, K1 and O1 tidal waves in the Bohai Sea, the Yellow Sea and the East China Sea(B-Y-E) simultaneously. Compared with previous researches, by using the adjoint assimilation technique to inverse open boundary conditions and bottom friction coefficients based on altimetric data from TOPEX/Poseidon (T/P)and tidal gauges data, the precision of the numerical simulation is significantly improved. Selecting 14 days of simulated results after t11e initial warming run to conduct harmonic analysis, the results can show the characteristics of M2, S2, K1 and O1 tidal wave systems perfectly in B-Y-E. Compared with 9 current stations, the calculated harmonic constants of tidal currents for M2 and K1 are in good agreement With the observed ones.

  11. What Depth Should Deep-Sea Water be Pumped up from in the South China Sea for Medicinal Research?

    Institute of Scientific and Technical Information of China (English)

    HE Shan; LIU Hongbing; YANG Xue; LI Chunxia; GUAN Huashi

    2013-01-01

    In this study,seawater was pumped up from 150,200,300,500 and 1000m in the South China Sea and analyzed to make certain what depth should deep-sea water (DSW) be pumped up for medicinal usage.The pumping depth of DSW was determined on the basis of chemical ingredients.The analyses of inorganic elements and dissolved organic matter (DOM) were performed by inductively coupled plasma mass spectrometry (ICP-MS) and ultra performance liquid chromatography-mass spectrometry (UPLC-MS) respectively.The raw data were used for hierarchical cluster analysis (HCA) and principal component analysis (PCA).The results showed that seawater pumped up from 500m and 1000m was similar in their chemical ingredients,and was different from the seawater pumped up from other depths.These results indicated that seawater from more than 500 m depth had relatively stable chemical ingredients and could be used as DSW in the South China Sea.

  12. Data from renewable energy assessments for resort islands in the South China Sea

    Directory of Open Access Journals (Sweden)

    M. Reyasudin Basir Khan

    2016-03-01

    Full Text Available Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article “Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea” published in Energy (Khan et al., 2015 [1].

  13. Sea Level Rise and Land Subsidence Contributions to the Signals from the Tide Gauges of China

    Science.gov (United States)

    Parker, Albert

    2016-06-01

    The tide gauges measure the local oscillations of the sea level vs. the tide gauge instrument. The tide gauge instrument is generally subjected to the general subsidence or uplift of the nearby inland, plus some additional subsidence for land compaction and other localised phenomena. The paper proposes a non-linear model of the relative sea level oscillations including a long term trend for the absolute sea level rise, another term for the subsidence of the instrument, and finally a sinusoidal approximation for the cyclic oscillations of periodicities up to decades. This non-linear model is applied to the tide gauges of China. The paper shows that the limited information available for China does not permit to infer any proper trend for the relative rates of rise, as the tide gauge records are all short or incomplete and the vertical movement of the tide gauge instruments is unassessed. The only tide gauge record of sufficient length that may be assembled for China is obtained by combining the North Point and Quarry Bay tide gauges in Hong Kong (NPQB). This NQPB composite tide gauge record is shown to have similarities with the tide gauge records of Sydney, equally in the West pacific, and San Diego, in the east Pacific, oscillating about the longer term trend mostly determined by the local subsidence. As it is very well known that China generally suffers of land subsidence, and the tide gauge installations may suffer of additional subsidence vs. the inland, it may be concluded from the analysis of the other worldwide tide gauges that the sea levels of China are very likely rising about the same amount of the subsidence of the tide gauges, with the sea level acceleration component still negligible.

  14. Progress of Large-Scale Air-Sea Interaction Studies in China

    Institute of Scientific and Technical Information of China (English)

    蒲书箴; 赵进平; 于卫东; 赵永平; 杨波

    2004-01-01

    This paper summarizes the progress of large-scale air-sea interaction studies that has been achieved in China in the four-year period from July 1998 to July 2002, including seven aspects in the area of the air-sea interaction, namely air-sea interaction related to the tropical Pacific Ocean, monsoon-related air-sea interaction, air-sea interaction in the north Pacific Ocean, air-sea interaction in the Indian Ocean, air-sea interactions in the global oceans, field experiments, and oceanic cruise surveys. However more attention has been paid to the first and the second aspects because a large number of papers in the reference literature for preparing and organizing this paper are concentrated in the tropical Pacific Ocean, such as the ENSO process with its climatic effects and dynamics, and the monsoon-related air-sea interaction. The literature also involves various phenomena with their different time and spatial scales such as intraseasonal, annual, interannual, and interdecadal variabilities in the atmosphere/ocean interaction system, reflecting the contemporary themes in the four-year period at the beginning of an era from the post-TOGA to CLIVAR studies. Apparently, it is a difficult task to summarize the great progress in this area, as it is extracted from a large quantity of literature, although the authors tried very hard.

  15. Microgastropod records in paleoceanographical environment of southern shelf of South China Sea since 14 ka

    Institute of Scientific and Technical Information of China (English)

    冯伟民

    2002-01-01

    Very diversified and abundant benthic microgastropods and planktonic microgastropods (pteropods) from core NS93-12-25 could provide a glance of change of the sea level in the south continental shelf of the South China Sea since last 14 ka. Research shows that general sea level changes of this sea area were rising and later rising after a short period of falling in this period. In the range from the bottom of the core to the core depth of 200 cm, individuals in big size are common in microgastropods and Turritella filiola is very rich, signifying the environment of the inner continental shelf in the last deglaciation stage. In the core depth range of 200—150 cm the continuously getting light of the ??18O, the regularly decreasing of the percentage content of T. filiola and the high diversification of microgastropods indicate the rising of the sea level. Especially at the core depth range of 175—150 cm the pteropods became dominant, making sure the fact that the high sea level possibly occurred in the early Holocene. Channels of surrounding straits connecting the adjacent sea thus were opened. But at the core depth of about 100 cm T. filiola became very rich again. This possibly implies that there was a short term of the sea level falling, resulting in the temporal closure of the channels. In the core depth range of 55—50 cm the Scaliola' s representatives relatively develop and this may be inferred to the cooling of climate.

  16. Ocean pollution from land-based sources: East China Sea, China.

    Science.gov (United States)

    Li, Daoji; Daler, Dag

    2004-02-01

    The environment of East China Sea (ECS) has been faced by huge stresses from anthropogenic activities and population growth in the Yangtze River drainage basin and the areas along the coasts. Improper use of natural resources and short-term economic objectives have resulted in severe environmental degradation in a fairly short time frame and the degradation has now reached a level where the health and well being of the coastal populations are threatened. The main pollutants are inorganic nitrogen, phosphate, oil hydrocarbons, organic matters and heavy metals. Nutrients cause eutrophication of the coastal waters and the estuarine area and very often stimulate the occurrence of red tides. The environmental pollution of Yangtze River basin directly impact on the state of the marine environment in the ECS. The ecosystem stability is maintained by a steady water discharge from the river, that mixes with the marine salty water in the estuary, and the sediment loads from the river that balance ocean erosion in the delta and its adjacent coastal area. The large-scale water transfer and dam constructions in the Yangtze River basin will change this basis. For the ECS the challenge is to reverse the negative processes taking place and to restore ecosystem balance. The main challenge is to integrate socioeconomic and environmental decision making in order to promote sustainable development. A better understanding of the driving forces in society that cause these environmental pressures is required in order to overcome these obstacles. International cooperation may be an important contributor to the progress and in particular provide access to financial, technological, scientific and human resource assistance.

  17. Toxic metal pollution in the Yellow Sea and Bohai Sea, China: distribution, controlling factors and potential risk.

    Science.gov (United States)

    Xiao, Cailing; Jian, Huimin; Chen, Lufeng; Liu, Chang; Gao, Huayang; Zhang, Chuansong; Liang, Shengkang; Li, Yanbin

    2017-03-20

    The Bohai Sea (BS) and Yellow Sea (YS), which are adjacent to the most urbanized and industrialized areas in China, are facing a variety of environmental problems. Two cruises were conducted to investigate the pollution status of toxic metals in BS and YS sediments. They generally presented a decreasing trend from near shore to offshore. In addition, two high concentration areas were observed in the central south YS and north of the Shandong Peninsula. The results of multiple regression analyses suggest that Hg is mainly controlled by anthropogenic loading, whereas for Cr, Cu, Ni, Pb and Zn, sediment properties, especially the Fe oxides content, play a more important role. For As and Cd, the contribution of anthropogenic loading and sediment properties are comparable. The risk assessment indicates that Hg, As, Cd and Ni should be listed as the primary contaminant metals in the BS and YS.

  18. Sea surface height anomaly and geostrophic circulation variations in the South China Sea from TOPEX/POSEIDON altimetry

    Institute of Scientific and Technical Information of China (English)

    刘克修; 马继瑞; 许建平; 韩桂军; 范振华

    2002-01-01

    --The sea surface height anomaly (SSHA) and geostrophic circulation in the South ChinaSea (SCS) are studied using TOPEX/POSEIDON (T/P) altimetry data. The SSHA, which is obtained after tidal correction based on the tidal results from T/P data, is predominated by seasonal alternating monsoons. The results reveal that the SSHA in the central part of the SCS is positive in spring and summer, but negative in autumn and winter. It is also found that the SSHA in the SCS can be approached with the sum of tidal constituents SA and SSA. The geostrophic circulations in the SCS are calculated according to sea surface dynamic topography, which is the sum of SSHA and mean sea surface height. It is suggested that the circulation in the upper layer of the SCS is generally cyclonic and notably western intensified during autumn and winter, while the western intensification is weak during spring and summer. It is also indicated that the Kuroshio intrudes into the northeastern SCS throuth the Luzon Strait in winter. But there is no indication of Kuroshio intruding into the SCS in summer.

  19. Phosphorus speciation and distribution in surface sediments of the Yellow Sea and East China Sea and potential impacts on ecosystem

    Institute of Scientific and Technical Information of China (English)

    SONG Guodong; LIU Sumei

    2015-01-01

    For better understanding the phosphorus (P) cycle and its impacts on one of the most important fishing grounds and pressures on the marine ecosystem in the Yellow Sea (YS) and East China Sea (ECS), it is essential to distinguish the contents of different P speciation in sediments and have the knowledge of its distribution and bioavailability. In this study, the modified SEDEX procedure was employed to quantify the different forms of P in sediments. The contents of phosphorus fractions in surface sediments were 0.20–0.89μmol/g for exchangeable-P (Exch-P), 0.37–2.86μmol/g for Fe-bound P (Fe-P), 0.61–3.07μmol/g for authigenic Ca-P (ACa-P), 6.39–13.73μmol/g for detrital-P (DAP) and 0.54–10.06μmol/g for organic P (OP). The distribution of Exch-P, Fe-P and OP seemed to be similar. The concentrations of Exch-P, Fe-P and OP were slightly higher in the Yellow Sea than that in the East China Sea, and low concentrations could be observed in the middle part of the ECS and southwest off Cheju Island. The distribution of ACa-P was different from those of Exch-P, Fe-P and OP. DAP was the major fraction of sedimentary P in the research region. The sum of Exch-P, Fe-P and OP may be thought to be potentially bioavailable P in the research region. The percentage of bioavailable P in TP ranged from 13%to 61%. Bioavailable P burial flux that appeared regional differences was affected by sedimentation rates, porosity and bioavailable P content, and the distribution of bioavailable P burial flux were almost the same as that of TP burial flux.

  20. Three-dimensional calculations of the currents in the Huanghai Sea and East China Sea during June of 1999

    Institute of Scientific and Technical Information of China (English)

    Huiqun Wang; Yaochu Yuan; Yonggang Liu; Mingyu Zhou

    2003-01-01

    Based on the wind and hydrographic data obtained by R/V Xiangyanghong 14 duringJune of 1999, the currents in the Huanghai Sea and East China Sea are computed by the three dimen-sional non-linear diagnostic, semidiagnostic models and prognostic in the σ coordinate. The computed re-sults show that the density and velocity fields and so on have been adjusted when time is about 3 days,namely the solution of semidiagnostic calculation is obtained. In the northwest part of the computed re-gion, the Huanghai coastal current flows southeastward, and then it flows out the computed region southof Cheju Island. In the west side of the southern part of the computed region, there is other current,which is mainly inshore branch of Taiwan Warm Current, and it flows cyclonically and turns to thenortheast. In the region north of the above two currents, there is a cyclonic eddy southwest of Cheju Is-land, and it has characteristics of high density and low temperature. There is an offshore branch of Tai-wan Warm Current in the west side of the Kuroshio, and it makes a cyclonic meander, then flows north-eastward. The Kuroshio in the East China Sea is stronger, and flows northeastward. Its maximum hori-zontal velocity is 108.5 cm/s at the sea surface, which is located at the northern boundary, and it is106.1 cm/s at 30 m level, 102.2 cm/s at 75 m level and 85.1 cm/s at 200 m level, respectively, whichare all located at the southern boundary. Comparing the results of diagnostic calculation with those ofsemidiagnostic and prognostic calculations indicates that the horizontal velocity field agrees qualitatively,and there is a little difference between them in quantity. The comparison between the computed veloci-ties and the obeered velocities at the mooring station show that they agree each other.

  1. Ancient Changjiang channel system in the East China Sea continental shelf during the last glaciation

    Institute of Scientific and Technical Information of China (English)

    LI Guangxue; LIU Yong; YANG Zigeng; YUE Shuhong; YANG Wenda; HAN Xibin

    2005-01-01

    Based on the data of high-resolution seismic profiles, an ancient river channel system of the last glaciation occurred along the Zhedong and Xihu depression in the southeast of Hupijiao rise. The distribution of the channel fill system shows that the ancient Changjiang River went through the Changjiang depression into the low land plain of the outside continental shelf during the low sea level cycle of the last glaciation. The big channel fill into Okinawa Trough is not found due to the depletion of the river kinetic energy in the low land plain. The river discharge dispersal was of an important role to the dilution of the northern Okinawa Trough sea at that time. Six ancient river channel systems (A―F), which are main distributaries of ancient Changjiang in the East China Sea continental shelf during the last glaciation, may be buried off the modern Changjiang estuary. The distribution of these channels coincides with the zonal elevations in the sea floor.

  2. Coupling between SST and wind speed over mesoscale eddies in the South China Sea

    Science.gov (United States)

    Sun, Shuangwen; Fang, Yue; Liu, Baochao; ᅟ, Tana

    2016-11-01

    The coupling between sea surface temperature (SST) and sea surface wind speed over mesoscale eddies in the South China Sea (SCS) was studied using satellite measurements. Positive correlations between SST anomalies (SSTA) and wind speed anomalies were found over both cyclonic and anticyclonic eddies. In contrast to the open oceans, the spatial patterns of the coupling over mesoscale eddies in the SCS depend largely on the seasonal variations of the background SST gradient, wind speed, and wind directional steadiness. In summer, the maximum SSTA location coincides with the center of eddy-induced sea surface height anomalies. In winter, the eddy-induced SSTA show a clear dipole pattern. The spatial patterns of wind speed anomalies over eddies are similar to those of the SSTA in both seasons. Wind speed anomalies are linearly correlated with SSTA over anticyclonic and cyclonic eddies. The coupling coefficients between SSTA and wind speed anomalies in the SCS are comparable to those in the open oceans.

  3. Remote sensing of pigment concentration and sea surface temperature on the continental shelf of China

    Science.gov (United States)

    Tang, Danling

    The combination of a population of more than 1.2 billion people and the recent rapid industrialization and large-scale infrastructure projects have placed a very heavy burden on the coastal environment in China. Algal blooms and red tides pose a serious threat to public health, fisheries and aquaculture industry. Consequently, a thorough assessment of their impacts on the coastal zone is urgently needed. This research is the first application of the historical satellite remote sensing archive to investigate temporal and spatial patterns of pigment concentrations (PC) and sea surface temperatures (SST) on the entire continental shelf of China. Firstly, I examined the temporal (annual/monthly) and spatial patterns of PC and SST on the continental shelf of China. The image availability for the study area was examined. A total of 2139 scenes were obtained from the study area during the years of the Nimbus-7 satellite mission (from 1978 to 1986), from which 76 monthly and 8 annual composite CZCS images were generated. AVHRR (Advanced Very High Resolution Radiometer) data from NOAA (National Oceanic & Atmospheric Administration) satellites were also examined. A distinctive high PC belt of about 50 km wide existed along the coastline of China, and a large plume of high PC was observed which extended nearly 500 km to the east from the Yangtze River. PC were high in the Yellow Sea (about 1--2 mg m-3 it decreased seawards and southeastwards with a minimum value in the Philippine Sea (about 0.2 mg m-3 ). Annual PC increased from 1979 and reached a peak in 1981; it dropped in 1982 with a strong El Nino. In the northern area (Yellow Sea), there were two peaks of PC in each year (spring and fall). In the southern area (northern South China Sea), PC was relatively low and constant over each year. A basin-wide gyre appeared in the center of the Yellow Sea in April 1986. Secondly, I focused on the Luzon Strait, a channel between the Philippine Sea and the South China Sea. High

  4. Crustal activities recorded in coral reefs in the northwestern South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHAN Wenhuan; YAO Yantao; ZHANG Zhiqiang; SUN Zongxun; ZHAN Meizhen; SUN Longtao; LIU Zaifeng

    2006-01-01

    Coral reefs in the northwest of South China Sea have recorded the information from not only the environmental variation but also the crustal activities there during their development. The main crustal activities correlated with the coral reef development include fault, seismic, and volcano activities,etc. The high-resolution spark seismic profiles in the northwestern South China Sea show that the fault activities in the coral reef region have been clearly recorded, and appear as neonatal faults incising reefs. Earthquakes in the coral reef region are rather intense, especially the two occurring on December,31, 1994, and January, 10, 1995, around the southwest of Leizhou Peninsula, with the magnitude of 6.1and 6.2, respectively. They have great influence on the growth of the local coral reefs. Quaternary volcanos are active in the northwestern South China Sea, especially around the southwest of Leizhou Peninsula, and they have obvious control of the coral reef development. Some submarine volcanoes form the substrates of coral reef, while a few emerge above the sea surface and form coral islands.

  5. Provenance of a prominent sediment drift on the northern slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The sedimentation rate of the sediment drift in the southeast of Dongsha Islands is as high as 49 cm/ka in the last 1.05 Ma. Although the sedimentation rate changes with time, the con tents of rare elements of the sediments remain almost the same, indicating that the source area of the sediments has been constant with time. On the triangular diagrams of La-Th-Sc and Th-Sc-Zr/10, the samples from the southeast of Dongsha Islands fall within the continental island arc field, overlapping the samples from Taiwan, while the samples from the Pearl River, those from the west of the Philippines that contain volcanic material, are separated from them. This indicates that the sediments from the southeast of Dongsha Islands have a close relationship to those from Taiwan in terms of provenance. In fact, the sediments on the northern slope of the South China Sea were derived from northeast direction, as well as from Taiwan, most probably transported from Taiwan through Penghu channel into the South China Sea. The terrigenous part of the deep-sea sediments in the north of the South China Sea was provided by different sources.

  6. Wind Profiles and Wave Spectra for Potential Wind Farms in South China Sea. Part II: Wave Spectrum Model

    Directory of Open Access Journals (Sweden)

    Yichao Liu

    2017-01-01

    Full Text Available Along with the commercialization of offshore wind energy in China, the South China Sea has been identified as ideal for constructing offshore wind farms, especially for farms consisting of floating wind turbines over deep waters. Since the wind profiles and wave spectra are somewhat primitive for the design of an offshore wind turbine, engineering models describing the wind and wave characteristics in the South China Sea area are necessary for the offshore wind energy exploitation given the meteorological, hydrological, and geographical differences between the South China Sea and the North/Norwegian Sea, where the commonly used wind profile and wave spectrum models were designated. In the present study; a series of numerical simulations were conducted to reveal the wave characteristics in the South China Sea under both typhoon and non-typhoon conditions. By analyzing the simulation results; the applicability of the Joint North Sea Wave Project (JONSWAP spectrum model; in terms of characterizing the wind-induced wave fields in the South China Sea; was discussed. In detail; the key parameters of the JONSWAP spectrum model; such as the Phillips constant; spectral width parameter; peak-enhancement factor, and high frequency tail decay; were investigated in the context of finding suitable values.

  7. Scenarios of Local Tsunamis in the China Seas by Boussinesq Model

    Institute of Scientific and Technical Information of China (English)

    赵曦; 刘桦; 王本龙

    2014-01-01

    The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runup in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea.

  8. China-Japan Sea Route Sees New Development

    Institute of Scientific and Technical Information of China (English)

    BySunLimei

    2004-01-01

    ON November6,a super express service corporation that is formed by four Japanese companies in Shanghai would deploy high-speed Ro/Ro ships on the China-Japanroutes,pushing comperition on nautical speed to a new high.Yet the market signal that is sent via this upgrading of shipping speed would not be mere increased competition.

  9. Seasonal variation of black carbon over the South China Sea and in various continental locations in South China

    Directory of Open Access Journals (Sweden)

    D. Wu

    2013-07-01

    Full Text Available Black carbon (BC is an important atmospheric constitute as an air pollutant and as a climate forcer. To our knowledge, field measurements of BC have not been reported over the South China Sea. Observation of light absorption coefficients (σabs and BC concentrations by Aethalometer were conducted on Yongxing Island in the South China Sea and at five continental sites in the Pearl River Delta (PRD region, South China during the South China Sea monsoon period (rainy season, 16 May–20 June 2008 and the northeast monsoon period (dry season, 12 December 2008–8 January 2009. At the oceanic site, the daily average BC concentrations vary from 0.28 to 2.14 μg m−3 and seasonal variations of BC were small (0.67 in dry season and 0.54 μg m−3 in rainy season. Similarly, little seasonal difference was found at a background site in PRD (2.88 in dry season and 2.62 μg m−3 in rainy season. At PRD urban sites, the daily average concentration of BC ranges from 1.56 to 37.9 μg m−3, higher in the dry season (12.6 μg m−3 and lower in the rainy season (6.4 μg m−3. The observed average σabs values in rainy vs. dry seasons are 119 vs. 62 Mm−1 at the PRD urban sites, 29 vs. 26 Mm−1 at the PRD background site, and 8.4 vs. 7.2 Mm−1 at the marine site. A bi-peak pattern in diurnal BC variation was observed at all sites while this pattern is the most prominent at the urban sites. The first peak appears in the early morning rush hour and the second peak in early evening, with the evening peak more pronounced in dry season.

  10. Black carbon and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of China's marginal seas

    Institute of Scientific and Technical Information of China (English)

    KANG Yanju; WANG Xuchen; DAI Minhan; FENG Huan; LI Anchun; SONG Qian

    2009-01-01

    This study investigates the distribution of black carbon (BC) and its correlation with total polycyclic aromatic hydrocarbons (ΣPAH) in the surface sediments of China's marginal seas. BC content ranges from <0.10 to 2.45 mg/g dw (grams dry weight) in the sediments studied, and varied among the different coastal regions. The Bohai Bay sediments had the highest BC contents (average 2.18 mg/g dw),which comprises a significant fraction (27%-41%) of the total organic carbon (TOC) preserved in the sediments. In comparison, BC in the surface sediments of the North Yellow Sea, Jiaozhou Bay, East China Sea and the South China Sea is less abundant and accounted for an average of 6%, 8%, 14% and 5%,respectively, of the sedimentary organic carbon pool. The concentration of ΣPAH in the surface sediments ranges from 41 to 3 667 ng/g dw and showed large spatial variations among the sampling sites of different costal regions. The Bohai Bay has the highest ΣPAH values, ranging from 79 to 3 667 ng/g dw. This reflects the high anthropogenically contaminated nature of the sediments in the bay. BC is positively correlated to TOC but a strong correlation is not found between BC and ΣPAH in the surface sediments studied, suggesting that BC and PAHs preserved in the sediments are derived from different sources and controlled by different biogeochemical processes. Our study suggests that the abundance of BC preserved in the sediments could represent a significant sink pool of carbon cycling in China's marginal seas.

  11. Decline in the species richness contribution of Echinodermata to the macrobenthos in the shelf seas of China

    Science.gov (United States)

    Jin, Shaofei; Wang, Yongli; Xia, Jiangjiang; Xiao, Ning; Zhang, Junlong; Xiong, Zhe

    Echinoderms play crucial roles in the structure of marine macrobenthic communities. They are sensitive to excess absorption of CO2 by the ocean, which induces ocean acidification and ocean warming. In the shelf seas of China, the mean sea surface temperature has a faster warming rate compared with the mean rate of the global ocean, and the apparent decrease in pH is due not only to the increased CO2 absorption in seawater, but also eutrophication. However, little is known about the associated changes in the diversity of echinoderms and their roles in macrobenthic communities in the seas of China. In this study, we conducted a meta-analysis of 77 case studies in 51 papers to examine the changes in the contribution of echinoderm species richness to the macrobenthos in the shelf seas of China since the 1980s. The relative species richness (RSR) was considered as the metric to evaluate these changes. Trends analysis revealed significant declines in RSR in the shelf seas of China, the Yellow Sea, and the East China Sea from 1997 to 2009. Compared with the RSR before 1997, no significant changes in mean RSR were found after 1997, except in the Bohai Sea. In addition, relative change in the RSR of echinoderms and species richness of macrobenthos led to more changes (decrease or increase) in their respective biomasses. Our results imply that changes in species richness may alter the macrobenthic productivity of the marine benthic ecosystem.

  12. River discharge contribution to sea-level rise in the Yangtze River Estuary, China

    Science.gov (United States)

    Kuang, Cuiping; Chen, Wei; Gu, Jie; Su, Tsung-Chow; Song, Hongling; Ma, Yue; Dong, Zhichao

    2017-02-01

    Sea level changes in the Yangtze River Estuary (YRE) as a result of river discharge are investigated based on the monthly averaged river discharge from 1950 to 2011 at the Datong station. Quantification of the sea level contribution is made by model computed results and the sea level rates reported by the China Sea Level Bulletin (CSLB). The coastal modeling tool, MIKE21, is used to establish a depth-averaged hydrodynamic model covering the YRE and Hangzhou Bay. The model is validated with the measured data. Multi-year monthly river discharges are statistically calculated based on the monthly river discharges at Datong station from 1950 to 2011. The four characteristic discharges (frequency of 75%, 50% and 25%, and multi-year monthly) and month-averaged river discharge from 1950 to 2011 are used to study the seasonal and long-term changes of sea level. The computed sea level at the Dajishan and Lvsi stations are used to study the multi-time scale structure of periodic variation in different time scale of river discharge series. The results reveal that (1) the sea level rises as the river discharge increases, and its amplification decreases from upstream to the offshore. (2) The sea level amplification on the south coast is greater than that on the north coast. When river discharge increases by 20,000 m3/s, the sea level will increase by 0.005-0.010 m in most of Hangzhou Bay. (3) The sea level at the Dajishan station, influenced by river discharge, increased 0.178 mm/y from 1980 to 2011. Correspondingly, the sea level rose at a rate of 2.6-3.0 mm/y during the same period. These values were provided by the CSLB. The increase in sea level (1980-2011) at the Dajishan station caused by river discharge is 6.8-8.9% of the total increase in sea level. (4) The 19-20 year dominant nodal cycle of sea level at the Dajishan and Lvsi stations is in accord with 18.6 year nodal cycle of main tidal constituents on Chinese coasts. It implies that the sea-level change period on the

  13. Establishment of trophic continuum in the food web of the Yellow Sea and East China Sea ecosystem: Insight from carbon and nitrogen stable isotopes

    Institute of Scientific and Technical Information of China (English)

    CAI Deling; LI Hongyan; TANG Qisheng; SUN Yao

    2005-01-01

    Stable carbon and nitrogen isotope ratios (δ13C and δ15N) are used to study the trophic structure of food web in the Yellow Sea and East China Sea ecosystem. The trophic continuum of pelagic food web from phytoplankton to top preyer was elementarily established, and a trophic structure diagram in the Yellow Sea and East China Sea was outlined in combination with carbon isotopic data of benthic organisms, which is basically consistent with and makes some improvements on the simplified Yellow Sea food web and the trophic structure diagram drawn based on the biomass of main resource population during 1985―1986. This result indicates that the stable isotope method is a potential useful means for further studying the complete marine food web trophic continuum from viruses to top predators and food web stability.

  14. SEASONAL VARIATIONS OF CIRCULATION AND SUSPENDED MATTER TRANSPORT IN THE YELLOW AND EAST CHINA SEAS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Princeton Ocean Model (POM) was modified and applied to study the monthly mean circulation in the Yellow Sea and the East China Sea. The calculated results showed almost all major characteristics of the circulation systems and their seasonal evolutions. Offshore branch and inshore branch of the Taiwan Warm Current derived from the two sides of the Taiwan Island vary significantly in different seasons. The Tsushima Warm Current is a multi-source current, and especially in winter, mid-shelf water is its main source. The Yellow Sea Warm Current (YSWC) is the strongest in winter, and a part of the YSWC water always adds into the Tsushima Warm Current through the north and south sides of the Cheju Island. The calculated thermal structures showed distinct path of the YSWC in winter and the position and scope of the Yellow Sea Cold Water Mass in summer.   Based on the circulation simulation, suspended matter transport was modeled numerically by adding its governing equation into the POM. Simulated results on the temporal and spatial distribution of total suspended matter concentration revealed and further proved that seasonal characteristics of suspended matter transport are: storage in summer and autumn, transport in winter and spring in the Yellow and East China Seas. Shelf circulation plays a crucial role in long-term suspended matter transport.

  15. Impacts of Typhoon Megi (2010) on the South China Sea

    Science.gov (United States)

    2014-06-01

    Doney (1994), Oceanic vertical mixing: A review and a model with a nonlocal boundary layer param- eterization, Rev. Geophys., 32, 363–403. Lee, I.-H...satellite data, in situ measurements and numerical modeling based on the East Asian Seas Nowcast/ Forecast System (EASNFS), we performed detailed...investigations. To obtain realistic typhoon-strength atmospheric forcing, the EASNFS applied typhoon-resolving Weather Research and Forecasting (WRF) model wind

  16. 6 Kilos: Can Vietnamese Submarines Help Reclaim the South China Sea?

    Science.gov (United States)

    2013-11-01

    Storm is brewing in the treacherous South China Sea,” The World Today, December 2012 & January 2013, 29. 12 COUNTER ARGUMENT Skeptics view...Regional Naval Balance? Koh Swee Lean Collin says that while Hanoi has reached its goal of operating in a third at-sea domain, “notwithstanding the media...hype, Vietnam’s new Kilos are far from being the game changer in the regional naval balance.” 29 Collin then argues that the acquisition needs to

  17. SST INTRASEASONAL OSCILLATION AND ATMOSPHERIC FORCING SYSTEM OF THE SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This study used National Center for Environmental Prediction (NCEP) reanalysis data to confirm that the variance of sea surface temperature (SST) in the South China Sea (SCS) has pronounced intraseasonal oscillations characterized by quasi-standing waves; and was aimed to document how intraseasonal time scale SST formed and developed in the SCS. The results derived from the composite analysis indicated the existence of a local low-level atmospheric dynamic forcing system over the SCS. The main formation mechanism of SST intraseasonal oscillation is the low-level rotational atmospheric circulation forcing over the SCS on intraseasonal time scales and the solar radiation variations caused by cloud amount changes.

  18. Advances in Marine Microbial Symbionts in the China Sea and Related Pharmaceutical Metabolites

    Directory of Open Access Journals (Sweden)

    Zhiyong Li

    2009-04-01

    Full Text Available Marine animals and plants such as sponges, sea squirts, corals, worms and algae host diverse and abundant symbiotic microorganisms. Marine microbial symbionts are possible the true producers or take part in the biosynthesis of some bioactive marine natural products isolated from the marine organism hosts. Investigation of the pharmaceutical metabolites may reveal the biosynthesis mechanisms of related natural products and solve the current problem of supply limitation in marine drug development. This paper reviews the advances in diversity revelation, biological activity and related pharmaceutical metabolites, and functional genes of marine microbial symbionts from the China Sea.

  19. Historical change of mercury pollution in remote Yongle archipelago, South China Sea.

    Science.gov (United States)

    Liu, Xiaodong; Xu, Liqiang; Chen, Qianqian; Sun, Liguang; Wang, Yuhong; Yan, Hong; Liu, Yi; Luo, Yuhan; Huang, Jing

    2012-04-01

    We collected three ornithogenic coral sand sedimentary profiles from Jinyin Island, Jinqing Island and Guangjin Island of Yongle archipelago, South China Sea and reconstructed the deposition flux of anthropogenic Hg over the past 700 years in the study area. On the whole, the anthropogenic Hg flux is relatively low; it remained at a low level before the Industrial Revolution with a small peak at about 1450-1550 AD, which may record the enhanced metallurgy activity in Ming Dynasty of China. During the 20th century, the deposition flux of anthropogenic Hg increased rapidly, but two troughs occurred during the periods around 1940s and 1970s, corresponding to the economic depression caused by World War II, Civil War in China (1945-1949), and the Culture Revolution (1966-1976) in China. Since the 1970s the deposition flux of anthropogenic Hg has been persistently increasing, apparently the result of fast economic development in East and Southeast Asia countries around South China Sea.

  20. Hydrological, plankton and pigment observations in the South China Sea; 06 December 1971 to 28 December 1971 (NODC Accession 0000939)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report records the data collected during the cruise of the R.V. Jalanidhi in the South China Sea and the water around the Seribu Islands. The region of the...

  1. WATER TEMPERATURE and other data from REEVES in the South China Sea on 1990-09-30 (NCEI Accession 9000257)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession was collected in South China Sea (Nan Hai) from ship Reeves on September 30, 1990. The real time data of water temperature at varying...

  2. A numerical study of the South China Sea deep circulation and its relation to the Luzon Strait transport

    Institute of Scientific and Technical Information of China (English)

    袁东亮

    2002-01-01

    A fine-resolution MOM code is used to study the South China Sea basin-scale circulation and its relation to the mass transport through the Luzon Strait. The modal domain includes the South China Sea, part of the East China Sea, and part of the Philippine Sea so that the currents in the vicinity of the Luzon Strait are free to evolve. In addition, all channels between the South China ,Sea and the Indonesian seas are closed so that the focus is on the Luzon Strait transport. The model is driven by specified Philippine Sea currents and by surface heat and salt flux conditions. For simplicity, no windstress is applied at the surface.The simulated Luzon Strait transport and the South China Sea circulation feature a sandwich vertical structure from the surface to the bottom. The Philippine Sea water is simulated to enter the South China Sea at the surface and in the deep ocean and is carried to the southern basin by western boundary currents. At the intermediate depth, the net Luzon Strait transport is out of the South China Sea and is fed by a western boundary current flowing to the north at the base of the thermocline. Corresponding to the western boundary currents, the basin circulation of the South China Sea is cyclonic gyres at the surface and in the abyss but an anti-cyclonic gyre at the intermediate depth. The vorticity balance of the gyre circulation is between the vortex stretching and the meridional change of the planetary vorticity.Based on these facts, it is hypothesized that the Luzon Strait transports are determined by the diapycnal mixing inside the entire South China Sea. The South China Sea plays the role of a "mixing mill" that mixes the surface and deep waters to return them to the Luzon Strait at the intermediate depth. The gyre structures are consistent with the Stommel and Arons theory (1960), which suggests that the mixlng-induced circulation inside the South China Sea should be cyclonic gyres at the surface and at the bottom but an anti

  3. Pollen record of the last 280 ka from deep sea sediments of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Environmental history of the northern continental shelf of the South China Sea during the last 280 ka BP, e.g. Marine Isotope Stages 1-8 (MIS 1-8) was reconstructed based on poi len record from the top 225m of ODP 1144 Site. During the interglacial periods, pollen assem blages are predominated by pine similar to those of the present day indicating that the environ ment of the interglacial periods was more or less close to that of today. Nevertheless, those from glacial periods are characterized by a large amount of herbaceous pollen, e.g. Artemisia,Gramineae, Cyperaceae, etc. inferring that grassland covered the merged continental shelf when the sea level lowered and the continental shelf was exposed. The exposed areas of the shelf were insignificant before MIS 5, but enlarged since MIS 4 and reached its maximum during MIS 2 ac cording to ratios of pollen percentages between pine and herbs. The history of different exposure of the shelf can be compared with transgression records of the coastal areas of China and might result from neotectonic movement of Chinese continent. Some changes also took place in the components of grassland growing on the shelf during glaciations. Gramineae is the main element at MIS 8. Then Artemisia increased upwards the profile and at last became the main component at the Last Glacial Maximum (MIS 2). Such changes in vegetation might be in response to cooler and drier climate.

  4. Bothid larvae (Pleuronectiformes - Pisces) of the Gulf of Thailand and South China Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    and frequency of occurance. Class intervals 1-5 6-10 11-20 21-40 41-80 Above81 Frequency of occurance Gulf of Thailand 9 12 14 15 10 5 South China 4 3 3 4 3 0 Total 13 15 17 19 13 5 BOTHID LARVAE - GULF OF THAILAND AND SOUTH CHINA SEA 57 Fig. Average number.... (In Japanese and English). Lalithambika Devi, C.B., 1977. Distribution of larvae of flat fishes (Heterosomata) in the Indian Ocean. Proc. Sym. Warm water Zoopl. Spl. Publ. UNESCO I NIO 19-20. Lalithambika Devi, C.B., 1986. Studies on the flat fish...

  5. Interannual variations of bomb radiocarbon during 1977-1998 recorded in coral from Daya Bay, South China Sea

    Institute of Scientific and Technical Information of China (English)

    SHEN; Chengde(沈承德); YU; Kefu(余克服); SUN; Yanmin(孙彦敏); YI; Weixi(易惟熙); YANG; Ying(杨英); ZHOU; Bin(周斌)

    2003-01-01

    22 annual layered samples of coral from 1977 to 1998 were collected from Daya Bay, South China Sea, their bomb-14C(nuclear weapons testing 14C) concentrations were determined and studied, and the atmosphere-sea exchange rate and diffusion thickness were estimated and found to be 17 mol·m-2·a-1 and 32 μm, respectively. The interannual variation of coral △14C is mainly controlled by oceanic factors. In ENSO years, the coastwise upwelling current of South China Sea gets intensified, hence the coral △14C displays its bottom value. The coral △14Cdoes not respond vividly to the variation of the solar radiation energy. In thepast 20 years or so, the general situation and the oceanic thermal structure ofSouth China Sea are still stable even though interannual variation occurs in the atmosphere-sea interaction and the upwelling current driven by the tropical energy.

  6. Effects of the Indo-China Peninsula Heat Fluxes on the 1998 South China Sea Summer Monsoon

    Institute of Scientific and Technical Information of China (English)

    SHI Xueli; Johnny C. L. CHAN; K. C. CHOW; DING Yihui

    2005-01-01

    Sensitivity experiments to investigate the role and importance of the Indo-China Peninsula (ICP) heat fluxes (sensible and latent heat fluxes) on the South China Sea summer monsoon (SCSSM) onset and its subsequent evolution have been carried out using a regional climate model. Two sensitivity experiments have been conducted: cutting off the sensible heat flux (noted as IChfx) and latent heat flux (noted as ICqfx).Results show that by cutting off the underlying heat flux of the ICP, the precipitation decreases and low-level geopotential height increases over the local regions as well as the remote regions of the East China Sea, southern Japan, and western North Pacific. The westerly (easterly) zonal winds at 850 hPa (200 hPa)are generally weakened in May and June, especially before and during the onset of the SCSSM towards the end of May.It is worth noting that although the observed sensible heat flux is only about 1/3 of the latent heat flux,the differences between the control run and each of the two sensitivity experiments are comparable.

