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Sample records for adjacent east china

  1. Basement structures of East and South China Seas and adjacent regions from gravity inversion

    NASA Astrophysics Data System (ADS)

    Guan, Dongliang; Ke, Xiaoping; Wang, Yong

    2016-03-01

    The satellite-derived gravity gives us an opportunity to investigate the basement structures of the East and South China Seas since the satellite gravimetry could provide large scale gravity data with high resolution of 1 arc-min by 1 arc-min. We isolate the residual gravity anomaly corresponding to the basement by subtracting the gravity anomalies of sediments and Moho undulations from satellite-derived free-air gravity anomalies. Two methods, namely gravity inversion method and convolution method based on flexure isostasy model, are used to calculate the Moho undulations in order to guarantee the accuracy of the Moho undulations since it occupies large percentages of the gravity anomalies. We invert the isolated gravity anomaly for the basement depths of East and South China Seas and adjacent areas with resolution of 1 arc-min by 1 arc-min. The basement depths of East and South China Seas range from 0.5 km to 12 km and the Moho depths vary between 6 km and 32 km. The basement topography reveals many tectonic depressions and two spreading axes concealed by the sediments, which are unseen in the bathymetry. The two spreading axes correspond to the spreading ridges derived from magnetic anomaly and the SW-NE oriented spreading axis extends SW much farther than that identified from magnetic anomaly, almost reaching to the Nam Con Son Basin. We also find that the faults constrain the distributions of basement depressions since the faults usually lie along the places where large changes of basement depth take place. Reversely, the basement map could be used to identify the unknown faults. Besides, according to the four profiles in the East and South China Seas, the mirror-image relation was found between the basement topography and the underlying Moho undulations that when the basement depth increases or decreases, the corresponding Moho depth decreases or increases.

  2. Metal elements in the bottom sediments of the Changjiang Estuary and its adjacent continental shelf of the East China Sea.

    PubMed

    Cao, Lu; Hong, Gi Hoon; Liu, Sumei

    2015-06-15

    The metal elements (Al, Fe, Mn, Cr, Co, Ni, Cu, Zn, As, Pb and Ca) in the bottom sediment of the Changjiang Estuary and its adjacent continental shelf of the East China Sea were studied to map their spatial distribution and to assess their potential risk to the marine biota. These metal concentrations except Ca were generally higher in the inner shelf and northeastern part, and were found to decrease from the coast to the offshore of the Changjiang Estuary. Sedimentary Ca was most abundant in the outer shelf sediments and decreased in inner shelf. Arsenic (As) appeared to be contaminated due to economic development from 1980s in the inner shelf overall, but the potential ecological risk from the selected metals was low in the coastal sea off the Changjiang. PMID:25869200

  3. On the tectonic problems of the southern East China Sea and adjacent regions: Evidence from gravity and magnetic data

    NASA Astrophysics Data System (ADS)

    Shang, Luning; Zhang, Xunhua; Han, Bo; Du, Runlin

    2016-02-01

    In this paper, two sets of gravity and magnetic data were used to study the tectonics of the southern East China Sea and Ryukyu trench-arc system: one data set was from the `Geological-geophysical map series of China Seas and adjacent areas' database and the other was newly collected by R/V Kexue III in 2011. Magnetic and gravity data were reorganized and processed using the software MMDP, MGDP and RGIS. In addition to the description of the anomaly patterns in different areas, deep and shallow structure studies were performed by using several kinds of calculation, including a spectrum analysis, upward-continuation of the Bouguer anomaly and horizontal derivatives of the total-field magnetic anomaly. The depth of the Moho and magnetic basement were calculated. Based on the above work, several controversial tectonic problems were discussed. Compared to the shelf area and Ryukyu Arc, the Okinawa Trough has an obviously thinned crust, with the thinnest area having thickness less than 14 km in the southern part. The Taiwan-Sinzi belt, which terminates to the south by the NW-SE trending Miyako fault belt, contains the relic volcanic arc formed by the splitting of the paleo Ryukyu volcanic arc as a result of the opening of the Okinawa Trough. As an important tectonic boundary, the strike-slip type Miyako fault belt extends northwestward into the shelf area and consists of several discontinuous segments. A forearc terrace composed of an exotic terrane collided with the Ryukyu Arc following the subduction of the Philippine Sea Plate. Mesozoic strata of varying thicknesses exist beneath the Cenozoic strata in the shelf basin and significantly influence the magnetic pattern of this area. The gravity and magnetic data support the existence of a Great East China Sea, which suggests that the entire southern East China Sea shelf area was a basin in the Mesozoic without alternatively arranged uplifts and depressions, and might have extended southwestward and connected with the

  4. Temporal distribution of bacterial community structure in the Changjiang Estuary hypoxia area and the adjacent East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Min; Xiao, Tian; Wu, Ying; Zhou, Feng; Huang, Huiqin; Bao, Shixiang; Zhang, Wuchang

    2012-06-01

    Bacterial community structure and the effects of environmental factors on the microbial community distribution were investigated in the Changjiang Estuary hypoxia area and its adjacent area in the East China Sea (ECS) in June, August and October, 2006. Profiles of bacterial communities were generated by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes followed by DNA sequence analysis. The dominant bacterial groups were affiliated to Gammaproteobacteria, Cytophaga-Flavobacteria-Bacteroides (CFB), Deltaproteobacteria, Cyanobacteria and Firmicutes, which were mostly from the marine seawater ecosystem. Effects of environmental factors on the bacterial community distribution were analyzed by the ordination technique of canonical correspondence analysis (CCA). The environmental factors significantly influencing bacterial community structure were different in the three months; dissolved organic carbon (DOC) and temperature in June and nitrite in August. No environmental variables displayed significant influence on the bacterial community at the 5% level in October. The seasonal environmental heterogeneity in the Changjiang Estuary and the adjacent ECS, such as seasonal hydrodynamic conditions and riverine input of nutrients, might be the reason for the difference in the key environmental factors determining the bacterial community in the three months.

  5. Controlling factors of summer phytoplankton community in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Jiang, Zhibing; Chen, Jianfang; Zhou, Feng; Shou, Lu; Chen, Quanzhen; Tao, Bangyi; Yan, Xiaojun; Wang, Kui

    2015-06-01

    We analyzed the composition and distribution of phytoplankton in relation to physicochemical factors in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf in June and August 2009. Diatoms and dinoflagellates dominated the community, particularly in eutrophic inshore waters controlled by the Changjiang Diluted Water (CDW), coastal current, and upwelling. However, high densities of cyanobacteria and cryptophytes were observed in the oligotrophic offshore waters influenced by the Taiwan Warm Current (TWC) and Kuroshio. In June, the northeastward CDW plume combined with the Yellow Sea Coastal Current induced algal bloom in the northern part of the CE. In August, the enhanced CDW formed two narrow, low-salinity tongues that extended eastward and southward (associated with the upwelling and coastal current), resulting in phytoplankton blooms off the CE and in the Zhejiang coastal waters, respectively. Phytoplankton abundance in August was considerably higher than in June, with increased solar radiation, CDW, and upwelling. The maximum abundance occurred on the surface in inshore turbid waters and on the subsurface (5-30 m) in offshore clear waters with increased stratification. Based on multidimensional scaling and cluster analysis, we found appreciable spatio-temporal variations in algal community composition. Different ecological groups corresponded with hydrographic distributions. Canonical correspondence analysis showed that nutrients, salinity, temperature, and suspended particulate matter were the main variables associated with community distribution. We suggest that the variations in summer phytoplankton community are highly correlated with the significant monthly and spatial variability in physicochemical properties, which are primarily controlled by the CDW and TWC.

  6. Community composition and distribution of sulfate- and sulfite-reducing prokaryotes in sediments from the Changjiang estuary and adjacent East China Sea

    NASA Astrophysics Data System (ADS)

    He, Hui; Zhen, Yu; Mi, Tiezhu; Xu, Bochao; Wang, Guoshan; Zhang, Yu; Yu, Zhigang

    2015-11-01

    Sulfate- and sulfite-reducing prokaryotes (SSRP) communities play a vital role in both sulfur and carbon cycles. Community composition and abundance of SSRP were investigated using dissimilatory sulfite reductase β subunit (dsrB) gene sequencing in sediments from the Changjiang estuary and its adjacent area in the East China Sea (ECS). Clone libraries were constructed and real-time fluorescence quantitative polymerase chain reaction (qPCR) was applied to understand the community information of SSRP. In addition to sequences affiliated to sulfate-reducing prokaryotes (SRP), those affiliated with sulfite-reducing prokaryotes (SiRP) were also observed. Four phylotypes of SRP in this study showed genetic similarity to Desulfobulbaceae, Syntrophobacteraceae, Desulfobacteraceae and Peptococcaceae, and an unknown group that could not be clearly affiliated with known lineages was found. Salinity, temperature and contents of total organic carbon (TOC) were most closely correlated with the SSRP communities by canonical correspondence analysis (CCA). 210Pb activities demonstrated the sedimentary environment at S33 was more stable than that at S31. Intense resuspension and reconstruction of sediments made the vertical abundance profile of SSRP fluctuate violently. For surface sediments, the dsrB gene copy numbers near the Changjiang estuary were higher than those in the mouth of Hangzhou Bay and the mud deposits along the Zhejiang coast, and contents of TOC were positively related to the copy numbers of dsrB gene. Our data provided valuable information to achieve a better understanding of the potential role of SSRP in sediments from the Changjiang estuary and adjacent East China Sea.

  7. Distribution of organochlorine pesticides in sediments from Yangtze River Estuary and the adjacent East China Sea: implication of transport, sources and trends.

    PubMed

    Zhou, Shanshan; Yang, Huayun; Zhang, Anping; Li, Yi-Fan; Liu, Weiping

    2014-11-01

    Thirty-eight surface sediments and two sediment cores were collected from Yangtze River Estuary (YRE) and adjacent East China Sea (ECS) to study the distribution patterns, origins, potential transport and burden of organochlorine pesticides (OCPs) in the marginal sea. Residues of OCPs ranged from 0.190 to 5.17 ng g(-1) dry weight with a distinct "band type" pattern under the control of Yangtze River inputs and ECS circulation system. Differences in transmission media and redox conditions in situ respectively resulted in the divergent distributions of α/β-HCH and DDD/DDE. The compositional pattern analysis implied that OCPs in the inner shelf of ECS were derived from both "weathered" and fresh sources, whereas those in the outer shelf of ECS had undergone high metabolism. Concurrent with the land-sea migration, vertical profiles of sediment cores showed increasing trends or rebound since the 1990s, characteristic of two evident "jumps" of DDE+DDD/DDT and DDT/DDE ratios. Moreover, the primary distribution pattern founded for HCHs and the considerable mass inventories calculated (6.20 metric tones for OCPs) together suggested that the contaminated sediments in the studied area to be a potential source of OCPs to the global ocean. PMID:25113180

  8. 73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, LOOKING WEST BY NORTHWEST, SHOWING EASTERNMOST ARCH OF FORMER GREAT HALL NORTH ARCADE - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  9. Lock 4 View east of lock wall and adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lock 4 - View east of lock wall and adjacent roadway built atop tow path. The gate pocket can be seen at center. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  10. 6. Detail, vertical guides adjacent to east portal of Tunnel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail, vertical guides adjacent to east portal of Tunnel 28, view to southwest, 135mm lens with electronic flash fill. - Central Pacific Transcontinental Railroad, Tunnel No. 28, Milepost 134.75, Applegate, Placer County, CA

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

    PubMed

    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. PMID:27243109

  12. Rayleigh wave tomography of China and adjacent regions

    NASA Astrophysics Data System (ADS)

    Huang, Zhongxian; Su, Wei; Peng, Yanju; Zheng, Yuejun; Li, Hongyi

    2003-02-01

    This paper presents a tomographic study on the S wave velocity structure of China and adjacent regions. Group velocity dispersions of fundamental Rayleigh waves along more than 4000 paths were determined with frequency-time analysis. The study region was divided into a 1° × 1° grid, and velocities in between grid nodes were calculated by bilinear interpolation. The Occam's inversion scheme was adopted to invert for group velocity distributions. This method is robust and allows us to use a fine grid in model parameterization and thus helps to restore a more realistic velocity pattern. Checkerboard tests were carried out, and the lateral resolution was estimated to be 4°-6° in China and its eastern continental shelves. The resulting group velocity maps from 10 to 184 s showed good correlation with known geological and tectonic features. The pure path dispersion curves at each node were inverted for shear wave velocity structures. The three-dimensional velocity model indicates thick lithospheres in the Yangtze and Tarim platforms and hot upper mantles in Baikal and western Mongolia, coastal area and continental shelves of eastern China, and Indochina and South China Sea regions. The Tibetan Plateau has a very thick crust with a low-velocity zone in its middle. Beneath the crust a north dipping high-velocity zone, mimicking a subducting plate, reaches to 200 km in depth and reaches to the Kunlun Mountains northward. In northern Tibet a low-velocity zone immediately below the Moho extends eastward then turns southward along the eastern edge of the plateau until it connects to the vast low-velocity area in Indochina and the South China Sea.

  13. Late Mesozoic and Cenozoic rifting and its dynamic setting in Eastern China and adjacent areas

    NASA Astrophysics Data System (ADS)

    Ren, Jianye; Tamaki, Kensaku; Li, Sitian; Junxia, Zhang

    2002-02-01

    basin margins and were deposited in a broad downwarped lacustrine depression. At the same time, within plate rifting of the Lake Baikal and Shanxi graben climaxed and spreading of the Japan Sea and South China Sea occurred. Quaternary rifting was marked by basalt eruption and accelerated subsidence in the area of Tertiary rifting. The Okinawa Trough is an active rift involving back-arc extension. Continental rifting and marginal sea opening were clearly developed in various kind of tectonic settings. Three rifting styles, intracontinental rifting within fold belt, intracontinental rifting within craton and continental marginal rifting and spreading, are distinguished on the basis of nature of the basin basement, tectonic location of rifting and relations to large strike-slip faults. Changes of convergence rates of India-Eurasia and Pacific-Eurasia may have caused NW-SE-trending extensional stress field dominating the rifting. Asthenospheric upwelling may have well assisted the rifting process. In this paper, a combination model of interactions between plates and deep process of lithosphere has been proposed to explain the rifting process in East China and adjacent areas. The research on the Late Mesozoic and Cenozoic extensional tectonics of East China and adjacent areas is important because of its utility as an indicator of the dynamic setting and deformational mechanisms involved in stretching Lithosphere. The research also benefits the exploration and development of mineral and energy resources in this area.

  14. Late compressional features, East China Sea Shelf Basin

    SciTech Connect

    Cunningham, A.E.; Prebish, M.R.; Eisenstadt, G. ); Norris, J.W.; Letsch, D.K. )

    1994-07-01

    Many anticlinal folds observed in the East China Sea Shelf Basin are interpreted to result from a change in regional stress from tensional to compressional. This compression is interpreted to have occurred during the late Eocene to Oligocene Yuquan movement. These features were observed most frequently south of the Mingyuefeng 1 well within China's recently offered Fourth Round Acreage. Many of these structures are interpreted to be related to reverse and strike-slip motion along reactivated, Late Cretaceous to late Eocene, synrift, normal faults. An early to middle Miocene regional unconformity truncates the crest of most anticlinal features, and does not appear to be involved in the folding episode. Late Eocene to Oligocene compressional highs present attractive structural targets in the East China Sea Shelf Basin. The deformed sedimentary section thickens toward the rift-basin boundary faults, suggesting synrift sedimentation. Consequently, there is no thinning of the synrift section across the crest of the structural highs formed by postrift compression. The timing of these compressional structural highs, however, must be compared with the hydrocarbon generation and migration history from source rocks in adjacent half grabens to properly assess accumulation potential.