  7. Notes on shark and ray types at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China.

    Science.gov (United States)

    White, William T; Last, Peter R

    2013-01-01

    Most of the shark and ray type material at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China was examined during a museum visit by the senior author in 2009. The status of the shark and ray species described from the South China Sea in the 1980s and deposited in this collection is discussed. Squalus acutirostris is considered a junior synonym of Squalus mitsukurii from the western North Pacific. Centrophorus ferrugineus is considered a junior synonym of Centrophorus squamosus. Centroscymnus macrops is confirmed as a junior synonym of Centroscymnus coelolepis. Scymnodon niger is confirmed as a junior synonym of Zameus squamulosus. Isistius labialis is considered a synonym of Isistius brasiliensis. Halaelurus immaculatus is confirmed as a valid species of the genus Bythaelurus. Urolophus marmoratus is considered a junior synonym of the widespread Plesiobatis daviesi. Springeria nanhaiensis is a questionable synonym of Sinobatis borneensis, following previous researchers. Springeria stenosoma is considered as questionably valid but with further investigation into generic placement required. The validity of species with SCSFRI type specimens not examined in this study are also briefly discussed.

  8. Denudation History of South China Block and Sediment Supply to Northern Margin of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yan Yi; Hu Xiaoqiong; Lin Ge; Xia Bin; Li Xiaoyong; Remesh Chandra Patel

    2009-01-01

    On the basis of apatite fission track (AFT) analyses,this article aims to provide a quantitative overview of Cenozoic morphotectonic evolution and sediment supply to the northern margin of the South China Sea (SCS).Seventeen granite samples were collected from the coast to the inland of the South China block.Plots of AFT age against sample location with respect to the coastline show a general trend of youngling age away from the coast,which implies more prolonged erosion and sediment contribution at the inland of the South China Sea during post break-up evolution.Two-stage fast erosion process,Early Tertiary and Middle Miocene,is deduced from simulated cooling histories.The first fast cooling and denudation during Early Tertiary are recorded by the samples along the coast (between 70 and 60 Ma) and the inland (between 50 and 30 Mu),respectively.This suggests initial local erosion and deposition in the northern margin of the SCS during Early Tertiary.Fast erosion along the coast ceased since ca.50 Ma,while it had lasted until ca.30 Ma inland,indicating that the erosion was transferred from the local coastal zone initially toward the continental interior with unified subsidence of the northern margin,which resulted in the formation of a south-dipping topography of the continental margin.The thermal stosis in the South China block since ca.30 Mu must det'me the time at which the northern margin became dynamically disconnected from the active rifting and stretching that was taking place to the south.The lower erosion rate is inconsistent with higher sedimentary rate in the Pearl River Mouth basin during Late Oligocene (ca.25 Ma).This indicates that the increased sedimentation in the basin is not due to the erosion of the granite belt of the South China block,but perhaps points to the westward propagation of the paleo-Pearl River drainage related to the uplift of the eastern margin of Tibet plateau and southward jumping of spreading axis of the South China Sea

  9. Potassium-argon/argon-40-argon-39 geochronology of Cenozoic alkali basalts from the South China Sea

    Institute of Scientific and Technical Information of China (English)

    YAN Quanshu; SHI Xuefa; YANG Yaomin; WANG Kunshan

    2008-01-01

    Based on the isotopic chronologic results of Cenozoic alkali basalts from the South China Sea,the characteristics of volcanic activi-ty of the South China Sea after spreading were studied.The potassium - argon ages of eight alkali basalt samples from the South China Sea,and the argon - argon ages of two samples among them are reported.Apparent ages of the whole rock are 3.80 to 7.91 Ma with an average value of 5.43 Ma (potassium- argon,whole rock),and there is little difference among samples at the same location,e.g.,4.76~5.78 Ma for location S04-12.The argon - argon ages for the two samples are 6.06 and 4.71 Ma,which lie within the age scope of potassium - argon method.The dating results indicate that rock-forming age is from late Miocene to Pli-ocene,which is consistent with erupting event for alkali basalts from adjacent regions of the South China Sea.Volcanic activities occur after the cessation of spreading of the South China Sea,which are controlled by lithospheric fault and the spreading center formed during the spreading period of the South China Sea.These dating results,combined with geochemical characteristics of these basalts,the published chronological data for the South China Sea and its adjacent regions,and the updated geophysical data near Hainan Island,suggest that after the cessation of spreading of the South China Sea,there occur widely distributing magmatic activities which primarily is alkali basalt,and the volcanic activity continues to Quaternary.The activity may be relative to Hainan mantle plume originated from core/mantle boundary.

  10. The Possible Physical Barrier and Coastal Dispersal Strategy for Japanese Grenadier Anchovy, Coilia nasus in the East China Sea and Yellow Sea: Evidence from AFLP Markers

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Han

    2015-02-01

    Full Text Available In order to ascertain the taxonomic status of the Ariake Sea population of Japanese grenadier anchovy, Coilia nasus, and assess the contemporary possible genetic barrier between the west and east coastal waters of the East China Sea, we used amplified fragment length polymorphism (AFLP markers to detect the genetic structure of C. nasus, in the East China Sea and Yellow Sea. Eighty-one individuals of C. nasus were collected from five locations and 12 individuals of Coilia mystus were sampled from the Yangtze River Estuary. A total of 371 loci were detected by five primer combinations, 310 of which were polymorphic (83.56%. Analysis of molecular variation (AMOVA and pairwise fixation index (FST revealed significant genetic differentiation among five samples, indicating limited gene flow among populations. The dendrogram for populations by neighbor-joining (NJ cluster analysis provided evidence of a clear relationship between genetic and geographic patterns, supporting significant genetic differentiation between China coastal populations and Ariake Sea populations. Compared to the genetic divergence between C. nasus and C. mystus, the level of genetic differentiation between China and the Ariake Sea populations of C. nasus is obvious below the species level, indicating isolated populations of C. nasus in the Ariake Sea. Isolation by distance analysis revealed that direct ocean distance with deep-water at the continental slope and high salinity between west and east coastal waters of the East China Sea served as major physical barrier to C. nasus, supporting the coastal dispersal pattern in this estuarine species, and rejecting offshore dispersal strategy.

  11. Two new species of Glyphocrangon (Decapoda: Caridea: Glyphocrangonidae) from the East China Sea and the Philippines.

    Science.gov (United States)

    Han, Qingxi; Li, Xinzheng

    2014-08-18

    The present paper reports two new species of Glyphocrangon (Crustacea, Caridea, Glyphocrangonidae) collected respectively from the East China Sea and the Philippines. G. singularis sp. nov., from the East China Sea, is similar to G. fimbriata Komai & Takeuchi, 1994 with the presence of fringe of setae on dactyl of the third to fifth pereopods, but differs from G. fimbriata by the rostrum shape and the armature on the carapace; G. denticulata sp. nov., from the Philippines, is similar to G. pugnax De Man, 1918 with the entire anterior third carina, but differs from G. pugnax by armatures of the antennal scaphocerite and carapace, the lengths of rostrum and the spines of fifth abdominal somite, and the colouration of carapace. 

  12. Provenance of a prominent sediment drift on the northern slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    SHAO; Lei

    2001-01-01

    [1]Sarnthein, M., Pflaumann, U., Wang, P. X. et al., Preliminary report on Sonne-95 cruise “Monitor Monsoon“ to the South China Sea, Reports, Geol.-Palaont. Inst. Univ. Kiel, 68, 1994, 125.[2]Wang, L., Sarnthein, M., High-reso1ution paleoceanographic records during the last 4000 years from the northern slope of the South China Sea, Quaternary Sciences, 1999, 1:27-31.[3]Wang, P.X., Prell, W. L., Blum, P. et al., Proceedings of the Ocean Drilling Program, Initial Reports South China Sea,Volume 184, College Station TX (Ocean Drilling Program), 2000, 18-20.[4]Shao, L., Dong, W., Liu, Z. et al., Trace elements analysis of sediments from the South China Sea, Journal of Tong ji Uni versity, 1999, 27(supp.): 55-60.[5]Taylor, S. R., McLennan, S. M., The Continental Crust: Its Composition and Evolution, in An Examination of the Geo chemical Record Preserved in Sedimentary Rocks, Oxford: Blackwell Scientific Publication, 1985, 1-301.[6]McLennan, S. M., Rare earth elements in sedimentary rocks, Influence of provenance and sedimentary processes, in Geo chemistry and Mineralogy of Rare Earth Elements (ed. Lipin, B. R. et al.), Washington: The Mineralogical Society of America, 1989, 169-200.[7]McLennan, S. M., Hemming, S., McDaniel, M. J. et al., Geochemical approaches to sedimentation, provenance and tec tonics, in Processes Controlling the Composition of Clastic Sediments (ed. Jonhanson, M. J. et al.), Boulder: Geological Society of America, Special Paper 284, 1993, 21-40.[8]Rollinson, H. R., Using Geochemical Data: Evaluation, Presentation, Interpretation, London: Longman Scientific, Tech nical, 1993, 352.[9]Cullers, R. L., Basu, A., Suttner, L. J., Geochemical signature of provenance in sand-mixed material in soils and stream sediments near the Tobacco Root batholith, Montana, USA, Chem. Geol., 1988, 70: 335-348.[10]Bhatia, M. R., Crook, K. A. W., Trace element characteristics of graywackes and tectonic setting discrimination of

  13. The first isolation of a cyanophage-Synechococcus system from the East China Sea.

    Science.gov (United States)

    Zhang, Yan; Xu, Min; Zhao, Yijun; Cheng, Kai

    2013-10-01

    A cyanophage strain and its host Synechococcus were isolated from the East China Sea. The host Synechococcus sp. SJ01 was characterized by its 16S rRNA, ITS, and psbA gene sequences as well as by its morphological appearance and pigmentation. The cyanophage, strain S-SJ2, was able to cause a lytic infection of the coastal Synechococcus. TEM of negative-stained specimens showed that the phage isolate has an isometric head with a diameter of 68 nm and a long tail with a length of 280 nm. The cyanophage-Synechococcus system from the East China Sea shares many properties with other marine cyanophage-Synechococcus systems worldwide.

  14. The deep thermal characteristic of continental margin of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Heat flow plays an important role in the study of thermal structure and thermal evolution of continental margin of the northern South China Sea. The analysis of heat flow value shows that margin heat flow in the northern South China Sea is relatively high setting, but the percentage of crustal heat flow is lower than 35% in terrestrial heat flow. The terrestrial heat flow exhibited a current of rise from the Northern Continental Margin to the Southern Central Basin. However, the proportion of crustal heat flow in terrestrial heat flow slowly dropped down in the same direction. It is suggested that the main factor causing high heat flow setting is the moving up of hot material from asthenosphere.

  15. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports

    DEFF Research Database (Denmark)

    Daryabor, Farshid

    2016-01-01

    of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic......A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re......-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast...

  16. Response of the South China Sea summer monsoon onset to air-sea heat fluxes over the Indian Ocean

    Institute of Scientific and Technical Information of China (English)

    CHEN Jinnian; ZUO Tao; WANG Hongna

    2012-01-01

    We objectively define the onset date of the South China Sea (SCS) summer monsoon,after having evaluated previous studies and considered various factors.Then,interannual and interdecadal characteristics of the SCS summer monsoon onset are analyzed.In addition,we calculate air-sea heat fluxes over the Indian Ocean using the advanced method of CORARE3.0,based on satellite remote sensing data.The onset variation cycle has remarkable interdecadal variability with cycles of 16 a and 28 a.Correlation analysis between air-sea heat fluxes in the Indian Ocean and the SCS summer monsoon indicates that there is a remarkable lag correlation between them.This result has important implications for prediction of the SCS summer monsoon,and provides a scientific basis for further study of the onset process of this monsoon and its prediction.Based on these results,a linear regression equation is obtained to predict the onset date of the monsoon in 2011 and 2012.The forecast is that the onset date of 2011 will be normal or 1 pentad earlier than the normal year,while the onset date in 2012 will be 1-2 pentads later.

  17. Current status of small yellow croaker resources in the southern Yellow Sea and the East China Sea

    Institute of Scientific and Technical Information of China (English)

    LIN Longshan; LIU Zunlei; JIANG Yazhou; HUANG Wei; GAO Tianxiang

    2011-01-01

    We used data from bottom trawl surveys to study the factors influencing the abundance of small yellow croaker, Larimichthys polyactis, in the southern Yellow Sea (SYS) and the East China Sea (ECS). The resource density index (RDI) was generally higher in summer and autumn than in spring and winter. RDIs were also significantly greater in the SYS than in the ECS in summer and autumn. The bottom water salinity and depth of spatial distribution of small yellow croaker was similar between the two areas in summer, but different in other seasons. Regression analysis suggested that environmental factors such as bottom water temperature, salinity, and depth influenced the RDIs in summer in these areas.Growth condition factor (GCF) in the two areas varied monthly and the croaker in the SYS grew more slowly than those in the ECS. This was likely due to the low bottom temperature of the Yellow Sea Cold Water Mass in summer and autumn or to higher human fishing pressure in the ECS. To ensure sustainable utilization of the croaker stocks in these regions, we recommend reducing the fishing intensity, increasing the cod-end mesh size, and improving the protection of juveniles.

  18. Simulation of the extreme waves generated by typhoon Bolaven (1215) in the East China Sea and Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    JUN Ki Cheon; JEONG Weon Mu; CHOI Jin Yong; PARK Kwang Soon; JUNG Kyung Tae; KIM Mee Kyung; CHAE Jang Won; QIAO Fangli

    2015-01-01

    Record-breaking high waves occurred during the passage of the typhoon Bolaven (1215) (TYB) in the East China Sea (ECS) and Yellow Sea (YS) although its intensity did not reach the level of a super typhoon. Winds and directional wave measurements were made using a range of in-situ instruments mounted on an ocean tower and buoys. In order to understand how such high waves with long duration occurred, analyses have been made through measurement and numerical simulations. TYB winds were generated using the TC96 typhoon wind model with the best track data calibrated with the measurements. And then the wind fields were blended with the reanalyzed synoptic-scale wind fields for a wave model. Wave fields were simulated using WAM4.5 with adjustment ofCd for gust of winds and bottom friction for the study area. Thus the accuracy of simulations is considerably enhanced, and the computed results are also in better agreement with measured data than before. It is found that the extremely high waves evolved as a result of the superposition of distant large swells and high wind seas generated by strong winds from the front/right quadrant of the typhoon track. As the typhoon moved at a speed a little slower than the dominant wave group velocity in a consistent direction for two days, the wave growth was significantly enhanced by strong wind input in an extended fetch and non-linear interaction.

  19. Magnetic Susceptibility in Surface Sediments in the Southern South China Sea and Its Implication for Sub-sea Methane Venting

    Institute of Scientific and Technical Information of China (English)

    Chen Zhong; Yan Wen; Tang Xianzan; Liu Jianguo; Chen Muhong; Yang Huaping

    2009-01-01

    In order to understand the characteristics of magnetic variability and their possible implication for sub-sea methane venting,magnetic susceptibility (MS) of 145 surface sediment samples from the southern South China Sea (SCS) was investigated.Magnetic particles extracted from 20 representative samples were also examined for their mineral,chemical compositions and micromorphology.Results indicate that MS values range between -7.73×10-8 and 45.06x10-8 m3/kg.The high MS zones occur at some hydrecarbon-bearing basins and along main tectonic zones,and low ones are distributed mainly within the river delta or along continental shelves.Iron concretions and manganese concretions are not main contributors for high MS values in sediments,while authigenic iron sulphide minerals are possibly responsible for the MS enhancement.This phenomenon is suspected to be produced by the reducing environment where the high upward venting methane beneath the seafloor reacts with seawater sulfate,resulting in seep precipitation of highly susceptible intermediate mineral pyrrhotite,greigite and paramagnetic pyrite.It suggests that MS variability is possibly one of the geochemical indicators for mapping sub-sea zones of methane venting in the southern SCS.

  20. Numerical simulation of rifting controlled by magmatic underplating in the South China Sea

    Science.gov (United States)

    Xu, Hehua

    2016-04-01

    South China Sea is one of the largest basins in the western Pacific marginal sea, which is located in the intersection area of the Eurasia, the India-Australian and the Pacific-Philippines plate. Although the duration of seafloor spreading and the extension mechanism are still controversial.It is widely accepted that the South China Sea was opened by seafloor spreading in the Cenozoic. From the point of its structural development history, South China Sea has its own unique development model, which is formed by the continent rifting and expansion, while the tectonic evolution has close relationship with geological peripheral units. According to the seismic detection and magnetic integrated geophysics, the studies found that high-speed lower crust layers are widespread in the northern South China Sea and the northeast of continental margin, these layers are mainly located in continental slopes and some high-degree tensional continental shelves. Researches suggested that materials of high-speed in lower crustal layers are formed by the bottom magmatic underplating rather than serpentinized mantle peridotite. These layers are formed in Cenozoic and has close relationship with extension. However, in most kinematic and dynamic models of rift formation and evolution, the effects of magmatism have been neglected. This study established a two-dimensional thermal - mechanical coupled finite element model to simulate the role of underplated magmatic bodies in the localization of deformation. We examine the response of the lithosphere to an applied constant boundary velocity at the edge of the model. The mamatic underplating is introduced as a material with an anomalous high temperture and a magic upper mantle composition. The mechanical problem is coupled with the thermal problem through temperature-dependent viscosity. Since extension of lithosphere and underlying mantle is associated with intense and simultaneous viscous and brittle/plastic(faulting) deformations, we use

  1. Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Sediments from the Bohai Sea, China

    Science.gov (United States)

    Liu, Jihua; Hu, Ningjing; Shi, Xuefa

    2015-04-01

    Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Sediments from the Bohai Sea, China Liu Jihua, Hu Ningjing, Shi Xuefa First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous organic contaminants in the environment. Indeed, 16 PAH compounds have been listed as priority pollutants by the United States Environmental Protection Agency and the European Union because of their potential toxicity to humans and ecosystems. As POPs are released or escape into the environment, their global accumulation in marine sediments generates a complex balance between inputs and outputs. Furthermore, PAHs in coastal sediments can serve as effective tracers of materials transport from land-to-sea (Fang et al., 2009). Hence, investigations of PAHs in sediments can provide useful information for further understanding of environmental processes and material transport. In this study, sixteen polycyclic aromatic hydrocarbons (PAHs) were extracted from a total of 112 surface sediment samples collected across the entire territory of the Bohai Sea. The detectable concentrations of PAHs ranged from 97.2 to 300.7 ng/g across all samples, indicating low contamination levels of PAHs compared with reported values for other coastal sediments in China and developed countries. The highest concentrations were found within three belts in the vicinity of Luan River Estuary-Qinhuangdao Harbor, the Cao River Estuary-Bohai Sea Center, and north of the Yellow River Estuary. The distribution patterns of PAHs and source identification implied that PAH contamination in the Bohai Sea mainly originates from offshore oil exploration, sewage discharge from rivers and shipping activities. Further Principal components analysis (PCA)/multivariate linear regression (MLR) analysis suggested that the contributions of spilled oil products (petrogenic), coal combustion and traffic

  2. Observed characteristics of atmospheric ducts over the South China Sea in autumn

    Science.gov (United States)

    Cheng, Yinhe; Zhou, Shengqi; Wang, Dongxiao; Lu, Yuanzheng; Huang, Ke; Yao, Jinglong; You, Xiaobao

    2016-05-01

    The observed characteristics of lower atmospheric ducts over the South China Sea (SCS) were analyzed based on Global Position Systerm (GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012. Duct occurrence, thickness, and strength over the SCS were about 40%, 150-m thick, and 8 M units, respectively, which were larger than during the summer monsoon period. Most ducts occurred at heights military applications.

  3. Analysis on the indicator species and ecological groups of pelagic ostracods in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Zhaoli

    2008-01-01

    Ecological adaptation and ecological groups of pelagic ostraceds were examined in the East China Sea (23°30' ~ 33°00'N,118°30'~ 128°00'E),in relation to temperature and salinity.The data were collected in four surveys conducted from 1997 to 2000.The density,yield density,or negative exponent models were used to determine the optimal temperature and salinity of wa-ter for the thriving growth of pelagic ostracods.Thereafter,ecological groups and potential distribution patterns of pelagic ostracods were determined based on the predicted parameters such as optimal temperature and salinity,consulting the geographic distribu-tion.The analytical results indicate that,among the numerical dominant pelagic ostraceds in the East China Sea (ECS),Eucon-choecia aculeata,E.elongata,E.chierchiae,E.maimai,and Cypridina dentata,etc.are offshore subtropical water species.These species are widely distributed in the area,and they can be brought by the warm current to north offshore during spring and winter.The predicated optimal temperature (OT) and optimal salinity (OS) for Paraconchoecia decipiens,P.echinata,P.spini-fera,P.oblonga,Conchoecia magna and Porroecia porrecta are all greater than 25℃ and 34 separately.These species are mainly distributed in the waters of the Kuroshio,the Taiwan Warm Current,and the Taiwan Strait,and therefore are designated as ocean-ic tropical water species.On the other hand,Pseudoconchoecia concentrica is considered as offshore subtropical water species based on its geographical distribution although its OT is 19~C.The other species,though their OSs are approximately 34 and with OTs ranging from 20° to 25℃,are considered as offshore subtropical water species because they were found to be widely distribu-ted from the South China Sea to the East China Sea.

  4. Shrimps and lobsters from the continental slope of the East China Sea

    OpenAIRE

    山本, 圭介; 長澤, 和也

    2011-01-01

    The specimens of shrimps and lobsters collected from the continental slope of the East China Sea using a bottom trawl net in September 1993 contained 32 species in 11 families (Solenoceridae-2; Aristeidae-5; Penaeidae-2; Oplophoridae-3; Nematocarcinidae-1; Pasiphaeidae-2; Psalidopodidae-1; Pandalidae-7; Glyphocrangonidae-2; Polychelidae-3; Nephropidae-4). The pandarids were the most specious. Haliporoides sibogae was most abundantly collected, followed by Aristeus virilis and Glyphocrangon pe...

  5. Seasonal variability of tropical cyclones generated over the South China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Guihua; WANG Hui; QI Yiquan

    2007-01-01

    The seasonal variability of tropical cyclones (CTCs) generated over the South China Sea (SCS) from 1948 to 2003 is analyzed. It peaks in occurrence in August and few generate in late winter (from January to March). The seasonal activity is attributed to the variability of atmosphere and ocean environments associated with the monsoon system. It is found that the monsoonal characteristics of the SCS basically determine the region of tropical cyclone (TC) genesis in each month.

  6. Mesoscale eddies in the South China Sea and their impact on temperature profiles

    Institute of Scientific and Technical Information of China (English)

    WANG Guihua; SU Jilan; LI Rongfeng

    2005-01-01

    Some life history statistics of the mesoscale eddies ofthe South China Sea (SCS) derived from altimetry data will be further discussed according their different formation periods.A total of three ATLAS (autonomous temperature line acquisition system)mooring buoys data will be analyzed to discuss eddies' impact on temperature profiles.They identify that the intraseasonal variation of SCSthermocline is partly controlled by mesoscale eddies.

  7. Stability of submarine slopes in the northern South China Sea: a numerical approach

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; LUAN Xiwu

    2013-01-01

    Submarine landslides occur frequently on most continental margins.They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations.In this paper,submarine slope stability is evaluated using a 2D limit equilibrium method.Considerations of slope,sediment,and triggering force on the factor of safety (FOS) were calculated in drained and undrained (φ=0) cases.Results show that submarine slopes are stable when the slope is <16° under static conditions and without a weak interlayer.With a weak interlayer,slopes are stable at <18° in the drained case and at <9° in the undrained case.Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure.The slope became unstable at >13° with earthquake peak ground acceleration (PGA) of 0.5 g;whereas with a weak layer,a PGA of 0.2 g could trigger instability at slopes > 10°,and >3 ° for PGA of 0.5 g.The northern slope of the South China Sea is geomorphologically stable under static conditions.However,because of the possibility of high PGA at the eastern margin of the South China Sea,submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope.Therefore,submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake,the most important factor for triggering submarine slides on the northern slope of the South China Sea.Considering the distribution of PGA,we consider the northern slope of the South China Sea to be stable,excluding the Taiwan Bank slope,which is tectonically active.

  8. Species characteristics of lead in sea foods collected from coastal water of Fujian, Southeastern of China

    Science.gov (United States)

    He, Ye; Chen, Zhiqiang; Mo, Fan; Huang, Limei; Xu, Liangjun; Wu, Yongning; Xue, Zhimin; Fu, Fengfu

    2016-09-01

    Various sea foods including fish, shellfish and shrimp were collected from different coastal areas of Fujian in China, and their Pb species characteristics were investigated in detail. The results indicated that there are two different species characteristics of Pb existing in sea food samples. About half of samples were detected to have only Pb2+, and another half of samples were detected to have both Pb2+ and trimethyl lead (TML). The results also revealed that Pb species characteristics in the sea foods rather depend on the species of sea food than the sampling area. In comparison with shellfish/shrimp samples, fish samples have higher concentrations of TML and Pb2+. Especially, the average concentration of TML in the TML-detected fish samples is about 3 times of that in the TML-detected shellfish/shrimp samples, indicating that fish has stronger ability to uptake and accumulate TML. The concentrations of total lead in all samples are lower than the maximum allowable limit of national standard, suggesting that the sea foods collected from Fujian are safe for consumption. By considering that TAL has more toxicity than Pb2+, the effect of TML in sea foods on the human health should be paid more attention in the future.

  9. Quaternary transgressive and regressive depositional sequences in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Based on the interpretation more than 4000 km sparker single channel seismic profiles and the comparison with Borehole DZQ4 on the outer shelf of the East China Sea (ECS), the seismic sequences, sedimentary facies and paleo-sedimentary environment are studied to establish the chronology framework and discuss the Quaternary transgressive and regressive sequences of the ECS shelf as well as their response to glacio-eustatic sea-level changes. The sea level of the ECS fluctuated with global climate changes in the Quaternary. During the sea level rise, the Pacific tidal wave impacted actively on the ECS continental shelf and the reciprocating tidal currents in NW-SE direction formed tidal sand ridges, which represent large transgressive deposits visible on the seismic profiles. In response to sea level fall, the Yangtze River deltas prograded seaward and built massive subaqueous deltas to form regressive sequences on the seismic profiles. Alternative transgression and regression sequences were vertically distributed on the ECS shelf with the frequent eustacy in the Quaternary. The gentle slope of the ECS shelf makes it possible for the coastline to migrate hundreds of kilometers forth and back on the shelf because of tens of meters sea level changes, in the meanwhile, the Yangtze River discharged large amounts of sediments into the ECS resulting in large-scale subaqueous deltas and tidal sand ridges. There have developed 3 stages of tidal sand ridges and 4 stages of deltas on the ECS shelf since oxygen isotope stage 8.

  10. A continental slope stability evaluation in the Zhujiang River Mouth Basin in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; WANG Jianhua

    2014-01-01

    In nature, a slope stability is determined by the ratio of a sliding resistance to a slide force. The slide force of a marine deep-water continental slope is mainly affected by sediment mechanics properties, a topography, and a marine seismic. However, the sliding resistance is mainly affected by sedimentary patterns and a sedi-mentary stress history. Both of these are different from case to case, and their impact can be addressed when the data are organized in a geographic information system (GIS). The study area on the continental slope in Zhujiang River Mouth Basin in South China Sea provides an excellent opportunity to apply GIS spatial analysis technology for the evaluation of the slope stability. In this area, a continental slope topography and a three-dimension (3-D) topography mapping show a sea-floor morphology and the distribution of a slope steepness in good detail, and the sediment analysis of seabed samples and an indoor appraisal reveals the variability of a sediment density near the sea-floor surface. On the basis of the results of nine geotechnical studies of submarine study areas, it has worked out that an equivalent cyclic shear stress ratio is roughly between 0.158 and 0.933, which is mainly depending on the initial water content of sediment. A regional density, slope and level of anticipated seismic shaking information are combined in a GIS framework to yield a map that illustrates a continental slope stability zoning under the influencing factors in Zhujiang River Mouth Basin in the South China Sea. The continental slope stability evaluation can contribute to north resources development in the South China Sea, the marine functional zoning, the marine engineering con-struction and adjust measures to local conditions, at the same time also can provide references for other deep-water slope stability analysis.

  11. New Navy Fighting Machine in the South China Sea

    Science.gov (United States)

    2012-06-01

    search combination radar. Type 052 also carries 16 C-802 missiles.47 One Luhai (Type 051B) destroyer, the Shenzhen (DDGHM-167), remains in China’s...reported at 4,500 nm at 14 kts. She is complimented with a crew of 42 officers and 250 men. Shenzhen has two dedicated air search radars covering A... climate of the DoD, the resource conservation aspect of LTA excites interest as well as spurs rebuke, especially from programs looking to survive in

  12. Balance of Risk in the South China Sea

    Science.gov (United States)

    2015-06-01

    2014), 3. 9 Economy, “China’s Imperial President.”; Carl Thayer, “China’s New Fishing Regulations: An Act of State Piracy ?” The Diplomat, January 13...2014, http://thediplomat.com/2014/01/chinas-new-fishing- regulations-an-act-of-state- piracy /.; Taylor Fravel, “Hainan’s New Fishing Rules: A...Surveillance and the Fisheries Law Enforcement Command], 凤凰网[Phoenix News Online ] October 19, 2012, http://news.ifeng.com/mainland/special

  13. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1007 in the Philippine Sea and South China Sea (Nan Hai) from 2010-06-01 to 2010-06-10 (NODC Accession 0089637)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089637 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1007 in the Philippine Sea and South China Sea (Nan...

  14. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1204 in the Philippine Sea and South China Sea (Nan Hai) from 2012-04-24 to 2012-05-14 (NCEI Accession 0129849)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0129849 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1204 in the Philippine Sea and South China Sea...

  15. HELIUM, PARTICULATE ORGANIC CARBON and other data from HEIYO, KAIYO and other platforms in the NW Pacific, Philippine Sea and East China Sea from 1939-08-17 to 1988-09-27 (NCEI Accession 9000197)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A tape containing part of the annual exchange of chemical data from the Japan Oceanographic Data Center collected from East China Sea (Tung Hai), Philippine Sea, NW...

  16. Physical and underway data collected aboard the KILO MOANA during cruise KM0909 in the Philippine Sea and South China Sea (Nan Hai) from 2009-03-20 to 2009-04-09 (NODC Accession 0089676)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089676 includes physical and underway data collected aboard the KILO MOANA during cruise KM0909 in the Philippine Sea and South China Sea (Nan Hai)...

  17. Physical and underway data collected aboard the KILO MOANA during cruise KM0910 in the Philippine Sea and South China Sea (Nan Hai) from 2009-04-14 to 2009-05-04 (NODC Accession 0089592)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089592 includes physical and underway data collected aboard the KILO MOANA during cruise KM0910 in the Philippine Sea and South China Sea (Nan Hai)...

  18. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1004 in the Philippine Sea and South China Sea (Nan Hai) from 2010-04-06 to 2010-04-07 (NODC Accession 0089634)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089634 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1004 in the Philippine Sea and South China Sea (Nan...

  19. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1305 in the Philippine Sea and South China Sea (Nan Hai) from 2013-05-07 to 2013-05-16 (NCEI Accession 0132725)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0132725 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1305 in the Philippine Sea and South China Sea (Nan...

  20. Physical and underway data collected aboard the MELVILLE during cruise MV0904 in the Philippine Sea and South China Sea (Nan Hai) from 2009-03-22 to 2009-03-27 (NODC Accession 0089606)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089606 includes physical and underway data collected aboard the MELVILLE during cruise MV0904 in the Philippine Sea and South China Sea (Nan Hai)...

  1. Lithospheric Thermal Isostasy of North Continental Margin of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Chen Shi; Zhang Jian; Sun Yujun; Shi Yaolin

    2009-01-01

    Accompanied with rifting and detaching of the north continental margin of the South China Sea,the ernst and the lithosphere become thinner away from the continental margin resulting from the tectonic activities,such as tensile deformation,thermal uplift,and cooling subsidence,etc..Integrated with thermal,gravimetric,and isostatic analysis techniques,based on the seismic interpretation of the deep penetration seismic soundings across the northern margin of the South China Sea,we reconstructed the lithospheric thermal structure and derived the variation of the crust boundary in the east and west parts of the seismic profde by using gravity anomaly data.We mainly studied the thermal isostasy problems using the bathymetry of the profiles and calculated the crust thinning effect due to the thermal variety in the rifting process.The results Indicate that the thermal isostasy may reach 2.5 kin,and the compositional variations in the ilthospheric density and thickness may produce a variation of 4.0 kin.Therefore,the compositional isostatic correction is very important to recover the relationship between surface heat flow and topography.Moreover,because of the high heat flow characteristic of the continental margin,building the model of lithospheric geotherm in this region is of great importan for studying the Cenozoic tectonic thermal evolution of the north passive continental margin of the South China Sea.

  2. Molecular approach to the identification of fish in the South China Sea.

    Directory of Open Access Journals (Sweden)

    Junbin Zhang

    Full Text Available BACKGROUND: DNA barcoding is one means of establishing a rapid, accurate, and cost-effective system for the identification of species. It involves the use of short, standard gene targets to create sequence profiles of known species against sequences of unknowns that can be matched and subsequently identified. The Fish Barcode of Life (FISH-BOL campaign has the primary goal of gathering DNA barcode records for all the world's fish species. As a contribution to FISH-BOL, we examined the degree to which DNA barcoding can discriminate marine fishes from the South China Sea. METHODOLOGY/PRINCIPAL FINDINGS: DNA barcodes of cytochrome oxidase subunit I (COI were characterized using 1336 specimens that belong to 242 species fishes from the South China Sea. All specimen provenance data (including digital specimen images and geospatial coordinates of collection localities and collateral sequence information were assembled using Barcode of Life Data System (BOLD; www.barcodinglife.org. Small intraspecific and large interspecific differences create distinct genetic boundaries among most species. In addition, the efficiency of two mitochondrial genes, 16S rRNA (16S and cytochrome b (cytb, and one nuclear ribosomal gene, 18S rRNA (18S, was also evaluated for a few select groups of species. CONCLUSIONS/SIGNIFICANCE: The present study provides evidence for the effectiveness of DNA barcoding as a tool for monitoring marine biodiversity. Open access data of fishes from the South China Sea can benefit relative applications in ecology and taxonomy.

  3. On tectonic movement in the South China Sea during the Cenozoic

    Institute of Scientific and Technical Information of China (English)

    LIN Changsong; CHU Fengyou; GAO Jinyao; TAN Yonghua

    2009-01-01

    The tectonic movement taking place at the end of Cretaceous and the beginning of Cenozoic had opened the Ce-nozoic phase of polycyclic tectonic movements, then the whole crust of the South China Sea had been mainly subjected to the regional stress field of tectonic tension, which was characterized by rifting depression. Seven times of regional tectonic movement and sedimentation had been assembled into a geological development history of polycyclic oscillation. Especially, the tectonic movements were strongly intensified at the end of Cretacious and the beginning of Paleagene, between Late Eocene and Mid-Oligocene, during Mid- and Late Miocene. These three times of tectonic movement had built the most important regional tectonic interfaces in the South China Sea. Crust movements of the South China Sea were the result and epitome of interaction of the Eurasia, Pacific and Indo-Australia plates, that is, they were introduced by polycyclic changes of directions, rates and strengths of lithospheric movements and asthenospheric flows across the Pacific and Indo-Australia plates.

  4. Preservation of black carbon in the shelf sediments of the East China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Concentrations and carbon isotopic (14C, 13C) compositions of black carbon (BC) were measured for three sediment cores collected from the Changjiang River estuary and the shelf of the East China Sea. BC concentrations ranged from 0.02 to 0.14 mg/g (dry weight), and accounted for 5% to 26% of the sedimentary total organic carbon (TOC) pool. Among the three sediment cores collected at each site, sediment from the Changjiang River estuary had relatively high BC contents compared with the sediments from the East China Sea shelf, suggesting that the Changjiang River discharge played an important role in the delivery of BC to the coastal region. Radiocarbon measurements indicate that the ages of BC are in the range of 6910 to 12250 years old B.P. (before present), that is in general, 3700 to 9000 years older than the 14C ages of TOC in the sediments. These variable radiocarbon ages suggest that the BC preserved in the sediments was derived from the products of both biomass fire and fossil fuel combustion, as well as from ancient rock weathering. Based on an isotopic mass balance model, we calculated that fossil fuel combustion contributed most (60%―80%) of the BC preserved in these sediments and varied with depth and locations. The deposition and burial of this "slow-cycling" BC in the sediments of the East China Sea shelf represent a significant pool of carbon sink and could greatly in-fluence carbon cycling in the region.

  5. A parabolic model of drag coefficient for storm surge simulation in the South China Sea.

    Science.gov (United States)

    Peng, Shiqiu; Li, Yineng

    2015-10-26

    Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models.

  6. Eddy-entrained Pearl River plume into the oligotrophic basin of the South China Sea

    Science.gov (United States)

    He, Xianqiang; Xu, Dongfeng; Bai, Yan; Pan, Delu; Chen, Chen-Tung Arthur; Chen, Xiaoyan; Gong, Fang

    2016-08-01

    The South China Sea (SCS) is the world's largest tropical marginal sea with an oligotrophic basin. In June 2015, a rare large phytoplankton bloom, which is ~500 km long, 100 km wide and lasting more than 19 days, was captured in the northern SCS basin by satellite daily chlorophyll images. Water within the bloom area had a feature of low salinity and high temperature measured by an accidental-passing cruise. Meanwhile, satellite sea level anomaly images and drifter trajectory proved there was a cyclonic eddy nearby. No typhoon and heavy rain happened in this period, so we believed the bloom was triggered by the injection of nutrient-rich Pearl River plume driven by eddy. This is the first report on eddy-entrained Pearl River plume into the SCS, which would raise a new view on irregular transportation of nutrient and carbon and its related biogeochemical influence on the oligotrophic ocean.

  7. Cloudiness regime shift during 1946~1992 recorded by coral in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    By extracting and comparing long-term trend components of coral gray value, sea surface temperature, cloudiness, and net heat flux for the period of 1946~1992, the relationships among them are addressed. There exists a prominent regime shift in the cloudiness associated with the corresponding variabilities of sea surface temperature and net heat flux occurred in the mid-1960s, which can be successfully recorded by coral gray value, a climatic proxy. Long-term cloudiness variations in the South China Sea are completely opposite to the equatorial western Pacific in the past five decades, whereas they share a similar trend to that over Asian monsoon prevailing waters. The fact that the coral gray value is highly correlated to cloudiness provides a unique perspective on utilizing this coral to study cloudiness variations in the pre-instrumental period.

  8. Deep crustal structures of eastern China and adjacent seas revealed by magnetic data

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Through reduction to the North Pole and upward continuation of the total field magnetic anomalies, we analyze magnetic patterns and spatial distributions of different tectonic blocks and crustal faults in eastern China and adjacent seas. Depths to the Curie isotherms are further estimated from radially averaged amplitude spectra of magnetic data reduced to the pole. Data reductions effectively enhance boundaries of regional tectonic belts, such as the Dabie ultra-high metamorphic belt, the Tanlu Fault, and the Diaoyudao Uplift. Curie depths are estimated at between 19.6 and 48.9 km, with a mean of 31.7 km. The Subei Basin and the south Yellow Sea Basin in the lower Yangtze block show relatively deep Curie isotherms, up to about 35 km in depth, whereas in the surrounding areas Curie depths are averaged at about 25 km. This implies that the lower Yangtze Block has experienced a unique tectonic evolution and/or has unique basement lithology and structures. From a regional perspective, sedimentary basins, such as the Subei Basin, the south Yellow Sea Basin, and the East China Sea Basin, normally show deeper Curie isotherms than surrounding uplifts such as the Diaoyudao Uplift and the Zhemin Uplifts. Curie isotherms also upwell significantly in volcanically active areas such as the Ryukyu Arc and the Cheju Island, confirming strong magmatic and geothermal activities at depth.