  15. Changes in Climate over the South China Sea and Adjacent Regions: Response to and Feedback on Global Climate Change

    NASA Astrophysics Data System (ADS)

    Yang, Song

    2016-04-01

    El Niño-Southern Oscillation and the Asian monsoon have experienced significant long-term changes in the past decades. These changes, together with other factors, have in turn led to large climate change signals over the South China Sea and adjacent regions including Southeast Asia, the western Pacific, and the tropical Indian Ocean. An attribution analysis of the feedback processes of these signals indicate the predominant importance of water vapor and cloud radiative feedbacks. Experiments with multiple earth system models also show that these regional climate change signals exert significant influences on global climate. The increases in atmospheric heating over Southeast Asia and sea surface temperature in the adjacent oceans in the past decades have weakened the Indian and African monsoons, led to a drying effect over East Asia, and generated wave-train patterns in both the northern and southern hemispheres, explaining several prominent climate features in and outside Southeast Asia.

  16. Contrasting microbial assemblages in adjacent water masses associated with the East Australian Current.

    PubMed

    Seymour, Justin R; Doblin, Martina A; Jeffries, Thomas C; Brown, Mark V; Newton, Kelly; Ralph, Peter J; Baird, Mark; Mitchell, James G

    2012-10-01

    Different oceanographic provinces host discrete microbial assemblages that are adapted to local physicochemical conditions. We sequenced and compared the metagenomes of two microbial communities inhabiting adjacent water masses in the Tasman Sea, where the recent strengthening of the East Australian Current (EAC) has altered the ecology of coastal environments. Despite the comparable latitude of the samples, significant phylogenetic differences were apparent, including shifts in the relative frequency of matches to Cyanobacteria, Crenarchaeota and Euryarchaeota. Fine-scale variability in the structure of SAR11, Prochlorococcus and Synechococcus populations, with more matches to 'warm-water' ecotypes observed in the EAC, indicates the EAC may drive an intrusion of tropical microbes into temperate regions of the Tasman Sea. Furthermore, significant shifts in the relative importance of 17 metabolic categories indicate that the EAC prokaryotic community has different physiological properties than surrounding waters. PMID:23760900

  17. The high education of optical engineering in East China

    NASA Astrophysics Data System (ADS)

    Liu, Xu; Liu, Xiangdong; Wang, Xiaoping; Bai, Jian; Liu, Yuling

    2014-07-01

    The history and the development of the high education in the field of optical engineering in the area of East China will be presented in the paper. The overall situation of research and human resource training in optics and photonics will also be reviewed, it shows that China needs lots of talents and experts in this field to support the world optical industry in East China.

  18. Asynchroneity of the Holocene Moisture Variations across the Mongolian Plateau and the adjacent Siberia and China

    NASA Astrophysics Data System (ADS)

    FENG, Zhaodong; WANG, Wei; RAN, Min

    2014-05-01

    Based on the review of high-standard Holocene climatic reconstructions from the Mongolian Plateau and the adjacent Siberia and China, temporal and spatial patterns of the Holocene moisture evolution are synthesized. The regionally-averaged moisture index (i.e., RAMI) for the winter monsoon-dominated southern Siberia exhibits a general declining trends since 10.6-9.6 cal. kyr BP, being consistent with the trends of the annual precipitation and the warm-season temperature in the Russian Plain. The consistency might be attributable to the Holocene declining trend of the warm-season temperature in North Atlantic region. The RAMI for the westerlies-affected northern Xinjiang had a persistent increasing trend since ~8 cal. kyr BP. The wetting trend of northern Xinjiang might be attributable to the increasing trend of winter insolation and to the associated increasing trend of cold-season temperature in northwestern Europe. The chronological correspondences between dry phases and warm intervals in the arid areas of the entire Mongolian Plateau lend a support to our earlier proposal that the mid-Holocene dry phase in the arid Mongolian Plateau was most likely the result of mid-Holocene high warm-season temperature. The RAMI for China is the delayed reflections of the East Asian summer monsoon strength to the solar radiation. That is, the peak insolation (14-6 cal. kyr BP) was responded by the Oceanic Thermal Optimum (12-5 cal. kyr BP) with some time lags and the Oceanic Thermal Optimum was then responded by the Holocene Moisture Optimum in southern China (10-5 cal. kyr BP) and then in northern China (9-6 cal. kyr BP). The RAMI for the Tibetan Plateau shows that the moisture has been persistently declining since ~11 cal. kyr BP and that the period between ~11.5 and 7.5 cal. kyr BP was the Holocene Moisture Optimum. The parallel trends between the moisture level in the Tibetan Plateau and the Indian summer monsoon strength retrieved from the Arabian Sea suggest that the

  19. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2016-05-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index (I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  20. Geology and petroleum prospects in East China Sea

    SciTech Connect

    Liu, G.

    1986-07-01

    Geologic studies of the petroleum potential of the East China Sea have progressed through three stages. (1) The tectonic divisions and evolution of the East China Sea were investigated using geophysical data, including gravimetric, magnetic, and seismic information. (2) Seismic data over the Shelf basin were interpreted and mapped, to understand the Cenozoic structural history of the East China Sea. (3) More detailed seismic shooting has allowed for detailed prospect mapping and seismo-stratigraphic studies. This stage has resulted in the mapping of numerous drillable prospects, several among them having been proved to contain commercial quantities of oil and gas. Presently, results from the Lingfeng 1 well point to new and different directions for exploration in the basin.

  1. A new version of regional ocean reanalysis for coastal waters of China and adjacent seas

    NASA Astrophysics Data System (ADS)

    Han, Guijun; Li, Wei; Zhang, Xuefeng; Wang, Xidong; Wu, Xinrong; Fu, Hongli; Zhang, Xiaoshuang; Zhang, Lianxin; Li, Dong

    2013-07-01

    A new regional ocean reanalysis over multiple decades (1958-2008) for the coastal waters of China and adjacent seas has been completed by the National Marine Data and Information Service (NMDIS) under the CORA (China Ocean ReAnalysis) project. Evaluations were performed on three aspects: (1) the improvement of general reanalysis quality; (2) eddy structures; and (3) decadal variability of sea surface height anomalies (SSHAs). Results showed that the quality of the new reanalysis has been enhanced beyond ˜40% (39% for temperature, 44% for salinity) in terms of the reduction of root mean squared errors (RMSEs) for which the reanalysis values were compared to observed values in the observational space. Compared to the trial version released to public in 2009, the new reanalysis is able to reproduce more detailed eddy structures as seen in satellite and in situ observations. EOF analysis of the reanalysis SSHAs showed that the new reanalysis reconstructs the leading modes of SSHAs much better than the old version. These evaluations suggest that the new CORA regional reanalysis represents a much more useful dataset for the community of the coastal waters of China and adjacent seas.

  2. A regional ocean reanalysis system for coastal waters of China and adjacent seas

    NASA Astrophysics Data System (ADS)

    Han, Guijun; Li, Wei; Zhang, Xuefeng; Li, Dong; He, Zhongjie; Wang, Xidong; Wu, Xinrong; Yu, Ting; Ma, Jirui

    2011-05-01

    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.

  3. Distribution of drifting seaweeds in eastern East China Sea

    NASA Astrophysics Data System (ADS)

    Komatsu, Teruhisa; Tatsukawa, Kenichi; Filippi, Jean B.; Sagawa, Tatsuyuki; Matsunaga, Daisuke; Mikami, Atsuko; Ishida, Kenichi; Ajisaka, Tetsuro; Tanaka, Katsuhiko; Aoki, Masakazu; Wang, Wei-Ding; Liu, Hui-Fei; Zhang, Shou-Du; Zhou, Min-Dong; Sugimoto, Takashige

    2007-09-01

    In offshore waters with relatively low primary production, drifting seaweeds composed of Sargassum species form an identical ecosystem such as an oasis in desert. Commercially important pelagic fishes such as jack mackerel ( Trachurus japonicus) and yellow tail ( Seriola quinqueradiata) spawn in East China Sea pass their juvenile period accompanying drifting seaweeds. Therefore drifting seaweeds are very important not only in offshore ecosystem but also fishery resources. However the distribution of drifting seaweeds in East China Sea has scarcely known. Then we conducted two research cruises of R/V Hakuho-Maru in May 2002 and in March 2004. During the cruises, drifting seaweeds were visually observed from the bridge and sampled with a towing net. The observation revealed that the drifting seaweeds were distributed along the front between the Kuroshio Current and coastal waters and mainly composed of one seaweed species, Sargassum horneri (Turner) C. Agardh from spring to early summer. There are no reports on geographical distribution of this species in the coasts south of southern Kyushu Island in Japan. Kuroshio Current flows northeastward there. Buoys with GPS attached to drifting seaweeds released off Zhejiang Province, China, in March 2005 to track their transport. Their positions monitored by ORBCOM satellite showed that they were transported to the area in East China Sea, where the drifting seaweeds were observed during the cruises, in 2 months. These facts suggest that S. horneri detached from Chinese coast in March or months earlier than March could be transported to fringe area of continental shelf and waters influenced by Kuroshio Current from March to May. Therefore the Sargassum forests, especially S. horneri, along the Chinese coast play a very important role in the ecosystem of the East China Sea as a source of drifting seaweeds.

  4. Upward Continuation Apply Newly to Process Gravity Anomaly Data in the East China Sea

    NASA Astrophysics Data System (ADS)

    Han, Bo; Zhang, Xunhua; Jiang, Jinyu

    2014-05-01

    The research area lies in the East China Sea and its adjacent area and the concrete is between 120-130 degree of east longitude and 20-30 degree of north latitude and it also lies between Eurasian Plate and Pacific Plate. The structures of the area transform differently and they are namely Uplifted Zone of Zhejiang-Fujian, East China Sea Shelf Basin, Okinawa Trough Back-arc Basin, Ryukyu Arc, Ryukyu trench and Philippine Sea from west to east. Bouguer gravity anomaly can reflect deep structure characters and it is help to judge deep structures. The bouguer gravity anomalies of the area change differently from west to east. The anomalies increase gradually from land to the middle of Okinawa trough and near land anomaly contour strike accords with coastline and the middle of Okinawa trough reflect the highest anomalies in this area. Gravity anomalies re-increase from Ryukyu fore-arc basin to trench and Ryukyu island arc appears the low anomalies. Philippine Sea appears high gravity anomalies background. Upward continuation method has been used to process original gravity anomaly as a common method and its destination is to weaken local anomaly and at last strengthen deep anomaly and it's important to deep structure study. Upward 5 km, 10 km and 20 km have been used to process data and the results been compared. However, the research area is very large and the deep structure is complex, it isn't suitable to use single height to upward continuation processing bouguer gravity anomaly. Then we propose multiple upward heights continuation to process gravity data respectively in different area. We use upward 20km to process data in the area from land to the slope and upward 10km from Okinawa trough to Ryukyu island arc and upward 5km from Ryukyu trench to Philippine Sea. At last we obtain multiple upward height result and the calculated result confirms that it is fit to use this method. Gravity anomalies contours become smoother than before and the deep structures become

  5. Interdecadal changes in summer TC activity in East China Sea

    NASA Astrophysics Data System (ADS)

    Choi, Ki-Seon; Cha, Yu-Mi; Kang, Sung-Dae; Kim, Hae-Dong

    2015-04-01

    The study analyzed the time series of the tropical cyclone (TC) frequencies which passed through the East China Sea between July and September from 1963 to 2012. The result of applying the statistical change-point analysis to this time series shows that a climate regime shift occurred in 1983 when the TC frequencies which pass the East China Sea area started increasing. The study then analyzed the average difference after 1983 (1984-2012) and before 1983 (1963-1983). The TC genesis frequency shows a tendency in mainly appearing in the tropical and subtropical Northwestern Pacific between 1963 and 1983 and the southern part between 1984 and 2012. The TC passage frequency shows a pattern that the TCs move from the far northeast sea of Philippines and change direction to Korea and Japan, passing through the East China Sea between 1984 and 2012. Meanwhile, the TC passage frequency shows a pattern which moves from the far southeast sea of the Philippines to southern China in the west direction in the previous period (1963-1983). These TC movement patterns coincide with the development status of the subtropical western North Pacific high (SWNPH) which averages for each period. It shows that the SWNPH in the second period stays away from the SWNPH in the second period from the northeast direction, but that the SWNPH in the first period expands to western Taiwan. This study analyzes the difference between the two periods in the 500-hPa streamline to understand the changes in such TC activities in the two groups. The anomalous anticyclonic circulations centered in the southern part of Japan are fortified in most of the subtropical Northwestern Pacific. The anomalous southerlies from the anomalous circulations are outstanding in the East China Sea area, Korea, and Japan. Therefore, the TCs generated in the tropical and subtropical Northwestern Pacific move along with the anomalous steering flow (anomalous southwesterlies) and up toward the East China Sea area, Korea, and

  6. Molecular phylogeny and morphological revision of Myotis bats (Chiroptera: Vespertilionidae) from Taiwan and adjacent China.

    PubMed

    Ruedi, Manuel; Csorba, Gábor; Lin, Liang-Kong; Chou, Cheng-Han

    2015-01-01

    In taxonomic accounts, three species of Myotis have been traditionally reported to occur on the island of Taiwan: Watase's bat (M. formosus watasei Kishida), the Formosan broad-muzzled bat (M. muricola latirostris Kishida) and the Formosan mouse-eared bat (M. adversus taiwanensis Linde). The discovery in 1997 of an unknown taxon not fitting to the description of any of these species encouraged us to re-examine more thoroughly the systematics and phylogeny of Myotis bats inhabiting Taiwan. We used a combination of morphologic and molecular methods to aid the identification of the different taxa from this island and reconstruct their phylogenetic relationships. Multivariate analyses based on 17 craniodental characters of 105 specimens caught across Taiwan and further external characters allowed us to discriminate eight taxa of Myotinae co-occurring on this island. A subset of 80 specimens were further sequenced for the cytochrome b gene (1140 bp) and subjected to phylogenetic reconstructions including representative species from adjacent China and from all main lineages of the worldwide Myotis radiation. These molecular reconstructions showed that the Myotinae from Taiwan are phylogenetically diverse and are issued from several independent clades. The genetic results were completely congruent with the phenetic groupings based on craniodental and external morphology, as each of the eight Taiwanese taxa proved to be reciprocally monophyletic. Two unnamed taxa that did not fit into any of the known species were described as species new to science. Furthermore the taxon latirostris usually associated to the Asian M. muricola, was phylogenetically and morphologically distant from any other known Myotis and was assigned here to the fossil (Miocene) genus Submyotodon. Submyotodon latirostris, M. secundus sp. n. and M. soror sp. n. are endemic species from Taiwan, whereas the other five Myotis are more widespread and also found in the mainland. An identification key is

  7. Archaeoseismological Study of Prehistoric Earthquakes in Anhui Province, China and Adjacent Areas

    NASA Astrophysics Data System (ADS)

    Yao, D.; Shen, X.; Gong, X.; Wu, W.; Hu, Z.; Zheng, H.; Chen, A.; Zhao, P.; Yang, Y.