  9. Four Newly Recorded Free-living Marine Nematodes(Comesomatidae) from the East China Sea

    Institute of Scientific and Technical Information of China (English)

    HUA Er; ZHANG Zhinan

    2007-01-01

    Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gubemaculum median piece. The characters of S. breviseta agree quite well with the European original descriptions and only differ in the male amphid tums (5.5 vs.4.0 tums) and unmodified preanal supplements (5-7 vs. 6). S. pulchra can be recognized by amphid 2.75 turns, irregularly arranged lateral dots, and the first three supplements anterior to the anus, which are more widely spaced than the following ones. The excretory system of S. breviseta and S. pulchra shows sexual dimorphism. S. celtica is defined by amphids 2.00-2.25 turns, weakly developed pharyngeal bulb, curved apophyses and 12-13 conspicuous supplements. C. deltensis is characterized by amphids 4.75 tums, ovate pharyngeal posterior bulb, sperm dimorphism, 7 thin preanal supplements, and long tail cylindrical portion (50%-53% of tail length).All the three Sabatieria species are for the first time recorded in Chinese waters. C. deltensis was originally isolated from the Bohai Sea and Yellow Sea and newly recorded in the East China Sea.

  10. Four newly recorded free-living marine nematodes (Comesomatidae) from the East China Sea

    Science.gov (United States)

    Hua, Er; Zhang, Zhinan

    2007-01-01

    Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gubernaculum median piece. The characters of S. breviseta agree quite well with the European original descriptions and only differ in the male amphid turns (5.5 vs. 4.0 turns) and unmodified preanal supplements (5-7 vs. 6). S. pulchra can be recognized by amphid 2.75 turns, irregularly arranged lateral dots, and the first three supplements anterior to the anus, which are more widely spaced than the following ones. The excretory system of S. breviseta and S. pulchra shows sexual dimorphism. S. celtica is defined by amphids 2.00-2.25 turns, weakly developed pharyngeal bulb, curved apophyses and 12-13 conspicuous supplements. C. deltensis is characterized by amphids 4.75 turns, ovate pharyngeal posterior bulb, sperm dimorphism, 7 thin preanal supplements, and long tail cylindrical portion (50%-53% of tail length). All the three Sabatieria species are for the first time recorded in Chinese waters. C. deltensis was originally isolated from the Bohai Sea and Yellow Sea and newly recorded in the East China Sea.

  11. Large scale northward expansion of warm water species Skeletonema tropicum (Bacillariophyceae) in China seas

    Institute of Scientific and Technical Information of China (English)

    LIU Dongyan; JIANG Jinjie; WANG Yan; ZHANG Yong; DI Baoping

    2012-01-01

    Skeletonema tropicum is regarded as a species with an affinity to warm waters and it has never been reported in seas where temperatures drop below 11 ℃ in winter.Previous studies in China reported that S.tropicum was restricted to subtropical and warm temperate seas (East and South China Seas),but the species was recently found during August cruises of 2009 and 2010 in Jiaozhou Bay,Yellow Sea,located several hundred kilometers to the north.Here,winter water temperatures often drop below 5℃.Identification of S.tropicum was confirmed under light and scanning electronic microscopes and maximum cell abundance in Jiaozhou Bay was estimated as 1.73×104cell/L.This record of S.tropicum in Jiaozhou Bay represents a significant northward expansion in the geographic range of the species.Ship ballast water was identified as a possible carrier of S.tropicum from southern places along Chinese coastline,and in addition,thermal pollution from local power stations and seawater desalination plants may provide suitable conditions for species over-wintering.

  12. Quaternary palaeoceanographic changes in the northern South China Sea (ODP Site 1146): radiolarian evidence

    Science.gov (United States)

    Wang, Rujian; Clemens, Steven; Huang, Baoqi; Chen, Muhong

    2003-12-01

    The abundance and accumulation rates of siliceous microfossils in the northern South China Sea, including radiolarians, diatoms and sponge spicules, increased during most glacial intervals within the past 1100 kyr. Similar trends are observed in the index of thermocline surface radiolarians (TSR), diatom accumulation rates (DAR), charcoal accumulation rates (CAR) and the abundance of radiolarian species Cycladophora davisiana davisiana. Decreasing sea-surface temperature accompanied by increased seasonality since 900 ka is indicated by a decline in the tropical radiolarian assemblage, including Tetrapyle octacantha and Octopyle stenozona, and by an increase in the subtropical assemblage, including Pterocorys zancleus, Peromelissa phalacra and Ommatartuts tetrathalamus tetrathalamus. Rapid increases at about 800 to 700 ka of siliceous microfossils, charcoal, subsurface and intermediate radiolarians, as well as the TSR index and the DAR, imply a fundamental shift in climate and a shoaling thermocline. Although these fundamental changes in the silicious fauna and flora of the South China Sea take place within the context of a developing 100-kyr cycle, they do not change in step with changing sea-level as indicated by marine 18O. This is most clearly illustrated by the step-like increase in silica accumulation (radiolaria, diatoms and sponge spicules) at 680 ka. Rather, these fundamental changes probably reflect intensified surface productivity associated with enhanced East Asian winter-monsoon circulation. Copyright

  13. Biweekly Sea Surface Temperature over the South China Sea and its association with the Western North Pacific Summer Monsoon

    Science.gov (United States)

    Vaid, B. H.

    2017-02-01

    The association of the biweekly intraseasonal (BWI) oscillation in the Sea Surface Temperature (SST) over the South China Sea (SCS) and the Western North Pacific Summer Monsoon is authenticated using version 4 the Tropical Rainfall Measuring Mission Microwave Imager data (SST and rain) and heat fluxes from Ocean Atmosphere Flux project data during 1998-2012. The results suggest that the SCS involves ocean-atmosphere coupling on biweekly timescales. The positive biweekly SST anomalies lead the rain anomalies over the SCS by 3 days, with a significant correlation coefficient ( r = 0.6, at 99 % significance levels) between the SST-rain anomalies. It is evident from lead/lag correlation between biweekly SST and zonal wind shear that warm ocean surface induced by wind shear may contribute to a favorable condition of the convective activity over the SCS. The present study suggests that ocean-to-atmospheric processes induced by the BWI oscillation in the SCS SST results in enhanced sea level pressure and surface shortwave radiation flux during the summer monsoon. Besides, it is observed that the SCS BWI oscillation in the changes of SST causes a feedback in the atmosphere by modifying the atmospheric instability. This suggests that the active/break biweekly cycle of the SST over the SCS is related by sea level pressure, surface heat fluxes and atmospheric instability. The potential findings here indicate that the biweekly SST over the SCS play an important role in the eastward and the southward propagation of the biweekly anomalies in the Western North Pacific.

  14. Diversity, distribution, and new phylogenetic information of calcareous dinoflagellates from the China Sea

    Institute of Scientific and Technical Information of China (English)

    Hai-Feng GU; Zhao-He LUO; Yan WANG; Dong-Zhao LAN

    2011-01-01

    Calcareous dinoflagellates have been recorded from subarctic to tropical areas, inhabiting both neritic and oceanic regions. In the present study we analyse 12 sediment samples from the China Sea to establish the existence of calcareous dinoflagellates in this area. A total of 11 calcareous dinoflagellate species were recorded,among them, three genera (Calciodinellum, Leonella, Posoniella) and seven species (Calciodinellum albatrosianum,C. levantinum, C. operosum, Leonella granifera, Posoniella tricarinelloides, Scrippsiella irregularis, and S. regalis)were reported from the China Sea for the first time. Cysts of S. irregularis and S. precaria are identical, with a mesoepicystal archeopyle, representing the loss of 2-4' and 1-3a paraplates; however, their thecal plates vary slightly and differ from each other in 78 positions of the internal transcribed spacer sequence. Scrippsiella trochoidea is dominant in coastal areas, whereas Calciodinellum albatrosianum is the most abundant offshore. Scrippsiella irregularis is distributed widely along the coast of China, whereas S. precaria is recorded only in northern China.Leonella granifera is the second most abundant species offshore, comprising 15-40% of the cyst assemblage.

  15. Estimation of ocean primary productivity and its spatio-temporal variation mechanism for East China Sea based on VGPM model

    Institute of Scientific and Technical Information of China (English)

    LIGuosheng; GAOPing; WANGFang; LIANGQiang

    2004-01-01

    According to calculation results of ocean chlorophyll concentration based on SeaWiFS data by SeaBAM model and synchronous ship-measured data, this research set up an improved model for Case I and Case Ⅱ water bodies respectively. The monthly chlorophyll distribution in the East China Sea in 1998 was obtained from this improved model on calculation results of SeaBAM. The euphotic depth distribution in 1998 in the East China Sea is calculated by using remote sensing data of K490 from SeaWiFS according to the relation between the euphotic depth and the oceanic diffuse attenuation coefficient. With data of ocean chlorophyll concentration, euphotic depth, ocean surface photosynthetic available radiation (PAR), daily photoperiod and optimal rate of daily carbon fixation within a water column, the monthly and annual primary productivity spatio-temporal distributions in the East China Sea in 1998 were obtained based on VGPM model. Based on analysis of those distributions, the conclusion can be drawn that there is a clear bimodality character of primary productivity in the monthly distribution in the East China Sea. In detail, the monthly distribution of primary productivity stays the lowest level in winter and rises rapidly to the peak in spring. It gets down a little in summer, and gets up a little in autumn. The daily average of primary productivity in the whole East China Sea is 560.03 mg/m2/d, which is far higher than the average of subtropical ocean areas. The annual average of primary productivity is 236.95 g/m2/a. The research on the seasonal variety mechanism of primary productivity shows that several factors that affect the spatio-temporal distribution may include the chlorophyll concentration distribution, temperature condition, the Yangtze River diluted water variety, the euphotic depth, ocean current variety, etc. But the main influencing factors may be different in each local sea area.

  16. Mechanism of formation of low level jets in the South China Sea during spring and summer of 1998

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The mechanism responsible for the formation of the low-level jet (LLJ) over the South China Sea during spring and summer of 1998 was analyzed through using the assimilated grid data provided by the South China Sea monsoon experiment (SCSMEX). More analyses were emphasized on a heavy rainfall process in the Zhujiang Delta area between 8th and 10th June 1998 in which a LLJ played a key role. Furthermore, the MM5 meso-scale model was utilized in studying the effects of the weather systems on the LLJ. The results showed that the kinetic energy associated with the LLJ transferred upward when the LLJ formed, which results in the fact that the big velocity of the LLJ expanded upward to higher level. Simulation verifies that a synoptic-scale low pressure in the low troposphere of the west of South China moved toward the east, with a low-troposphere synoptic-scale high pressure in the western Pacific moving toward the west. In this process, the approach of both systems leads to the reinforcement of pressure gradient force between them, making the kinetic energy needed by the formation of the LLJ increase. Through this process the LLJ formed and developed over the South China Sea between the low and high pressures. Because the formation of the LLJ indicates the enhancement of summer monsoon in the South China Sea, the mechanism responsible for formation of the LLJ could be used in explaining an enhancement of summer monsoon in the South China Sea.

  17. GENERAL SITUATION ABOUT ACTIVITY OF SUMMER MONSOON OVER SOUTH CHINA SEA IN 2004 ASIAN SUMMER MONSOON INDEX

    Institute of Scientific and Technical Information of China (English)

    LI Chun-hui; LIANG Jian-yin

    2006-01-01

    Based on daily NCEP reanalysis data, OLR and satellite rainfall data, the characteristic of the activities of South China Sea summer monsoon(SCSSM) in 2004 were analyzed. The results showed that the establishment of SCSSM was little later than normal and the intensity was stronger than normal. Influenced by the location of the northwest Pacific subtropical high, which was much northward and westward than normal,SCSSM was active mainly in the South China Sea areas. There existed obvious intraseasonal oscillation and two significant periods of SCSSM, one was about 20-30 days and the other about 40-50 days. The transportation of moisture was concentrated on the South China Sea and the northwest Pacific regions, reducing the northward transportation and resulting in drought in southern China.

  18. Distributions and sea-to-air fluxes of chloroform, trichloroethylene, tetrachloroethylene, chlorodibromomethane and bromoform in the Yellow Sea and the East China Sea during spring.

    Science.gov (United States)

    He, Zhen; Yang, Gui-Peng; Lu, Xiao-Lan; Zhang, Hong-Hai

    2013-06-01

    Halocarbons including chloroform (CHCl3), trichloroethylene (C2HCl3), tetrachloroethylene (C2Cl4), chlorodibromomethane (CHBr2Cl) and bromoform (CHBr3) were measured in the Yellow Sea (YS) and the East China Sea (ECS) during spring 2011. The influences of chlorophyll a, salinity and nutrients on the distributions of these gases were examined. Elevated levels of these gases in the coastal waters were attributed to anthropogenic inputs and biological release by phytoplankton. The vertical distributions of these gases in the water column were controlled by different source strengths and water masses. Using atmospheric concentrations measured in spring 2012 and seawater concentrations obtained from this study, the sea-to-air fluxes of these gases were estimated. Our results showed that the emissions of C2HCl3, C2Cl4, CHBr2Cl, and CHBr3 from the study area could account for 16.5%, 10.5%, 14.6%, and 3.5% of global oceanic emissions, respectively, indicating that the coastal shelf may contribute significantly to the global oceanic emissions of these gases.

  19. Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

    Science.gov (United States)

    Zhai, Hongchang; Ning, Xiuren; Tang, Xuexi; Hao, Qiang; Le, Fengfeng; Qiao, Jing

    2011-03-01

    Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chi a)-like type, divinyl chlorophyll a (DV Chi a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

  20. Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

    Institute of Scientific and Technical Information of China (English)

    ZHAI Hongchang; NING Xiuren; TANG Xuexi; HAO Qiang; LE Fengfeng; QIAO Jing

    2011-01-01

    Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chl a)-like type, divinyl chlorophyll a (DV Chl a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus,cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region,diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

  1. MANAGING INTRA-REGIONAL CONFLICTS IN SOUTHEAST ASIA. THE CASE OF THE SOUTH CHINA SEA

    Directory of Open Access Journals (Sweden)

    Ioana-Bianca BERNA

    2013-10-01

    Full Text Available This paper is aiming to address the Association of Southeast Asian Nations’ (ASEAN’s management of intra-regional conflicts by integrating the study of the core-source of its current position, comparing and contrasting the different two most significant periods of its existence: the early Post-Cold War Era and its current unveilings, and hedging towards explaining why its barely-enough pragmatism is no longer a solvable demeanor for its survival. The paper will focus on the The South China Sea conflict in the pursuance to explain the distinctions that ASEAN’s management of intra-regional confl icts has gained through experience, through realizing its limited containment capacity as far the regional role of great powers is concerned, or through a critical removal of passivism in the confi dence-winning processes of extra-regional partners. The paper’s choice to address The South China Sea as an intra-regional conflict may be surprising for some, or may inflate others more straightforward as far as the choice for instrumental methods is concerned. In order to better explain this paper’s macro-purposes, the South-China Sea confl ict is an intra-regional confl ict, as the Southeast Asian states involved have divergent claims regarding the sovereignty dilemma. Secondly, more interesting issues might be brought to the table with the involvement of a great power in an intra-regional confl ict. Last but not least, as connected to the previous argument, ASEAN’s engaging and sensitizing of China may generate, from an early start, effects on the perceptionbuilding process between the actors involved.

  2. Air-sea exchange of gaseous mercury in the tropical coast (Luhuitou fringing reef) of the South China Sea, the Hainan Island, China.

    Science.gov (United States)

    Ci, Zhijia; Zhang, Xiaoshan; Wang, Zhangwei

    2016-06-01

    The air-sea exchange of gaseous mercury (mainly Hg(0)) in the tropical ocean is an important part of the global Hg biogeochemical cycle, but the related investigations are limited. In this study, we simultaneously measured Hg(0) concentrations in surface waters and overlaying air in the tropical coast (Luhuitou fringing reef) of the South China Sea (SCS), Hainan Island, China, for 13 days on January-February 2015. The purpose of this study was to explore the temporal variation of Hg(0) concentrations in air and surface waters, estimate the air-sea Hg(0) flux, and reveal their influencing factors in the tropical coastal environment. The mean concentrations (±SD) of Hg(0) in air and total Hg (THg) in waters were 2.34 ± 0.26 ng m(-3) and 1.40 ± 0.48 ng L(-1), respectively. Both Hg(0) concentrations in waters (53.7 ± 18.8 pg L(-1)) and Hg(0)/THg ratios (3.8 %) in this study were significantly higher than those of the open water of the SCS in winter. Hg(0) in waters usually exhibited a clear diurnal variation with increased concentrations in daytime and decreased concentrations in nighttime, especially in cloudless days with low wind speed. Linear regression analysis suggested that Hg(0) concentrations in waters were positively and significantly correlated to the photosynthetically active radiation (PAR) (R (2) = 0.42, p sea Hg(0) fluxes were estimated to be 1.73 ± 1.25 ng m(-2) h(-1) with a large range between 0.01 and 6.06 ng m(-2) h(-1). The high variation of Hg(0) fluxes was mainly attributed to the greatly temporal variation of wind speed.

  3. Macrobenthic community structure and species composition in the Yellow Sea and East China Sea in jellyfish bloom

    Science.gov (United States)

    Peng, Songyao; Li, Xinzheng; Wang, Hongfa; Zhang, Baolin

    2014-05-01

    To understand the characteristics of macrobenthic structures and the relationship between environment and benthic assemblages in jellyfish bloom, we studied the macrobenthos and related environmental factors in the coastal waters of the Yellow Sea and East China Sea. Data were collected during two seasonal cruises in April and August of 2011, and analyzed with multivariate statistical methods. Up to 306 macrobenthic species were registered from the research areas, including 115 species of Polychaeta, 78 of Crustacea, 61 of Mollusca, 30 of Echinodermata, and 22 of other groups. Nine polychaete species occurred at frequencies higher than 25% from the sampling stations: Lumbrineris longifolia, Notomastus latericeus, Ninöe palmata, Ophelina acuminata, Nephtys oligobranchia, Onuphis geophiliformis, Glycera chirori, Terebellides stroemii, and Aricidea fragilis. Both the average biomass and abundance of macrobenthos are higher in August (23.8 g/m2 and 237.7 ind./m2) than those in April (11.3 g/m2 and 128 ind./m2); the dissimilarity of macrobenthic structures among stations is as high as 70%. In terms of the dissimilarity values, we divided the stations into four clusters in spring and eight in summer. The ABC curve shows that the macrofauna communities in high jellyfish abundance were not changed. Canonical correspondence analysis showed that depth, temperature, median grain size, total organic carbon of sediment and total nitrogen in sediment were important factors affecting the macrozoobenthic community in the study area.

  4. Environment and security in the South China Sea region : the role of experts, non-governmental actors and governments in regime building processes

    OpenAIRE

    1999-01-01

    Background: The Spratly islands in the South China Sea are today the focal point of a territorial dispute that represents a serious threat to the regional security in Southeast Asia. Six governments - China, Vietnam, Taiwan, the Philippines, Malaysia and Brunei - have laid claims to all or some of the more than 230 islets, reefs and shoals in the Spratly area. The Peoples Republic of China (PRC) is a key player in the South China Sea conflict. However, the South China Sea is not jus...

  5. Thermal fronts and cross-frontal heat flux in the southern Huanghai Sea and the East China Sea

    Institute of Scientific and Technical Information of China (English)

    PARK Sunghyea; CHU Peter C

    2008-01-01

    Synoptic features in/around thermal fronts and cross-frontal heat fluxes in the southern Huanghai/Yellow Sea and East China Sea(HES) were examined using the data collected from four airborne expendable bathythermograph surveys with horizontal approxmately 35 km and vertical 1 m( from the surface to 400 m deep) spacings. Since the fronts are strongly affected by HES current system, the synoptic thermal features in/around them represent the interaction of currents with surrounding water masses. These features can not be obtained from climatological data. The identified thermal features are listed as follows: (1) multiple boundaries of cold water, asymmetric thermochne intrusion, locally-split front by homogeneous water of approxmately 18 ℃, and mergence of the front by the Taiwan Warm Current in/around summertime southern Cheju-Changjiang/Yangtze front and Tsushima front; (2) springtime frontal eddy-like feature around Tsnshima front; (3) year-round cyclonic meandering and summertime temperature-inversion at the bottom of the surface mixed layer in Cheju-Tsushima front; and (4) multistructure of Kuroshio front. In the Kureshio front the mean variance of vertical temperature gradient is an order of degree smaller than that in other HES fronts.The southern Cheju-Changjiang front and Cheju-Tsushima front are connected with each other in the summer with comparable cross-frontal temperature gradient. However, cross-frontal heat flux and lateral eddy diffusivity are stronger in the southern Cheju-Changjiang front. The cross-frontal heat exchange is the largest in the mixing zone between the modified Huanghai Sea bottom cold water and the Tsushima Warm Current, which is attributable to enhanced thermocline intrusions.

  6. A Preliminary Study on the Lithosphere-Asthenosphere Boundary beneath the South China Sea

    Science.gov (United States)

    Lee, T. T. Y.; Chen, C. W.

    2014-12-01

    The lithosphere-asthenosphere boundary (LAB) is an important boundary at which the rigid lithosphere translates coherently upon the viscous asthenosphere. New observations have been made on LAB through detailed seismic analysis, especially that from receiver functions. Previous studies have found LAB depth varies significantly, systematically getting shallower from continental to oceanic lithosphere. In smaller scale, the depth and sharpness of LAB also differ from region to region, suggesting the effects of a combination of thermal and compositional origins. In this study, we investigate the LAB beneath the South China Sea, a region poorly instrumented that conventional seismological are less effective and impractical. The South China Sea is on the Sunda Plate, which is considered to be once the southeastern part of the Eurasia Plate before separating with a distinct moving direction from that of India-Eurasia continental collision. The South China Sea is Phanerozoic in age and continental in nature, but the striped magnetic anomalies observed from the sea floor have suggested multiple spreading events since early Miocene, indicating the presence of latter formed oceanic lithosphere. Previous seismic studies of this region focused mainly on shallow basin structure pertaining to petroleum exploration. The lithospheric structure, particularly the LAB, remains elusive, while it provides important insight into the complex tectonic history in this region. To image the LAB, we use the precursor of SS phase. The precursor bounces at the LAB discontinuity at depth would appear before the SS and presents a signal amenable to analysis for depth and properties. We collect seismic waveform data recorded mainly at Japan and Cocos Islands of corresponding teleseismic events from Southern Sumatera and Japan, with SS and potential precursors bouncing beneath the South China Sea. We employ an analysis technique, velocity spectral analysis (vespagrams), to identify precursory

  7. Clay minerals and geochemistry of the bottom sediments in the northwestern East China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Clay minerals of 34 sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sediment source and the dominant circulation pattern. The predominant clay mineral in our study area is illite comprising more than 67% of the whole clay fraction. The highest concentration of illite (>68%) is found in the southeastern offshore parts beyond the reach of terrigenous input from the Jeju Island. It means that these illites are largely transported by the Kuroshio Current from the South China Sea (SCS). Smectite is highly concentrated in the northwest middle part and in the outer-shelf mud patch. It seems to be due to the high supply of smectite transported from China where fine-grained sediments are discharged from modern and ancient Huanghe (Yellow) River. The relatively high abundant kaolinite is likely derived from the Changjiang (Yangtze) River via the Taiwan Warm Current. In contrast,large amounts of chlorite and high chlorite/kaolinite ratios occur in the northwestern area, reflecting the transportation by the Yellow Sea Coastal Current from the southern Yellow Sea. The discrimination diagrams clearly show that the sediments in the northwestern East China Sea are ultimately sourced from Chinese rivers, especially from the Huanghe River, whereas the sediment in the northeast part might come from the Jeju Island. The muddy sediments of the Changjiang River's submerged delta have much lower 87Sr/86Sr ratios (0.7162-0.7180) than those of the Shandong Peninsular mud wedge (0.7216-0.7249),which are supposed to be originated from the Huanghe River, suggesting the distribution pattern of 87Sr/86Sr ratios as a new tracer to discriminate the provenance of shelf sediments in the study area. The 87Sr/86Sr ratios of the outer-shelf muddy sediments ranged from 0.7169 to 0.7216 in a wide range and was between those of the Huanghe River and Changjiang

  8. Evaluation and fusion of SST data from MTSAT and TMI in East China Sea, Yellow Sea and Bohai Sea in 2008

    Institute of Scientific and Technical Information of China (English)

    WU Yumei; SHEN Hui; CUI Xuesen; YANG Shenglong; FAN Wei

    2012-01-01

    Two typical satellite sea surface temperature (SST) datasets,from the Multi-functional Transport Satellite (MTSAT) and Tropical Rainfall Measuring Mission Microwave Imager (TMI),were evaluated for the East China Sea,Yellow Sea,and Bohai Sea throughout 2008.Most monthly-mean availabilities of MTSAT are higher than those of TMI,whereas the seasonal variation of the latter is less than that of the former.The analysis on the one-year data shows that the annual mean availability of MTSAT (61%) is greater than that of TMI (56%).This is mainly because MTSAT is a geostationary satellite,which achieves longer observation than the sun-synchronous TMI.The daily availability of TMI (28%-75%) is more constant than that of MTSAT (9%-93%).The signal of infrared sensors on MTSAT is easily disturbed on cloudy days.In contrast,the TMI microwave sensor can obtain information through clouds.Based on in-situ SSTs,the SST accuracy of TMI is superior to that of MTSAT.In 2008,the root mean square (RMS)error of TMI and MTSAT were 0.77 K and 0.84 K,respectively.The annual mean biases were 0.14 K (TMI) and -0.31 K (MTSAT).To attain a high availability of SSTs,we propose a fusion method to merge both SSTs.The annual mean availability of fusion SSTs increases 17% compared to MTSAT.In addition,the availabilities of the fusion SSTs become more constant.The annual mean RMS and bias of fusion SSTs (0.78 K and -0.06 K,respectively) are better than those of MTSAT (0.84 K and -0.31 K).

  9. The Distribution of Dissolved Aluminum in the Yellow and East China Seas

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Water samples containing dissolved aluminum were collected from the Yellow and East China Seas in October-November 2000. The average concentrations of dissolved Al in the Yellow Sea (YS) and East China Sea (ECS) were 0.042 and 0.056 μ molL-1, respectively. The concentration of dissolved aluminum decreased gradually across the continental shelf. The lower concentrations appeared in the YS cold water center and in the bottom layer at the shelf edge of the ECS, where they were 0.016 and 0.011 μmolL-1, respectively. The distribution of dissolved A1 was controlled by physical mixing processes rather than biological uptake processes. The impact of different water masses along the PN transect was calculated based on the mass balance model. The results show that the impact of the Changjiang River was mainly concentrated on the coastal area and the top thermocline water on the ECS shelf, where the impact percentage decreased from 12.6% to 1.1% in the surface water, while the contribution of the Kuroshio water was dominant on the ECS shelf in this survey, increasing from 77.6% to 97.8% along the PN transect from the Changjiang River Estuary to the Ryukyu Islands. It is concluded that aluminum can serve as a proper tracer for studying the impact of Changjiang terrestrial matter on the ECS shelf water.

  10. Assessment of Wave Energy in the South China Sea Based on GIS Technology

    Directory of Open Access Journals (Sweden)

    Gang Lin

    2017-01-01

    Full Text Available China is now the world’s largest user of coal and also has the highest greenhouse gas emissions associated with the mining and use of coal. Under today’s enormous pressures of the growing shortage of conventional energy sources and the need for emission reductions, the search for clean energy is the most effective strategy to address the energy crisis and global warming. This study utilized satellite remote sensing technology, geographic information system (GIS technology, and simulated wave data for the South China Sea. The characteristic features of the wave energy were obtained by analysis through the wave resource assessment formula and the results were stored in a GIS database. Software for the evaluation of wave energy in the South China Sea was written. The results should provide accurate, efficient references for wave energy researchers and decision-makers. Based on a 24-year WW3 model simulation wave data and GIS technology, this study presented the characteristic of the wave energy in the SCS; results demonstrated that the SCS has the feasibility and viability for wave energy farming.

  11. 3-D BAROCLINIC NUMERICAL SIMULATION OF THE SOUTH CHINA SEA I. UPPER CIRCULATION

    Institute of Scientific and Technical Information of China (English)

    蔡树群; 甘子钧; 刘秦玉

    2001-01-01

    A three-dimensional baroclinic shelf sea model was employed to simulate the seasonal characteristics of the South China Sea (SCS) upper circulation. The results showed that: in summer, an anticyclonic eddy, after its formation between the Bashi Channel and Dongsha Islands in the northeastern SCS, moves southwestward until it disperses slowly. There exists a northward western boundary current along the east shore of the Indo-China Peninsula in the western SCS and an anticyclonic gyre in the southern SCS. But at the end of summer and beginning of autumn, a weak local cyclonic eddy forms in the Nansha Trough, then grows slowly and moves westward till it becomes a cyclonic gyre in the southern SCS in autumn. At the beginning of winter, there exists a cyclonic gyre in the northern and southern SCS, and there is a southward western boundary current along the east shore of the Indo-China Peninsula. But at the end of winter, an anticyclonic eddy grows and moves toward the western boundary after forming in the Nansha Trough. The eddy's movement induces a new opposite sign eddy on its eastern side, while the strength of the southward western boundary current gets weakened. This phenomenon continues till spring and causes eddies in the southern SCS.

  12. Mesozoic subduction-accretion zone in northeastern South China Sea inferred from geophysical interpretations

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A segment of Mesozoic subduction-accretion zone was inferred across the northeastern South China Sea at approximately NE45° orientation. Basic evidence includes the following: A belt of peek gross horizontal Bouguer gravity gradient (PGHGBA) is comparable in size and intensity to that of the Manila subduction-accretion zone. A belt of high positive magnetic anomalies appears to the north and sub-parallel to the PGHGBA, representing the volcanic arc associated to the subduction zone. The PGHGBA crosses obliquely both Cenozoic structures and present seafloor topography, indicating a pre-Cenozoic age. The segment is offset left-laterally by NW-running strike-slip faults, in concord with the Mesozoic stress field of South China. In addition, the existence of the subduction zone is supported by wide-angle seismic data obtained in different years by different institutions. At approximate localities, a north-dipping ramp of Moho surface is indicated by records of ocean-bottom seismometers, and a strong reflector about 8 km beneath the Moho reflector is indicated by both OBS and long-cable seismic records. The identification of a segment of Mesozoic subduction zone in NE South China Sea fills nicely the gap of the Great Late Mesozoic Circum SE Asia Subduction-acrretion Zone, which extended from Sumatra, Java, SE Kalimantan to N Palawan, and from Taiwan, Ryukyu to SW Japan.

  13. The Current Situation and Trend in South China Sea%当前南海形势及走向

    Institute of Scientific and Technical Information of China (English)

    吴士存

    2015-01-01

    南海问题的实质是南沙岛礁主权和海域管辖权争议,涉及“五国六方”。近年来,受美国全球战略调整等多重因素的影响,南海问题持续升温,有关争端国不断加大权益声索和实际管控力度,地区局势愈演愈烈。南海是我国国防安全海上屏障、发展制海权的重要战略出海口、经济和能源安全的海上运输要道及未来的能源和资源基地。新阶段,南海局势将继续保持升温态势,因此我国需要从国家总体发展战略全局出发,把握并延长战略机遇期,通盘考虑国际和国内影响因素,长远谋划妥善处理南海问题战略和战术决策,有效化解面临的巨大挑战,确保整体利益最大化。%The essence of the South China Sea issue is the dispute among five states and Chinese Taiwan over the sovereignty of Nansha Islands and jurisdiction of maritime zones in the South China Sea. In recent years,relevant disputants have been intensifying the attempts to bolster their claims and actual control. Regional situation has been moving towards greater tensions. The South China Sea acts as a maritime shield for China to strengthen na_tional defense,an important sea outlet for China to gain sea power,significant sea lanes for China to safeguard e_conomic and energy security,and a base for China to secure energy and other resources in the future. Therefore, it is imperative for China to maintain the maritime rights. In a new historical period when the South China Sea situation continue to intensify,we should approach the South China Sea issue from the standpoint of overall na_tional development strategy,seek important opportunities for strategic development,take international and domes_tic factors into account,develop long_term strategic and tactical countermeasures to alleviate the current situa_tion and maximize China′s interests.

  14. South China Sea disputes: ASEAN’s Role in Addressing Disputes with China

    Science.gov (United States)

    2013-12-13

    Declaration on the Conduct of Parties EEZ Exclusive Economic Zone UNCLOS UN Convention of the Law of the Sea viii ILLUSTRATIONS Page......by the signing of the ASEAN Declaration ( Bangkok Declaration) by the foreign ministers of its five founder nations, namely Indonesia, Malaysia

  15. Influence of small river derived sediment on the Northeastern South China Sea sedimentation processes in the last 40 K years

    Science.gov (United States)

    Cheng, Wan-Yen; Lin, Saulwood; Lou, Jiann-Yuh; Wei, Kuo-Yen; Liu, CharShine; Chen, Shing-Li; Wang, Yun-Shuen

    2015-04-01

    Small rivers derived particles are major source of sediment to the ocean in the present time. Small rivers in Taiwan are subjected to fast tectonic activity, high precipitation rate and erosion rate. The combined annual river particle load from small rivers on the Island of Taiwan is higher than that of the Mississippi River. A large fraction of those rivers particle may finding its way into the surrounding seas and ocean, e.g. South China Sea, East China Sea, and the Philippine Sea. Furthermore, due to the nature of particle transportation off rivers from Taiwan were connected by a number of canyon systems close by the river mouth, majority of those river particles were facilitated in delivering and deposited later further into the South China Sea deep basin. The objectives of this study are to understand spatial variations in sedimentation rates and to resolve the temporal differences in sedimentation in the Northeastern South China Sea region, and to evaluate influence of small river particles to the marginal sea. A set of cores was collected in overlying water depth within 1600 - 3300 m for mutilsensor core logging of magnetic susceptibility, density, and porosity. Foraminifera (G. sacculifer, G. conglobatus, O. universa) were picked and AMS C14 analyses for age determination. Grain size, organic carbon, carbonate and biogenic silica content were measured. The results show that large sedimentation rates difference existed in the study area. Earlier studies on sedimentation rate in the region west of our study area were in range of about 10 cm/kyr while our rates are about 20-40 cm/kyr and much higher near Taiwan. Bulk sedimentation rate were higher during the transition period between LGM and Holocene and lower during Holocene. Our results demonstrated that large quantity of particles from small rivers in Taiwan are and were major source of particle and are the dominating factor in controlling sediment deposition in the northeastern South China Sea.

  16. Can China Defend A "Core Interest" In The South China Sea?

    Science.gov (United States)

    2011-01-01

    issue low-level military threats, bullying its southern neighbors with its existing fleet of ships, submarines, aircraft, and missiles. Such actions may...Singapore, Malaysia , Indonesia, and even Vietnam are procuring submarine forces to hedge against China. Extraregional powers such as Japan and Australia are

  17. An abrupt cooling event early in the last interglacial in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    TU; Xia

    2001-01-01

    [1]Grootes, P. M., Stulver, M., Johnson, J. W. C. et al., Comparison of oxygen isotope records from GISP2 and GRIP Greenland ice cores, Nature, 1993, 366:552-554.[2]Maslin, M., Sarnthein, M., Knaack, J. J. et al., Intra-interglacial cold events: An Eemian-Holocene comparison, The Geo logical Society of London, Special Publications, 1998, 131:91-99.[3]Wang, P., Prell, W., Blum, P. et al., Proceedings of the Ocean Drilling Program, Initial Reports, 2000, 184.[4]Thompson, P. R., Bé, A. W. H., Disappearrence of pink-pigmented Globigerinoides ruber at 120,000yr BP in the Indian and Pacific Oceans, Nature, 1976, 280:554-558.[5]Martinson, D. G., Piasias, N. G., Hays, J. D. et al., Age dating and the orbital theory of the ice ages: Development of a high-resolution 0 to 300000-year chronostratigraphy, Quaternary Research, 1987, 27: 1-29.[6]Thompson, P. R., Planktonic foraminifera in the West North Pacific during the past 150,000 years: Comparison of modern and fossil assemblages, Palaeogeogr. Palaeoclimatol. Palaeoecol., 1981, 35:241-279.[7]Tu, X., Zheng, F., Chen, M. et al., Planktonic foraminifera in continental slope of southern South China Sea and their im plications to paleotemperature of surface sea water, Tropic Oceanology (in Chinese with English abstract), 2000, 19(3): 40-49.[8]Wang, L., Sarnthein, M., Erlenkeuser, H. et al., East Asian monsoon climate during the late Pleistocene: High-resolution sediment records from the South China Sea, Marine Geology, 1999, 156: 245-284.[9]Eglintin, G., Bradshaw, S. A., Rosell, A. et al., Molecular record of secular sea surface temperature changes on 100-year timescales for glacial terminations I, Ⅱ, and IV, Nature, 1992, 356: 423-426.[10]Maslin, M., Sarnthein, M., Knaack, J.-J., Subtropical Eastern Atlantic climate during the Eamian, Naturwissenschaften,1996, 83:122-126.[11]Sarnthein, M., Tiedemann, R., Younger Dryas-style cooling events at glacial terminations I-VI at ODP Site 658

  18. Influence of the modified global ocean tide model with local tides of East and South China Seas on load gravity in China and its neighbor area

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jiang-cun; SUN He-ping

    2005-01-01

    By using 11 global ocean tide models and tidal gauge data obtained in the East China Sea and South China Sea, the influence of the ocean loading on gravity field in China and its neighbor area is calculated in this paper. Furthermore, the differences between the results from original global models and modified models with local tides are discussed based on above calculation. The comparison shows that the differences at the position near the sea are so large that the local tides must be taken into account in the calculation. When the global ocean tide models of CSR4.0, FES02, GOT00, NAO99 and ORI96 are chosen, the local effect for M2 is less than 0.10×10-8 m·s-2 over the area far away from sea. And the local effect for O1 is less than 0.05 ×10-8 m·s-2 over that area when choosing AG95 or CSR3.0 models. This numerical result demonstrates that the choice of model is a complex problem because of the inconsistent accuracy of the models over the areas of East and South China Seas.

  19. The coral grayness in northern South China Sea and its description of interdecadal variation of precipitation in south China

    Institute of Scientific and Technical Information of China (English)

    GU Dejun; WANG Dongxiao; SUN Donghuai; GAO Rongzhen; JI Zhongping

    2006-01-01

    The interdecadal variation of coral grayness in northern South China Sea (SCS) is studied using the annual mean coral grayness in northern SCS from 1789 to 1992 and annual precipitation at Guangzhou from 1908 to 1992 by Singular Spectrum Analysis (SSA), correlation analysis, Mann-Kendall's abrupt change analysis and composite analysis. The interdecadal variation of south China precipitation as reflected by the series of Guangzhou precipitation rebuilt with the coral grayness is discussed. The results show that the variation of coral grayness in SCS has significant terms of tendency, much-weighted interdecadal variation and weak interannual variation.There was a century-scale abrupt change of coral grayness at the end of the 1880s that changed from positive anomalies to negative anomalies. The global field of SST difference corresponding to the point of abrupt change was negative anomalies over the SCS and neighboring northern Indian Ocean, most of central and western Pacific Ocean and coastal areas of the northern Atlantic Ocean. The large-scale distribution of SST anomalies is concomitant with the century-scale abrupt change of coral grayness in SCS. Negative correlation exists between the coral grayness in SCS and precipitation in Guangzhou on the interdecadal scale and the interdecadal precipitation in Guangzhou as reflected by the interdecadal data of SCS coral grayness shows that the interdecadal variation of south China precipitation changes significantly from phase to phase. The current study aims at contributing in the effort of identifying alternative indexes for climate change in south China on the interdecadal scale and beyond.