    2014-12-01

    Damaging earthquakes on faults typically recur at intervals of centuries to millennia but the seismographs that record them have only been around for about hundred years. Complete records of earthquakes of Ms5 or above for Anhui Province of China and its adjacent areas began in 1336 and most previous records were lost. To reduce the hazard from earthquakes we need a longer record of them than can be provided from such instruments. Archaeoseismological evidence has the potential to determine earthquake activity over millennial time spans, especially when integrated with historical documents and geological evidence. In recent years, taking advantage of large-scale civil excavations, our research team including earthquake and archaeological scientists have cataloged, identified, and analyzed deformation relics of the late-Quaternary period, especially the Neolithic Age. Prehistoric earthquake traces were found in the cultural layers of the Western Zhou Dynasty and the Spring and Autumn Period in Southwest Anhui, the late Dawenkou cultural period in North Anhui, and the Eastern Zhou in South Henan. Along the segment of the Tanlu Fault Zone on the border of Jiangsu-Anhui Provinces, several rapid deformation events mainly in the form of oblique translational thrust had occurred since Late Pleistocene, which was confirmed by microscopic studies. The research findings have partly filled the gap of earthquake records in the area and enriched research methodologies in archaeology, prehistoric earthquakes and earthquake prediction. The project was sponsored by China Earthquake Science Special Research Funding Program (#201308012)

  8. Benthic meiofaunal composition and community structure in the Sethukuda mangrove area and adjacent open sea, East coast of India

    NASA Astrophysics Data System (ADS)

    Thilagavathi, Balasubramanaian; Das, Bandana; Saravanakumar, Ayyappan; Raja, Kuzhanthaivel

    2011-06-01

    The ecological aspects of meiofaunal communities in the Muthupettai mangrove forest, East coast of India, has not been investigated in the last two decades. Surface water temperature ranged from 23.5 °C to 31.8 °C. Salinity varied from 24 to 34 ppt, while water pH fluctuated from 7.4 to 8.3. Dissolved oxygen concentration ranged from 3.86 to 5.33 mg/l. Meiofauna analysis in this study identified a total of 106 species from the mangrove and adjacent open sea area of Sethukuda. Among these, 56 species of foraminiferans, 20 species of nematodes, 7 species of harpacticoid copepods, 4 species of ostrocodes, and 2 species of rotifers were identified. Furthermore, a single species was identified from the following groups: ciliophora, cnidaria, gnathostomulida, insecta, propulida, bryozoa and polychaete larvae. Meiofaunal density varied between 12029 to 23493 individuals 10 cm/m2. The diversity index ranged from 3.515 to 3.680, species richness index varied from 6.384 to 8.497, and evenness index varied from 0.839 to 0876 in the mangrove area and adjacent open sea.

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

    PubMed

    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. PMID:15083656

  10. [Plague in China. Threat of transmission to regions of Siberia and Far East].

    PubMed

    Maramovich, A S; Kosilko, S A; Innokent'eva, T I; Voronova, G A; Bazanova, L P; Nikitin, A Ia; Okunev, L P

    2008-01-01

    In China plague has been officially registered from 1754 (638 epidemics with total number of cases 2.5 millions and case-fatality rate 87.5%). Endemic areas started to form on the south of the country and then the disease gradually spread on seaside provinces, where to the end of the 19th century, due to reach of island territories and large international seaports, was characterized by pandemic spread. Epidemic manifestations of plague in China were observed during more than 200 years in 23 out of 36 administrative areas affecting continental and North-Eastern regions of the country, which are immediately adjacent to border of Russia. Pneumonic plague in Manchuria clearly demonstrated the role of transport communications in transmission of this deadly infection and possibility of its spread on border regions of Siberia and Far East. Lengthy country's border, intensive migration flows, large-scale international integration, developing of near-border trade, simplification of policy for transboundary traveling are the reasons for differentiated number of sanitary protective measures on administrative borders of Siberia and Far East. PMID:18368762

  11. Holocene paleomagnetic secular variation from East China Sea and a PSV stack of East Asia

    NASA Astrophysics Data System (ADS)

    Zheng, Yan; Zheng, Hongbo; Deng, Chenglong; Liu, Qingsong

    2014-11-01

    Paleomagnetic secular variation (PSV) provides information on the mechanisms of the geodynamo and can also be used for stratigraphic correlation on a regional scale. In this study, we constructed PSV curves of relative rapidly deposited Holocene marine sequence from East China Sea. Results show that the dominant magnetic carriers are pseudo-single domain (PSD) to multidomain (MD) magnetites. Paleomagnetic directions are preserved by coarse-grained magnetite, even affected by post-depositional diagenetic alteration. The PSV record of core MD06-3040 exhibits six major inclination peaks and five declination swings during the Holocene. The periodicities for inclination are about 2000 and 550 years, and for declination are about 1400 and 500 years. The PSV of MD06-3040 is comparable to archeomagnetic and historic results for the last 2500 years and to PSV results from lake sediments in southern China and Japan during the Holocene. A PSV stack of East Asia is constructed by sedimentary and archeological PSV results, which can be used as an important reference curve for a large region, and the PSV correlation between sites can be applied for relative dating of East Asia.

  12. Wintertime current meter measurements from the East China Sea

    SciTech Connect

    Trump, C.L.; Burt, W.V.

    1981-09-01

    An array of three current meters were anchored on the continental shelf of the East China Sea during the last half of February 1975 as part of the Japanese Air Mass Transformation Experiment, AMTEX-75. The results indicate that the currents are dominated by the rotational semidiurnal M/sub 2/ tidal component superimposed on a slow mean drift to the northeast. Differences in direction of several days duration between two of the current meters suggest the presence of transient mesoscale eddies or meanders in the flow regime.

  13. Detection of trends in precipitation extremes in Zhejiang, east China

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Xu, Yue-Ping; Booij, M. J.; Lin, Shengji; Zhang, Qingqing; Lou, Zhanghua

    2012-01-01

    Extreme weather exerts a huge impact on human beings and it is of vital importance to study the regular pattern of meteorological and hydrological factors. In this paper, a selection of seven extreme indices is used to analyze the trend of precipitation extremes of 18 meteorological stations located in Zhejiang Province, east China using the Mann-Kendall test. Then the precipitation trends in the plum season (from May to July) and typhoon season (from August to October) are studied separately. The results show that the precipitation trend varies from east to west. There is a positive trend in the east and a negative one in the west. The largest part of Zhejiang Province shows a positive trend in heavy precipitation and the most significant upward trend is detected in Dinghai with 3.4 mm/year for precipitation on very wet days. Although the upward trend of extreme precipitation is not prevailing, the range of increase in specific areas is apparent, like Dinghai with 1.3 mm/year. Precipitation intensity exhibits an upward trend in most areas and a typical upward trend can be found in Dachendao, Tianmushan, and Yuhuan with 0.04, 0.02, and 0.05 mm/year respectively. Precipitation intensity in both plum and typhoon seasons has increased too, especially for the coastal stations.

  14. 77 FR 13171 - China North East Petroleum Holdings Limited, Order of Suspension of Trading

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION China North East Petroleum Holdings Limited, Order of Suspension of Trading March 1, 2012. It... accurate information concerning the securities of China North East Petroleum Holdings Limited (``NEP''),...