  20. Distribution and Sea-to-air Flux of Nitrous Oxide in the East China Sea during the Summer of 2013

    Science.gov (United States)

    Wang, Lan; Zhang, Guiling; Zhu, Zhuoyi; Li, Jia; Liu, Sumei; Ye, Wangwang; Han, Yu

    2016-07-01

    Dissolved nitrous oxide (N2O) at different depths of 73 stations in the Changjiang (Yangtze River) Estuary and the East China Sea (ECS) were determined from August 4 to 31 of 2013, and the sea-to-air fluxes of N2O were also estimated in this study. N2O concentrations in the surface waters ranged from 6.33 to 44.40 nmol L-1 with an average of (9.27±4.30) nmol L-1 and the values in the bottom waters ranged from 5.19 to 26.98 nmol L-1 with an average of (11.87±3.71) nmol L-1. The concentrations of N2O decreased with distance from the Changjiang Estuary to the open sea. The vertical distributions of N2O indicated great spatial variations. A region of significant bottom-water hypoxia, with oxygen concentration less than 1.5 mg L-1, occurred at the north of the ECS, and increased bottom N2O concentrations was observed. Frequent vertical mixing may enhance the emission of N2O from this hypoxic area. N2O in the surface waters of all stations were over-saturated, and the N2O saturations ranged from 106% to 658%, with an average of (149±62)%. We estimated the sea-to-air fluxes of N2O as (30.6±59.1) μmol m-2 d-1 from the Changjiang Estuary, (9.8±8.8) μmol m-2 d-1 from the coastal and shelf, and (21.0±12.7) μmol m-2 d-1 from the continental slope using the Wanninkhof 1992 equation, (24.9±47.2) μmol m-2 d-1, (8.0±6.7) μmol m-2 d-1 and (16.5±9.6) μmol m-2 d-1 using the Nightingale 2000 equation, respectively. N2O emission from the ECS was estimated to be about (8.2-16.0)×10-2 Tg-N2O yr-1, suggesting that the ECS was a significant net source of atmospheric N2O.

  1. Decadal variability of chlorophyll a in the South China Sea:a possible mechanism

    Institute of Scientific and Technical Information of China (English)

    LIU Fenfen; CHEN Chuqun; ZHAN Haigang

    2012-01-01

    Four climatologies on a monthly scale (January,April,May and November) of chlorophyll a within the South China Sea (SCS) were calculated using a Coastal Zone Color Scanner (CZCS) (1979-1983) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) (1998-2002).We analyzed decadal variability of chlorophyll a by comparing the products of the two observation periods.The relationships of variability in chlorophyll a with sea surface wind speed (SSW),sea surface temperature (SST),wind stress (WS),and mixed layer depth (MLD) were determined.The results indicate that there is obvious chlorophyll a decadal variability in the SCS.The decadal chlorophyll a presents distinct seasonal variability in characteristics,which may be as a result of various different dynamic processes.The negative chlorophyll a concentration anomaly in January was associated with the warming of SST and a shallower MLD.Generally,there were higher chlorophyll a concentrations in spring during the SeaWiFS period compared with the CZCS period.However,the chlorophyll a concentration exhibits some regional differences during this season,leading to an explanation being difficult.The deepened MLD may have contributed to the positive chlorophyll a concentration anomalies from the northwestern Luzon Island to the northeastern region of Vietnam during April and May.The increases of chlorophyll a concentration in northwestem Borneo during May may be because the stronger SSW and higher WS produce a deeper mixed layer and convective mixing,leading to high levels of nutrient concentrations.The higher chlorophyll a off southeastem Vietnam may be associated with the advective transport of the colder water extending from the Karimata Strait to southeastem Vietnam.

  2. Microphysical Characteristics of Sea Fog over the East Coast of Leizhou Peninsula, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lijuan; NIU Shengjie; ZHANG Yu; XU Feng

    2013-01-01

    Microphysical properties of sea fog and correlations of these properties were analyzed based on the measurements from a comprehensive field campaign carried out from 15 March to 18 April 2010 on Donghai Island (21°35″N,110°32′5″E) in Zhanjiang,Guangdong Province,China.There were four types of circulation pattern in favor of sea fog events in this area identified,and the synoptic weather pattern was found to influence the microphysical properties of the sea fogs.Those influenced by a warm sector in front of a cold front or the anterior part of low pressure were found to usually have a much longer duration,lower visibility,greater liquid water content,and bigger fog droplet sizes.A fog droplet number concentration of N> 1 cm-3 and liquid water content of L≥0.001 g m-3 can be used to define sea fogs in this area.The type of fog droplet size distribution of the sea fog events was mostly monotonically-decreasing,with the spectrum width always being >20 μ.m.The significant temporal variation of N was due in large part to the number concentration variation of fog droplets with radius <3 μm.A strong collection process appeared when droplet spectrum width was >10 μm,which subsequently led to the sudden increase of droplet spectrum width.The dominant physical process during the sea fog events was activation with subsequent condensational growth or reversible evaporation processes,but turbulent mixing also played an important role.The collection process occurred,but was not vital.

  3. Quaternary transgressive and regressive depositional sequences in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    LIUZhenxia; YINPing; XIONGYingqian; S.Beme; A.Trentesaux; LIChaoxin

    2003-01-01

    Based on the interpretation more than 4000 km sparker single channel seismic profiles and the comparison with Borehole DZQ4 on the outer shelf of the East China Sea (ECS),the seismic sequences,sedimentary facies and paleo-sedimentary environment are studied to establish the chronology framework and discuss the Quaternary transgressive and regressive sequences of the ECS shelf as well as their response to glacio-eustatic sea-level changes.The sea level of the ECS fluctuated with global climate changes in the Quaternary.During the sea level rise,the pacific tidal wave impacted actively on the ECS continental shelf and the reciprocating tidal currents in NW-SE direction formed tidal sand ridges,which represent large transgressive deposits visible on the seismic profiles.In response to sea level fall,the Yangtze River deltas prograded seaward and built massive subaqueous deltas to form regressive sequences on the seismic profiles.Alternative transgression and regression sequences were vertically distributed on the ECS shelf with the frequent eustacy in the Quaternary.The gentle slope of the ECS shelf makes it possible for the coastline to migrate hundreds of kilometers forth and back on the shelf because of tens of meters sea level changes,in the meanwhile,the Yangtze River discharged large amounts of sediments into the ECS resulting in large-scale subaqueous deltas and tidal sand ridges.There have developed 3 stages of tidal sand ridges and 4 stages of deltas on the ECS shelf since oxygen isotope stage 8.

  4. Crustal structure and extension mode in the northwestern margin of the South China Sea

    Science.gov (United States)

    Gao, Jinwei; Wu, Shiguo; McIntosh, Kirk; Mi, Lijun; Liu, Zheng; Spence, George

    2016-06-01

    Combining multi-channel seismic reflection and gravity modeling, this study has investigated the crustal structure of the northwestern South China Sea margin. These data constrain a hyper-extended crustal area bounded by basin-bounding faults corresponding to an aborted rift below the Xisha Trough with a subparallel fossil ridge in the adjacent Northwest Sub-basin. The thinnest crust is located in the Xisha Trough, where it is remnant lower crust with a thickness of less than 3 km. Gravity modeling also revealed a hyper-extended crust across the Xisha Trough. The postrift magmatism is well developed and more active in the Xisha Trough and farther southeast than on the northwestern continental margin of the South China Sea; and the magmatic intrusion/extrusion was relatively active during the rifting of Xisha Trough and the Northwest Sub-basin. A narrow continent-ocean transition zone with a width of ˜65 km bounded seaward by a volcanic buried seamount is characterized by crustal thinning, rift depression, low gravity anomaly and the termination of the break-up unconformity seismic reflection. The aborted rift near the continental margin means that there may be no obvious detachment fault like that in the Iberia-Newfoundland type margin. The symmetric rift, extreme hyper-extended continental crust and hotter mantle materials indicate that continental crust underwent stretching phase (pure-shear deformation), thinning phase and breakup followed by onset of seafloor spreading and the mantle-lithosphere may break up before crustal-necking in the northwestern South China Sea margin.

  5. Study on Marine Corrosion and Antifouling Behavior of Copper Alloys Exposed to Sea Areas in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The relationship of corrosion resistance and antifouling behavior of 19 Cu alloys exposed to seawater of Qingdao ,Xiamen,Yulin sea areas in China for 1,2,4,8 year intervals was studied .The experiments were carried on by analyzing the composition of corrosion films formed on the surface of alloy specimens during the immersion time and by using OM,SEM,EDXA and AES experiment methods.The results verify the view point that it is the cuprous oxide film which played an important role in antifouling property of Cu alloys in seawater and throw a light on the view point in details further.The influence of different sea areas on the antifouling property of Cu alloys is also discussed.

  6. Climate Change and China as a Global Emerging Regulatory Sea Power in the Arctic Ocean

    DEFF Research Database (Denmark)

    Cassotta Pertoldi-Bianchi, Sandra; Hossain, Kamrul; Ren, Jingzheng;

    2015-01-01

    The impact of climate change in the Arctic Ocean such as ice melting and ice retreat facilitates natural resources extraction. Arctic fossil fuel becomes the drivers of geopolitical changes in the Arctic Ocean. Climate change facilitates natural resource extractions and increases competition...... between states and can result in tensions, even military ones. This article investigates through a political and legal analysis the role of China as an emerging regulatory sea power in the Arctic Ocean given its assertive “energy hungry country behaviour” in the Arctic Ocean. The United Nations Convention...... on the Law of the Sea (UNCLOS) and the Arctic Council (AC) are taken into consideration under climate change effects, to assess how global legal frameworks and institutions can deal with China’s strategy in the Arctic Ocean. China’s is moving away from its role as “humble power” to one of “informal...

  7. Comparative analysis of environmental carrying capacity of the Bohai Sea Rim area in China.

    Science.gov (United States)

    Lin, Lu; Liu, Yi; Chen, Jining; Zhang, Tianzhu; Zeng, Siyu

    2011-11-01

    Environmental carrying capacity is an essential metric for measuring regional sustainability. Although the term "carrying capacity" has been applied for over a century, the concept definition, quantitative methods and comprehensive evaluation remain arguable. This study analyzed the carrying capacity of four environmental elements, including water resources, air, surface water and offshore sea, and integrated them into a comprehensive index to represent overall regional profiles of resources and environment. The method was then applied to thirteen municipalities in the Bohai Sea Rim area, one of the most rapidly developing regions in transition China. The results show that the comprehensive environmental carrying capacity of the municipalities in the south sub-region were largest in 2007, while that of the west municipalities were lowest. The regional economic development exceeded the overall environmental carrying capacity by 36% and the west sub-region area deserves overwhelming attention for future industrial allocation.

  8. Shoaling of internal solitary waves at the ASIAEX site in the South China Sea

    Directory of Open Access Journals (Sweden)

    K. G. Lamb

    2014-07-01

    Full Text Available The interaction of barotropic tides with Luzon Strait topography generates westward propagating internal bores and solitary waves trains which eventually shoal and dissipate on the western side of the South China Sea. Two-dimensional numerical simulations of this shoaling process at the site of the Asian Seas International Acoustic Experiment (ASIAEX have been undertaken in order to investigate the sensitivity of the shoaling process to the stratification and the underlying bathymetry, and to explore the influence of rotation. A range of wave amplitudes are considered. Comparisons with adiabatic shoaling waves are also made and the potential impact of a non-slip boundary condition are briefly explored. On the slope secondary solitary waves and mode-two wave packets are generated which propagate towards the shelf. Comparisons with observations made during the ASIAEX experiment are made.

  9. Carbon isotopic record of foraminifers in surface sediments from the South China Sea and its significance

    Institute of Scientific and Technical Information of China (English)

    CHENG Xinrong; WANG Pinxian; HUANG Baoqi; LIU Chuanlian; JIAN Zhimin; ZHAO Quanhong; LI Jianru; TIAN Jun; XU Jian

    2005-01-01

    The study is based on stable carbon isotopic measurements of 112 foraminiferal samples from surface sediments at 40 sites in the South China Sea (SCS).δ13C of foraminifers and △δ13C between planktonic and benthic foraminiferal species exhibit a low value area at the northeastern and southern ends of the SCS. It is correlated with the nutrient distributional pattern in the SCS and circumjacent area, the influence of the northeastern and southwestern monsoons on water flow and water chemistry in the SCS. The monsoons have not only brought nutrients to the upper part of the sea but also disturbed water and decreased difference between the surface and bottom water. Its influence is most obvious at both ends, which resulted in the low value areas in δ13C and △δ13C at the ends. The distributional pattern of the stable carbon isotope in the SCS is a reflection of the East Asian monsoons.

  10. Computation of Wave, Tide and Wind Current for the South China Sea Under Tropical Cyclones

    Institute of Scientific and Technical Information of China (English)

    朱良生; 宋运法; 邱章; 陈秀华; 麦波强; 丘耀文; 宋丽莉

    2003-01-01

    Based on the third-generation oceanic wave prediction model (WAVEWATCH Ⅲ),the third-generation nearshore wave calculation model (SWAN) and the mathematical tide, tidal current and cyclone current model, which have been improved, interconnected and expanded, a coupled model of offshore wave, tide and sea current under tropical cyclone surges in the South China Sea has been established. The coupled model is driven by the tropical cyclone field containing the background wind field. In order to test the hindcasting effect of the mathematical model, a comparison has been made between the calculated results and the observational results of waves of 15 cyclone cases, water levels and current velocities of the of 7 cyclones. The results of verification indicate that the calculated and observed results are basically identical.

  11. Nitrogen deposition fuels harmful algal blooms in the East China Sea

    Science.gov (United States)

    Mackey, K. R.; Kavanaugh, M.; Chien, C. T.; Chen, Y.; Glover, D. M.; Paytan, A.

    2015-12-01

    Chinese marginal seas support vast fisheries and vital economies, but their productivity is threatened by eutrophication and increasing harmful algal blooms (HABs). Here we provide direct experimental evidence that aerosol enrichment shifts seawater chemistry by increasing the ratio of N to phosphorus (N:P) and supports the growth of bloom-forming phytoplankton in the East China Sea. We use a combination of field-based aerosol addition incubation experiments, along with ocean color data on blooms dominated by different taxa to show that HAB forming dinoflagellates are particularly responsive to aerosol inputs. Moreover, we show that the effect of N deposition is strongest in offshore waters further from the Yangtze River outflow, consistent with the large anthropogenic flux of N from this source. This study shows the potential for aerosols to control N:P ratios in offshore waters and to shape the phytoplankton community, contributing to the success of bloom-forming organisms.

  12. CHARACTERISTICS OF FREQUENCY SPECTRUM VARIATION OF INTRASEASONAL OSCILLATION OF CONVECTION DURING SOUTH CHINA SEA SUMMER MONSOON

    Institute of Scientific and Technical Information of China (English)

    LIN Ai-lan; LIANG Jian-yin; LI Chun-hui

    2006-01-01

    Datasets of equivalent temperature of black body (TBB) and sea surface temperature (SST) ranging from 1980 to 1997 are used to diagnose and analyze the characteristics of frequency spectrum and strength of intraseasonal variation of convection. The relationship between the strength of intraseasonal oscillation of convection, strength of convection itself and SST in the South China Sea (SCS) is studied. It is shown that, there are distinguishable annual, interannual and interdecadal variations in both strength and frequency spectrum of intraseasonal variation of convection in SCS. There are connections between strength of convection, strength of ISO1 in the summer half (s.h.) year and SST in ensuing winter half (w.h.) year in SCS.The strong (weak) convection and strong (weak) ISO1 are associated with negative (positive) bias of SST in ensuing w.h. year in SCS.

  13. Responses of thermal structure and vertical dynamic structure of South China Sea to Typhoon Chanchu

    Institute of Scientific and Technical Information of China (English)

    陈宜展; 詹杰民; 罗莹莹; 唐灵; 韦永康

    2014-01-01

    The response of the South China Sea (SCS) to Typhoon Chanchu (2006) was examined using the MM5 and POM model. In the POM model, sea surface boundary conditions were forced by the simulation wind field from MM5, the velocity forcing was introduced in the eastern boundary and the computational schemes of heat fluxes at the surface were introduced. Comparison with the observation data shows that the simulated results are reliable. In the response process of the SCS to Typhoon Chanchu, the influence of the heat fluxes on thermal structure of the SCS was regionally different. Strong wind forcing would lead to upwelling phenomenon in the lateral boundary of deep water basin. Furthermore, the Ekman pumping theory was used to discuss subsurface upwelling and downwelling phenomenon in typhoon forced stage.

  14. Cambrian Sequence Stratigraphy and Sea Level Cycles of North China Platform

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The Cambrian of the North China platform consists chiefly of shallow water deposits and shows the sedimentary characters of an epicontinental sea basin. Controlled mainly by global sea level changes and sedimentary influx, the depositional sequences all exhibit as composite sequences. From bottom upward, 14 sequences (3rd order) are recognized, which may be grouped into 5 sequence sets and further into 2 mesosequences (2nd order). It is suggested herein that the Cambrian/Ordovician boundary may better be set at the MFS (maximum flooding surface) of the sequence OSq1, above which the conodont Cordylodus lindstroemi occurs. This position is about 40 m above the traditional Cambrian/Ordovician boundary and is within the Yeli Formation.

  15. Paleoceanographic evolution recorded in the northern South China Sea since 4 Ma

    Institute of Scientific and Technical Information of China (English)

    HUANG Baoqi; JIAN Zhimin; WANG Pinxian

    2005-01-01

    Upper water structure over the last 4 million years in the northern South China Sea (SCS) was reconstructed by sea surface temperature (SST) and primary productivity estimated by changes in the abundance of planktonic foraminifer, planktonic foraminifer transfer function, and the accumulation rate of benthic foraminifera. Results of SST and primary productivity show that SST gradually decreased since 4 Ma, but differential seasonal temperature and primary productivity increased in steps mainly at about 3.1, 2.7, 2.1, 1.6, 0.9 and 0.5 Ma. Comparison with tectonics and orbital variations indicates that phased rising of the Tibet since 3.6 Ma, closing of Panama and Indonesian seaways, and orbital changes were responsible for the changes of upper water structure in the SCS, respectively.

  16. Spatial and temporal variation of picoplankton distribution in the Yellow Sea, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yuan; ZHAO Li; XIAO Tian; ZHAO Sanjun; XUAN Jiliang; LI Chaolun; NING Xiuren

    2011-01-01

    Seven surveys were carried out in April, September, October, December 2006 and March, May, August 2007 in the Yellow Sea, China. Variations in the spatial and temporal distribution of Synechococcus, picoeukaryotes and heterotrophic bacteria are quantified using flow cytometry. Synechococcus and heterotrophic bacteria are most abundant from late spring to autumn, while picoeukaryotes concentration is high in spring. Synechococcus and heterotrophic bacteria concentrated high in the northwest part of the Yellow Sea in spring and autumn, while picoeukaryotes distributed evenly over the whole study area except for a small frontal zone in the coastal area on the west (in spring) and central Yellow Sea (in autumn). Under mixing conditions, the vertical distribution of the three picoplankton groups showed a well-mixed pattern. Upon a well-established stratification, the maximum abundance of picoplankton occurred above the mixed layer depth (~30 m). Cell sizes of Synechococcus and picoeukaryotes were estimated by converting forward scatter signals (FSC) from cytometry analysis to cell diameter, showing the results of 0.65-0.82 μm for Synechococcus and 0.85-1.08 μm for picoeukaryotes. The average integrated carbon biomasses ranged 15.26-312.62 mgC/m2 for Synechococcus, 18.54-61.57 mgC/m2 for picoeukaryotes, and 402.63-818.46 mgC/m2 for heterotrophic bacteria. The distribution of Synechococcus and heterotrophic bacteria was temperature dependent, and picoplankton presence was poor in the Yellow Sea Cold Water Mass.

  17. Distribution of nutrients and eutrophication assessment in the Bohai Sea of China

    Institute of Scientific and Technical Information of China (English)

    WANG Xiulin; CUI Zhengguo; GUO Quan; HAN Xiurong; WANG Jiangtao

    2009-01-01

    Water samples were collected in 120 stations in the Bohai Sea of China to analyze the distribution of dissolved nutrients and assess the degree of eutrophication in August 2002. The result shows that the average concentration of DIN increased and the PO4-P concentration sharply decreased compared to the previous data of corresponding period. The high concentrations of DIN and PO4-P occurred in coastal waters, especially in the bays and some river estuaries, while the high concentrations of SiO3-Si in the surface and middle depth occurred in the central area of the Bohai Sea. The average ratio of DIN/ PO4-P was much higher than the Redfield Ratio (16:1). Apparently, PO4-P was one of the limiting nutrient for phytoplankton growing in the sea. The average concentrations of DON and DOP were higher than their inorganic forms. The results of eutrophication assessment show that 22.1% of all stations were classified as violating the concentration levels of the National Seawater Quality Standard (GB 3097-1997) for DIN and only 3.9% for PO4-P. The average eutrophication index in the overall area was 0.21±0.22 and the high values occurred in Bohai Bay, Liaodong Bay and near the Yellow River estuary. This means that the state of eutrophication was generally mesotrophic in the Bohai Sea, but relatively worse in the bays, especially some river estuaries.

  18. Analysis of seasonal variation of water masses in East China Sea

    Science.gov (United States)

    Qi, Jifeng; Yin, Baoshu; Zhang, Qilong; Yang, Dezhou; Xu, Zhenhua

    2014-07-01

    Seasonal variations of water masses in the East China Sea (ECS) and adjacent areas are investigated, based on historical data of temperature and salinity ( T-S). Dynamic and thermodynamic mechanisms that affect seasonal variations of some dominant water masses are discussed, with reference to meteorological data. In the ECS above depth 600 m, there are eight water masses in summer but only five in winter. Among these, Kuroshio Surface Water (KSW), Kuroshio Intermediate Water (KIW), ECS Surface Water (ECSSW), Continental Coastal Water (CCW), and Yellow Sea Surface Water (YSSW) exist throughout the year. Kuroshio Subsurface Water (KSSW), ECS Deep Water (ECSDW), and Yellow Sea Bottom Water (YSBW) are all seasonal water masses, occurring from May through October. The CCW, ECSSW and KSW all have significant seasonal variations, both in their horizontal and vertical extents and their T-S properties. Wind stress, the Kuroshio and its branch currents, and coastal currents are dynamic factors for seasonal variation in spatial extent of the CCW, KSW, and ECSSW, whereas sea surface heat and freshwater fluxes are thermodynamic factors for seasonal variations of T-S properties and thickness of these water masses. In addition, the CCW is affected by river runoff and ECSSW by the CCW and KSW.

  19. Numerical Simulation of Wintertime Mesoscale Eddies in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    陈敏; 侯一筠; 方国洪

    2003-01-01

    A POM based three-dimension baroclinic prognostic model in σ-coordinate was established to simulate the eddies in the East China Seas wintertime circulation, considering the topography, inflow and outflow on the open boundary, Changjiang runoff, heat, flux, and wind stress on the sea surface. The model results showed that three branches separate from the Kuroshio flow toward the interior of the Yellow Sea, and form three eddies respectively. The middle eddy is centered at 124°37′E,37°00′N,the southern eddy is centered at 124°00′E,35°30′N. The large cyclonic eddy centered at 125°06′E,30°30′N and located southwest of Cheju Island is a closed structure formed by the northeastward flowing Taiwan Warm Current, northwestward flowing Yellow Sea Warm Current and southward flowing coastal current. The Kuroshio intrusion engenders an eddy west of Kyushu Island of Japan. The branching of the Kuroshio is the direct dynamic cause of the formation of this large eddy. Moreover, both the topographic influence and the northward wind prevailing in winter affect the eddy's formation obviously.

  20. The presence of natural radioactivity and 137Cs in the South China Sea bordering peninsular Malaysia.

    Science.gov (United States)

    Amin, Y M; Mahat, R H; Nor, R M; Khandaker, Mayeen Uddin; Takleef, Ghazwa Hatem; Bradley, D A

    2013-10-01

    The presence of natural radioactivity and (137)Cs has been investigated in fresh media obtained from South China Sea locations off the coast of peninsular Malaysia. The media include seafood, sea water and sediment. The samples were collected some weeks prior to the devastating 2011 Tōhoku earthquake and associated tsunami, the occurrence of which precipitated the Fukushima incident. All samples showed the presence of naturally occurring (226)Ra, (228)Ra and primordial (40)K, all at typically prevailing levels. The concentrations of natural radioactivity in molluscs were found to be greater than that of other marine life studied herein, the total activity ranging from 337 to 393 Bq kg(-1) dry weight. The total activity in sea water ranged from 15 to 88 Bq l(-1). Sediment samples obtained at deep sea locations more than 20 km offshore further revealed the presence of (137)Cs. The activity of (137)Cs varied from ND to 0.5 Bq kg(-1) dry weight, the activity increasing with offshore distance and depth. The activity concentrations presented herein should be considered useful in assessing the impact of any future radiological contamination to the marine environment.

  1. THE INTRUSION AND INFLUENCES OF INTRASEASONAL LONG ROSSBY WAVES IN THE EAST CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    LIN Xiao-pei; WU De-xing; LAN Jian

    2004-01-01

    The analysis of sea level data from tide stations and ocean general circulation model(OGCM)shows that the intraseasonal long Rossby wave results in the intraseasonal variations of Kuroshio axis and transport in the upper reaches of the Kuroshio in the East China Sea(ECS).Due to the transport modulation induced by Ryukyu Islands,the intraseasonal variation is very weak in the lower reaches of the Kuroshio in the ECS.A two-layer model reveals the relation among Kuroshio frontal unstable wave with topography,transport and the axis position of the Kuroshio,from which we can infer that the intrusion of intraseasonal long Rossby wave may stimulate the Kuroshio frontal unstable wave in the upper reaches of the Kuroshio in the ECS.The altimeter data also shows that the sea level anomaly resulting from intraseasonal long Rossby wave could pass the channel between Taiwan and Ryukyu Islands and propagate northeastward in accord with the Kuroshio frontal unstable wave.However,the sea level anomalies passing through the gaps of Ryukyu Islands are relative weak and have negligible effects on the Kuroshio variation.

  2. Impact of atmospheric nitrogen deposition on phytoplankton productivity in the South China Sea

    Science.gov (United States)

    Kim, Tae-Wook; Lee, Kitack; Duce, Robert; Liss, Peter

    2014-05-01

    The impacts of anthropogenic nitrogen (N) deposition on the marine N cycle are only now being revealed, but the magnitudes of those impacts are largely unknown in time and space. The South China Sea (SCS) is particularly subject to high anthropogenic N deposition, because the adjacent countries are highly populated and have rapidly growing economies. Analysis of data sets for atmospheric N deposition, satellite chlorophyll-a (Chl-a), and air mass back trajectories reveals that the transport of N originating from the populated east coasts of China and Indonesia, and its deposition to the ocean, has been responsible for the enhancements of Chl-a in the SCS. We found that atmospheric N deposition contributed approximately 20% of the annual biological new production in the SCS. The airborne contribution of N to new production in the SCS is expected to grow considerably in the coming decades.

  3. Arctic sea ice, Eurasia snow, and extreme winter haze in China.

    Science.gov (United States)

    Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

    2017-03-01

    The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction.

  4. Arctic sea ice, Eurasia snow, and extreme winter haze in China

    Science.gov (United States)

    Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

    2017-01-01

    The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction. PMID:28345056

  5. Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo

    Directory of Open Access Journals (Sweden)

    Shu-Hua Qi

    2011-11-01

    Full Text Available Five zoanthoxanthin alkaloids (1–5 and four sesquiterpenes (6–9 were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (1–2, 8-hydroxy-6β-methoxy-14-oxooplop-6,12-olide (6 and 3β-methoxyguaian-10(14-en-2β-ol (7 were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae.

  6. Relation between relative permeability and hydrate saturation in Shenhu area, South China Sea

    Institute of Scientific and Technical Information of China (English)

    Li Chuan-Hui; Zhao Qian; Xu Hong-Jun; Feng Kai; Liu Xue-Wei

    2014-01-01

    Nuclear magnetic resonance measurements in hydrate-bearing sandstone samples from the Shenhu area, South China Sea were used to study the effect of gas hydrates on the sandstone permeability. The hydrate-bearing samples contain pore-fi lling hydrates. The data show that the pore-fi lling hydrates greatly affect the formation permeability while depending on many factors that also bear on permeability; furthermore, with increasing hydrate saturation, the formation permeability decreases. We used the Masuda model and an exponent N = 7.9718 to formulate the empirical equation that describes the relation between relative permeability and hydrate saturation for the Shenhu area samples.

  7. Numerical Forecasting Experiment of the Wave Energy Resource in the China Sea

    OpenAIRE

    2016-01-01

    The short-term forecasting of wave energy is important to provide guidance for the electric power operation and power transmission system and to enhance the efficiency of energy capture and conversion. This study produced a numerical forecasting experiment of the China Sea wave energy using WAVEWATCH-III (WW3, the latest version 4.18) wave model driven by T213 (WW3-T213) and T639 (WW3-T639) wind data separately. Then the WW3-T213 and WW3-T639 were verified and compared to build a short-term w...

  8. NUMERICAL STUDY ON THE FORMATION OF THE SOUTH CHINA SEA WARM CURRENT I. BAROTROPIC CASE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this work, Princeton Ocean Model (POM) was used to study the formation of the South China Sea Warm Current (SCSWC) in the barotropic case. Monthly averaged wind stress and the inflow/outflow transports in January were used in the numerical simulation which reproduced the SCSWC. The effects of wind stress and inflow/outflow were studied separately. Numerical experiments showed that the Kuroshio intrusion through the Luzon Strait and the slope shelf in the northern SCS are necessary conditions for the formation of the SCSWC. In a flat bottom topography experiment, the wind stress driven northeast current in the northern SCS is a compensatory current.

  9. Briarane Diterpenes from the South China Sea Gorgonian Coral, Junceella gemmacea

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    2014-01-01

    Full Text Available Four new briarane diterpenoids, junceellolides M–P (1–4, were isolated together with seven known analogs (5–11 from the South China Sea gorgonian, Junceella gemmacea. The structures of these compounds were elucidated by detailed spectroscopic analysis and comparison with the reported data. The absolute configuration of compounds 1–3 were determined based on an ECD experiment, while the absolute configuration of compound 4 was genetically determined. All the compounds were isolated for the first time from J. gemmacea. These compounds showed no growth inhibitory activity against A549, MG63 and SMMC-7721 cell lines in an in vitro bioassay.

  10. Implications of IODP Expedition 349 Age Results for the Spreading History of the South China Sea

    Science.gov (United States)

    Briais, Anne

    2016-04-01

    The International Ocean Discovery Program (IODP) Expedition 349 in the South China Sea drilled three sites (U1431, U1433, and U1434) into the basaltic crustal basement near the fossil spreading center in the East and Southwest Subbasins. These results provided age constraints on the termination of seafloor spreading in the South China Sea (SCS) basin. Shipboard biostratigraphic analysis of microfossils from the sediment immediately above or between flows in the basaltic basement indicates early Miocene ages: 16.7-17.6 Ma for Site U1431 in the East Subbasin, ~18-21 Ma for Site U1433 in the Southwest Subbasin. Since Expedition 349, Ar/Ar dating of basalt samples from these two sites have confirmed these ages in the east, and have provided an age of 17 Ma in the Southwest. The similarity in crustal age between sites suggests that the last stages of spreading have been coeaval in both the East and Southwest Subbasins, forming a single mid-ocean ridge system with a series of transform faults and discontinuities between the two subbasins. Expedition 349 also drilled Site U1435 on a bathymetric high along the northwestern continent-ocean boundary. Onboard core description, biostratigraphy and magnetostratigraphy revealed that sediment at this site shows a sharp discontinuity at about 33 Ma, interpreted to represent the breakup unconformity and date the beginning of seafloor spreading in the East Subbasin. The results of IODP Exp. 349, as well as results from deep-towed magnetic surveys, thus imply that oceanic seafloor spreading in the SCS, from 33 to ~16-18 Ma, is coeval with a large part of the left-lateral motion along the Ailao Shan-Red River Fault Zone (dated 34 to 17 Ma). This episode of the extension of the South China Sea basin is therefore more likely driven by the extrusion of the Indochina tectonic block resulting from the collision of India with Eurasia than by the subduction of a proto-South China Sea to the south.

  11. Normal incidence measurement in a subaqueous sand dune field in the South China Sea.

    Science.gov (United States)

    Chiu, Linus Y S; Chang, Andrea Y Y

    2014-11-01

    Regions with subaqueous sand dunes have been discovered on the upper continental slope of the northern South China Sea. These large subaqueous sand dunes are expected to cause errors in the measurement of normal incidence reflection. This letter presents experiment results of two normal incidence survey tracks conducted in 2013, and the errors in reflection coefficient estimation and the resulting sediment properties induced by sand dune bedforms. The results demonstrate that the reflected energy is focused and scattered by different parts of sand dune bedforms and that they produce significant variation in the estimated reflection coefficients and the inverted geoacoustic properties.

  12. New record of Lobophora rosacea (Dictyotales; Phaeophyceae) from the South China Sea

    Science.gov (United States)

    Sun, Zhongmin; Wang, Yongqiang; Yan, Pengcheng; Guo, Hui; Yao, Jianting; Tanaka, Jiro; Kawai, Hiroshi

    2016-04-01

    Lobophora rosacea C.W. Vieira, Payri et De Clerck is reported from the South China Sea for the first time. Our specimens are very similar to L. rosacea recently described from New Caledonia, not only in morphology but also in rbcL and cox3 gene sequences. The fan-shaped thallus grows erectly, attaching to the substrate by a basal holdfast. The thallus is composed of a single layer of large medullary cells and three to four layers of cortical cells on both sides of the medulla. Mature sporophytes are detected, with sporangium sori scattered on both surfaces of the thallus.

  13. Resonant interaction of acoustic waves with subaqueous bedforms: Sand dunes in the South China Sea.

    Science.gov (United States)

    Chiu, Linus Y S; Chang, Andrea Y Y; Reeder, D Benjamin

    2015-12-01

    The large subaqueous sand dunes in the South China Sea are expected to produce the coupling of energy between acoustic normal modes. In this letter, resonant interaction between acoustic propagating modes and subaqueous bedforms are numerically investigated as a function of bedform wavelength, acoustic frequency and bedform packet length. The results demonstrate that bedform wavelength impacts acoustic mode coupling behavior, with the principal transfer of energy occurring between acoustic modes whose eigenvalue difference is equal to the peak value in the bedform wavenumber spectrum. The observed effect of wavelength is greater than that of acoustic frequency and bedform packet length.

  14. A new species of Eunice (Polychaeta: Eunicidae) from Hainan Island, South China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Xuwen; SUN Ruiping; LIU Ruiyu(J.Y LIU)

    2013-01-01

    Ataxonomic survey ofbenthic marine animals from coastal regions of Hainan Island,South China Sea,revealed specimens of a new species ofEunice (Polychaeta:Eunicida:Eunicidae),Eunice uschakovi n.sp.,collected from the intertidal zone.The species belongs to the group of Eunice that has yellow tridentate subacicular hooks and branchiae scattered over an extensive region of the body.It resembles E.miurai and E.havaica in having both bidentate and tridentate falcigers,but can be readily distinguished by branchial features.Comparisons between E.uschakovi and the two related species are presented.

  15. Cembranoid, Steroid, and Sesquiterpenoid Derivatives from the South China Sea Soft Coral Sinularia numerosa

    Institute of Scientific and Technical Information of China (English)

    秦铭俐; 李晓明; 王斌贵

    2012-01-01

    Two new cembranoids, namely, sinumerolides A and B (1 and 2), one new steroid, 7fl-hydroxygorgosterol (7), along with four known cembranoid derivatives (3-6), four known steroids (8-11), and four known africane ses- quiterpenoids (12-15), were isolated and identified from the marine soil coral Sinularia numerosa that was col- lected from South China Sea waters. The structures of these metabolites were elucidated on the basis of extensive spectroscopic analysis and by comparison of their spectral data with those of literature reports. The isolated com- pounds were evaluated for the antimicrobial and cytotoxic activity.

  16. Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

    KAUST Repository

    Wang, Chang Yun

    2011-08-01

    Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1-10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite. © 2011 Elsevier Ltd.

  17. Multi-scale variability of subsurface temperature in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    高荣珍; 周发琇; 王东晓

    2002-01-01

    Using Morlet wavelet transform and harmonic analysis the multi-scale variability of subsurface temperature in the South China Sea is studied by analyzing one-year (from April 1998 to April 1999) ATLAS mooring data. By wavelet transform, annual and semi-annual cycle as well as intraseasonal variations are found, with different dominance, in subsurface temperature. For annual harmonic cycle, both the downward net surface heat flux and thermocline vertical movement partially control the subsurface temperature variability. For semi-annual cycle and intraseasonal variability, the subsurface temperature variability is mainly linked to the vertical displacement of thermocline.

  18. Intraseasonal variability of the subsurface temperature observed in the South China Sea (SCS)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Using Morlet wavelet transform we investigated the intraseasonal variability of the subsurface temperature in the SCS by analyzing ATLAS mooring data obtained during the South China Sea Monsoon Experiment (SCSMEX). It is found for the first time that subsurface temperature in the SCS exists intraseasonal variability, particularly in winter. The strongest intraseasonal variability ranges from 50 to 100 m with its maximum amplitude about 1.0--2.0℃. The subsurface temperature intraseasonal variability in the SCS is primarily induced by local wind stress curl via adjusting the vertical displacement of thermocline. It reveals the important characteristic of intraseasonal variations in the SCS upper ocean vertically.

  19. BEHAVIOR OF THE CHANGJIANG DILUTED WATER IN THE EAST CHINA SEA OBSERVED WITH SATELLITE TRACKING DRIFTER

    Directory of Open Access Journals (Sweden)

    Syful Anas

    2012-11-01

    Full Text Available The Changjiang River is the largest river in China with an average discharge of 9x1011 m3 /year . The Changjiang river supplies about 80% of total discharge of fresh water from rivers around the Yellow Sea, East China Sea and Bohai Sea. Its monthly mean transport has a large seasonal variation from 103 m3s-1 in January to 4.8x 104 m3s-1 in July around an annual mean of 3 x104 m3s-1 , and large inter annual variation in the annual mean from 2,2x 103 to 3,5 x 103 m3s-1 during the 19-year period from 1970 to 1988 (Yanagi, 1994 . The East China Sea Current, associated with the Changjiang discharge, flows southward along the Fujian and the Zhejiang Coast of China in winter and Northeastward to the Cheju island in summer, which forms thin low salinity plume called Changjiang Diluted Water (CDW in summer (Breadsley. et al , 1983, 1985; Hu, 1994, Guan ,1994.CDW moves differently in season. It moves southward in winter and eastward in summer according to its salinity distribution. The relation between wind and movement of the low salinity water also has been suggested in many ways.Generally all of drifter moved northeastward at first, then after 10 days each drifter moved to different sites. Each drifter moving though velocities is about 0.1 m/s and 0.2 m/s. Most of drifters were generally moving to northeastward to the right of the wind direction at these events. It indicates that the sudden changes of drifters trajectory are caused by abrupt changes of winds.Temporal variation in salinity gradually increase during the drifters were in the moved eastward . The salinity rapidly increase during the typhoon passage. Before and after the salinity rapidly increase during typhoon passage, it was mostly constant or very gentle.The vertical velocity generated by wind just after deployment drifters for ten days in drifter deployment in 2007 was about 10-5 – 10-6 ms-1. The vertical velocity during typhoon passage on August 2007 was larger than on passed the

  20. Anaerobic ammonium oxidation, denitrification and dissimilatory nitrate reduction to ammonium in the East China Sea sediment

    Directory of Open Access Journals (Sweden)

    G. D. Song

    2013-03-01

    Full Text Available Benthic nitrogen transformation pathways were investigated in the sediment of the East China Sea in June of 2010 using the 15N isotope pairing technique. Slurry incubations indicated that denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA as well as nitrate release by nitrate storing organisms occurred in the East China Sea sediments. These four processes did not exist independently, the nitrate release therefore diluted the 15N labeling fraction of NO3−, a part of the 15NH4+ derived from DNRA also formed 30N2 via anammox. Therefore current methods of rate calculations led to over and underestimations of anammox and denitrification respectively. Following the procedure outlined in Thampdrup and Dalsgaard (2002, denitrification rates were slightly underestimated by on average 6% without regard to the effect of nitrate release, while this underestimation could be counteracted by the presence of DNRA. On the contrary, anammox rates calculated from 15NO3− experiment were significantly overestimated by 42% without considering nitrate release. In our study this overestimation could only be compensated 14% by taking DNRA into consideration. In a parallel experiment amended with 15NH4+ + 14NO3−, anammox rates were not significantly influenced by DNRA due to the high background of 15NH4+ addition. Excluding measurements in which bioirrigation was present, integrated denitrification rates decreased from 10 to 4 mmol N m−2 d−1 with water depth, while integrated anammox rates increased from 1.5 to 4.0 mmol N m−2 d−1. Consequently, the relative contribution of anammox to the total N-loss increased from 13% at the shallowest site near the Changjiang estuary to 50% at the deepest site on the outer shelf. This study represents the first time in which anammox has been demonstrated to play a significant role in benthic nitrogen cycling in the East China Sea sediment, especially on the outer shelf. N

  1. Two new species of Hexactinellida (Porifera) from the South China Sea.

    Science.gov (United States)

    Gong, Lin; Li, Xinzheng; Qiu, Jian-Wen

    2015-10-28

    In this paper, two new sponge species, Semperella jiaolongae sp. nov. (Amphidiscosida, Pheronematidae) and Saccocalyx microhexactin sp. nov. (Lyssacinosida, Euplectellidae) are described based on materials from the South China Sea. Semperella jiaolongae sp. nov. is diagnosed mainly by the dermal areas present on both sides of the body, occurring together with atrial areas randomly distributed on one side, and the distinctive shape of micropentactins. Saccocalyx microhexactin sp. nov. is characterized by possession of two types of drepanocomes and one of microhexactins. An analysis based on partial sequence of the 16S rRNA gene was undertaken to show the congruence between morphological identification and phylogenetic classification of the two new species.

  2. New record of Lobophora rosacea (Dictyotales; Phaeophyceae) from the South China Sea

    Science.gov (United States)

    Sun, Zhongmin; Wang, Yongqiang; Yan, Pengcheng; Guo, Hui; Yao, Jianting; Tanaka, Jiro; Kawai, Hiroshi

    2017-01-01

    Lobophora rosacea C.W. Vieira, Payri et De Clerck is reported from the South China Sea for the first time. Our specimens are very similar to L. rosacea recently described from New Caledonia, not only in morphology but also in rbcL and cox3 gene sequences. The fan-shaped thallus grows erectly, attaching to the substrate by a basal holdfast. The thallus is composed of a single layer of large medullary cells and three to four layers of cortical cells on both sides of the medulla. Mature sporophytes are detected, with sporangium sori scattered on both surfaces of the thallus.

  3. Community structure and biodiversity of free-living marine nematodes in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoshou; XU Man; ZHANG Jinghuai; LIU Dan; LI Xiao

    2015-01-01

    A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples collected at five stations in the deep sea (from 313 to 1 600 m) and one station in shallow waters (87 m) during the cruise in September, 2010. Results showed that the abundance of marine nematodes ranged from 224 to 1 996 ind./(10 cm2). A total of 69 free-living marine nematode genera, belonging to 26 families and three orders, were identified. The most dominant genera wereSabatieria,Linhystera,Aegialoalaimus andDaptonema according to SIMPER analysis. Results of CLUSTER analysis revealed four types of marine nematode community (or station groups) in the sampling area. In terms of trophic structure, non-selective deposit feeders (1B) and selective deposit feeders (1A) were the dominant trophic types with highest genera numbers and abundances, which implied that organic detritus was the main food source of marine nematodes in the northern South China Sea. The percentage of male nematode was low, ranging from 2.22% to 17.81%, while those of juvenile individuals ranged from 36.99% to 82.09%. For genera level diversity of marine nematodes, Shannon-Wiener diversity indices (H') ranged from 3.76 to 4.57 and had highly significant negative correlation with water depth. In general, diversity indicesH' at the five stations in deep sea (over 200 m) were lower than that at the station in shallow waters (87 m). BIOENV analysis showed that the most important environmental factor controlling marine nematode communities was water depth.

  4. Empirical prediction of the onset dates of South China Sea summer monsoon

    Science.gov (United States)

    Zhu, Zhiwei; Li, Tim

    2016-05-01

    The onset of South China Sea summer monsoon (SCSSM) signifies the commencement of the wet season over East Asia. Predicting the SCSSM onset date is of significant importance. In this study, we establish two different statistical models, namely the physical-empirical model (PEM) and the spatial-temporal projection model (STPM) to predict the SCSSM onset. The PEM is constructed from the seasonal prediction perspective. Observational diagnoses reveal that the early onset of the SCSSM is preceded by (a) a warming tendency in middle and lower troposphere (850-500 hPa) over central Siberia from January to March, (b) a La Niña-like zonal dipole sea surface temperature pattern over the tropical Pacific in March, and (c) a dipole sea level pressure pattern with negative center in subtropics and positive center over high latitude of Southern Hemisphere in January. The PEM built on these predictors achieves a cross-validated reforecast temporal correlation coefficient (TCC) skill of 0.84 for the period of 1979-2004, and an independent forecast TCC skill of 0.72 for the period 2005-2014. The STPM is built on the extended-range forecast perspective. Pentad data are used to predict a zonal wind index over the South China Sea region. Similar to PEM, the STPM is constructed using 1979-2004 data. Based on the forecasted zonal wind index, the independent forecast of the SCSSM onset dates achieves a TCC skill of 0.90 for 2005-2014. The STPM provides more detailed information for the intraseasonal evolution during the period of the SCSSM onset (pentad 25-35). The two models proposed herein are expected to facilitate the real-time prediction of the SCSSM onset.

  5. Coral reefs in the South China Sea: Their response to and records on past environmental changes

    Institute of Scientific and Technical Information of China (English)

    YU KeFu

    2012-01-01

    This paper reviews both the recent and longer-term (Holocene) ecological history of coral reefs in the South China Sea (SCS).(1) Local ecological monitoring since the 1960s shows that the coral reefs in the South China Sea have declined dramatically,reflecting the rapid decrease of living coral cover and the great loss of symbiotic zooxanthellae.Collectively,this has led to a significant decrease of annual CaCO3 production.Heavy anthropogenic activities and global warming are recognized as major triggers of the observed coral reef degradation.Observations show that the modern coral reefs in the SCS are a source of atmospheric CO2 in summer.(2) Coral reefs of the SCS have been widely used to reveal longer-term environmental variations,including Holocene high-resolution sea surface temperature (SST) and abrupt climate events,millennial-scale E1 Ni(n)o variations,millennial-and centennial-scale sea level oscillations,strong and cyclic storm activities,East Asian monsoon intensities,variation in seawater pH,and recent seawater pollution,(3) Coral reefs of the southern SCS have experienced repeated episodes of bleaching over the last 200 years due to high SST and intense E1 Ni(n)o events; coral reefs of the northern SCS suffered high levels of mortality during several abrupt winter cold-water bleaching events during the middle Holocene warm period.On average,recovery after the middle Holocene cold-bleaching took 20-30 years; recovery following other middle Holocene environmental stresses took approximately 1020 years.Such findings have significantly contributed to the understanding of the present ecological pressures faced by the coral reefs in the SCS,the histories of Holocene climate/environment changes,and the long-term models of coral reef responses to various past environmental changes.

  6. Empirical prediction of the onset dates of South China Sea summer monsoon

    Science.gov (United States)

    Zhu, Zhiwei; Li, Tim

    2017-03-01

    The onset of South China Sea summer monsoon (SCSSM) signifies the commencement of the wet season over East Asia. Predicting the SCSSM onset date is of significant importance. In this study, we establish two different statistical models, namely the physical-empirical model (PEM) and the spatial-temporal projection model (STPM) to predict the SCSSM onset. The PEM is constructed from the seasonal prediction perspective. Observational diagnoses reveal that the early onset of the SCSSM is preceded by (a) a warming tendency in middle and lower troposphere (850-500 hPa) over central Siberia from January to March, (b) a La Niña-like zonal dipole sea surface temperature pattern over the tropical Pacific in March, and (c) a dipole sea level pressure pattern with negative center in subtropics and positive center over high latitude of Southern Hemisphere in January. The PEM built on these predictors achieves a cross-validated reforecast temporal correlation coefficient (TCC) skill of 0.84 for the period of 1979-2004, and an independent forecast TCC skill of 0.72 for the period 2005-2014. The STPM is built on the extended-range forecast perspective. Pentad data are used to predict a zonal wind index over the South China Sea region. Similar to PEM, the STPM is constructed using 1979-2004 data. Based on the forecasted zonal wind index, the independent forecast of the SCSSM onset dates achieves a TCC skill of 0.90 for 2005-2014. The STPM provides more detailed information for the intraseasonal evolution during the period of the SCSSM onset (pentad 25-35). The two models proposed herein are expected to facilitate the real-time prediction of the SCSSM onset.

  7. Sea surface height and transport stream function of the South China Sea from a variable-grid global ocean circulation model

    Institute of Scientific and Technical Information of China (English)

    魏泽勋; 方国洪; 崔秉昊; 方越; 何宜军

    2003-01-01

    A fine-grid model (1/6°) covering the South China Sea (SCS), East China Sea and Japan/East Sea, which is embedded into a coarse-grid (3°) global model, was established to study the SCS circulation. In the present paper, we report the model-produced monthly and annual mean transport stream functions and sea surface heights(SSH) and their anomalies of the SCS. Comparison to the TOPEX/Poseidon data shows that the model-produced monthly sea surface height anomalies (SSHA) are in good agreement with altimeter measurements. Based on the results, the circulation of the SCS, especially the upper layer circulation, is discussed. In the surface layer, the western Philippine Sea water intrudes into the SCS through the Luzon Strait in autumn, winter and spring, but not in summer. However, as far as the whole water column is concerned, the water intrudes into the SCS through the Luzon Strait all the year round. This indicates that in summer the water still intrudes into the SCS in the subsurface and intermediate layers. The area near the northern continental slope of the SCS is dominated by a cyclonic circulation all the year round. The SCS Southern Anticyclonic Gyre, SE Vietnam Off-Shore Current in summertime and SCS Southern Cyclonic Gyre in wintertime are reproduced reasonably. The difference between the monthly averaged SSH and SSHA is significant, indicating the importance of the mean SSH in the SCS circulation.

  8. On the Paleogene coal-measure distribution over the China sea area

    Institute of Scientific and Technical Information of China (English)

    LI Zeng-xue; LI Ying; ZHOU Jing; LIU Hai-yan; L(U) Da-wei; WANG Ping-li

    2012-01-01

    The Paleogene coal accumulation basins of China are part of the global Tertiary coal-accumulated zone of the Pacific Rim located in the eastern coastal provinces and areas.Although the coal-bearing basins of the China Sea area are faults and depressed basins,they come up in groups.The overall structures are suitable for the development of coal-bearing deposition.The continuity of basin groups are good,and the coal-bearing depositions are thick.For example,the coal-bearing deposition is more than a kilometer thick at the Qiongdongnan Basin and Xihu Sag in the East China Sea,which the continental Paleogene coal basins cannot reach.Research shows that the coal accumulation basins in the sea area consist of many sags.There are two types of coal accumulation sags:half-graben sag and graben sag.In terms of water depth,coal accumulation sags can also be classified as deep-water half-graben sag and shallow-water half-graben sag; the graben sag is the deep-water sag.There are two distinct coal-accumulated zones in the basin:gentle slope and steep slope,with the gentle slope being the dominant one.The marshes of the supratidal zone and intertidal zone in a tidal flat system is favorable for the coal accumulation process widely taking place.There are two types of peat accumulation:autochthonous accumulation and allochthonous accumulation.Because of tectonic activities in the basins,allochthonous accumulations may be the more important form of coal-forming activities in the sea area.The very thick coal-bearing deposition in the sea area provides a rich material base for the assemblage of coal-related gas.Also,as a result of the deep burial depth,the degree of coal metamorphism is relatively high,so the coal-bearing strata become good hydrocarbon source rocks.

  9. Coupled Modes of Rainfall over China and the Pacific Sea Surface Temperature in Boreal Summertime

    Institute of Scientific and Technical Information of China (English)

    LI Chun; MA Hao

    2011-01-01

    In this study,monthly NCEP/NCAR reanalysis data and NOAA ERSST as well as observed precipitation data from 160 stations in China were used to investigate coupled modes affecting the rainfall over China and sea surface temperature (SST) in the Pacific during boreal summertime based on singular value decomposition (SVD) method.The SVD analysis revealed three remarkable coupled modes:rainfall over North China associated with an ENSO-like SST pattern (ENSO NC),rainfall over the Yangtze River valley associated with SST anomalies in the western tropical Pacific (WTP-YRV),and rainfall over the Ycllow River loop valley associated with tropical Pacific meridional mode-like SST pattern (TPMM-YRLV).These coupled SVD modes appear robust and closely correlated with the single field,Furthermore,the covariabilities among of the three coupled modes have different characteristics at the decadal time scale.In addition,the possible atmospheric teleconnections of the coupled rainfall and SST modes were discussed.For the ENSO-NC mode,anomalous low-pressure and high-pressure over the Asian continent induces moisture divergence over North China and reduces summer rainfall there.For the WTP-YRV mode,East Asia-Pacific teleconnection induces moisture convergence over the Yangtze River valley and enhances the summer rainfall there.The TPMM SST and the summer rainfall anomalies over the YRVL are linked by a circumglobal,wave-train-like,atmospheric teleconnection.

  10. Genetic Differentiation among Populations and Color Variants of Sea Cucumbers (Stichopus Japonicus from Korea and China

    Directory of Open Access Journals (Sweden)

    Jung-Ha Kang, Yi-Kyong Kim, Mi-Jung Kim, Jung-Yeon Park, Chul-Min An, Bong-Seok Kim, Je-Cheon Jun, Sang-Kyu Kim

    2011-01-01

    Full Text Available The Far Eastern sea cucumber, Stichopus japonicus, is a favored food in Eastern Asia, including Korea, Japan, and China. Aquaculture production of this species has increased because of recent declines in natural stocks and government-operated stock release programs are ongoing. Therefore, the analyses of genetic structure in wild and hatchery populations are necessary to maintain the genetic diversity of this valuable marine resource. In addition, given that sea cucumber color affects market price, with the rare, possibly reproductively isolated, red type being the most valuable, an understanding of the genetic structure and diversity in color variation of green and red types is necessary. We analyzed the genetic structure of wild and hatchery-produced green type S. japonicus from Korea and China, and wild red type from Korea using 9 microsatellite makers. The number of alleles per locus ranged from 11 to 29 across all populations. The mean allele numbers of the green types from Korea (10.6 and China (10.1 were similar, but differed slightly from that of the red type (9.1. Pairwise multilocus FST and genetic distance estimations showed no significant differences between the green types from Korea and China, whereas the differences between the green and red types were significant. This was clearly illustrated by a UPGMA dendrogram, in which the two close subclusters of green types were completely separated from the red type. In addition, the allele frequencies of the green and red types were significantly different. Assignment tests correctly assigned 100% (quality index 99.97% of individuals to their original color types and demonstrated the feasibility of microsatellite analysis for discrimination between color types.

  11. Neotectonic regime on the passive continental margin of the northern South China Sea

    Science.gov (United States)

    Lüdmann, Thomas; Wong, How Kin

    1999-09-01

    Between 1989 and 1994, more than 6600 km of reflection seismic profiles were obtained in the South China Sea off Hong Kong with the German research vessel Sonne during cruises SO-50B, SO-72A and SO-95. A seismo-stratigraphic interpretation of this data set leads to a new age assignment of the unconformity T 0 which we place within the Pleistocene. Both Neogene unconformities T 1 and T 0 are generated by uplift of the Dongsha Rise and truncation of their overlying strata. This uplift is caused by intrusion of magma into the upper crust. Our seismic profiles show plutons which have penetrated the sedimentary cover, whereby their original stratification in the contact zone is eliminated. These magmato-tectonic events may be correlated to the two main collision phases between Taiwan and the continental margin of East China 5-3 and 3-0 ma ago. The collisional events subsequent to the NNW to WNW drift of Taiwan transformed the compression into strike-slip movements along the continental margin of Southeastern China. The accompanying stress regime is transtensional, with subsidence of the cooling oceanic crust since the cessation of rifting and its consumption beneath the Manila Trench providing the extensional stress. The strike-slip movements remobilized many of the rift and drift faults providing pathways for magma ascent. The tectonic framework of the northern South China Sea is characterized by Miocene faults trending NE-SW. These faults are scarce but are distributed throughout the study area. Pliocene faults striking ENE-WSW to NE-SW are concentrated west of the Dongsha Islands and are mostly strike-slip in character. Recent faults are generally oriented NE-SW subparallel to the synrift faults. They result in part from local uplifts where they are normal in character, but strike-slip motion also occurs. Most of the faults involve the basement and represent reactivated zones of weakness of the rift and drift phases.

  12. Impacts of earthquake on atoll in Nansha Islands, South China Sea

    Science.gov (United States)

    Guo, Lei; Zhan, Wenhuan; Xiong, Lijia; Chen, Wujin; Yao, Yantao; Li, Jian

    2016-04-01

    Coral reef is a kind of rock soil masses. It is a special marine geotechnical medium, which are made up of the reef coral debris undergo very long geological age. Atoll is the predominant type of coral reefs in South China Sea. In recent years, there are more and more construction projects on the reef flat in Nansha Islands, South China Sea. Therefore, it is very important to estimate the stability of coral reefs, especially the atolls. According to the geological structure characters of atoll in Nansha Islands, a model of reef body is presented in this paper to study the influence of earthquake. Meanwhile, Geostudio, which is a popular geotechnical engineering simulation software, is used to stimulate the stress and deformation situation of reef body under different six kinds of earthquake intensity. The factor of safety can be calculated by the limit equilibrium method. And the possible scenario of earthquake-induced landslides and sliding scale can be defined through the Newmark sliding block method. The stress distribution and deformation behavior are studied. The main relations between atoll and earthquake are analyzed as follows: (1) the safety factor of reef slope exceeds 1.993 under self-gravity state; (2) It may cause slope's instability and bring slumping when the safety factor is less than one. The factor of safety decreases with increased earthquake intensity and it may fluctuate around a particular value when earthquake intensity continues to increase; (3) The smaller shallow landslide as new developed part of the reef is subject to collapse under earthquake action and the bigger slope of reef is more stable. The results show that it is feasible to evaluate the stability of coral reef by using geotechnical engineering simulation method, which can help to provide some information for construction on coral reefs in South China Sea. In the meantime,the authers wish to thank the National Natural Science Foundation of China (NO.41376063)and the National

  13. Anomalous subsidence at South China Sea rifted margin: Sediments digging their own hole

    Science.gov (United States)

    Brune, Sascha; Clift, Peter; Quinteros, Javier

    2015-04-01

    Rifted continental margins subside as a consequence of combined crustal thinning and mantle lithosphere cooling. While standard models predict a slowing of subsidence after the end of rifting, the deep basins on the northern margin of the South China Sea, notably the Baiyun Sag exhibit subsidence that accelerated several million years after the end of active extension. Additionally, backstripping analysis at the South China margin has shown that the amount of subsidence is much greater than that predicted from the degree of brittle upper crustal extension seen in seismic profiles. Here we explain these observations by linking climate change onshore and deformation of the crystalline crust offshore: Early Miocene monsoon intensification increased erosion and thus the sediment flux to offshore basins after the cessation of active extension. When the sediment load encountered the weak crust of the South China Sea margin, it induced lower crustal flow away from the basin axis so that the deep Baiyun basin was formed nearly without brittle extension. We corroborate this concept using seismic observations and backstripping techniques, as well as thermo-mechanical forward modeling. The numerical forward model is a 2D version of the finite element code SLIM3D. The code includes nonlinear temperature- and stress-dependent elasto-visco-plastic rheology and is able to reproduces a wide range of rift-related deformation processes such as flexure, lower crustal flow, and faulting. We find that two factors allow to satisfy the observational constraints: (1) Post-rift increase of sediment load: The East Asian Summer Monsoon strengthened around the start of the Miocene (~23 Ma), several million years after continental rupture. Changes in the flora of continental China date from around this time and sedimentation rates across continental margins and deltas in South and Southeast Asia increased, as might be expected under the influence of heavier precipitation driving faster erosion

  14. Sporopollen and algae research of core B106 in the northern South China Sea and its paleoenvironmental evolution

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the high-resolution sporopollen and algae research of the sediments from core B106 in the northem South China Sea,three sporopollen assemblage zones have been distinguished in ascending order:Zone 1 (294-194 cm):pinus-Quercus (evergreen)-Gramineae-Polypodia-ceae- Pterdium-Dicranopteris.Zone 2 (194-94 cm):Pinus-Quercus (evergreen)-Polypodiaceae-Pteridium- Dicranopteris.Zone 3 (94-4 cm):Pinus-Polypodiaceae-Pteridium-Quercus(evergreen)-Dicranopteris.The three sporopollen zones correspond to three stages of vegetation,climate and paleoenvironment evolution of the northern part of the South China Sea since 11 000 years ago.Combined with AMS 14C dating,the sporopollen and algae data can be a scientific basis for stratigraphic division and reconstruction of paleoclimate and paleoenvironment in the South China Sea.

  15. Observation of Directional Ocean Wave Spectra in China Seas and Northwest Pacific Ocean Using SAR Retrieval Software

    Science.gov (United States)

    Liu, Xiaoyan; Zeng, Kan; He, Mingxia

    2014-11-01

    A software to retrieve directional ocean wave spectra from SAR images has been developed for China seas and northwest Pacific. The software, written with C programming language, is based on the MPI method proposed by Hasselmann. It is designed to support the wave mode SAR data of ERS, Envisat, Sentinel and so on. The directional ocean wave spectra produced by this software are validated with buoy data in global ocean area, northwest Pacific and China seas and the retrieved significant wave height (SWH) errors are 5.2%, 4.9% and 9.3% respectively. About 15,000 directional ocean wave spectra are obtained with the software from the wave mode data of Envisat/ASAR over the China seas and northwest Pacific during the period between Jan 2003 and Jan 2012. The preliminary analysis is presented.

  16. Surface elevation change and susceptibility of coastal wetlands to sea level rise in Liaohe Delta, China

    Science.gov (United States)

    Wang, Guo-dong; Wang, Ming; Lu, Xian-guo; Jiang, Ming

    2016-10-01

    The Liaohe Delta in China is an ecologically and commercially important wetland system under threat from sea level rise and marsh subsidence. Sediments deposited in coastal marshes could offer wetlands a potentially important means for adjusting surface elevation with rising sea level, yet coastal wetland stability in Liaohe Delta is not well understood due to limited data from long-term experiments. In this study, wetland surface elevation and vertical accretion were measured from 2011 to 2015 using a surface elevation table (SET) and feldspar marker horizons in two Phragmites and two Suaeda marshes receiving Liaohe River water. The analysis shows that the Phragmites marshes exhibited higher rates of marsh accretion and elevation change than the Suaeda marshes. The two Phragmites marsh sites had average surface elevation change rates at 8.8 and 9.3 mm yr-1, vertical accretion at 17.4 and 17.6 mm yr-1, and shallow subsidence at 8.6 and 8.3 mm yr-1. The average rates of elevation change, vertical accretion, and shallow subsidence at two Suaeda marsh sites were 5.8 and 6.3 mm yr-1, 13.6 and 14.8 mm yr-1, and 7.8 and 8.5 mm yr-1, respectively. The trends suggest that coastal marshes in Liaohe Delta are experiencing changes in average soil elevation that range from a net increase of 0.3 mm y-1 to 6.9 mm y-1 relative to averaged sea level rise in Bohai Sea reported by the 2016 State Oceanic Administration People's Republic of China projection (2.4-5.5 mm y-1), which indicated that the four wetland sites would adjust to the sea level rise and even continue to gain elevation, especially for the Phragmites sites. Nevertheless, the vulnerability of coastal wetlands in Liaohe Delta need further assessment considering the accelerated sea level rise, the high rate of subsidence, and the declining sediment delivery owing to anthropogenic activities such as dam constructions in the river basin.

  17. Standing stock and community structure of photosynthetic picoplankton in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    NING Xiuren; LI W K W; CAI Yuming; LIU Chenggang; SHI Junxian

    2005-01-01

    The investigation on community structure of standing stock of photosynthetic picoplankton: Synechococcus (Syn), Prochlorococcus (Pro) and Picoeukaryotes (Euk) and their environmental regulation mechanisms in the northern South China Sea was carried out in the summer of 1999. The results showed that the average abundances of Syn, Pro and Euk in the study sea areas were (5.0± 7.6)×104cell/cm3 (51%), (4.6±4.2)×104 cell/cm3 (47%) and (1.8±1.1)×l03 cell/cm3 (2%) respectively, and those of their carbon biomass were (12.5±18.9) μg/dm3 (74%), (2.7±2.5) μg/dm3 (16 %) and (1.7±1.0) μg/dm3 (10%). The most of high values of Syn appeared in the estuaries, coastal zone and continental shelf in the sea area to the east of Leizhou Peninsula and Hainan Island where nutrients were rich, and those appeared in the Beibu Gulfwere the second, while those appeared in continental slope and open sea were tens times lower than the above those. Its distribution in water column was mainly above the thermocline and its abundance below it sharply decreased. Two different populations of Pro were found, the surface population and deep one. The distribution pattern of the former was similar to that of Syn; while with marked difference from that of the former, the abundance and biomass of the latter markedly increased towards outer sea, continental slope and open sea where nutrients were poor; the high values in the water column mainly appeared at the bottom of euphoric zone and above the nitrocline, where it often vigorously grow. The distribution difference of Euk in the various sea areas is not as obvious as those of Syn and Pro, but it was high in coastal and shelf waters and low in continental slope and open sea. The high values in the water column were mostly appeared at the bottom of euphoric zone. This difference of distribution pattern for the three type of photosynthetic picoplankton depends on environmental effects and their ecophysiological differences.

  18. ASEAN Way and the South China Sea Dispute%东盟方式与南海争端

    Institute of Scientific and Technical Information of China (English)

    李国选

    2015-01-01

    ASEAN takes its unique behavioral norms " ASEAN way" to handle the complex South China Sea disputes, and effectively eases the South China Sea conflict between the ASEAN member countries and China, which avoids the worst situation in the South China Sea and creates a peripheral environment of peace and security. This paper aims to analyze the fundamental objectives, means and utility of the " ASEAN way" to deal with the South China Sea disputes and interpret the " ASEAN way" in detail, which provides inspiring significance to China for handling the South China Sea disputes, promote regional cooperation and create a favorable external environment for the economic development.%东盟采取其独特的处理内外关系的“东盟方式”处理复杂的南海争端,有效地缓和了东盟成员国之间及其同中国在南海问题上的冲突,避免了南海地区最差局面的出现,为该地区的发展创造了一个和平安全的环境。东盟方式处理南海争端的框架涵盖处理南海争端的基本目标、基本手段和效用。东盟方式处理南海争端的进程对中国解决南海争端、推动区域合作和创造良好的经济发展外部环境具有启发性意义。

  19. Fishers and Territorial Anxieties in China and Vietnam: Narratives of the South China Sea Beyond the Frame of the Nation

    Directory of Open Access Journals (Sweden)

    Edyta Roszko

    2016-12-01

    Full Text Available In the geopolitical conflict over the South China Sea (SCS, fishers are at the center of Chinese and Vietnamese cartographic imaginations that define the sea as either “Chinese” or “Vietnamese” and hence tied to the disputed territories of the Paracel and Spratly Islands. While their historical presence and customary fishing rights in the SCS have been much publicized in the context of this territorial dispute, the long-standing Cham seafaring trade networks and legacy are ignored by both countries. The ethnic and national categories of Cham, Việt, and Han intersect with occupational categories such as those of fisher, trader, shipbuilder, sailor, and pirate, which in the past represented shifting, relational, and situational activities by the same people. The contemporary use of such professional and national labels produces particular political effects by projecting recent closures and enclosures onto the past, in spite of the common historical, cultural, and ethnic flows that always existed in the SCS. Rather than aiming to legitimize or delegitimize Vietnam’s or China’s territorial claims to the SCS, this article argues that seafaring narratives should be liberated from abstract, anachronistic discourses of sovereignty, territoriality, and territorial anxieties that separate the interconnected histories of the Cham, Vietnamese, and Chinese.

  20. Effect of Surface waves On air-sea momentum flux in high wind conditions for typhoons in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Liangming Zhou; Aifang Wang; Peifang Guo; Zhifeng Wang

    2008-01-01

    The WAVEWATCH-Ⅲ wave model is implemented in the South China Sea to investigate the air-sea momentum flux in high wind conditions during 23 passages of typhoon occurred in 2005.The wave model is driven by the reanalyzed surface winds assimilated by sevcral meteorologic data sources.The friction velocity was calculated and the relationships between different air-sea momentum param. eters were studied.The results show that the drag coefficient decreases with the wave age generally and levels off for wind speeds higher than 35 m/s under typhoon wind forcing.The spatial variations of air-sea momentum flux parameters in high wind conditions forced by typhoons are completely different from those at weak wind speeds and significantly depend on the relative position from the typhoon center.

  1. Remote sensing model and dynamic mechanism for seasonal changes of the euphotic depth in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    LI Guosheng; YANG Shilin; LIANG Qiang

    2003-01-01

    Based on remote sensing data and models, spatial distribution of the monthly euphotic depth in the East China Sea in 1998 has been obtained. The character of the seasonal changes of the euphotic depth is summarized, and the dynamic mechanism of the key influencing factors is analyzed. The results indicate that the controlling factors of the seasonal changes of euphotic depth in the East China Sea are the seasonal changes of temperature, diluted water from the Yangtze River, the ocean currents and the front process of different water masses.

  2. Impacts of South East Biomass Burning on local air quality in South China Sea

    Science.gov (United States)

    Wai-man Yeung, Irene; Fat Lam, Yun; Eniolu Morakinyo, Tobi

    2016-04-01

    Biomass burning is a significant source of carbon monoxide and particulate matter, which is not only contribute to the local air pollution, but also regional air pollution. This study investigated the impacts of biomass burning emissions from Southeast Asia (SEA) as well as its contribution to the local air pollution in East and South China Sea, including Hong Kong and Taiwan. Three years (2012 - 2014) of the Hybrid Single Particle Lagrangian-Integrated Trajectory (HYSPLIT) with particles dispersion analyses using NCEP (Final) Operational Global Analysis data (FNL) data (2012 - 2014) were analyzed to track down all possible long-range transport from SEA with a sinking motion that worsened the surface air quality (tropospheric downwash from the free troposphere). The major sources of SEA biomass burning emissions were first identified using high fire emissions from the Global Fire Emission Database (GFED), followed by the HYSPLIT backward trajectory dispersion modeling analysis. The analyses were compared with the local observation data from Tai Mo Shan (1,000 msl) and Tap Mun (60 msl) in Hong Kong, as well as the data from Lulin mountain (2,600 msl) in Taiwan, to assess the possible impacts of SEA biomass burning on local air quality. The correlation between long-range transport events from the particles dispersion results and locally observed air quality data indicated that the background concentrations of ozone, PM2.5 and PM10 at the surface stations were enhanced by 12 μg/m3, 4 μg/m3 and 7 μg/m3, respectively, while the long-range transport contributed to enhancements of 4 μg/m3, 4 μg/m3 and 8 μg/m3 for O3, PM2.5 and PM10, respectively at the lower free atmosphere.

  3. Air–sea CO2 fluxes in the East China Sea based on multiple-year underway observations

    Directory of Open Access Journals (Sweden)

    X.-H. Guo

    2015-04-01

    Full Text Available This study reports thus far a most comprehensive dataset of surface seawater pCO2 (partial pressure of CO2 and the associated air–sea CO2 fluxes in a major ocean margin, the East China Sea (ECS based on 24 surveys conducted in 2006 to 2011. We showed highly dynamic spatial variability of sea surface pCO2 in the ECS except in winter when it ranged in a narrow band of 330 to 360 μatm. In this context, we categorized the ECS into five different domains featured with different physics and biogeochemistry to better characterize the seasonality of the pCO2 dynamics and to better constrain the CO2 flux. The five domains are (I the outer Changjiang estuary and Changjiang plume, (II the Zhejiang–Fujian coast, (III the northern ECS shelf, (IV the middle ECS shelf, and (V the southern ECS shelf. In spring and summer, pCO2 off the Changjiang estuary was as low as 400 μatm in fall. pCO2 along the Zhejiang–Fujian coast was low in spring, summer and winter (300 to 350 μatm but was relatively high in fall (> 350 μatm. In the northern ECS shelf, pCO2 in summer and fall was > 340 μatm in most areas, higher than in winter and spring. In the middle and southern ECS shelf, pCO2 in summer ranged from 380 to 400 μatm, which was higher than in other seasons (2 flux in the entire ECS shelf was −10.0 ± 2.0 mmol m−2 d−1 in winter, −11.7 ± 3.6 mmol m−2 d−1 in spring, −3.5 ± 4.6 mmol m−2 d−1 in summer and −2.3 ± 3.1 mmol m−2 d−1 in fall. It is important to note that the standard deviations in these flux ranges mostly reflect the spatial variation of pCO2, which differ from the spatial variance nor the bulk uncertainty. Nevertheless, on an annual basis, the average CO2 influx into the entire ECS shelf was −6.9 ± 4.0 mmol m−2 d−1, about twice the global average in ocean margins.

  4. Microfossils, carbonate lysocline and compensation depth in surface sediments of the northeastern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Chen Ronghua; Xu Jian; Meng Yi; Wang Dongjun; Liu Chuanlian; Huang Baoqi; Zhang Fuyuan

    2003-01-01

    Based on the quantitative analyses of abundance of planktonic foraminifera, benthic foraminifera, calcareous nannofossils, the ratios of calcareous to siliceous microfossils, and the determination of carbonate contents in the surface sediments of the northeastern South China Sea, it has been found that the carbonate contents, the abundance of planktonic foraminifera and calcareous nannoplankton, and the ratio of calcareous microfossils decrease rapidly while the ratio of the benthic foraminifera to the total foraminiferal fauna, specific value of siliceous microfossils, and the percentage of the agglutinated tests in the benthic foraminiferal fauna increase with the water depth. The results indicate that the microfossils abundance and ratio, and the carbonate content are closely related to the carbonate lysocline and carbonate compensation depth (CCD) in the study area. In addition, the carbonate lysocline and the CCD are different between the southern and northern parts of the South China Sea. Both the lysocline and the CCD are deeper in the south with 2 600 and 3 600 m than in the north with 2 200 and 3 400 m,respectively.

  5. Influence of particle composition on thorium scavenging in the marginal China seas

    Institute of Scientific and Technical Information of China (English)

    YANG Weifeng; CHEN Min; CAO Jianping; QIU Yusheng; ZHANG Run; MA Qiang; TONG Jinlu; YANG Junhong; YANG Zhi; L(U) E

    2009-01-01

    Thorium-234 and particle composition (organic matter, biogenic silica, carbonate and lithogenic component) were examined in the East China Sea (ECS) and the northern South China Sea (NSCS)in order to constrain the particle types scavenging thorium isotopes. Good positive correlations between particulate organic matter (POM) or carbonate and thorium-234 in suspended particulate matter (SPM) indicates that POM and carbonate are efficient to scavenge thorium-234. No relationship between biogenic silica and thorium-234 suggests that geochemical behavior of thorium-234 may be not influenced by biogenic silica. A simple model was used to evaluate the affinity of thorium-234 to different particle components. The results show that POM is the most efficient scavenger for thorium-234 in the ECS and the NSCS, followed by carbonate. The authors' results lend support to the utility of thorium-234 as a proxy of POC and carbonate in the upper layer. However, the strong dependence of thorium scavenging on particle composition challenges thorium-230 as a constant flux proxy.

  6. The Functions of China Marginal Sea Sediments in the Cycle of Biogenic Elements

    Institute of Scientific and Technical Information of China (English)

    Sun Yunming; Song Jinming

    2002-01-01

    The contents of biogenic elements in China marginal sea sediments are related to their grain sizes, river transport, et al. In general, the finer the grain size is, the higher the contents of organic matter and OC, N, P are, the lower the contents of S and Si are. The biogeochemical environments of sediments are related to Eh, pH, temperature content of OC,Fe3+/Fe2+ radio, water dynamics condition, grain size of sediment, S system in sediment interstitial waters, et al., and they influence the early diageneses and cycle of biogenic elements in sediments. In most regions of China marginal sea, the flux directions of S2-, HS-,3- NH4+H4SiO4, PO4 , across the sediment-water interface are from sediment to the overlying seawater, the flux directions of SO42-, HCO3-, NO3-, NO2- across the sediment-water interface are from the overlying seawater to sediment. The irrigation of living things is important in the cycle of the biogenic elements across sediment-water interfaces.

  7. Interplay between the Indonesian Throughflow and the South China Sea Throughflow

    Institute of Scientific and Technical Information of China (English)

    LIU Qinyan; HUANG Ruixin; WANG Dongxiao; XIE Qiang; HUANG Qizhou

    2006-01-01

    Analysis both based on the wind stress and ocean assimilation dataset shows that the interannual variability of the Indonesian Throughflow and the South China Sea (Luzon Strait) Throughflow is out of phase. Wind anomaly forcing in the equatorial Pacific plays an important role in setting up this phase relation. During El Ni(n)o events, the westerly wind bursts intensify the Northern Equator Current and induce a northward shift of its bifurcation point.As a result, the partition of volume transport between the Kuroshio and the Mindanao Current is changed,with the Kuroshio transport decreased and the Mindanao Current increased. The undershooting/overshooting phenomena occur at the Luzon Strait and the Sulawesi-Mindanao passage, caused by variability of these two currents. Water transport from the Pacific to the South China Sea increases with the Kuroshio transport decreased, and transport from the Pacific to the Indian Ocean decreases with the Mindanao Current transport increased. The situation is reversed during La Ni(n)a. Therefore, the ocean dynamic meaning is profound to study the interannual variability relationship between the Indonesian Throughflow and the Luzon Strait Throughflow.

  8. Crust and upper mantle structure in east China and sea areas

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Eastern China and vicinal sea areas (98°~150°E, 5°~50°N) are located in the junction zone of Eurasian and Pacific plates, and it is also profoundly influenced by the collision between Indian and Eurasian plates. We utilized surface wave data recorded by 35 digital seismic stations in the area, extracted dispersion curves of fundamental-mode Rayleigh waves along 1 252 paths by means of time-frequency analysis based on multiple-filter and other tech-niques. The study area was divided into a grid of 1°′1°, group velocity distributions of fundamental Rayleigh waves between 10~158 s were determined by Occam¢s inversion. These velocity distributions roughly depict the lateral variations of shear wave velocities in different depth ranges. With the determined pure path dispersions we further inverted for the S wave velocity structures along two profiles from eastern Tibet to Pacific Ocean and from South China Sea to Mongolia. It is found that the lateral heterogeneity is obvious down to 400 km depth, and the velocity structures are correlated with tectonic units in the study area.