  15. Pollution from China increases cloud droplet number, suppresses rain over the East China Sea

    SciTech Connect

    Bennartz, Ralph; Fan, Jiwen; Rausch, J; Leung, Lai-Yung R; Heidinger, Andrew K

    2011-05-18

    Rapid economic growth over the last 30 years in China has led to a significant increase in aerosol loading, which is mainly due to the increased emissions of its precursors such as SO2 and NOx. Here we show that these changes significantly affect wintertime clouds and precipitation over the East China Sea downwind of major emission sources. Satellite observations show an increase of cloud droplet number concentration from less than 200 cm-3 in the 1980s to more than 300 cm-3 in 2005. In the same time period, precipitation frequency reported by voluntary ship observers was reduced from more than 30% to less than 20% of the time. A back trajectory analysis showed the pollution in the investigation area to originate from the Shanghai-Nanjing and Jinan industrial areas. A model sensitivity study was performed, isolating the effects of changes in emissions of the aerosol precursors SO2 and NOx on clouds and precipitation using a state-of-the-art mesocale model including chemistry and aerosol indirect effects. Similar changes in cloud droplet number concentration over the East China Sea were obtained when the current industrial emissions in China were reduced to the 1980s levels. Simulated changes in precipitation were somewhat smaller than the observed changes but still significant. Citation: Bennartz, R., J. Fan, J. Rausch, L. R. Leung, and A. K. Heidinger (2011), Pollution from China increases cloud droplet number, suppresses rain over the East China Sea, Geophys. Res. Lett., 38, L09704, doi:10.1029/ 2011GL047235.

  16. A disparity between erosional hazard and accretion of the sundarbans with its adjacent east coast, Bangladesh: a remote sensing and GIS approach

    NASA Astrophysics Data System (ADS)

    Pahlowan, E. U.; Hossain, A. T. M. S.

    2015-10-01

    The Sundarbans, UNESCO affiliated world heritage site and world largest mangrove forest covering with (~10000) km2 along the coastal areas of Bangladesh and India. Bangladesh is one of the most vulnerable countries due to sea level rise caused by global warming. In the present situation world mangrove forest are declining at alarming rate. The extensions of this mangrove forest continuously changing with the nature of Bay of Bengal coast. This paper presents the contrast result of erosional hazard and accretion of Sundarbans with its adjacent east coast of Bangladesh. This study based on images of Landsat MSS, Thematic Mapper (TM), Enhanced Thematic Mapper (ETM), and Operational Land Imager (OLI) from Landsat 8. Landsat images from 1980 to 2014 were analyzed. The result shows the net erosion rate of Sundarbans is higher than its adjacent east coast. The study area has been divided into two phases - Phase I and Phase II. Phase I represents only Sundarbans and Phase II represents adjacent east coast. These two phases has equal longitudinal distance. Many small channels and river supply water and sediment into the Sundarbans. The adjacent east coast of Sundarbans lies on the Meghana estuary that experienced with huge amount of sediment flow. The Sundarbans has been facing erosional stage with a rate of net erosion about 3 km2 y-1 whereas the adjacent east coast facing an accretional stage with rate of accretion about 1 km2y-1. The highest erosion rate of Phase I (Sundarbans) was 10.61 km2y-1 and highest erosion of Phase II adjacent east coast was 18-km2 y-1 in the period of 1989-1999. The highest accretion rate in the Sundarbans was 6.48 km2 y-1 in the period of 1999-2006 and in the Phase II, accretion rate was 16.43 km2 y-1 in the period of 1980-1989. The lowest erosion rate was 3 km2 y-1 in Phase I and 2.11 km2 y-1 in Phase II in the period of 1999- 2006. The reworking area in phase I is about 37 km2 and phase II is about 51 Km2.So, water is highly active in

  17. Industry sector analysis, China: Petrochemical industry in east China. Export trade information

    SciTech Connect

    Not Available

    1993-01-01

    The market survey covers the petrochemical equipment and technology market in East China. The analysis contains statistical and narrative information on projected market demand, end-users; receptivity of Chinese consumers to U.S. products; the competitive situation, and market access (tariffs, non-tariff barriers, standards, taxes, distribution channels). It also contains key contact information and information on upcoming trade events related to the industry.

  18. Middle East Respiratory Syndrome and Medical Students: Letter from China

    PubMed Central

    Liu, Mengxue; Jiang, Chengsheng; Donovan, Connor; Wen, Yufeng; Wenjie, Sun

    2015-01-01

    Objectives: The present study aimed to investigate the knowledge of Middle East Respiratory Syndrome (MERS) among Chinese medical students. Methods: A structured questionnaire on MERS was conducted among 214 medical students in China. Results: The average correction of the single question varied from 36.0% to 89.7%. There is a significant difference on MERS knowledge among different majors of medical students (p < 0.05). Management students scored significantly higher than students of other majors (p < 0.05). Conclusion: Chinese medical students had good knowledge of MERS. The MERS knowledge score varied among students of different majors. Education on disease control should be included in the school curriculum. PMID:26512679

  19. Pollution from China increases cloud droplet number, suppresses rain over the East China Sea

    NASA Astrophysics Data System (ADS)

    Bennartz, Ralf; Fan, Jiwen; Rausch, John; Leung, L. Ruby; Heidinger, Andrew K.

    2011-05-01

    Rapid economic growth over the last 30 years in China has led to a significant increase in aerosol loading, which is mainly due to the increased emissions of its precursors such as SO2 and NOx. Here we show that these changes significantly affect wintertime clouds and precipitation over the East China Sea downwind of major emission sources. Satellite observations show an increase of cloud droplet number concentration from less than 200 cm-3 in the 1980s to more than 300 cm-3 in 2005. In the same time period, precipitation frequency reported by voluntary ship observers was reduced from more than 30% to less than 20% of the time. A back trajectory analysis showed the pollution in the investigation area to originate from the Shanghai-Nanjing and Jinan industrial areas. A model sensitivity study was performed, isolating the effects of changes in emissions of the aerosol precursors SO2 and NOx on clouds and precipitation using a state-of-the-art mesocale model including chemistry and aerosol indirect effects. Similar changes in cloud droplet number concentration over the East China Sea were obtained when the current industrial emissions in China were reduced to the 1980s levels. Simulated changes in precipitation were somewhat smaller than the observed changes but still significant.

  20. Environmental consequences of rapid urbanization in zhejiang province, East china.

    PubMed

    Yang, Xuchao; Yue, Wenze; Xu, Honghui; Wu, Jingsheng; He, Yue

    2014-07-01

    Since reforms carried out in the late 1970s, China has experienced unprecedented rates of urban growth. Remote sensing data and surface observational data are used to investigate the urbanization process and related environmental consequences, focusing on extreme heat events and air pollution, in Zhejiang Province (ZJP, East China). Examination of satellite-measured nighttime light data indicates rapid urbanization in ZJP during the past decade, initially forming three urban clusters. With rapid urban sprawl, a significant Urban Heat Island (UHI) effect has emerged. During extreme heat events in summer, the UHI effect significantly exacerbates nocturnal heat stress in highly urbanized areas. Taking a long-term view, urbanization also causes additional hot days and hot degree days in urban areas. Urbanization also imposes a heavy burden on local and regional air quality in ZJP. Degraded visibility and an increase in haze days are observed at most meteorological stations, especially in the three urban clusters. The results show that urbanization has led to serious environmental problems in ZJP, not only on the city scale, but also on the regional scale. Maintaining a balance between the continuing process of urbanization and environmental sustainability is a major issue facing the local government. PMID:25019266