  9. Changes in Phytoplankton Community Structure in Western South China Sea Over the Past 450 Kyrs

    Science.gov (United States)

    Li, L.; Wang, H.; Li, J.; Zhao, M.; Wang, P.; Zhang, C.

    2008-12-01

    Molecular biomarkers (brassicasterol, dinosterol, alkenones, C30 1,15-diol/keto-ol and cholesterol) were measured in an IMAGES core MD05-2901 (14°22.50'N, 110°44.60'E, w.d. 1454 m), to reconstruct the phytoplankton community structure over the past 450 kyrs in the western South China Sea on the eastern slope off Vietnam. Our results showed that diatoms, which are most sensitive to nutrition supply, exhibited relatively high productivity in interglacial period and lower productivity in glacial period, possibly caused by summer monsoon-induced upwelling. Dinoflagellates exhibited simillar phenomena as diatoms. But, coccolithphorids did not show clear glacial/intergalcial patterns and had a gradual increasing trend from 450 kyrs to 200 kyrs followed by a gradual decreasing trend until the present. Eustigmatophytes exhibited higher contents in glacial than interglacial periods and almost the same variations with terrestrial n- alkanes. Relationships among the major biomarker groups indicated complex responses of different phytoplanktons to changes in paleoclimate and paleoenvironment in the past 450 kyrs in western South China Sea.

  10. Assessment for water quality by artificial neural network in Daya Bay, South China Sea.

    Science.gov (United States)

    Wu, Mei-Lin; Wang, You-Shao; Gu, Ji-Dong

    2015-10-01

    In this study, artificial neural network such as a self-organizing map (SOM) was used to assess for the effects caused by climate change and human activities on the water quality in Daya Bay, South China Sea. SOM has identified the anthropogenic effects and seasonal characters of water quality. SOM grouped the four seasons as four groups (winter, spring, summer and autumn). The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on the water quality in Daya Bay. Spatial pattern is mainly related to anthropogenic activities and hydrodynamics conditions. In spatial characteristics, the water quality in Daya Bay was divided into two groups by chemometrics. The monitoring stations (S3, S8, S10 and S11) were in these area (Dapeng Ao, Aotou Harbor) and northeast parts of Daya Bay, which are areas of human activity. The thermal pollution has been observed near water body in Daya Bay Nuclear Power Plant (S5). The rest of the monitoring sites were in the south, central and eastern parts of Daya Bay, which are areas that experience water exchanges from South China Sea. The results of this study may provide information on the spatial and temporal patterns in Daya Bay. Further research will be carry out more research concerning functional changes in the bay ecology with respect to changes in climatic factor, human activities and bay morphology in Daya Bay.

  11. REEXAMINATION OF THE ROLE OF VERTICAL CIRCULATION IN SEDIMENTATION IN THE YELLOW AND EAST CHINA SEAS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on figures available, role of upwelling in some fine sediment patches on China Sea shelves is examined from the viewpoints of physical process and biological process, respectively. It is further vertified with more data wherever upwelling exists on continental shelf mud must occur-coincidence of upwelling areas with mud patches. Marine rain is named for physical process and marine snow is used as usual. It is pointed out that marine rain and marine snow are usually coexistent and interact each other. It is concluded that the mud patch southeast of Cheju Is. is formed by marine rain rather than marine snow since terrigenous elements are high and biogenic elements are not and that judging from sediment trap data the mud in the Okinawa Trough is accumulated by horizontal transport via wind-driven transverse circulation from inner shelf in winter and by vertical flux through biological activities (marine snow) and aeolian deposit in spring.   A number of controversies on fine sediment issues on China Sea shelves need to be further deliberated. Interaction between marine rain and snow also needs to be experimentally and theoretically studied.

  12. Observed 3D Structure, Generation, and Dissipation of Oceanic Mesoscale Eddies in the South China Sea

    Science.gov (United States)

    Zhang, Zhiwei; Tian, Jiwei; Qiu, Bo; Zhao, Wei; Chang, Ping; Wu, Dexing; Wan, Xiuquan

    2016-04-01

    Oceanic mesoscale eddies with horizontal scales of 50–300 km are the most energetic form of flows in the ocean. They are the oceanic analogues of atmospheric storms and are effective transporters of heat, nutrients, dissolved carbon, and other biochemical materials in the ocean. Although oceanic eddies have been ubiquitously observed in the world oceans since 1960s, our understanding of their three-dimensional (3D) structure, generation, and dissipation remains fragmentary due to lack of systematic full water-depth measurements. To bridge this knowledge gap, we designed and conducted a multi-months field campaign, called the South China Sea Mesoscale Eddy Experiment (S-MEE), in the northern South China Sea in 2013/2014. The S-MEE for the first time captured full-depth 3D structures of an anticyclonic and cyclonic eddy pair, which are characterized by a distinct vertical tilt of their axes. By observing the eddy evolution at an upstream versus downstream location and conducting an eddy energy budget analysis, the authors further proposed that generation of submesoscale motions most likely constitutes the dominant dissipation mechanism for the observed eddies.

  13. Performance Calculation of Floating Wind Turbine Tension Leg Platform in the South China Sea

    Directory of Open Access Journals (Sweden)

    Hai Feng Wang

    2015-10-01

    Full Text Available The harvesting of wind energy is expected to increase greatly in the future because of its stability, abundance, and renewability in large coastal states such as China. The floating support structure will likely become the major structural form for wind turbines in the future due to its cost advantages when the water depth reaches 50 m. The 5MW wind turbine model from National Renewable Energy Lab (NREL and the modified tension leg platform model proposed by Harbin Institute of Technology (HIT were applied to certain sea conditions in the South China Sea in order to consider the effects of external load coupling actions. In this study, the internal force, mooring system force, as well as the acceleration, displacement and velocity of the floating structure of the modified HIT Tension Leg Platform (HIT-TLP were calculated. During this process, the physical parameters of its tension leg structure at a specific frequency domain were obtained to find the technical reserves for its practical application in the future.

  14. Nitrogen mineralization and immobilization in sediments of the East China Sea: Spatiotemporal variations and environmental implications

    Science.gov (United States)

    Lin, Xianbiao; Hou, Lijun; Liu, Min; Li, Xiaofei; Zheng, Yanling; Yin, Guoyu; Gao, Juan; Jiang, Xiaofen

    2016-11-01

    Nitrogen (N) mineralization and immobilization are important processes of N biogeochemical cycle in marine sediments. This study investigated gross N mineralization (GNM) and NH4+ immobilization (GAI) in the sediments from the East China Sea (ESC), using 15N stable isotope dilution technique. Results show that measured rates of GNM and GAI ranged from 0.04 to 6.1 µg N g-1 d-1 and from undetectable to 9.82 µg N g-1 d-1, respectively. In general, both GNM and GAI rates were significantly greater in summer as compared to winter, and the high rates occurred mainly in the muddy area and increased gradually from the Yangtze Estuary to Zhe-Min Coastal muddy areas. The GNM and GAI processes were related closely to sediment temperature, pH, ammonium (NH4+), nitrate (NO3-), total organic carbon (TOC), and total nitrogen (TN) contents in the muddy area, while they were associated tightly with sediment temperature, pH, NH4+, TOC, TN, sulfide, and Fe(III) concentrations in the sandy area. In addition, the total mineralized and immobilized N in the East China Sea (ECS) were estimated to be approximately 2.1 × 106 t N yr-1 and 2.7 × 106 t N yr-1, respectively. Overall, these results highlight the importance of N mineralization and immobilization in controlling the N budget in the ECS and improve the understanding of both processes and associated controlling mechanisms in the coastal marine ecosystem.

  15. Modern microbialites and their environmental significance, Meiji reef atoll, Nansha (Spratly) Islands, South China Sea

    Institute of Scientific and Technical Information of China (English)

    SHEN JianWei; WANG Yue

    2008-01-01

    Meiji (Mischief) coral atoll, in Nansha (Spratly) Islands, South China Sea, consists of an annular reef rim surrounding a central lagoon. On the atoll rim there are either protuberant 'motu' (small coral patch reefs on the rim of atoll) islets or lower sandy cays that contain modern microbialite deposits on the corals in pinnacles and surrounding bottoms of the atoll. Microbialites, including villiform, hairy, and thin spine growth forms, as well as gelatinous masses, mats and encruststion, developed on coral colonies and atoll rim sediments between 0 and 15 m deep-water settings. The microbialites were produced by natural populations of filamentous cyanobacteria and grew on (1) bulbous corals together with Acropora sp., (2) on massive colonies of Galaxea fascicularis, (3) on dead Montipora digitata, and (4) on dead Acropora teres, some hairy microbialite growing around broken coral branches. This study demonstrates that microbial carbonates are developed in coral reefs of South China Sea and indicates that microbial processes may be important in the construction of modern reef systems. The results have significance in the determination of nature and composition in microorganisms implied in the formation ancient microbialites, and permit evaluation of the importance of microbial deposits in modern coral reefs and of 'microbialites' in biogeochemical cycles of modern coral reef systems. The results also provide evidence of modern analogues for ancient microbialites in shallow-water settings, and combine with sedimentological studies of ancient microbialites to understand their controls.

  16. Development of typhoon driven wave nowcasting model in Southeast China Sea

    Institute of Scientific and Technical Information of China (English)

    Zheng Jinhai; Feng Xiangbo; Yan Yixin

    2011-01-01

    Using optimal interpolation data assimilation of observed wave spectrum around Northeast coast of Taiwan Island, the typhoon driven wave nowcasting model in Southeast China Sea is setup. The SWAN ( simulating waves nearshore) model is used to calculate wave field and the input wind field is the QSCAT/NCEP (Quick Scatterometer/National Centers for Environmental Prediction) data. The two-dimensional wavelet transform is applied to analyze the Xband radar image of nearshore wave field and it reveals that the observed wave spectrum has shoaling characteristics in frequency domain. The reverse calculation approach of wave spectrum in deep water is proposed and validated with experimental tests. The two-dimensional digital low-pass filter is used to obtain the initialization wave field. Wave data during Typhoon Sinlaku is used to calibrate the data assimilation parameters and test the reverse calculation approach. Data assimilation corrects the significant wave height and the low frequency spectra energy evidently at Beishuang Station along Fujian Province coast, where the entire assimilation indexes are positive in verification moments. The nowcasting wave field shows that the present model can obtain more accurate wave predictions for coastal and ocean engineering in Southeast China Sea.

  17. Thinned crustal structure and tectonic boundary of the Nansha Block, southern South China Sea

    Science.gov (United States)

    Dong, Miao; Wu, Shi-Guo; Zhang, Jian

    2016-12-01

    The southern South China Sea margin consists of the thinned crustal Nansha Block and a compressional collision zone. The Nansha Block's deep structure and tectonic evolution contains critical information about the South China Sea's rifting. Multiple geophysical data sets, including regional magnetic, gravity and reflection seismic data, reveal the deep structure and rifting processes. Curie point depth (CPD), estimated from magnetic anomalies using a windowed wavenumber-domain algorithm, enables us to image thermal structures. To derive a 3D Moho topography and crustal thickness model, we apply Oldenburg algorithm to the gravity anomaly, which was extracted from the observed free air gravity anomaly data after removing the gravity effect of density variations of sediments, and temperature and pressure variations of the lithospheric mantle. We found that the Moho depth (20 km) is shallower than the CPD (24 km) in the Northwest Borneo Trough, possibly caused by thinned crust, low heat flow and a low vertical geothermal gradient. The Nansha Block's northern boundary is a narrow continent-ocean transition zone constrained by magnetic anomalies, reflection seismic data, gravity anomalies and an interpretation of Moho depth (about 13 km). The block extends southward beneath a gravity-driven deformed sediment wedge caused by uplift on land after a collision, with a contribution from deep crustal flow. Its southwestern boundary is close to the Lupar Line defined by a significant negative reduction to the pole (RTP) of magnetic anomaly and short-length-scale variation in crustal thickness, increasing from 18 to 26 km.

  18. Newly recorded Karlodinium veneficum dinoflagellate blooms in stratified water of the East China Sea

    Science.gov (United States)

    Dai, Xinfeng; Lu, Douding; Guan, Weibing; Wang, Hongxia; He, Piaoxia; Xia, Ping; Yang, Huajie

    2014-03-01

    Karlodinium veneficum is a cosmopolitan species, but has been poorly recorded in the East China Sea (ECS) due to its small size and difficulty in identification. The bloom dynamics of this species is not well understood globally. In this study, we examined its morphological characteristics that suggest the K. veneficum is the co-occurring bloom causative species of large scale Prorocentrum donghaiense blooms in spring 2011. The epicone of K. veneficum recorded in the investigated area is conical or rounded, and the hypocone is hemispherically rounded. The ventral pore is located at the left side of the apical groove. Nucleus is positioned centrally within the hypocone. Four large irregular chloroplasts are equally distributed in the epicone and hypocone. The mean length of cultured cells was 13.6±1.2 μm (range 11.0-15.8 μm) and the mean width was 10.0±1.1 μm (range 8.0-12 μm) (n=50). Cell abundance of K. veneficum population was low, in the region 1000-1600 cells L-1, along a transect in the East China Sea on April 19, 2011, when the water column was not distinctly stratified. Cell densities reached 3×107 cells L-1 along the same transect on May 13 2011 when the bloom occurred in the 10 m layer surface and the water column was distinctly stratified. Cell abundances therefore appear closely related to water column stratification.

  19. Study of the permeability in melting zone of South China Sea based on percolation theory

    Science.gov (United States)

    Wan, Ju-ying; Xu, He-hua; Li, Yan-zhen; Shu, Wei-bing

    2015-09-01

    Oceanic crust is formed at mid-ocean ridges. The melting zone extends up to several hundreds of km laterally, the upwelling area at the spreading axis is confined to a narrow belt of only 2-3 km width. Whereas the parameter of permeability that magma ascending from the mantle beneath mid-ocean ridges is still poorly understood, despite the important role of the process for the formation of crust. Based on continuum percolation, we build the random fracture network as magma migration channels of South China Sea; with momentum equation, we deduced the dynamic pressure distribution with passive corner flow. After which, the permeability of melting zone is calculated with finite element method. Numerical simulation results indicate that there exists a power law relationship between the permeability and magma migration channels. The simulated result is consistent with that calculated by fractal method. The discovery of the ruler provides sound theoretical basis for the formation and evolution of oceanic crust, and may help us better understanding the formation and evolution of South China Sea.

  20. Response of internal solitary waves to tropical storm Washi in the northwestern South China Sea

    Directory of Open Access Journals (Sweden)

    Z. H. Xu

    2011-11-01

    Full Text Available Based on in-situ time series data from an array of temperature sensors and an acoustic Doppler current profiler on the continental shelf of the northwestern South China Sea, a sequence of internal solitary waves (ISWs were observed during the passage of tropical storm Washi in the summer of 2005, which provided a unique opportunity to investigate the ISW response to the tropical cyclone. The passing tropical storm is found to play an important role in affecting the stratification structure of the water column, and consequently leading to significant variability in the propagating features of the ISWs, such as the polarity reversal and amplitude variations of the waves. The response of the ISWs to Washi can be divided into two stages, direct forcing by the strong wind (during the arrival of Washi and remote forcing via the near-inertial internal waves induced by the tropical storm (after the passage of Washi. The field observations as well as a theoretical analysis suggest that the variations of the ISWs closely coincide with the changing stratification structure and shear currents in accompanied by the typhoon wind and near-inertial waves. This study presents the first observations and analysis of the ISW response to the tropical cyclone in the South China Sea.

  1. Acceleration of modern acidification in the South China Sea driven by anthropogenic CO₂.

    Science.gov (United States)

    Liu, Yi; Peng, Zicheng; Zhou, Renjun; Song, Shaohua; Liu, Weiguo; You, Chen-Feng; Lin, Yen-Po; Yu, Kefu; Wu, Chung-Che; Wei, Gangjian; Xie, Luhua; Burr, George S; Shen, Chuan-Chou

    2014-06-03

    Modern acidification by the uptake of anthropogenic CO2 can profoundly affect the physiology of marine organisms and the structure of ocean ecosystems. Centennial-scale global and regional influences of anthropogenic CO2 remain largely unknown due to limited instrumental pH records. Here we present coral boron isotope-inferred pH records for two periods from the South China Sea: AD 1048-1079 and AD 1838-2001. There are no significant pH differences between the first period at the Medieval Warm Period and AD 1830-1870. However, we find anomalous and unprecedented acidification during the 20th century, pacing the observed increase in atmospheric CO2. Moreover, pH value also varies in phase with inter-decadal changes in Asian Winter Monsoon intensity. As the level of atmospheric CO2 keeps rising, the coupling global warming via weakening the winter monsoon intensity could exacerbate acidification of the South China Sea and threaten this expansive shallow water marine ecosystem.

  2. Propagated rifting in the Southwest Sub-basin, South China Sea: Insights from analogue modelling

    Science.gov (United States)

    Ding, Weiwei; Li, Jiabiao

    2016-10-01

    How the South China Sea rifted has long been a puzzling question that is still debated, particularly with reference to the Southwest Sub-basin (SWSB). Analogue modelling remains one of the most useful tools for testing rift models and processes. Here, we present and discuss a series of analogue modelling experiments designed to investigate the rifting process of the SWSB. Convincing geophysical results were compiled to provide realistic constraints to test the experimental results and interpretations. A heterogeneous lithosphere model with a varied lithospheric structure showed tectono-morphological features similar to the natural case of the SWSB, indicating that the initial thermal condition and rheological stratification of the lithosphere should have a dominant effect on the rifting process of the SWSB. Rigid tectonic blocks existed in the continental margin, such as the Macclesfield Bank and the Reed Bank, and they played important roles in both the shaping of the continent-ocean boundary and the coupling between the crust and mantle. The initial thermal condition and rheological stratification of the lithosphere under the South China Sea controlled the propagated rifting process of the SWSB. Extension was centred on the deep troughs between the rigid blocks, and the break-up occurred in these areas between them. The westward rifting propagation is best explained with a heterogeneous lithosphere model characterized by varied lithospheric structure, and it was responsible for producing the V-shaped configuration of the SWSB.

  3. Analysis and Design of Trial Well Mooring in Deepwater of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yongfeng Guo; Shaojun Ji; Changquan Tang; Jiansong Li; Huiquan Zhong; Ong Chin Yam Ian

    2012-01-01

    Mooring systems play an important role for semi-submersible rigs that drill in deepwater.A detailed analysis was carried out on the mooring of a semi-submersible rig that conducted a trial well drilling at a deepwater location in the South China Sea in 2009.The rig was 30 years old and had a shallow platform with a designed maximum operating water depth of 457 m.Following the mooring analysis,a mooring design was given that requires upgrading of the rig's original mooring system.The upgrade included several innovations,such as installing eight larger anchors,i.e.replacing the original anchors and inserting an additional 600 m of steel wires with the existing chains.All this was done to enhance the mooring capability of the rig in order for the rig to be held in position to conduct drilling at a water depth of 476 m.The overall duration of the drilling was 50 days and the upgraded mooring system proved to be efficient in achieving the goal of keeping the rig stationary while it was drilling the trial well in the South China Sea.This successful campaign demonstrates that an older semi-submersible rig can take on drilling in deep water after careful design and proper upgrading and modification to the original mooring system.

  4. 解读奥巴马政府的南海政策%Interpreting Obama Administration's South China Sea Policy

    Institute of Scientific and Technical Information of China (English)

    韦宗友

    2016-01-01

    自2010年以来,奥巴马政府的南海政策日益朝着“积极干涉”和“选边站”的立场转移,给中美关系及南海问题的解决增添了新变数。奥巴马政府不仅对中国的“断续线”主张提出质疑,还指责中国阻碍南海航行自由,要求中国停止在南海填海造地,鼓动菲律宾将南海争端提交国际仲裁,推动南海问题的国际化与多边化,积极向越南、菲律宾等国提供外交帮助和军事支持,甚至直接派遣飞机和舰船进入南海争议地区。奥巴马政府在南海问题上日益积极的干涉立场与举措,不仅折射出美国对中国战略意图和海洋抱负与日俱增的忧虑,也反映出美国维护亚太领导权、安抚亚太盟友及维护其海洋霸权的战略决心与考量。在美国国内对华强硬的声音抬头、中美在亚太地区竞争加剧及美国政治正进入大选周期的背景下,美国在南海问题上“积极干涉”和“选边站”的态势只会加强而不会弱化,并可能采取一些新的措施。中国需要综合平衡各种利害关系,积极稳妥应对南海困局。%Since 2010, the Obama administration's South China Sea policy has moved steadily toward posi-tive intervention and side-choosing, which negatively impacted Sino-U.S.relations and complicated the South China Sea issues.The Obama administration not only doubted the legality of China's nine-dash line claims, but also charged that China has interfered with the freedom of navigation in the South China Sea, and urged China to stop land reclamation in the South China Sea.Besides, U.S.also encouraged the Philippines'efforts to submit its maritime disputes with China to international arbitration to internationalize and multilateralize the South China Sea disputes, provided diplomatic support and military aid to Vietnam, the Philippines and other claimants, and even sent airplanes and ships to the disputed area.The change of Obama

  5. Study on the Seasonal Variation of the Suspended Sediment Distribution and Transportation in the East China Seas Based on SeaWiFS Data

    Institute of Scientific and Technical Information of China (English)

    WANG Wenjuan; JIANG Wensheng

    2008-01-01

    The monthly mean suspended sediment concentration in the upper layer of the East China Seas was derived from theretrieval of the monthly binned SeaWiFS Level 3 data during 1998 to 2006.The seasonal variation and spatial distribution of thesuspended sediment concentration in the study area were investigated.It was found that the suspended sediment distribution presentsapparent spatial characteristics and seasonal variations,which are mainly affected by the resuspension and transportation of the sus-pended sediment in the study area.The concentration of suspended sediment is high inshore and low offshore,and river mouths aregenerally high concentration areas.The suspended sediment covers a much wider area in winter than in summer,and for the samesite the concentration is generally higher in winter.In the Yellow and East China Seas the suspended sediment spreads farther to theopen sea in winter than in summer,and May and October are the transitional periods of the extension.Winds,waves,currents,ther-mocline,halocline,pycnocline as well as bottom sediment feature and distribution in the study area are important influencing factorsfor the distribution pattern.If the 10mg L-1 contour line is taken as an indicator,it appears that the transportation of suspended sedi-ment can hardly reach 124°00'E in summer or 126°00'E in winter,which is due to the obstruction of the Taiwan Warm Current andthe Kuroshio Current in the southern Yellow Sea and the East China Sea.

  6. Molecular biomarker record of paleooceanographic envi-ronment in the East China Sea during the last 35000 years

    Institute of Scientific and Technical Information of China (English)

    MENG; Xianwei

    2002-01-01

    [1]Wang Pinxian, Response of western Pacific marginal seas to glacial cycles: Paleooceanographic and sedimentological features, Marine Geology, 1999, 156: 5-39.[2]Cang Shuxi, Yan Jun, Paleooceanography of Restricted Sea Area, Western Pacific Ocean (in Chinese), Qingdao: Ocean University Press, 1992, 11-32.[3]Xu Xuedong, Motoyosh, O., surface-water evolution of the eastern East China Sea during the last 36000 years, Marine Geology, 1999, 156: 285-304.[4]Yan Jun, Cang Shuxi, Evolution of the paleo-Kuroshio system and its relation to climate change since the last interglacial, Marine Geology & Quaternary Geology (in Chinese), 1995, 15: 26-40.[5]Li Peiying, Wang Yongji, Liu Zhenxia et al., Chronostratigraphy and deposition rates in the Okinawa Trough region, Science in China, Ser. D, 1999, 42(4): 408-413.[6]Liu Zhenxia, Li Tiegang, Li Peiying et al., The Paleoclimatic events and cause in the Okinawa Trough during 50ka BP, Chinese Science Bulletin, 2001, 46(2): 153-157.[7]Tang Yunqian, Zhen Shilong, Liu Kewen, Biomarker distribution in sedimentary core, South China Sea, in Sedimentation Process and Geochemical Study (in Chinese), Beijing: Ocean Press, 1993, 135-141.[8]Dong Guangrong, Wang Guiyong, Li Xiaoze et al., Paleo-monsoon evolution of sandy region in the eastern China during last interglacial, Science in China (in Chinese), Ser. D, 1996, 26(5): 437-444.[9]Pelejero, C., Grimalt, J. O., Sarnthein, M. et al., Molecular biomarker record of sea surface temperature and climatic change in the South China Sea during the last 140000 years, Marine Geology, 1999, 156: 109-121.[10]Prahl, F. G., Pinto, L. A., A geochemical study of long-chain n-alkenones in Washington coastal sediments, Geochim. Cosmochim. Acta, 1987, 51: 1573-1582.[11]Prahl, F. G., Wakeham, S. G., Calibration of unsaturation patterns in long-chain ketone compositions for palaeo-temperature assessment, Nature, 1987, 300: 367-369.[12]Prahl, F. G., Muelhausen, L

  7. Assessment of wind products obtained from multiple microwave scatterometers over the China Seas

    Science.gov (United States)

    Wang, Zhixiong; Zhao, Chaofang

    2015-09-01

    Sea surface winds (SSWs) are vital to many meteorological and oceanographic applications, especially for regional study of short-range forecasting and Numerical Weather Prediction (NWP) assimilation. Spaceborne scatterometers can provide global ocean surface vector wind products at high spatial resolution. However, given the limited spatial coverage and revisit time for an individual sensor, it is valuable to study improvements of multiple microwave scatterometer observations, including the advanced scatterometer onboard parallel satellites MetOp-A (ASCAT-A) and MetOp-B (ASCAT-B) and microwave scatterometers aboard Oceansat-2 (OSCAT) and HY-2A (HY2-SCAT). These four scatterometer-derived wind products over the China Seas (0°-40°N, 105°-135°E) were evaluated in terms of spatial coverage, revisit time, bias of wind speed and direction, after comparison with ERA-Interim forecast winds from the European Centre for Medium-Range Weather Forecasts (ECMWF) and spectral analysis of wind components along the satellite track. The results show that spatial coverage of wind data observed by combination of the four sensors over the China Seas is about 92.8% for a 12-h interval at 12:00 and 90.7% at 24:00, respectively. The analysis of revisit time shows that two periods, from 5:30-8:30 UTC and 17:00-21:00 UTC each day, had no observations in the study area. Wind data observed by the four sensors along satellite orbits in one month were compared with ERA-Interim data, indicating that bias of both wind speed and direction varies with wind speed, especially for speeds less than 7 m/s. The bias depends on characteristics of each satellite sensor and its retrieval algorithm for wind vector data. All these results will be important as guidance in choosing the most suitable wind product for applications and for constructing blended SSW products.

  8. Preliminary results of the Source China Sea passive source OBS array experiment

    Science.gov (United States)

    Yang, T.; Liu, C.; Pei, Y.; Xia, S.

    2013-12-01

    The Scarborough, or Huangyan, Seamount chain in South China Sea (SCS) represents an extreme case of the global mid-ocean ridge system where the magmatism continues for many million years after the cessation of spreading. To understand this unique process, the South China Sea Deep (SCSD) program funded an experiment deploying a passive source OBS array to image the lithospheric structure beneath the extinct ridge. In April 2012, 18 passive source OBSs, including 15 Guralp CMG-40T OBS and 3 I-4C OBS, were deployed around the Huangyan Island for one year. 11 OBSs were successfully recovered this April, and their data are being processed. Here we present some preliminary results from analyses of this dataset, including the general quality of three-component seismograms, characteristics of seafloor ambient noise spectra, determining the OBS orientation from the Rayleigh wave polarization, and the dispersion analysis of Rayleigh waves. We found that, for most stations, seismograms from teleseismic, regional and local events are generally good with the horizontal records being comparable with vertical component. The noise levels in these seafloor stations are much higher than land-based stations, especially in shorter periods, likely suggesting the direct and stronger impact from the tempestuous SCS. Applications of more sophisticated seismic techniques such as surface wave tomography, seismic anisotropy, receiver function and ambient noise cross-correlation are underway. In addition to the low recovery rate, there are other lessons learned from this experiment. For example, at least two stations have detectable timing problems; Airgun shots should have been used to constrain the timings and orientations in both deployment and recovery. It is still challenging and costly to carry out long-term passive source seismic observations in deep sea.

  9. Tides and Their Dynamics over the Sunda Shelf of the Southern South China Sea

    Science.gov (United States)

    Ooi, See Hai; Abu Samah, Azizan; Akbari, Abolghasem

    2016-01-01

    A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performed on the inner domain. The model is forced at the sea surface by climatological monthly mean wind stress, freshwater (evaporation minus precipitation), and heat fluxes. Momentum and tracers (such as temperature and salinity) are prescribed in addition to the tidal heights and currents extracted from the Oregon State University TOPEX/Poseidon Global Inverse Solution (TPXO7.2) at the open boundaries. The results are validated against observed tidal amplitudes and phases at 19 locations. Results show that the mean average power energy spectrum (in unit m2/s/cph) for diurnal tides at the southern end of the East Coast of Peninsular Malaysia is approximately 43% greater than that in the East Malaysia region located in northern Borneo. In contrast, for the region of northern Borneo the semidiurnal power energy spectrum is approximately 25% greater than that in the East Coast of Peninsular Malaysia. This implies that diurnal tides are dominant along the East Coast of Peninsular Malaysia while both diurnal and semidiurnal tides dominate almost equally in coastal East Malaysia. Furthermore, the diurnal tidal energy flux is found to be 60% greater than that of the semidiurnal tides in the southern South China Sea. Based on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area. PMID:27622552

  10. Regime shift of the South China Sea SST in the late 1990s

    Science.gov (United States)

    Thompson, Bijoy; Tkalich, Pavel; Malanotte-Rizzoli, Paola

    2017-03-01

    Decadal variability of the South China Sea (SCS) sea surface temperature (SST) during 1982-2014 is investigated using observations and ocean reanalysis datasets. The SCS SST shows an abrupt transition from a cold-to-warm regime in the late 1990s. Based on the long-term SST variability two epochs are defined, 1982-1996 and 2000-2014 as cold and warm regimes respectively, spanning on either side of the 1997-1999 SCS warming. Despite the occurrence of strong El Nino induced warming events, the SST anomalies tend to be negative in the cold regime. Conversely during the warm regime, the positive SST anomalies have dominated over the La Nina driven cooling events. The cold (warm) SST regime is marked by net heat gain (loss) by the SCS. The long-term variations of net surface heat flux are mainly driven by the latent heat flux anomalies while the short wave flux plays a secondary role. Low-frequency variability of the South China Sea throughflow (SCSTF) appears to be closely related to the SCS SST regime shift. The SCSTF shows reversing trends during the cold and warm epochs. The weakened SCSTF in the warm regime has promoted the SCS warming by limiting the outward flow of warm water from the SCS. Meanwhile, enhanced SCSTF during the cold regime acts as a cooling mechanism and lead to persistent negative SST anomalies. The change in trend of the SCSTF and SST regime shift coincides with the switching of pacific decadal oscillation from a warm to cold phase in the late 1990s.

  11. Long-range correlations in remotely sensed chlorophyll in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHAN Haigang; SHI Ping; MAO Qinwen; ZHANG Tonghui

    2006-01-01

    A 8-year time series of 8-day Seaviewing Wide Field-of-view Sensor (SeaWiFS) data,which spans from Oct 1997 to Oct 2005, was used to study the temporal correlations and scaling behaviour of ocean chlorophyll fluctuations in the South China Sea (SCS) by means of detrended fluctuation analysis (DFA). Long-range correlations in chlorophyll fluctuations were detected in almost all the SCS. The scaling exponents vary over a wide range from 0.5 to 1.14, with an average value of 0.79. High values are found in the upwelling regions, such as the northwest of Luzon and the north of Sunda Shelf. Low values occur in the southwest of Luzon, the east of Hainan Island and a majority of the southern SCS. This spatial pattern is considerably different from that of the scaling exponents of the sea surface temperature (SST) time series. It is also demonstrated that SST exhibits more persistence than chlorophyll in almost all the SCS.

  12. Study on the storm surges induced by cold waves in the Northern East China Sea

    Science.gov (United States)

    Mo, Dongxue; Hou, Yijun; Li, Jian; Liu, Yahao

    2016-08-01

    Cold wave, a kind of severe weather system, can bring strong wind and induce significant sea level rise to the Northern East China Sea. Based on CFSR data, the study shows the monthly distributions of invaded days and the spatiotemporal distributions of cold-wave wind direction and wind speed. A three-dimensional numerical model (ROMS) was developed to study storm surges induced by cold waves. The role of wind direction, wind speed, wind duration, extratropical cyclone and tide-surge interaction is investigated by conducting different sensitivity experiments. The results indicate that storm surges mainly happen at the coasts perpendicular to the wind directions. Surge range and time lag are related to the geometry of the basin and the continental shelf. The response of the sea-level fluctuations to cold wave indicates that there is a positive correlation between crests and wind speed, a negative correlation between troughs and wind speed, but no obvious correlations to wind duration. Coupled weather cold waves, which yield a larger range and a multi-peak structure of surges, can be classified according to cold wave tracks and extratropical cyclones. The tide-surge interaction has an obvious and different effect on the magnitudes and phases of storm surges for different tidal stages.

  13. Initial insights into the age and origin of the Kubuqi sand sea of northern China

    Science.gov (United States)

    Yang, Xiaoping; Forman, Steven; Hu, Fangen; Zhang, Deguo; Liu, Ziting; Li, Hongwei

    2016-04-01

    The Kubuqi Desert is the only active sand sea in the semiarid regions of northern China and occurs along the southern margin of the Yellow River. Little is known about the age and origin of this large (17,000 km2) sand sea with a present annual precipitation of 200-480 mm. Sand drift potentials indicated net capable winds for aeolian transport are from the northwest, though winds are stronger to north beyond the dune field than within the sand sea. Geomorphic and stratigraphic observations indicate that Holocene aeolian sand often drapes over bedrock and river terraces as a palimpsest landscape. Field investigations identified four stratigraphic sections with multiple aeolian sand units and palaeosols, with age control by optically stimulated luminescence (OSL) dating of quartz grains. Palaeosols are weakly developed, mostly accumulative A horizon with organic carbon content farming from lost cities in the Kubuqi Desert during the Han (206 B.C. - A.D. 220) and the Tang (A.D. 608 - 907) Dynasties. Also, variable discharge of the Yellow River with local diversions for irrigation and throughout the catchment resulted in possibly an increased supply of aeolian particles for dune field expansion in the past 2 ka.

  14. An abrupt cooling event early in the last interglacial in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The high-resolution quantitative analysis of the planktonic foraminifera and the δ18O records of the section between 96.49-137.6 mcd at ODP Site 1144 on the continental slope ot northern South China Sea reveals an abrupt cooling event of sea surface temperature (SST) dur ing the last interglacial (MIS 5.5, i.e. 5e). The dropping range of the winter SST may come to 7.5℃corresponding to 1.2‰ of the δ18O value of sea surface water. This event is comparable with those discovered in the west Europe and the northern Atlantic Ocean, but expressed in a more intensive way. It is inferred that this event may have been induced by middle- to Iow-latitude processes rather than by polar ice sheet change. Since the Kuroshio-index species Pulleniatina obliquilocu lata displayed the most distinct change at the event, it may also be related to the paleocean ographic change of the Iow-latitude area in the western Pacific Ocean. This event can be consid ered as one of "Younger Dryas-style coolings" and is indicative of climate variability of the last in terglacial stage.

  15. First record of Thalassiosira curviseriata Takano (Bacillariophyta) and its bloom in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XIE Wenling; LI Yang; GAO Yahui

    2008-01-01

    A bloom caused by a diatom,Thalassiosira curviseriata Takano (Bacillariophyta),is recorded in the East China Sea for the first time in China during a red tide investigation cruise (MC2005 - 2) from 27 March to 12 April 2005.This bloom was developed with the competition of Chaetoceros debilis and Skeletonema spp.The highest cell density of T.curviseriata,which has reached 1.27 × 106 cells/dm3,was found in the surface and middle water layers of Stss ZD,ZB in the East China Sea (27.22°~29.48°N,121.53°~ 122.98°E)in early spring in 2005.During the blooming period of T.curviseriata,the population with high cell density was found in the water area with temperature of 10 ~ 15 ℃ and salinity of 29.0 ~ 33.5.The percentage of the predominant spe-cies,T.curviseriata,has reached 95.8% of total diatom cells at one time in the middle water layer.The morphological character-istics of T.curviseriata,were observed with light microscope (LM) and transmission electronic microscope (TEM).The cells are 5.0 ~ 12.6 μm in diameter,connecting each other by mucilaginous thread to form spiral and curved chains.Description and LM and TEM images of T.curviseriata are presented.T.curviseriata is ecologically characterized by eurythermy and euryhalinity,and its population variation is affected mainly by silicate,the ratios of phosphorus to silicon and nitrogen to sihcon.

  16. Some Comments on the Preliminary Ruling of the South China Sea Arbitration Case

    Institute of Scientific and Technical Information of China (English)

    Luo Guoqiang

    2016-01-01

    The preliminary ruling by the South China Sea arbitration case gives a number of explanations on the UN Convention, which are in favor of the Philippines, especially the Arbitral Tribunal made preliminary ruling over the appeal demands unclearly excluded by both the UN Convention and the Chinese Statement and established jurisdiction, but made no preliminary ruling regarding the clearly excluded appeal demands, and established them directly into the substantive consideration, and that phenomenon has strong subjective approach. The preliminary ruling is the joint processing of legal abuse by the Arbitral Tribunal and the Philippine side, so the hope on the Arbitration case should not be placed on the inside of the Arbitral Tribunal but on the outside of the Arbitral Tribunal. The matters established under the jurisdiction by the preliminary ruling is not related to the core matter of the South China Sea disputes, bears a little practical impact on the Chinese side. However, the Arbitral Tribunal may take the opportunity to review the "historic rights" such as those excluded in order to give covert support to the Philippines and other islands-claiming countries so as to affect the overall situation of the case. In view of the defects in designing of Annex Ⅶ of the UN Convention and the possible abuse of the system, the Chinese side should get prepared. Only on the basis of internationally accepted practice and the UN Convention, should China make rational and convincing arguments, recognize the preliminary ruling is the result of legal abuse, and safeguard national rights and interest with the international law and prevent the civil abuse actions.