  1. Environmental Consequences of Rapid Urbanization in Zhejiang Province, East China

    PubMed Central

    Yang, Xuchao; Yue, Wenze; Xu, Honghui; Wu, Jingsheng; He, Yue

    2014-01-01

    Since reforms carried out in the late 1970s, China has experienced unprecedented rates of urban growth. Remote sensing data and surface observational data are used to investigate the urbanization process and related environmental consequences, focusing on extreme heat events and air pollution, in Zhejiang Province (ZJP, East China). Examination of satellite-measured nighttime light data indicates rapid urbanization in ZJP during the past decade, initially forming three urban clusters. With rapid urban sprawl, a significant Urban Heat Island (UHI) effect has emerged. During extreme heat events in summer, the UHI effect significantly exacerbates nocturnal heat stress in highly urbanized areas. Taking a long-term view, urbanization also causes additional hot days and hot degree days in urban areas. Urbanization also imposes a heavy burden on local and regional air quality in ZJP. Degraded visibility and an increase in haze days are observed at most meteorological stations, especially in the three urban clusters. The results show that urbanization has led to serious environmental problems in ZJP, not only on the city scale, but also on the regional scale. Maintaining a balance between the continuing process of urbanization and environmental sustainability is a major issue facing the local government. PMID:25019266

  2. A regional ionospheric TEC mapping technique over China and adjacent areas on the basis of data assimilation

    NASA Astrophysics Data System (ADS)

    Aa, Ercha; Huang, Wengeng; Yu, Shimei; Liu, Siqing; Shi, Liqin; Gong, Jiancun; Chen, Yanhong; Shen, Hua

    2015-06-01

    In this paper, a regional total electron content (TEC) mapping technique over China and adjacent areas (70°E-140°E and 15°N-55°N) is developed on the basis of a Kalman filter data assimilation scheme driven by Global Navigation Satellite Systems (GNSS) data from the Crustal Movement Observation Network of China and International GNSS Service. The regional TEC maps can be generated accordingly with the spatial and temporal resolution being 1°×1° and 5 min, respectively. The accuracy and quality of the TEC mapping technique have been validated through the comparison with GNSS observations, the International Reference Ionosphere model values, the global ionosphere maps from Center for Orbit Determination of Europe, and the Massachusetts Institute of Technology Automated Processing of GPS TEC data from Madrigal database. The verification results indicate that great systematic improvements can be obtained when data are assimilated into the background model, which demonstrates the effectiveness of this technique in providing accurate regional specification of the ionospheric TEC over China and adjacent areas.

  3. Influence of soil moisture in eastern China on the East Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Zuo, Zhiyan; Zhang, Renhe

    2016-02-01

    The sensitivity of the East Asian summer monsoon to soil moisture anomalies over China was investigated based on ensembles of seasonal simulations (March-September) using the NCEP GCM coupled with the Simplified Simple Biosphere Model (NCEP GCM/SSiB). After a control experiment with free-running soil moisture, two ensembles were performed in which the soil moisture over the vast region from the lower and middle reaches of the Yangtze River valley to North China (YRNC) was double and half that in the control, with the maximum less than the field capacity. The simulation results showed significant sensitivity of the East Asian summer monsoon to wet soil in YRNC. The wetter soil was associated with increased surface latent heat flux and reduced surface sensible heat flux. In turn, these changes resulted in a wetter and colder local land surface and reduced land-sea temperature gradients, corresponding to a weakened East Asian monsoon circulation in an anomalous anticyclone over southeastern China, and a strengthened East Asian trough southward over Northeast China. Consequently, less precipitation appeared over southeastern China and North China and more rainfall over Northeast China. The weakened monsoon circulation and strengthened East Asian trough was accompanied by the convergence of abnormal northerly and southerly flow over the Yangtze River valley, resulting in more rainfall in this region. In the drier soil experiments, less precipitation appeared over YRNC. The East Asian monsoon circulation seems to show little sensitivity to dry soil anomalies in NCEP GCM/SSiB.

  4. Two new species of the genus Stenichnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae) from Zhejiang, East China.

    PubMed

    Wang, Dan; Li, Li-Zhen

    2016-01-01

    Two new species of the glandulariine genus Stenichnus are described: St. zhejiangensis sp. n. and St. donggonganus sp. n., both of which are discovered from Zhejiang Province, East China. PMID:27470876

  5. Phytoplankton assemblage of Yangtze River Estuary and the adjacent east China sea in summer, 2004

    NASA Astrophysics Data System (ADS)

    Luan, Qingshan; Sun, Jun; Shen, Zhiliang; Song, Shuqun; Wang, Min

    2006-04-01

    A cruise was conducted from late August to early September 2004 with the intention of obtaining an interdisciplinary understanding of the Yangtze River Estuary including the biological, chemical and physical subjects. Water sample analysis indicated that total phytoplankton species richness was 137. Of them 81 were found in Bacillariophyta and 48 in Pyrrophyta, accounting for 59.1% and 35.0% respectively. The average cell abundance of surface water samples was 8.8×104 cells L-1, with the maximum, 102.9×104 cells L-1, encountered in the area (31.75°N, 122.33°E) and the minimum, 0.2×104 cells L-1, in (30.75°N, 122.17°E). The dominant species at most stations were Skeletonema costatum and Proboscia alata f. gracillima with the dominance of 0.35 and 0.27. Vertical distribution analysis indicated that obvious stratification of cell abundance and dominant species was found in the representative stations of 5, 18 and 33. Shannon-Wiener index and evenness of phytoplankton assemblage presented negative correlation with the cell abundance, with the optimum appearing in (30.75°N, 122.67°E). According to the PCA analysis of the environmental variables, elevated nutrients of nitrate, silicate and phosphate through river discharge were mainly responsible for the phytoplankton bloom in this area.

  6. Coastal upwelling in the East China Sea in winter

    NASA Astrophysics Data System (ADS)

    Qiao, Fangli; Yang, Yongzeng; Lü, Xingang; Xia, Changshui; Chen, Xianyao; Wang, Baodong; Yuan, Yeli

    2006-11-01

    The dynamic mechanisms of the upwelling off the East China Sea (ECS) coast in wintertime are studied. First, the upwelling signals off the ECS coast are identified by the observed temperature, salinity, nutrients, and dissolved oxygen data obtained during the cruises in January 1999. The MASNUM wave-tide-circulation coupled model is then employed to simulate the hydrography of the ECS. Comparisons between the simulations and observations show that the model performance is satisfactory. On the basis of successful simulation, four numerical experiments are conducted to investigate the upwelling mechanisms. The results suggest that the density (or salinity) front, which separates the inshore Low Salinity Coastal Water and the offshore Taiwan Warm Current (TWC), is the primary inducement for the upwelling. Owing to strong density gradient, the baroclinic pressure gradient force (PGF) is quite large near the frontal zone, and this PGF elicits an upwelling branch along the topography slope. Wind, TWC, and tide affect the density front in extension and intensity, thus exerting subsidiary influences on the upwelling. According to Ekman's theory, the northerly monsoon is downwelling favorable. However, the net effects of wind on the upwelling off the ECS coast in winter are positive because it drives the Changjiang River Diluted Water (CDW) flowing southward and forms the density front. Similarly, the resultant effects of TWC on the upwelling are negative for obstructing the pathway of CDW. Tide contributes to the upwelling because tidal mixing facilitates the expansion of CDW.