  17. A wave energy resource assessment in the China's seas based on multi-satellite merged radar altimeter data

    Institute of Scientific and Technical Information of China (English)

    WAN Yong; ZHANG Jie; MENG Junmin; WANG Jing

    2015-01-01

    Wave energy resources are abundant in both offshore and nearshore areas of the China's seas. A reliable assessment of the wave energy resources must be performed before they can be exploited. First, for a water depth in offshore waters of China, a parameterized wave power density model that considers the effects of the water depth is introduced to improve the calculating accuracy of the wave power density. Second, wave heights and wind speeds on the surface of the China's seas are retrieved from an AVISO multi-satellite altim-eter data set for the period from 2009 to 2013. Three mean wave period inversion models are developed and used to calculate the wave energy period. Third, a practical application value for developing the wave energy is analyzed based on buoy data. Finally, the wave power density is then calculated using the wave field data. Using the distribution of wave power density, the energy level frequency, the time variability indexes, the to-tal wave energy and the distribution of total wave energy density according to a wave state, the offshore wave energy in the China's seas is assessed. The results show that the areas of abundant and stable wave energy are primarily located in the north-central part of the South China Sea, the Luzon Strait, southeast of Taiwan in the China's seas; the wave power density values in these areas are approximately 14.0–18.5 kW/m. The wave energy in the China’s seas presents obvious seasonal variations and optimal seasons for a wave energy utilization are in winter and autumn. Except for very coastal waters, in other sea areas in the China's seas, the energy is primarily from the wave state with 0.5 m≤Hs≤4 m, 4 s≤Te≤10 s whereHs is a significant wave height andTe is an energy period; within this wave state, the wave energy accounts for 80% above of the total wave energy. This characteristic is advantageous to designing wave energy convertors (WECs). The practical application value of the wave energy is higher

  18. Numerical Analysis and Simulation Experiment of Lithospheric Thermal Structures in the South China Sea and the Western Pacific

    Institute of Scientific and Technical Information of China (English)

    Lin Ge; Peng Meili; Zhao Chongbin; Zhang Lu; Zhang Desheng; Liu Shilin

    2009-01-01

    The asthenosphere upwelled on a large scale in the western Pacific and South China Sea during the Cenozoic,which formed strong upward throughflow and caused the thermal structure to be changed obviously.The mathematical analysis has demonstrated that the upward throughflow velocity may have varied from 3×1011 to 6×1012 m/s.From the relationship between the lithospheric thickness and the conductive heat flux,the Hthospherie heat flux in the western Pacific should be above 30 mW/m2,which is consistent with the observed data.The huge low-speed zone within the upper mantle of the marginal sea in the western Pacific reflects that the upper mantle melts partially,flows regionally in the regional stress field,forms the upward heat flux at its bottom,and causes the change of the lithospheric thermal structure in the region.The numerical simulation result of the expansion and evolution in the South China Sea has demonstrated that in the early expansion,the upward throughflow velocity was relatively fast,and the effect that it had on the thickness of the lithosphere was relatively great,resulting in the mid-ocean basin expanding rapidly.After the formation of the ocean basin in the South China Sea,the upward throughflow velocity decreased,but the conductive heat flux was relatively high,which is close to the actual situation.Therefore,from the heat transfer point of view,this article discusses how the upward heat flux affects the lithospheric thermal structure in the western Pacific and South China Sea.The conclusions show that the upward heat throughflow at the bottom of the llthospheric mantle resulted in the tectonic deformation at the shallow crust.The intensive uplifts and rifts at the crust led to the continent cracks and the expansion in the South China Sea.

  19. COMPOSITE ANALYSIS OF SUMMER MONSOON ONSET PROCESS OVER SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    徐海明; 何金海; 周兵

    2001-01-01

    Based on the method of composite analysis, the onset process and preceding signs of summer monsoon over the South China Sea (SCS) is investigated. The result indicates that convection activities appear first over the Indo-China Peninsula prior to the onset of the monsoon, then around the Philippines just at the point of onset, implying that the convection activities around the Philippines serve as one of the reasons leading to the SCS monsoon onset. Before the SCS monsoon onset, the equatorial westerly over the Indian Ocean (75°E ~ 95°E ) experiences noticeable enhancement and plays an important role on the SCS monsoon onset. It propagates eastward rapidly and causes the establishment and strengthening of equatorial westerly in the southern SCS, on the one hand, it results in the migration southward of the westerly on south side of the south-China stationary front by means of shift northeastward of the westerly and convection over the Bay of Bengal, on the other. Further study also shows that the intensification of equatorial westerly in the Indian Ocean (75°E ~ 95°E) and the southern SCS is closely related to the reinforcement of the Southern-Hemisphere Mascarene high and Australian high, and cross-equatorial flow northward around Somali, at 85°E and 105°E, respectively.

  20. Relation between sea surface temperature anomaly in the Atlantic and summer precipitation over the Northeast China

    Institute of Scientific and Technical Information of China (English)

    白人海

    2001-01-01

    Based on global monthly average data set of sea surface temperature (SST) during 1950 -1992 and global monthly average 500 hPa height during 1950 - 1997 offered by NCAR/NCEP, the feature of SST anomaly in the Atlantic and its relation with summer precipitation over the Northeast China are analyzed. The results show that, the second eigenvector of the SST′s empirical orthogonal expanssion in winter season over the North Atlantic suggests that distribution of SST anomaly has unusual meridional difference; The location of its center is basically identical to center of significant correlation region between summer precipitation over the Northeast China and winter SST in the Atlantic. When winter SST in the North Atlantic is hot in south and cold in north, the blocking situation is stronger in the middle- high latitude. Correspondingly, the blocking high pressure in the northern North Pacific is also getting stronger,the westerlies circulation index in East Asia in next summer would be lower, asa result, more precipitation in the summer would be experienced over Northeast China and vice versa.

  1. Numerical study on the summer circulation of the upper South China Sea and its establishment

    Institute of Scientific and Technical Information of China (English)

    CAI Shuqun; SU Jilan; LONG Xiaomin; WANG Shengan; HUANG Qizhou

    2005-01-01

    A coupled single-layer/two-layer model is employed to study the South China Sea (SCS) upper circulation and its response before and after the onset of summer monsoon. It is found that, in summer, due to the β effect and the first baroclinic mode of the wind-driven current, a northward western boundary jet current is formed along the Indo-China Peninsula coast, and it leaves the coast at about 13° N and diffuses towards northeast; next to the Indo-China Peninsula, a large anticyclonic gyre in the southern SCS and a cyclonic eddy to the north of this gyre are induced. There are two possible mechanisms for the generation of this anticyclonic gyre: first, it is induced by the summer wind stress curl; second, it is associated with the westward moving of two anticyclonic eddies, which are originally generated to the west of Palawan Island and over the Nansha Trough respectively, in winter. The cyclonic eddy north of this anticyclonic gyre may be induced by the summer wind stess curl or related to the southwestward moving of the cyclonic eddy/gyre induced by the Kuroshio branch in the northern SCS.

  2. Study on Precipitation Anomalies of North of China in April and Its relationship to Sea Surface Temperature Evolvement

    Science.gov (United States)

    Song, Y.; Li, Z.; Guan, Y.

    2012-04-01

    Using monthly precipitation data in North of China for 1960-2007, American NCEP/NCAR monthly reanalysis data and NOAA SST (sea surface temperature) data, and SST indices data in Climate System Monitoring Bulletin collected by National Climate Center, this paper studied the general circulation, large-scale weather system anomalous characteristics and SSTA evolvement with more rainfall of North of China in April. The results showed that precipitation differences between months in spring in North of China were quite obvious, and the correlation coefficients between precipitation of North of China in April and that in March and in May were not significant respectively. The linear trend of precipitation in April was out of phase with that in spring. It was meaningful to study precipitation in April solely. The space pattern of first leading mode of EOF analysis for precipitation of North of China in April indicated that rainfall changed synchronously. In years of more rainfall in April showed negative phase of EU pattern in 500hPa geopotential height field of high latitude in the Northern Hemisphere, and North of China located at where cold and warm air masses met, which availed reinforcement of south wind and ascending motion. In middle and high latitudes was latitudinal circulation, and North of China was controlled by warm ridge and latitudinal large-scale front zone; In years of less rainfall, meridional circulation prevailed and large-scale front zone located northward and presented meridional pattern, and North of China was affected by cold air mass. At the same time, water vapor was transported strongly from Pacific, South China Sea and southwest of China, and reached Northeast of China. In years of less rainfall, the water vapor transportation was quite weak. The rainfall was related closely to sea surface temperature anomalies, especially to the Indian Ocean, the middle and east of Pacific, middle and south of Pacific and northwest of Pacific where there were

  3. Errors of Mean Dynamic Topography and Geostrophic Current Estimates in China's Marginal Seas from GOCE and Satellite Altimetry

    DEFF Research Database (Denmark)

    Jin, Shuanggen; Feng, Guiping; Andersen, Ole Baltazar

    2014-01-01

    and geostrophic current estimates from satellite gravimetry and altimetry are investigated and evaluated in China's marginal seas. The cumulative error in MDT from GOCE is reduced from 22.75 to 9.89 cm when compared to the Gravity Recovery and Climate Experiment (GRACE) gravity field model ITG-Grace2010 results...

  4. Catch rates as indicators of ecosystem health and exploitation status in the shrimp fishery in the South China sea

    DEFF Research Database (Denmark)

    Christensen, Steen; van Thi, Dang

    2008-01-01

    Based on catch and effort data analyses covering the period 1996-2002, time series of catch rates in the trawl fisheries in the South China Sea along the coasts of Bac Lieu and Ca Mau in South East Vietnam were estimated. The indicators include catch rates for total shrimp catch, five major shrimp...

  5. Two cyclic peptides produced by the endophytic fungus # 2221 from Castaniopsisfissa on the south China sea coast

    Institute of Scientific and Technical Information of China (English)

    Wen Qing YIN; Jie Ming ZOU; Zhi Gang SHE; L. L. P. Vrijmoed; E. B. Gareth Jones; Yong Cheng LIN

    2005-01-01

    New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 from Castaniopsisfissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.

  6. How economic, strategic, and domestic factors shape patterns of conflict and cooperation in the East China Sea dispute

    DEFF Research Database (Denmark)

    O'Shea, Paul

    2015-01-01

    Despite frequent talk of conflict and even war, economic and strategic factors suggest that the Sino-Japanese dispute over the East China Sea will not erupt into hot conflict, at least for the time being. However, for domestic reasons overt cooperation remains a distant prospect....

  7. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from RYOFU MARU in the Bismarck Sea, East China Sea and others from 1989-11-17 to 1995-03-07 (NODC Accession 0116982)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0116982 includes Surface underway data collected from RYOFU MARU in the Bismarck Sea, East China Sea (Tung Hai), North Pacific Ocean, Philippine Sea,...

  8. Nonhydrostatic effects of nonlinear internal wave propagation in the South China Sea

    Science.gov (United States)

    Zhang, Z.; Fringer, O. B.

    2007-05-01

    It is well known that internal tides are generated over steep topography at the Luzon Strait on the eastern boundary of the South China Sea. These internal tides propagate westward and steepen into trains of weakly nonlinear internal waves that propagate relatively free of dissipation until they interact with the continental shelf on the western side of the South China Sea, some 350 km from their generation point. The rate at which the internal tide transforms into trains of nonlinear waves depends on the Froude number at the generation site, which is defined as the ratio of the barotropic current speed to the local internal wave speed. Large Froude numbers lead to rapid evolution of wave trains while low Froude numbers generate internal tides that may not evolve into wave trains before reaching the continental shelf. Although the evolution into trains of weakly nonlinear waves results from the delicate interplay between nonlinear steepening and nonhydrostatic dispersion, the steepening process is represented quite well, at least from a qualitative standpoint, by hydrostatic models, which contain no explicit nonhydrostatic dispersion. Furthermore, hydrostatic models predict the propagation speed of the leading wave in wave trains extremely well, indicating that its propagation speed depends very weakly on nonlinear or dispersive effects. In order to examine how hydrostatic models introduce dispersion that leads to the formation of wave trains, we simulate the generation and evolution of nonlinear waves in the South China Sea with and without the hydrostatic approximation using the nonhydrostatic model SUNTANS, which can be run in either hydrostatic or nonhydrostatic mode. We show that the dispersion leading to the formation of wave trains in the hydrostatic model results from numerically-induced dispersion that is implicit in the numerical formulation of the advection terms. While the speed of the leading wave in the wave trains is correct, the amplitude and number

  9. Middle and Late Devonian brachiopod assemblages,sea level change and paleogeography of Hunan,China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Givetian through middle Famennian brachiopods of Hunan are used to define five biozones,comprising,in ascending order,the Stringocephalus Abundance Zone,the Ambocoeliid-Leiorhynchid Assemblage Zone,the Cyrtospiriferid Assemblage Zone,the Yunnanellina-Sinospirifer Assemblage Zone,and the Yunnanella-Hunanospirifer Assemblage Zone.They correspond approximately to the Po.hemiansatus Zone to Po.varcus Zone,S.hermanni Zone to Pa.punctata Zone,Pa.hassi Zone to Pa.linguiformis Zone,Pa.triangularis Zone to Upper Pa.crepida Zone,and Uppermost Pa.crepida Zone to Pa.marginifera Zone,respectively.Intensified rifting activity in South China during the Devonian began in the middle of the Lower Po.varcus Zone(a level marked by the first appearance of Po.rhenanus),which is consistent with the Lower-Middle Givetian substage boundary suggested by the International Subcommission on Devonian Stratigraphy(SDS).This assumed that rifting activity in the Lower Po.varcus Zone was signified by the deposition of the Baqi Formation in Guangxi and was marked largely by the extensive deposition of the Qiziqiao Formation in central Hunan,which probably led to an opposite pattern of relative sea level change-rising in deeper water trough areas and lowering in carbonate platform areas.The previously recognized S.hermanni Zone sea level rise in platform margin areas of Guangxi can be identified not only in the trough areas but also in platform areas,which probably indicates an overall marine transgression at this time,rather than tectonically induced sea level change.Similarly,this level coincides with the Middle-Upper Givetian substage boundary suggested by the SDS.Although the sea level rise may have occurred in the deeper water trough areas of South China towards the end of the Givetian,platformal areas experienced uplifting at various degrees,especially in the central and northern regions of Hunan where Early Frasnian deposits were apparently absent in many places.Similarly,the end

  10. A Numerical Simulation of the Winter-Time Current System in the China Sea and Adjacent Areas

    Institute of Scientific and Technical Information of China (English)

    李荣凤; 曾庆存

    1994-01-01

    The monthly mean circulations in the whole Pacific Ocean are investigated numerically by using a barotropic ocean model with finer horizontal resolutions. The current system in the China Sea and its adjacent areas has been well reproduced. Especially, some warm currents moving windward in winter, such as the South China Sea Warm Current (SCSWC), Taiwan Warm Current (TWO, Yellow Sea Warm Current (YSWC) and Tsushima Warm Current (TsWC) are simulated very well. Numerical results of January show that there exists indeed a so-called "Taiwan-Tsushima-Tsugaru Warm Current System" (TTTWCS) which originates from the area off the southeastern Hainan Island and enters the Pacific Ocean mainly through the Tsugaru Strait in January.

  11. Optimum selection on bridge erection with floating crane in East China Sea Bridge and Hangzhou Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    Shunquan Qin; Pu Zhou; Youheng Hua

    2004-01-01

    @@ Introduction With the rapid development of China′s economy, many bridges will be built over the Chinese coastal waters of Pacific Ocean. Among them, construction of East China Sea Bridge has been commenced in June 2001, and will be completed at the end of 2005, Hangzhou Bay Bridge was also started to construct in June 2003(Fig. 1). These two ultralong bridges are designed as twin expressway bridges standing side by side each carries a 3-lane one-way carriageway. The total width is 31.5m and 33.0m respectively. East China Sea Bridge starts from Nanhui District, Shanghai and extends to the Yangshan Deep Water Port Area, which is located at one of the Qiqu Islands. The total length of the bridge is about 31.0 km, in which 25 km are on the sea, and 22 km is in the unnavigable region. Hangzhou Bay Bridge across the mouth of Qiantang River.

  12. Validation, Analysis of the Chinese HY-2 Satellite Altimeter Data and their Applications in the China Sea and its Vicinity

    Science.gov (United States)

    Yang, Jungang; Zhang, Jie; Cui, Wei; Zhao, Xinhua; Han, Weixiao; Martinez, Bernat

    2016-08-01

    Chinese first altimetry satellite HY-2 has been on obit almost 5 years by now and a large amount of marine observing data of HY-2 altimeter have acquired. In this paper, sea surface height (SSH) data of HY-2 altimeter are validated by the SSH difference at the self- crossover of the HY-2 ascending and descending obit, and at the mutual-crossover of HY-2 and Jason-2 obit. Significant wave height (SWH) data of HY-2 altimeter are validated by the data of NDBC buoys. On the data application of HY-2 altimeter, mesoscale eddies in the South China Sea and the western Pacific Ocean, the characteristics of ocean wave in the China Sea and the characteristics of Kuroshio are analyzed by combing with Envsiat RA-2, Jason-1/2 data.

  13. The Legal Basis of the People’s Republic of China’s East China Sea Air Defense Identification Zone

    Directory of Open Access Journals (Sweden)

    Ching Chang

    2016-04-01

    Full Text Available As the People’s Republic of China defined its East China Sea Air Defense Identification Zone (ADIZ on November 23, 2013, there were three legal decrees, the Law of the People’s Republic of China on National Defense established on March 14, 1997, the Law of the People’s Republic of China on Civil Aviation established on October 30, 1995, and the Basic Rules on Flight of the People’s Republic of China established on July 27, 2001, which have been quoted as the legal basis to define the airspace within the area enclosed by China’s outer limit of the territorial sea and another six geographical points specified by the statement as the PRC East China Sea ADIZ. Following the government statement, another announcement of the aircraft identification rules for the East China Sea Air Defense Identification Zone of the People’s Republic of China was immediately issued by the PRC Ministry of National Defense. The purpose of this paper is to explore various key legal issues to ascertain the legal basis of this East China Sea ADIZ. Besides, the paper will further compare the air defense identification zone with airspaces such as aerodrome flight airspace, airway, air route, prohibited area, restricted area and danger area as well as air corridor, fuel dumping area and temporary flight airspace defined by the previously mentioned PRC legal decrees in order to identify their differences and similarities. It may also be assessed by the factual consequences after establishing the air defense identification zone to decide whether treating the measures of defining air defense identification as the attempt of claiming sovereignty, expanding sovereign territory or sphere of influence, enlarging air defense region, increasing the coverage of air military activities or even using it to present national strength and establishing pride or to test the responses of other states around the disputed territories is eventually reasonable judgments or overstated

  14. Deep-water sediment transport processes in the northeastern South China Sea: Mooring and shipboard-based observations

    Science.gov (United States)

    Liu, Z.; Zhao, Y.; Zhang, Y.; Li, J.; Li, X.; Wang, W.; Xu, J.

    2013-12-01

    Six moorings equipped with acoustic doppler current profiler (ADCP), recording current meter (RCM), and sediment trap have been deployed in the northeastern South China Sea at water depths ranging from 1700-3900 m to collect time-series data that can hopefully help better characterize the bottom current system and transport process in the region. Shipboard-based measurements including CTD, transmissometer, optical backscatter (OBS), and in-situ layered suspended particle sampling using large volume pump (LVP) were undertaken along three deep-water transects in the region during two cruises in the spring of 2012 and 2013. Preliminary results show for the first time the presence of continuous and relative stable contour currents and widespread deep-water nepheloid layers in the deep South China Sea. The contour currents flow southwestwards with average speeds of 2-4 cm/s (occasionally up to 11 cm/s) along lower slope of the northern South China Sea at depths of 1700-2500 m. The large-scale sediment waves recorded by high-resolution multibeam bathymetry appear to be related to activities of the contour currents. Intermediate and bottom nepheloid layers with an average suspended particle concentration of 0.6 mg/l are extended from the lower slope to the deep basin of the South China Sea. The intermediate nepheloid layers in depths ranging from 900 to 1100 m are thought to be controlled mainly by the interaction between the North Pacific Intermediate Water and the Pacific Deep Water masses. A sedimentary core (MD01-2905) previously collected on the sediment drift of ODP Site 1144, where three of the mooring systems are located, indicates that 60% of total fine-grained terrigenous sediment budget since the last glacial time have sourced from Taiwan. Our data suggest that the observed contour currents are the major carrier for transporting Taiwan-derived sediments to the northern slope of the South China Sea.

  15. Clay minerals in surface sediments of the Pearl River drainage basin and their contribution to the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU ZhiFei; Christophe COLIN; HUANG Wei; CHEN Zhong; Alain TRENTESAUX; CHEN JianFang

    2007-01-01

    Clay minerals have played a significant role in the study of the East Asian monsoon evolution in the South China Sea by being able to track oceanic current variations and to reveal contemporaneous paleoclimatic changes prevailing in continental source areas. As one of the most important rivers inputting terrigenous matters to the northern South China Sea, the Pearl River was not previously paid attention to from the viewpoint of clay mineralogy. This paper presents a detailed study on clay minerals in surface sediments collected from the Pearl River drainage basin (including all three main channels,various branches, and the Lingdingyang in the estuary) by using the X-ray diffraction (XRD) method.The results indicate that the clay mineral assemblage consists dominantly of kaolinite (35%-65%),lesser abundance of chlorite (20%-35%) and illite (12%-42%), and very scare smectite occurrences (generally <5%). Their respective distribution does not present any obvious difference throughout the Pearl River drainage basin. However, downstream the Pearl River to the northern South China Sea, the clay mineral assemblage varies significantly: kaolinite decreases gradually, smectite and illite increase gradually. Additionally, illite chemistry index steps down and illite crystallinity steps up. These variations indicate the contribution of major kaolinite, lesser illite and chlorite, and very scarce smectite to the northern South China Sea from the Pearl River drainage basin. The maximum contribution of clay minerals from the Pearl River is 72% to the northern margin and only 15% to the northern slope of the South China Sea. In both glacials and interglacials, kaolinite indicates that the ability of mechanical erosion occurred in the Pearl River drainage basin.

  16. Observations of Earthquake-Generated T-Waves in the South China Sea: Possible Applications for Regional Seismic Monitoring

    Directory of Open Access Journals (Sweden)

    Bor-Shouh Huang

    2013-01-01

    Full Text Available We present a detailed study of T-waves originating from earthquakes in the South China Sea region, near the Indochina Peninsula and Luzon islands which were recorded by a broadband seismic station at Nansha Island. Most of these T-waves appear to have been the source originating from earthquakes with epicentral distances greater than 600 km from this station. The T-waves in this region were identified via their apparent stable measured velocities of about 1.45 km s-1, and represent the first reported T-waves and the first T-waves observed from an island station in the South China Sea. However, during the period of analysis (November 2004 to December 2005 additional earthquakes also occurred beyond the South China Sea region, but in these instances, any associated T-waves were not picked up by the station at Nansha Island. An analysis of T-wave travel times reveals the possible locations of the P-wave to T-wave transitions at the ocean to crust interface were presumably situated near the earthquake source side. Our results indicate that the Sound Fixing and Ranging (SOFAR channel is well developed in the South China Sea region. Ultimately, developing a solid understanding of the effective transmission of T-waves through the ocean may provide new opportunities for detecting and locating small earthquakes which would be useful for both seismic monitoring and in helping to predict and reduce the damaging effects of earthquakes and tsunamis in the SouthChina Sea region.

  17. Modeled connectivity of Acropora millepora populations from reefs of the Spratly Islands and the greater South China Sea

    Science.gov (United States)

    Dorman, Jeffrey G.; Castruccio, Frederic S.; Curchitser, Enrique N.; Kleypas, Joan A.; Powell, Thomas M.

    2016-03-01

    The Spratly Island archipelago is a remote network of coral reefs and islands in the South China Sea that is a likely source of coral larvae to the greater region, but about which little is known. Using a particle-tracking model driven by oceanographic data from the Coral Triangle region, we simulated both spring and fall spawning events of Acropora millepora, a common coral species, over a 46-yr period (1960-2005). Simulated population biology of A. millepora included the acquisition and loss of competency, settlement over appropriate benthic habitat, and mortality based on experimental data. The simulations aimed to provide insights into the connectivity of reefs within the Spratly Islands, the settlement of larvae on reefs of the greater South China Sea, and the potential dispersal range of reef organisms from the Spratly Islands. Results suggest that (1) the Spratly Islands may be a significant source of A. millepora larvae for the Palawan reefs (Philippines) and some of the most isolated reefs of the South China Sea; and (2) the relatively isolated western Spratly Islands have limited source reefs supplying them with larvae and fewer of their larvae successfully settling on other reefs. Examination of particle dispersal without biology (settlement and mortality) suggests that larval connectivity is possible throughout the South China Sea and into the Coral Triangle region. Strong differences in the spring versus fall larval connectivity and dispersal highlight the need for a greater understanding of spawning dynamics of the region. This study confirms that the Spratly Islands are likely an important source of larvae for the South China Sea and Coral Triangle region.

  18. Observations of Earthquake-Generated T-Waves in the South China Sea: Possible Applications for Regional Seismic Monitoring

    Directory of Open Access Journals (Sweden)

    Bor-Shouh Huang

    2013-01-01

    Full Text Available We present a detailed study of T-waves originating from earthquakes in the South China Sea region, near the Indochina Peninsula and Luzon islands which were recorded by a broadband seismic station at Nansha Island. Most of these T-waves appear to have been the source originating from earthquakes with epicentral distances greater than 600 km from this station. The T-waves in this region were identified via their apparent stable measured velocities of about 1.45 km s-1, and represent the first reported T-waves and the first T-waves observed from an island station in the South China Sea. However, during the period of analysis (November 2004 to December 2005 additional earthquakes also occurred beyond the South China Sea region, but in these instances, any associated T-waves were not picked up by the station at Nansha Island. An analysis of T-wave travel times reveals the possible locations of the P-wave to T-wave transitions at the ocean to crust interface were presumably situated near the earthquake source side. Our results indicate that the Sound Fixing and Ranging (SOFAR channel is well developed in the South China Sea region. Ultimately, developing a solid understanding of the effective transmission of T-waves through the ocean may provide new opportunities for detecting and locating small earthquakes which would be useful for both seismic monitoring and in helping to predict and reduce the damaging effects of earthquakes and tsunamis in the South China Sea region.

  19. Timing of Holocene sea-level highstands by mass spectro-metric U-series ages of a coral reef from Leizhou Peninsula,South China Sea

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Systematic mass spectrometric 230Th ages are reported for a Porites coral reef terrace from Dengloujiao,Leizhou Peninsula, South China Sea. Seven episodes of coral growth were recognized in this terrace: 7125±96, 6764±29,5826±37, 5006±54, 2543±24, 1915±15, and 1513±22 calendar years before present (cal. aBP). 50% of the coral age population fall between 7200 and 6600 cal. aBP, marking post-glacial stabdization of global sea level. Considering the facts that ( i ) Dengloujiao reef fiat was measured at 1.6-2.5m above modern tidal datum plane; (ii) modern Porites corals in the South China Sea are living at least ~1 m below the modern tidal datum plane; (iii) the top 20-30 cm of the reef was eroded; and (iv) crustal subsidence in the region since mid-Holocene was negligible, we conclude that the above age groups record at least two major periods (7200-5000 and 2500-1500 cal. aBP) of high sea-level at least 2.9-3.8 m above the present-day level.

  20. Free polyamine content during algal bloom succession in the East China Sea in spring 2010

    Science.gov (United States)

    Liu, Yan; Zhao, Weihong; Li, Caiyan; Miao, Hui

    2017-01-01

    We measured the concentrations and distribution of major polyamines (spermine, putrescine and spermidine) in seawater during successive spring algal blooms in an area of frequent harmful blooms in the East China Sea. Spermine, putrescine, and spermidine concentrations were analyzed by high performance liquid chromatography and ranged from 1-64, 7-81, and 0-19 nmol/L. Spermine was present at the highest concentrations, followed by putrescine and spermidine. In late April, when a diatom bloom dominated by Skeletonema costatum dispersed, polyamine concentrations increased, presumably as a result of diatom decomposition. In early May, when a dinoflagellate bloom dominated by Prorocentrum donghaiense occurred, the polyamine concentration decreased from the level seen in late April. The abundant polyamines that decomposed and were released during the diatom bloom in late April may have promoted the growth of P. donghaiense, resulting in its dominance.

  1. Phytoplankton transport to coral reefs by internal solitons in the northern South China Sea

    Science.gov (United States)

    Wang, Yu-Huai

    2016-09-01

    Evidence is presented that waters containing high concentrations of chlorophyll are transported by internal waves to the fore-reef slope of Dongsha Atoll in the northern South China Sea. High vertical resolution mooring measurements of temperature, pressure, and chlorophyll fluorescence revealed that the internal soliton cores could transport chlorophyll vertically downward and increase concentrations by an order of magnitude near the seafloor, compared to background levels. The reef areas that are potentially nourished by the pulses of phytoplankton are dominated by alcyonacean soft corals, while other reef areas that are less or not at all affected by internal waves are dominated by scleractinian hard corals. This suggests that the delivery of phytoplankton by internal solitons provides a plentiful food source that benefits the growth of soft corals.

  2. Observations of upper layer turbulent mixing in the southern South China Sea

    Institute of Scientific and Technical Information of China (English)

    SHANG Xiaodong; QI Yongfeng; CHEN Guiying; LIANG Changrong

    2015-01-01

    A turbulent microstructure experiment was undertaken at a low latitude of 10°N in the South China Sea in late August 2012. The characteristics of the eddy diffusivity above 650 m were analyzed, which is one order of magnitude larger than that in the open ocean at that low latitude. Enhanced eddy diffusivities by strong shears and sharp changes in topography were observed. The strongest eddy diffusivity occurred in the mixed layer, and it reachedO(10–2 m2/s). Strong stratification in the thermocline inhibited the penetration of surface eddy diffusivities through the thermocline, where the mixing was weakest. Below the thermocline, where the background eddy diffusivity was approximatelyO(10–6 m2/s), the eddy diffusivity increased with depth, and its largest value wasO(10–3 m2/s).

  3. A New 1,4-Diazepine from South China Sea Marine Sponge Callyspongia Species

    Directory of Open Access Journals (Sweden)

    Shi-Hai Xu

    2010-02-01

    Full Text Available A new 1,4-diazepine, callysponine (1, was isolated from a South China Sea Callyspongia sp. marine sponge, together with four known proline-based diketopiperazines: cyclo-(S-Pro-R-Leu (2, cyclo-(S-Pro-R-Val (3, cyclo-(S-Pro-R-Ala (4, andcyclo-(S-Pro-R-Tyr (5. The new structure was determined on the basis of NMR and MS analysis, and the absolute stereochemistry was defined by NOESY spectroscopy and optical rotation. The structures of the known compounds were identified by comparison of their spectroscopic data with those reported in the literature. Callysponine (1 did not inhibit the growth of HepG2 (hepatoma carcinoma cell, A549 (lung carcinoma cell, and HeLa (cervical cancer cell cell lines.

  4. Mercury pollution in fish from South China Sea: levels, species-specific accumulation, and possible sources.

    Science.gov (United States)

    Liu, Jinling; Xu, Xiangrong; Yu, Shen; Cheng, Hefa; Hong, Yiguo; Feng, Xinbin

    2014-05-01

    Both total mercury (THg) and methylmercury (MeHg) levels in fish collected from South China Sea (SCS) were studied to understand Hg pollution in Chinese tropical marine ecosystems. The average THg concentrations in fish species ranged from 39.6 μg/kg for rabbitfish (Siganus fuscessens) to 417 μg/kg for thornfish (Terapon jarbua), while those of MeHg varied from 13 μg/kg (rabbitfish) to 176 μg/kg (thornfish). The median values of MeHg/THg ratios in different fish species ranged from 36 to 85%. Significant inter-species differences of THg and MeHg in fish were observed due to feeding habits and fish sizes. Overall, carnivorous fish had higher levels of THg, MeHg and MeHg/THg ratios than omnivorous and herbivorous fish. High Hg levels in fish of the SCS were probably related to Hg input from atmospheric deposition and anthropogenic activities.

  5. Carbamate derivatives and sesquiterpenoids from the South China Sea gorgonian Melitodes squamata

    Directory of Open Access Journals (Sweden)

    Li-Si Huang

    2012-01-01

    Full Text Available Five carbamate derivatives, obtucarbamates C and D (1, 2, dimethyl ((carbonylbis(azanediylbis(2-methyl-5,1-phenylenedicarbamate (3, obtucarbamates A and B (4, 5, and four aromadendrane-type sesquiterpenoids, (+-4β-N-methenetauryl-10β-methoxy-1β,5α,6β,7β-aromadendrane (6, (−-4β-N-methenetauryl-10β-methoxy-1β,5β,6α,7α-aromadendrane (7, (−-4α,10β-aromadendranediol (8, (+-4β,10β-aromadendranediol (9 were obtained from the South China Sea gorgonian coral Melitodes squamata Nutting. Compounds 1, 2, 6, and 7 were new, and their structures were established by spectroscopic analyses. Compounds 6 and 7 contained a taurine group that was rarely found in marine natural compounds, and 7 showed moderate antibacterial activity. The possible biosynthesis routes of 1–5 were conjectured.

  6. Prediction of Scour Depth around Offshore Pipelines in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yonggang Cao; Yuchuan Bai; Junqin Wang; Shizhi Liao; Dong Xu

    2015-01-01

    Scour depth prediction of offshore pipelines is of great significance to the design and construction of the submarine pipeline projects. In this paper, based on the CFD software package FLUENT and User Defined Function (UDF), an Eulerian two-phase model, which includes an Euler-Euler coupled model for water and sediment phases, and a turbulent model for the fluid phase, is adopted to predict the scour depth around pipelines. The model is verified by observation data obtained from laboratory experiments. On the basis of the simulations, the factors affecting the scour depth, including the effects of incipient velocity, pipe diameter and sediment particle size and so on, were investigated. Meanwhile, according to formulas of incipient velocity of various sediments, approximate calculation on theoretical scour depths is developed for pipelines of seven stations in the South China Sea, where engineering application information is available.

  7. Prediction of scour depth around offshore pipelines in the South China Sea

    Science.gov (United States)

    Cao, Yonggang; Bai, Yuchuan; Wang, Junqin; Liao, Shizhi; Xu, Dong

    2015-03-01

    Scour depth prediction of offshore pipelines is of great significance to the design and construction of the submarine pipeline projects. In this paper, based on the CFD software package FLUENT and User Defined Function (UDF), an Eulerian two-phase model, which includes an Euler-Euler coupled model for water and sediment phases, and a turbulent model for the fluid phase, is adopted to predict the scour depth around pipelines. The model is verified by observation data obtained from laboratory experiments. On the basis of the simulations, the factors affecting the scour depth, including the effects of incipient velocity, pipe diameter and sediment particle size and so on, were investigated. Meanwhile, according to formulas of incipient velocity of various sediments, approximate calculation on theoretical scour depths is developed for pipelines of seven stations in the South China Sea, where engineering application information is available.

  8. Experience on offshore cathodic protection retrofitting in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Guo Jinwen; L. Patterson; A. Amorelli; D. Condanni; B. Bazzoni

    2003-01-01

    Platforms Ⅰ and Ⅱ are steel structures located in offshore areas southeast of the Zhujiang(Pearl) River Delta, the northern South China Sea, in about 110 m water depth. The jackets, with aluminum sacrificial anodes for cathodic protection (CP) of the immersed zone, were launched in March 1995. In May 1996 a CP survey showed that, after almost one year of service, a low polarization level had been achieved and some extended unprotected zones existed, mainly in the deepest part of the Platform Ⅱ. Further to this, a joint activity was decided in order to assess the need of a possible retrofitting of the CP systems. The results of the activity carried out are dealt with, including technical and economical comparisons amongst several retrofitting options, both with sacrificial anodes and with impressed current systems. The adopted solution is illustrated and data are reported on the level of protection presently achieved.

  9. Evaluation of Petroleum System in Xihu Depression, East China Sea Shelf Basin

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    According to the theory of petroleum system and the characteristics of petroleum geology, the Xihu depression in the East China Sea shelf basin is divided into four petroleum systems: the Pinghu Formation as source rock and the Huagang Formation as reservoir rock, the Huagang Formation as source rock and reservoir rock, the Paleocene as source rock and the burial-hill as reservoir rock, and the Miocene as source rock and reservoir rock. The system with the Pinghu Formation as source rock and the Huagang Formation as reservoir rock is the most important one in the depression, which has high hydrocarbon generation and accumulation efficiency and is the most important object to hydrocarbon exploration at present.

  10. Pleistocene precession forcing of the upper ocean structure variations of the southern South China Sea

    Institute of Scientific and Technical Information of China (English)

    TIAN Jun; WANG Pinxian; CHENG Xinrong

    2004-01-01

    The precession plays a dominant role in driving the tropical monsoon variations. Our high resolution, millennial scale marine isotope records from ODP Site 1143 in the southern South China Sea (SCS) present the detailed history of the upper ocean structure variations over the past 1.56 Ma on glacial/interglacial timescale. The cross spectral analyses between the Earth's orbital variations and the isotopic differences reveal a high coherency between the East-Asian-monsoon-related thermocline and nutricline variations of the SCS and the precession. The variations of monsoon-related isotopic difference between species also demonstrate periodicities of 11-, 12- and 14- thousand years near semi-precession which originates in the tropics, highlighting the importance of the precession in driving the east Asian monsoon changes.

  11. SHORT TIME DYNAMICS OF CILIATE ABUNDANCE IN THE BOHAI SEA (CHINA)

    Institute of Scientific and Technical Information of China (English)

    张武昌; 王荣

    2002-01-01

    The ciliate community in the Bohai Sea (China) was studied from23 September to 7 October 1998. A hurricane struck the study area between the two grid station investigations, which were six days apart. Six tintinnid species(Favella panamensis, Leptotintinnus nordqvisti, Tintinnopsis butschlii, T. karajacensis, T. Radix and Wangiella dicollaria) were identified. Total cililate abundance in the surface layer ranged from 20 to 770 ind/l. In the first grid investigation, Tintinnopsis karajacensis dominated in the warm, low salinity waters at the Huanghe River mouth. Aloricate ciliate sp.1 dominated in the cold, high salinity waters in the northwest of the study area and the Bohai Strait. In the second grid investigation, T. Karajacensis almost disappeared. The abundance of aloricate ciliate sp.1 decreased drastically. The aloricate ciliate sp.2 dominatedat the Bohai Strait. The change of ciliate abundance may be due to the disturbance of hurricane.``

  12. Statistical Analysis of Tropical Disturbances over the South China Sea During 1997-2006

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; LAU Kai Hon

    2011-01-01

    Tropical disturbances over the South China Sea (SCS) during the period of 1997-2006 are analyzed using the Tropical Storm and Hurricane WX products. A total of 158 tropical disturbances were formed over the SCS from 1997 to 2006, with 54 developing tropical disturbances which developed into tropical depressions and 104 non-developing tropical disturbances which never developed into tropical depressions. The development rate of tropical disturbances into tropical depressions was 34.18% in these ten years. During the period of this study, total annual numbers of tropical disturbances and developing tropical disturbances over the SCS had significant decreasing trends; however, the development rate of tropical disturbances had an insignificant increasing trend.

  13. SOME FEATURES OF RING 94S— A KUROSHIO DETACHED EDDY IN THE SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Distributions of current and chemical tracers along two hydrographic sections across Ring 94S, a Kuroshio detached eddy in the South China Sea, were studied. Results suggest that while currents on its offshore side maintained quasi-geostophic, a balance was no reach on its onshore side. It is then suggested that interaction Ring 94S with the slope might play an important role that could break down the quasi-geostrophic balance and caused deformation of the current field. 18 O distribution supports previous discussion that water mass inside the ring is of Kuroshio origin. Distributions of chemical tracer reveal strong “stirring effect” at the edge of Ring 94S, which may play an important role in vertical exchange across the thermocline.

  14. A Study on Bottom Friction Coefficient in the Bohai, Yellow, and East China Sea

    Directory of Open Access Journals (Sweden)

    Daosheng Wang

    2014-01-01

    Full Text Available The adjoint tidal model based on the theory of inverse problem has been applied to investigate the effect of bottom friction coefficient (BFC on the tidal simulation. Using different schemes of BFC containing the constant, different constant in different subdomain, depth-dependent form, and spatial distribution obtained from data assimilation, the M2 constituent in the Bohai, Yellow, and East China Sea (BYECS is simulated by assimilating TOPEX/Poseidon altimeter data, respectively. The simulated result with spatially varying BFC obtained from data assimilation is better than others. Results and analysis of BFC in BYECS indicate that spatially varying BFC obtained from data assimilation is the best fitted one; meanwhile it could improve the accuracy in the simulation of M2 constituent. Through the analysis of the best fitted one, new empirical formulas of BFC in BYECS are developed with which the commendable simulated results of M2 constituent in BYECS are obtained.

  15. Evidence for thermocline ven-tilation in the South China Sea in winter

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on analysis of Levitus data in the South China Sea (SCS), this note addresses the seasonal feature of the mixed layer and thermocline in the northern SCS in winter, and demonstrates thermocline ventilation during the winter period. The ventilated thermocline is isopycnic layers between sigma 22.0 and 23.5, the other layers beneath is not ventilated yet. The process of thermocline ventilation is ac-companied by detrainment water from the mixed layer into the thermocline at the outcropping line and moves to the south. Forced by subduction, the seasonal southward propagating signal also appears in the unventilated thermo-cline. The horizontal component of the signal propagates along the isoline of potential vorticity (PV), in other words, moves around a seasonal PV pool.

  16. Barrier layer in the northeastern South China Sea and its formation mechanism

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Robust evidence for the barrier layer (BL) in the northeastern South China Sea (SCS) (16°-25°N, 112°-124°E) is presented. The occurrence rate of the BL peaks in the autumn (45.7%) and then the summer (31.1%) and the spring (23.3%), sequently. It is estimated that the annual occurrence rate of the BL reaches about 40.0% in the central northeastern SCS (18°-22°N, 112°-120°E) and the Luzon Strait. Stratification-formed (Rain-formed) mechanism is the major factor responsible for the occurrence of the BL in the northeastern SCS in the spring (the summer and autumn), respectively. The rainfall observation from TRMM provides reliable evidence for the latter.

  17. MARINE BIOFOULING IN OFFSHORE AREAS SOUTH OF HAINAN ISLAND, NORTHERN SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This study on the characteristics of fouling communities in offshore areas south of Hainan Island, northern South China Sea, was conducted at four sites there. At each station, test panels on iron frames were hung on the mooring system at different depths. Data on biofouling were mainly obtained by examination of the fouled test panels. Organisms attached to buoys and anchors were scraped off and examined also. The results showed that the thickness and biomass of marine growth that increased the fluid loading on offshore installations depended to a large extent on hard foulers, i.e. mollusks and acorn barnacles. Algae, hydroids, stalked barnacles and bryozoans were important fouling species. The occurrence frequency and biomass of acorn barnacles decreased with increasing distance from the shore.

  18. Some characteristics and evolution of the internal soliton in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the observational data of an internal soliton in the northern South China Sea (SCS) on June 14, 1998, the possible source of the internal soliton is analyzed, and some of its characteristic parameters such as phase speed, wave length, etc. are computed. Based on the analyses of the vertical modes of the internal wave, the characteristics of the wave-induced current during the propagation of the internal soliton are studied. A regularized long wave (RLW) equation numerical model considering effects of multi-fac- tors is employed, and the observed environmental parameters are used as the initial conditions to simulate the propagation and evolution of the internal soliton in the continental shelf of the northern SCS.

  19. Establishment and adjustment of monsoon-driven circulation in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    王东晓; 王卫强; 施平; 郭佩芳; 甘子钧

    2003-01-01

    The mechanisms of establishment and adjustment of the basin-scale circulation in the South China Sea (SCS) during the monsoon-forced spin-up are investigated using a high resolution circulation model in this paper. The process, in which the upper layer in the SCS evolved from the motionless state to the one when the basin-scale circulation initially established, was described, and the participation of various Kelvin and Rossby waves and their traveling time scales in different stages was revealed. It shows that the coastal trapped Kelvin waves and the westward propagating Rossby waves play important roles in the adjustment of the basin-scale circulation. Furthermore, the characteristic timescale of establishment for the basin-scale circulation in the upper layer of the SCS was obtained.

  20. Seismic, satellite, and site observations of internal solitary waves in the NE South China Sea.

    Science.gov (United States)

    Tang, Qunshu; Wang, Caixia; Wang, Dongxiao; Pawlowicz, Rich

    2014-06-20

    Internal solitary waves (ISWs) in the NE South China Sea (SCS) are tidally generated at the Luzon Strait. Their propagation, evolution, and dissipation processes involve numerous issues still poorly understood. Here, a novel method of seismic oceanography capable of capturing oceanic finescale structures is used to study ISWs in the slope region of the NE SCS. Near-simultaneous observations of two ISWs were acquired using seismic and satellite imaging, and water column measurements. The vertical and horizontal length scales of the seismic observed ISWs are around 50 m and 1-2 km, respectively. Wave phase speeds calculated from seismic observations, satellite images, and water column data are consistent with each other. Observed waveforms and vertical velocities also correspond well with those estimated using KdV theory. These results suggest that the seismic method, a new option to oceanographers, can be further applied to resolve other important issues related to ISWs.

  1. Responses of phytoplankton community to the input of different aerosols in the East China Sea

    Science.gov (United States)

    Meng, X.; Chen, Y.; Wang, B.; Ma, Q. W.; Wang, F. J.

    2016-07-01

    Atmospheric deposition can affect marine phytoplankton by supplying macronutrients and trace elements. We conducted mesocosm experiments by adding aerosols with different composition (dominated by mineral dust, biomass burning and high Cu, and secondary aerosol, respectively) to the surface seawater of the East China Sea. Chlorophyll a concentrations were found to be the highest and lowest after adding aerosols containing the highest Fe and dissolved inorganic nitrogen (DIN), respectively. The relative abundance of Haptophyceae increased significantly after adding mineral dust, whereas diatom, Dinophyceae and Cryptophyceae reached the maximum accompanied with the highest DIN. Our results suggest that Fe may be more important than DIN in promoting primary productivity in the sampled seawater. The input of mineral dust and anthropogenic aerosols may result in distinct changes of phytoplankton community structure.

  2. Dynamical mechanism of the stratospheric quasibiennial oscillation impact on the South China Sea Summer Monsoon

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The National Center for the Atmospheric Research (NCAR) middle atmospheric model is used to study the effects of the quasi-biennial oscillation in the stratosphere (QBO) on the tropopause and upper troposphere, and the relationship between the QBO and South China Sea Summer Monsoon (SCSSM) is explored through NCEP (the National Centers for Environmental Prediction)/NCAR, ECMWF (European Centre for Medium-Range Weather Forecasts) monthly mean wind data and in situ sounding data. The simulations show that the QBO-induced residual circulations propagate downwards, and affect the tropopause and upper troposphere during the periods of mid-late QBO phase and phase transition. Meanwhile, diagnostic analyses indicate that anomalous circulation similar to SCSSM circulation is generated to strengthen the SCSSM during the easterly phase and anomalous Hadley-like circulation weakens the SCSSM during the westerly. Though the QBO has effects on the SCSSM by meridional circulation, it is not a sole mechanism on the SCSSM TBO mode.

  3. Lead in the western South China Sea: Evidence of atmospheric deposition and upwelling

    Science.gov (United States)

    Chen, Mengli; Goodkin, Nathalie F.; Boyle, Edward A.; Switzer, Adam D.; Bolton, Annette

    2016-05-01

    In recent decades, rapid industrial developments have increased lead (Pb) inputs to the South China Sea. To quantify the increasing variability, we investigated 170 years of skeletal Pb and Pb isotopes from an offshore, central Vietnamese coral. The Pb/Ca in the coral was 10-16 nmol/mol before the mid-1950s and increased to more than 30 nmol/mol by 2000. While the regional phaseout of leaded petrol commenced in 2000, coral Pb/Ca continued increasing until 2004, possibly due to regional upwelling and the transport of previously emitted Pb from tropical Pacific waters. The 206Pb/207Pb ratio in the coral was 1.191-1.195 before mid-1950s, suggesting natural sources. Since then, the ratio decreased, reaching ~1.165 in 2004. Lead isotopes show high linearity between natural and Chinese emitted Pb, with the latter contributing ~40%~60% of the skeletal Pb after 2000.

  4. The rift architecture and extensional tectonics of the South China Sea

    Science.gov (United States)

    Cameselle, Alejandra L.; Ranero, César R.; Barckhausen, Udo; Franke, Dieter

    2016-04-01

    Non-volcanic rifted continental margins are classically described as the product of lithospheric stretching and breakup leading to mantle exhumation, and subsequent seafloor spreading. However, recent studies question this model and indicate a wider range of structural evolutions, that challenge the existing model (e.g. Australia-Antarctic Rift System (Direen et al. 2007, 2011); the Tyrrhenian basin (Prada et al., 2014) or the South China Sea (Cameselle et al. 2015)). Rifting in the South China Sea developed from a series of extensional events, from early Eocene to Late Oligocene, resulting in a V-shape oceanic basin affected by the occurrence of several spreading centers, ridges, transform faults and post-spreading volcanism. In recent years, this marginal basin - the largest in East Asia - has increasingly become one of the key sites for the study of rifting and continental break-up. Its relative small size - compared to many classic, Atlantic-type continental margin settings - allows to easily match conjugated rifted margins and its relative youth promotes the preservation of its original nature. To examine the rifting evolution of the South China Sea, we have reprocessed with modern algorithms multichannel seismic profiles acquired during Sonne49 and BGR84 cruises across the three major subbasins: NW, SW and East subbasins. State-of-the-art of processing techniques have been used to increase the signal to noise ratio, including Tau-P and Wiener predictive deconvolution, multiple attenuation by both radon filtering and wave-equation-based surface-related multiple elimination (SRME) and time migration. To complement seismic interpretation, available vintage multichannel seismic data have been reprocessed with a post-stack flow, including Wiener deconvolution, FK-filtering, space and time variant band-pass filter and time migration. The improving quality of the seismic images shows a range of features including post-rift and syn-rift sediments, the structure of

  5. Phylogenetic relationships of South China Sea snappers (genus Lutjanus; family Lutjanidae) based on mitochondrial DNA sequences.

    Science.gov (United States)

    Guo, Yusong; Wang, Zhongduo; Liu, Chuwu; Liu, Li; Liu, Yun

    2007-01-01

    Phylogenetic relationships of intra- and interspecies were elucidated based on complete cytochrome b (cyt b) and cytochrome c oxidase subunit II (COII) gene sequences from 12 recognized species of genus Lutjanus Bloch in the South China Sea (SCS). Using the combined data set of consensus cyt b and COII gene sequences, interspecific relationships for all 12 recognized species in SCS were consistent with Allen's morphology-based identifications, with strong correlation between the molecular and morphological characteristics. Monophyly of eight species (L. malabaricus, L. russellii, L. stellatus, L. bohar, L. johnii, L. sebae, L. fulvus, and L. fulviflamma) was strongly supported; however, the pairs L. vitta/L. ophuysenii and L. erythropterus/L. argentimaculatus were more similar than expected We inferred that L. malabaricus exists in SCS, and the introgression caused by hybridization is the reason for the unexpectedly high homogeneity.

  6. Antifouling steroids from the South China Sea gorgonian coral Subergorgia suberosa.

    Science.gov (United States)

    Zhang, Jun; Liang, Yan; Wang, Kai-Ling; Liao, Xiao-Jian; Deng, Zhou; Xu, Shi-Hai

    2014-01-01

    Two new unusual cholestane derivatives, pentacyclic steroid 16,22-epoxy-20β,23S-dihydroxycholest-1-ene-3-one (1) and 20β,23S-dihydroxycholest-1-ene-3,22-dione (2), along with two new pregnane derivatives, 15β,17α-dihydroxypregna-4,6-diene-3,20-dione (3) and 11α-hydroxypregna-4-ene-3,6,20-trione (4), were isolated from the South China Sea gorgonian coral Subergorgia suberosa. Their structures were established based on the extensive analyses of 2D NMR, IR, and HRMS. Antifouling tests against Balanus amphitrite larvae settlement indicated that 1 and 2 exhibited inhibitory effect with EC50 values of 5.3, and 14.5 μg/mL, respectively.

  7. Effect of oceanic current on typhoon-wave modeling in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    Cui Hong; He Hai-Lun; Liu Xiao-Hui; Li Yi

    2012-01-01

    We use the WAVEWATCH-Ⅲ model to quantify the effect of oceanic current on typhoon-wave modeling in the East-China-Sea (ECS).Typhoons Jelawat and Saomai in the autumn of 2000 are hindcasted.The oceanic currents in the ECS are mainly constituted of Kuroshio and typhoon-generated currents.The results show distinguishable differences in wave height and wave period under the typhoon conditions.The oceanic current causes the maximum differences,of up to a 0.5 m significant wave height and a 1 s mean wave period.Comparisons between typhoons Jelawat and Saomai show the dependence of the current effect on the typhoon characteristics.

  8. Geophysical Indicators of Gas Hydrate in the Northern Continental Margin, South China Sea

    Directory of Open Access Journals (Sweden)

    Xiujuan Wang

    2011-01-01

    Full Text Available Gas hydrate drilling results show that gas hydrate has a close relationship with strong bottom-simulating reflectors (BSRs identified from seismic data in the Baiyun sag, South China Sea. The BSRs observed on seismic profiles at the crests of submarine canyons indicate the likely existence of gas hydrate. We calculate the acoustic impedance using constrained sparse spike inversion (CSSI, the interval velocity, and the seismic reflection characteristics such as reflection strength, instantaneous frequency, blanking, and enhanced reflection to demonstrate the presence of gas hydrate. Higher acoustic impedance and P-wave velocity were identified above the BSR. A remarkable low impedance, low frequency, and acoustic blanking indicated the presence of gas below gas hydrate stability zone. The occurrence of gas hydrate at the crests of canyons suggests that the abundance of gas hydrate in Baiyun sag may be due to the migrating submarine canyons providing the structural reliefs and the topographic ridges.

  9. Antifouling briarane type diterpenoids from South China Sea gorgonians Dichotella gemmacea

    KAUST Repository

    Sun, Jian Fan

    2013-01-01

    Our continued investigation on the South China Sea gorgonian Dichotella gemmacea led to the isolation of 16 new briarane-type diterpenoids, dichotellides F-U (1-16), along with 18 known analogues (17-34). Their structures were determined by MS, 1D and 2D NMR spectra analyses and by comparison with those reported in literature. The absolute configuration of 15 was confirmed by single-crystal X-ray diffraction data. The antifouling test showed that compounds 3, 4, 6-11, 16, and 23 had potent antifouling activities at nontoxic concentrations with EC50 values of 4.1, 1.82, 6.3, 7.6, 4.6, 1.2, 5.6, 0.79, 2.0, and 0.2 μg/mL, respectively. © 2012 Elsevier Ltd. All rights reserved.

  10. NUMERICAL STUDY ON THE FORMATION OF THE SOUTH CHINA SEA WARM CURRENT Ⅱ. BAROCLINIC CASE

    Institute of Scientific and Technical Information of China (English)

    王凯; 方国洪; 施心慧

    2001-01-01

    In this part, Levitus' climatological temperature and salinity are incorporated in the numerical model developed in Part I. Diagnostic and prognostic experiment on the thermohaline circulation were conducted. The smooth Levitus' data do not include any information on the South China Sea Warm Current (SCSWC), so it is not in the model-produced diagnostic thermohaline circulation. Although the SCSWC does not appear in the wind-driven circulation in the barotropic case, it appears in the prognostic wind-driven circulation in the baroclinic case. This implies that the differing circulation pat-terns between barotropic case and bareclinic case are due to the stratification. The prognostic thermohaline circulation with wind stress and inflow/outflow transports at open boundaries are also discussed. Coupling of density and dynamic forces makes the circulation pattern more complicated, Even though the stratification is not always a direct cause of the formation of the SCSWC, it is at least an indirect cause.

  11. NUMERICAL STUDY ON THE FORMATION OF THE SOUTH CHINA SEA WARM CURRENT II. BAROCLINIC CASE

    Institute of Scientific and Technical Information of China (English)

    王凯; 方国洪; 施心慧

    2001-01-01

    In this part, Levitus' climatological temperature and salinity are incorporated in the numerical model developed in Part I. Diagnostic and prognostic experiment on the thermohaline circulation were conducted. The smooth Levitus' data do not include any information on the South China Sea Warm Current (SCSWC), so it is not in the model-produced diagnostic thermohaline circulation. Although the SCSWC does not appear in the wind-driven circulation in the barotropic case, it appears in the prognostic wind-driven circulation in the baroclinic case. This implies that the differing circulation patterns between barotropic case and baroclinic case are due to the stratification. The prognostic thermohaline circulation with wind stress and inflow/outflow transports at open boundaries are also discussed. Coupling of density and dynamic forces makes the circulation pattern more complicated. Even though the stratification is not always a direct cause of the formation of the SCSWC, it is at least an indirect cause.``

  12. A new diketopiperazine from South China Sea marine sponge Callyspongia sp.

    Science.gov (United States)

    Chen, Yinning; Peng, Yan; Gao, Chenghai; Huang, Riming

    2014-01-01

    Further chemical investigation on the marine sponge Callyspongia sp. collected from South China Sea led to the isolation of a new diketopiperazine, named callysponine A (1), as well as four known diketopiperazines, namely cyclo-(Gly-Pro) (2), cyclo-(Thr-Pro) (3), cyclo-(Ile-Pro) (4) and cyclo-(Pro-Pro) (5). The new structure was determined on the basis of NMR and MS analysis, and the absolute stereochemistry was defined by analysis of the coupling constants and optical rotation. The structures of the known compounds were identified by comparing their spectroscopic data with those reported in the literature. Compounds 1-5 did not inhibit the growth of HepG2 (hepatoma carcinoma cell), A549 (lung carcinoma cell) and HeLa (cervical cancer cell) cell lines.

  13. Chemical Constituents of the Sponge Mycale Sp ecies from South China Sea

    Directory of Open Access Journals (Sweden)

    Xuefeng Zhou

    2013-03-01

    Full Text Available Chemical investigation of the sponge Mycale species from the South China Sea afforded eleven known compounds, henicosanoic acid methyl ester (1 , hexadecyl ethers of glycerol ( 2 , N-docosanoyl-D-erythro-(2S,3R-16-methyl-heptadecasphing-4(E-enine ( 3 , dibutyl phthalate ( 4 , cholesterol ( 5 , 5α,8α-epidioxycholest-6,22-dien-3β-ol ( 6 , 5-hexadecyl-pyrrole-2-carboxaldehyde ( 7 , benzoic acid ( 8 , 4-hydroxybenzoic acid ( 9 , thymine ( 10 ,and uracil ( 11 . Compounds 1 – 4 , 6 – 9 were obtained from the sponge of the genus Mycale for the first time, and 4 and 6 showed toxicity in the brine shrimp lethality test with the LD 50 values at 2.9 μg/mL and 4. 7 μg/mL, respectively .

  14. Simulation of barotropic and baroclinic tides in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Ziku; LU Xianqing; TIAN Jiwei

    2005-01-01

    The four leading tidal constituents M2, S2, K1 and O1 in the South China Sea are simulated by using POM. The model is forced with tide-generating potential and four leading tidal constituents at the open boundary. In order to simulate more exactly, TOPEX/Poseidon altimeter data are assimilated into the model and the open boundary is optimized. The computed co-tidal charts for M2 and K1 constituents are generally consistent with previous results in this region. The numerical simulation shows that energetic internal tides are generated over the bottom topography such as the Dongsha Islands, the Xisha Islands, the Zhongsha Islands, the Nansha Islands and the Luzon Strait.

  15. Experiments in optimizing simulations of the subsurface chlorophyll maximum in the South China Sea

    Science.gov (United States)

    Wang, Siying; Li, Shiyu; Hu, Jiatang; Geng, Bingxu

    2016-04-01

    The subsurface chlorophyll maximum (SCM) is widespread in the oligotrophic ocean and significantly contributes to primary production. One reason for the SCM formation is believed to be the rapid export of phytoplankton from surface layers, which might be caused by aggregation, faster sinking rates under nutrient limitation, or the formation of a resting stage. In this study, these three processes were included in a biological model to investigate their contributions to subsurface chlorophyll. To further identify their individual effects on SCM formation, four modeling experiments were carried out. Three used a simple approach with either (a) density-dependent aggregation, (b) accelerated sinking rate of phytoplankton, or (c) a resting stage. The other experiment combined all three approaches (a-c). A set of observations in the South China Sea was used to optimize the four experiments and compare their abilities to replicate observed values. The results of the experiments with the resting stage showed the best fit to the field observations. All experiments were able to capture major features of the chlorophyll field (e.g. surface bloom and SCM). The experiment with accelerated sinking rate failed to reproduce the observed profile of particulate organic carbon. The experiment with only aggregation predicted lower chlorophyll concentrations in summer than those measured in the field, while experiments with the resting stage reproduced more accurate chlorophyll concentrations. Formulas including the resting stage more successfully captured the timing of phytoplankton export than did those including aggregation and accelerated sinking rate. The processes of aggregation and accelerated sinking rate made small contributions to the SCM formation in the last experiment. Overall, these results show that introducing the resting stage improves SCM simulations of the South China Sea. The results of the experiment with only the resting stage showed that the resting cells shift

  16. Ra-226 and Pb-210/Ra-226 Activity Ratio in the Northern South China Sea

    Science.gov (United States)

    Chi-Ju, L.; Yu-Chia, C.; Tsung-En, W.

    2004-05-01

    The surface water distributions and vertical profiles of Ra-226 in the northern South China Sea (SCS) have been measured. Surface water Ra-226 varies between 10 and 16 dpm/100 kg with higher values at stations adjacent to the landmass. Each Ra-226 profile shows an increase from the surface toward the bottom. Above 1000m depth Ra-226 is systematically about 5 dpm/100kg higher in the northern South China Sea than in the western North Pacific. This difference may be attributed to a strong Ra-226 source from the shelf and slope area of the SCS. Below this depth Ra-226 displays large variation within some of the profiles with lower limits being comparable to the activities of the western North Pacific but higher limits being systematically about 5 dpm/100kg higher. These high Ra-226 activities may reflect effects of the longer isolation time for the deep water in the SCS basin and strong Ra input from the underlying sediments. The Pb-210/Ra-226 activity ratio ranges between 1.4 and 2.7 in the surface water with higher activity ratio at the station closer to the Luzon Strait. The Pb-210 in excess over Ra-226 in the surface water due to atmospheric input may penetrate to a depth of about 200 to 500m. Below this depth, Pb-210/Ra-226 activity ratio ranges between 0.5 and 0.7 because Pb-210 is scavenged by settling particulates. Box model calculations within a mixed layer of 50m in the area yield a mean residence time of about 1 yr for Pb-210 if an atmospheric Pb-210 flux of 1 dpm/cm2/y is adopted. The activity ratio of about 0.5 to 0.7 in the deep water corresponds to a Pb-210 mean residence time of about 30 to 70 yrs with respect to particulate scavenging.

  17. Observed wintertime tidal and subtidal currents over the continental shelf in the northern South China Sea

    Science.gov (United States)

    Li, Ruixiang; Chen, Changsheng; Xia, Huayong; Beardsley, Robert C.; Shi, Maochong; Lai, Zhigang; Lin, Huichan; Feng, Yanqing; Liu, Changjian; Xu, Qichun; Ding, Yang; Zhang, Yu

    2014-08-01

    Synthesis analyses were performed to examine characteristics of tidal and subtidal currents at eight mooring sites deployed over the northern South China Sea (NSCS) continental shelf in the 2006-2007 and 2009-2010 winters. Rotary spectra and harmonic analysis results showed that observed tidal currents in the NSCS were dominated by baroclinic diurnal tides with phases varying both vertically and horizontally. This feature was supported by the CC-FVCOM results, which demonstrated that the diurnal tidal flow over this shelf was characterized by baroclinic Kelvin waves with vertical phase differences varying in different flow zones. The northeasterly wind-induced southwestward flow prevailed over the NSCS shelf during winter, with episodic appearances of mesoscale eddies and a bottom-intensified buoyancy-driven slope water intrusion. The moored current records captured a warm-core anticyclonic eddy, which originated from the southwestern coast of Taiwan and propagated southwestward along the slope consistent with a combination of β-plane and topographic Rossby waves. The eddy was surface-intensified with a swirl speed of >50 cm/s and a vertical scale of ˜400 m. In absence of eddies and onshore deep slope water intrusion, the observed southwestward flow was highly coherent with the northeasterly wind stress. Observations did not support the existence of the permanent wintertime South China Sea Warm Current (SCSWC). The definition of SCSWC, which was based mainly on thermal wind calculations with assumed level of no motion at the bottom, needs to be interpreted with caution since the observed circulation over the NSCS shelf in winter included both barotropic and baroclinic components.

  18. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas), Taiwan, in the South China Sea

    Science.gov (United States)

    Tang, Kuo-Hsun; Hsu, Chia-Min; Gan, Chai-Hsia; Kuo, Chao-Yang; Soong, Keryea; Chou, Hong-Nong

    2017-01-01

    Dongsha Atoll (also known as Pratas) in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park’s scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1–5 m; and deep, 10–15 m) in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP) of 28S nuclear large subunit ribosomal DNA (nlsrDNA). Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5%) was higher compared to deep (14.9%). Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE) of internal transcribed spacer 2 (ITS2) in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population. PMID:28133566

  19. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    Directory of Open Access Journals (Sweden)

    X. Y. Guo

    2013-04-01

    Full Text Available Based on absolute geostrophic velocity calculated from repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured at the same sections from 1964 to 2011, we obtained temporally averaged nitrate flux (the product of velocity and nitrate concentration and nitrate transport (integration of flux over a section through 4 sections along the Kuroshio path from the East China Sea (sections PN and TK to south of Japan (sections ASUKA and 137E. In addition, we examined section OK east of the Ryukyu Islands in order to understand the contribution of Ryukyu Current to the Kuroshio nutrient transport south of Japan. The mean nitrate flux shows a subsurface maximum core with a value of 10, 10, 11, 11, and 6 mol m–2 s–1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The depth of subsurface maximum core changes among five sections and is approximately 400, 500, 500, 400, and 800 m at sections PN, TK, ASUKA, 137E, and OK respectively. The mean downstream nitrate transport is 199.3, 176.3, 909.2, 1385.5, and 341.2 kmol m–1 at sections PN, TK, ASUKA, 137E, and OK respectively. The nutrient transports at these sections suggest the presence of Kuroshio nutrient stream from its upstream region to downstream. The deep current structure of Ryukyu Current (section OK makes it contribute more nitrate transport than the Kuroshio in the East China Sea (section TK to the Kuroshio south of Japan. In addition, the positive difference between the downstream nitrate transport through section ASUKA and the sum of nitrate transports through sections TK and OK, as well as the positive difference of downstream nitrate transport between sections 137E and ASUKA, suggest that the Kuroshio recirculation significantly intensifies the downstream (eastward nitrate transport by the Kuroshio.

  20. Permo-Carboniferous Sequence Stratigraphy and Sea Level Changes in North China Platform

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Through a sequence stratigraphic research on the Permo-Carboniferous in North China, it is suggested that the boundary of the Carboniferous and the Permian may be better moved down to the bottom of the main workable coalbed which is overlain by the limestones containing Pseudoschwagerina zone. This study mainly deals with the Upper Carboniferous, the Lower Permian and the lower part of the Middle Permian coal-bearing strata, which are 150-180 m thick totally and can be divided into 2 mesosequences, including 6 sequence sets and 19 sequences. The lithostratigraphic units are diachronous in North China. The upper two limestones of the Taiyuan Formation in the central part of the study area may be correlated with the bottom two limestones of the lower Taiyuan Formation in the southern part. The Shanxi Formation in the central and northern parts may be correlated with most of the Taiyuan Formation in the southern part. The Xiashihezi Formation in the northern part may be correlated with the upper part of Shanxi Formation in the central and southern parts. The Shangshihezi Formation in the northern part may be correlated with the Xiashihezi Formation in the southern part. The paleogeographical maps are compiled in a chrono-stratigraphic framework. From the Late Carboniferous to the Early Permian, 3 cycles of sea level change and transgression-regression occurred, and the major transgression took place in the Asselian. In the Late Carboniferous, the direction of transgression was from the east to the west, and in the Early Permian it was from the southeast and the southwest to the north. Three workable coalbed groups were formed in Asselian, early Sakmarian and late Sakmarian respectively. The TST coals developed under the bottom of the Asselian limestones are the best coals for coalbed meathane extracting. The Sakmarian coal beds were formed in HST. The coal beds of Lower Permian distribute southward along with the relative sea level falls and sediment progradation.

  1. Variation in downwelling diffuse attenuation coefficient in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The diffuse attenuation coefficient for downwelling irradiance (Kd(λ)) is an important parameter for ocean studies. Based on the optical profile data measured during three cruises in the northern South China Sea in autumn from 2003 to 2005, variations in the Kd(λ) spectra were analyzed. The variability of Kd(λ) shows much distinct features in both magnitude and spectra pattern, it is much higher in coastal waters than that of open oceanic waters; and the blue-to-green (443/555) ratio of Kd(λ) tends to increase with chlorophyll a concentration ([Chl-a]) from open ocean to coastal waters. These characteristics can be explained most by the increase of aw+p(443)/aw+p(555) with [Chl-a]. In short waveband, the relation between Kd(λ)-Kw(λ) and [Chl-a] can be well described by a power law function, indicating the large contribution of phytoplankton to the variations in Kd(λ). As for the spectral model of the diffuse attenuation coefficient, there are good linear relationships between Kd(490) and Kd(λ) in other wavelengths with own slope and intercept of a linear functions in the spectral range 412-555 nm. Kd(490) is well correlated with the spectral ratio of remote sensing reflectance; and should enough measurement data are given, this empirical algorithm would be used in the Kd(λ) retrieval from ocean color satellite data. The variation in Kd(λ) provides much useful information for us to study the bio-optical property in the northern South China Sea.

  2. Evolution of nonlinear internal waves in the East and South China Seas

    Science.gov (United States)

    Liu, Antony K.; Chang, Y. Steve; Hsu, Ming-K.; Liang, Nai K.

    1998-04-01

    Synthetic Aperture Radar (SAR) images from ERS-I have been used to study the characteristics of internal waves northeast and south of Taiwan in the East China Sea, and east of Hainan Island in the South China Sea. Rank-ordered packets of internal solitons propagating shoreward from the edge of the continental shelf were observed in the SAR images. On the basis of the assumption of a semidiurnal tidal origin, the wave speed can be estimated and is consistent with the internal wave theory. By using the SAR images and hydrographic data, internal waves of elevation have been identified in shallow water by a thicker mixed layer as compared with the bottom layer on the continental shelf. The generation mechanism includes the influences of the tide and the Kuroshio intrusion across the continental shelf for the formations of elevation internal waves. The effects of water depth on the evolution of solitons and wave packets are modeled by the nonlinear Kortweg-deVries (KdV) type equation and linked to satellite image observations. The numerical calculations of internal wave evolution on the continental shelf have been performed and compared with the SAR observations. For a case of depression waves in deep water, the solitons first disintegrate into dispersive wave trains and then evolve to a packet of elevation waves in the shallow water area after they pass through a "turning point" of approximately equal layer depths that has been observed in the SAR image and simulated by the numerical model. The importance of the dissipation effect in the coastal area is also discussed and demonstrated.

  3. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas, Taiwan, in the South China Sea

    Directory of Open Access Journals (Sweden)

    Shashank Keshavmurthy

    2017-01-01

    Full Text Available Dongsha Atoll (also known as Pratas in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park’s scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1–5 m; and deep, 10–15 m in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP of 28S nuclear large subunit ribosomal DNA (nlsrDNA. Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5% was higher compared to deep (14.9%. Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE of internal transcribed spacer 2 (ITS2 in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population.

  4. Biodiversity of free-living marine nematodes in the southern Yellow Sea, China

    Science.gov (United States)

    Liu, Xiaoshou; Xu, Man; Hua, Er; Zhang, Zhinan

    2016-02-01

    Biodiversity patterns of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener diversity index ( H') in the study area was 3.17. The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters, while the lower values were distributed in the southern Yellow Sea Cold Water Mass (YSCWM). The average of taxonomic diversity ( Δ) was 62.09 in the study region. The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM, while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM. Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent, which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better. A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794 (in the YSCWM) was outside of the 95% probability funnels, which may be due to the environmental stress. Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics (Mdø and Silt-clay fraction) and phaeophorbide a (Pha- a) were the most important factors to determine the biodiversity patterns of marine nematodes.

  5. Prediction of tropical cyclonegenesis over the South China Sea using SSM/I satellite

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2010-04-01

    Full Text Available We propose a method for predicting tropical cyclonegenesis over the South China Sea (SCS based on the total latent heat release (TLHR derived from the Special Sensor Microwave/Imager(SSM/I satellite observations. A threshold value (3×1014 W for distinguishing the non-developing and developing tropical disturbances is obtained based on the analysis for 25 developing and 43 non-developing tropical disturbances over the SCS during 2000 to 2005. One simple idealized model is further designed to verify that mean TLHR of 3×1014 W within 500 km of the center of tropical disturbance could maintain and develop the tropical disturbance, by heating the air at the upper level and dropping the sea level pressure by 3.2 hPa. A real time testing prediction of tropical cyclonegenesis over the SCS was conducted for the year of 2007 and 2008 using this threshold value of TLHR. We find that the method is successful in detecting the formation of tropical cyclones for 80% of all tropical disturbances over the SCS during 2007 and 2008.

  6. Atmospheric front over the East China Sea studied by multisensor satellite and in situ data

    Science.gov (United States)

    Ivanov, Andrei Y.; Alpers, Werner; Litovchenko, Konstantin T.; He, Ming-Xia; Feng, Qian; Fang, Mingqiang; Yan, Xiao-Hai

    2004-12-01

    A frontal feature visible on a synthetic aperture radar (SAR) image acquired by the Radarsat satellite over the East China Sea on 19 November 2000 is analyzed in conjunction with data acquired by Quikscat, TOPEX/Poseidon, Tropical Rain Measurement Mission (TRMM), Defense Meteorological Satellite Program (DMSP), and National Oceanic and Atmospheric Administration (NOAA) satellites, and with data obtained from ship measurements. Although this frontal feature is located close to the Kuroshio front, it is demonstrated that it is not a sea surface manifestation of an oceanic front, but rather of an atmospheric front extending over 800 km from an area of the Pacific Ocean northeast of Taiwan to the southern coast of Korea. It is a cold front moving in the southeast direction with a speed of approximately 45-50 km/hour and associated with a 40-km-wide rainband trailing the front. The Radarsat image, which has a resolution of 50 m, reveals fine-scale structures of the atmospheric front, in particular small-scale convective rain cells embedded in the front. Conclusion is drawn that accurate interpretation of frontal features in SAR images requires use of additional meteorological and remote sensing data and information.

  7. Deep water bottom current deposition in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There are some active bottom currents on the northern continental slope of the South China Sea (SCS). Reflection seismic profiles show that the bottom current channels occur in the water depth range of 1000 to 2700 m,extending from the NE to the SW,leading to accumulation of discontinuous drifts with higher sedimentation rates on the eastern side of the channel. The stacking pattern of the layers sug-gests that these drifts propagated southwestward,following the direction of the bottom currents. One sedimentary drift to the southeast of the Dongsha Islands has the highest sedimentation rate of 97cm/ka in the last 12 ka. The sedimentary characteristics of the sediment layers indicate that these bottom currents are most likley caused by the water movement of a branch of the West Pacific Ocean Current,which enters the northern SCS via the Bashi Strait. Once formed,the bottom currents trans-port sediments along the northern slope of SCS southwestward and finally disappear into the central basin of the SCS. Due to the bottom current activity,the deep-sea sedimentary process in the northern SCS is complex.

  8. Temperature shapes coral-algal symbiosis in the South China Sea

    Science.gov (United States)

    Tong, Haoya; Cai, Lin; Zhou, Guowei; Yuan, Tao; Zhang, Weipeng; Tian, Renmao; Huang, Hui; Qian, Pei-Yuan

    2017-01-01

    With the increase in sea surface temperature (SST), scleractinian corals are exposed to bleaching threats but may possess certain flexibilities in terms of their associations with symbiotic algae. Previous studies have shown a close symbiosis between coral the and Symbiodinium; however, the spatial variation of the symbiosis and the attribution underlying are not well understood. In the present study, we examined coral-algal symbiosis in Galaxea fascicularis and Montipora spp. from three biogeographic regions across ~10° of latitude in the South China Sea. Analysis of similarities (ANOSIM) indicated a highly flexible coral-algal symbiosis in both G. fascicularis and Montipora spp. and canonical correspondence analysis (CCA) showed that temperature explained 83.2% and 60.1% of the explanatory subclade variations in G. fascicularis and Montipora spp., respectively, which suggested that temperature was the main environmental factor contributing to the diversity of Symbiodinium across the three regions. The geographic specificity of the Symbiodinium phylogeny was identified, revealing possible environmental selection across the three regions. These results suggest that scleractinian corals may have the ability to regulate Symbiodinium community structures under different temperatures and thus be able to adapt to gradual climate change.

  9. The modeled atmospheric and oceanic response to the South China Sea SST anomaly

    Science.gov (United States)

    Zhu, Xiande; Wu, Lixin; Zhou, Jun; Gao, Jianjun

    2016-10-01

    The sensitivity of the global atmospheric and oceanic response to sea surface temperature anomaly (SSTA) throughout the South China Sea (SCS) is investigated using the Fast Ocean-Atmosphere Model (FOAM). Forced by a warming SST, the experiment explicitly demonstrates that the responses of surface air temperature (SAT) and SST exhibit positive anomalous center over SCS and negative anomalous center over the Northern Pacific Ocean (NPO). The atmospheric response to the warm SST anomalies is characterized by a barotropical anomaly in middle-latitude, leading to a weak subtropical high in summer and a weak Aleutian low in winter. Accordingly, Indian monsoon and eastern Asian monsoon strengthen in summer but weaken in winter as a result of wind convergence owing to the warm SST. It is worth noting that the abnormal signals propagate poleward and eastward away in the form of Rossby Waves from the forcing region, which induces high pressure anomaly. Owing to action of the wind-driven circulation, an anomalous anti-cyclonic circulation is induced with a primary southward current in the upper ocean. An obvious cooling appears over the North Pacific, which can be explained by anomalous meridional cold advection and mixing as shown in the analysises of heat budget and other factors that affect SST.

  10. Characteristics of nitrogen forms in the surface sediments of southwestern Nansha Trough, South China Sea

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The area of the southwestern Nansha Trough is one of the most productive areas of the southern South China Sea. It is a typical semi-deep sea area of transition from shoal to abyssal zone. To understand distributions and roles of nitrogen forms involved in biogeochemical cycling in this area, contents of nitrogen in four extractable forms: nitrogen in ion exchangeable form (IEF-N), nitrogen in weak acid extractable form (WAEF-N), nitrogen in strong alkali extractable form (SAEF-N) and nitrogen in strong oxidation extractable form (SOEF-N), as well as in total nitrogen content (TN) in surface sediments were determined from samples collected from the cruise in April - May 1999. The study area was divided into three regions (A, B and C) in terms of clay sediment (60%, respectively. Generally, region C was the richest in the nitrogen of all forms and region A the poorest, indicating that the finer the grain size is, the richer the contents of various nitrogen are. The burial efficiency of total nitrogen in surface sediments was 28.79%, indicating that more than 70% of nitrogen had been released and participated in biogeochemical recycling through sediment-water interface.

  11. Features of eddy kinetic energy and variations of upper circulation in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    贺志刚; 王东晓; 胡建宇

    2002-01-01

    The features of eddy kinetic energy (EKE) and the variations of upper circulation in the South China Sea (SCS) are discussed in this paper using geostrophic currents estimated from Maps of Sea Level Anomalies of the TOPEX/Poseidon altimetry data. A high EKE center is identified in the southeast, of Viemam coast with the highest energy level 1400 cm2@s-2 in both summer and autumn.This high EKE center is caused by the instability of the current axis leaving the coast of Vietnam in summer and the transition of seasonal circulation patterns in autumn. There exists another high EKE region in the