  7. Wave retrieval from SAR imagery in the East China Sea

    NASA Astrophysics Data System (ADS)

    Lou, Xiulin; Chang, Junfang; Liu, Xiaoyan

    2015-12-01

    Synthetic aperture radar (SAR) plays an important role in measuring directional ocean wave spectra with continuous and global coverage. In this article, satellite SAR images were used to estimate the wave parameters in the East China Sea. The Max-Planck Institut (MPI) method was applied to retrieve directional wave spectra from the SAR imagers with the Simulating WAves Nearshore (SWAN) model data as the first guess wave spectra. In order to validate the SAR retrieved wave spectra, a set of buoy measurements during the SAR imaging times was collected and used. The SAR retrieved significant wave heights (SWHs) were analyzed against the buoy measurements to assess the wave retrieval of this study. The root-mean-square error between the SAR SWHs and the buoy measurements is 0.25 m, which corresponds to a relative error of 12%. The case study here shows that the SWAN model data is a potential first guess wave spectra source to the MPI method to retrieve ocean wave spectra from SAR imagery.

  8. Turbulence in the East China Sea: The summertime stratification

    NASA Astrophysics Data System (ADS)

    Lozovatsky, Iossif; Lee, Jae-Hak; Fernando, H. J. S.; Kang, Sok Kuh; Jinadasa, S. U. P.

    2015-03-01

    A series of 134 microstructure profiles were taken in the central East China Sea from a drifting ship, covering more than 12 miles over the sloping bottom. The water depth z varied in the range 52-62 m; the tidal elevation of semidiurnal component was ±1 m. Prior to the onset of 25 h drift, a hydrographic section consisting of 9 stations, 15 miles apart, was taken in the area. A shallow mixed surface layer (SL) underlain by a diurnal pycnocline (z < 13 m), a sharp thermohalocline (13 < z < 30 m), and about 20 m tall bottom boundary layer (BBL) were the main features of summertime stratification. The splitting of upper pycnocline by a warmer, saltier intrusion led to the generation of turbulent patches at the lower, but not at the upper, density interface of this water body, suggesting asymmetry of mixing across the intrusion. In a limited range of the normalized squared buoyancy frequency, 2(N2/N02>)-3, where ɛm=4×10-6 W/kg and N0=5×10-3 s-1. Measurements in the sharp pycnocline and in lesser-stratified transitional layers between the pycnocline and the SL and BBL show that the cumulative distribution functions CDF(log10ɛ) can be modeled either by the generalized extreme value (GEV) distribution or the lognormal distribution.

  9. Ice-forming nuclei over the East China Sea

    NASA Astrophysics Data System (ADS)

    Rosinski, J.; Nagamoto, C. T.; Zhou, M. Y.

    Ice-forming nucleus (IFN) population was determined for aerosol particles collected on filters over the East China Sea. The mode of ice nucleation studied was condensation-followed-by-freezing; experiments were performed in a dynamic chamber at a constant temperature and with continuous cooling at Sw=0.3%. Ratios of IFN concentrations determined at a constant temperature to those determined during continuous cooling simulating an updraft were close to one (35%) and larger than one (65%). Ratios close to one indicate the absence of any deactivation of IFN during the growth of droplets; for ratios larger than one the dilution takes place during the entire cooling process, thus producing more dilute solutions of water-soluble salts in droplets and apparently deactivating some ice nucleating sites. IFN concentration maxima were found at 0600 and 1800 local time. Concentrations of IFN were found to be inversely proportional to the amount of air pollutants, but at a very high SO 42- ion concentration IFN concentrations increased.

  10. Contact Tracing for Imported Case of Middle East Respiratory Syndrome, China, 2015

    PubMed Central

    Kang, Min; Zhong, Haojie; Hou, Jie; Wang, Jun; Li, Jiansen; Wu, Jie; He, Jianfeng; Lin, Jinyan; Zhang, Yonghhui

    2016-01-01

    Confirmation of an imported case of infection with Middle East respiratory syndrome coronavirus in China triggered intensive contact tracing and mandatory monitoring. Using a hotline and surveillance video footage was effective for tracing all 110 identified contacts. Contact monitoring detected no secondary transmission of infection in China. PMID:27532887

  11. Contact Tracing for Imported Case of Middle East Respiratory Syndrome, China, 2015.

    PubMed

    Kang, Min; Song, Tie; Zhong, Haojie; Hou, Jie; Wang, Jun; Li, Jiansen; Wu, Jie; He, Jianfeng; Lin, Jinyan; Zhang, Yonghhui

    2016-09-01

    Confirmation of an imported case of infection with Middle East respiratory syndrome coronavirus in China triggered intensive contact tracing and mandatory monitoring. Using a hotline and surveillance video footage was effective for tracing all 110 identified contacts. Contact monitoring detected no secondary transmission of infection in China. PMID:27532887

  12. Influence of different water masses on planktonic ciliate distribution on the East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Zhang, Cuixia; Zhang, Wuchang; Ni, Xiaobo; Zhao, Yuan; Huang, Lingfeng; Xiao, Tian

    2015-01-01

    In summer 2006 and winter 2007, ciliate abundance and biomass were investigated in the East China Sea in connection with water masses, frontal zones, dissolved oxygen and chlorophyll a concentrations, and picoplankton and nanoflagellate abundances. In addition, tintinnid ciliates were identified to species based on lorica morphology. There was no significant difference of ciliate abundance and biomass between Changjiang diluted water (CDW) and shelf mixing water (SMW) in the Changjiang river estuary and its adjacent sea in summer, or among the coastal water (CoW), the SMW and the Kuroshio water (KW) on the shelf in winter. The influence of water masses on ciliate distribution was slight, except that distinct increases in ciliate abundance were observed in the vicinity of frontal structures. Most tintinnids were neritic species, with no discrimination between two water masses in the Changjiang river estuary. However, cosmopolitan and warm water species were very mainly restricted to SMW and KW; neritic species were essentially present in CoW and SMW on the continental shelf. Total ciliate biomass was closely correlated with picoplankton biomass in the CDW and KW. Picoeukaryotes and Synechococcus were the potential food source of ciliates. In winter, within KW, nanoflagellates would play a major role in the transfer of organic matter from picoplankton to ciliates in the microbial community within KW. In the low-oxygen and hypoxia area adjacent to the Changjiang estuary where relatively high ciliate abundance and biomass occurred, heterotrophic bacteria would appear to exhibit a potential prey effect on the distribution of bacterivorous aloricated ciliates and nanoflagellates acting as intermediates between bacteria and tintinnids.

  13. Cenozoic Tectono-stratigraphic sequences of the Shelf Rift Basin, East China Sea

    SciTech Connect

    Armentrout, J.M.; Prebish, M.; Cunningham, A.C.; Echols, R.J.; Braithwaite, P.; Sarg, J.F. ); Norris, J.W.; Letsch, D.K.; Bracken, B.B.; Denison, C.N. )

    1994-07-01

    The Tertiary section of the Jiaojiang, Qiantang, and Fushi depressions of the East China Sea Basin consists of at least eight rift-related depositional sequences identified seismically by regional onlap and truncation surfaces. Delineation of these sequences is based on interpretation of multifold seismic reflection profile data calibrated with several wells, including the Wenzhou 6-1-1 well. Upper Cretaceous( ) to Eocene synrift graben-restricted strata consist of two tectonically enhanced unconformity bounded sequences as evidenced by large angular discontinuities between each sequence. Discontinuous inclined-reflection seismic facies adjacent to the hanging wall correlate with nonmarine conglomeratic sandstone and are interpreted as possible alluvial fan facies. High-amplitude parallel reflections within the graben axes correlate with coaly siltstone strata and are interpreted as coastal plain and possibly lacustrine facies with source rock potential. Clinoform seismic facies prograding from the northwest footwall correlate with nonmarine to marginal marine conglomerate, sandstone, and siltstone, and are interpreted as possible delta or fan-delta facies with reservoir potential.

  14. Sedimentation rate control on diagenesis, East China Sea sediments

    NASA Astrophysics Data System (ADS)

    Zheng, Yan; Zheng, Hongbo; Kissel, Catherine; Laj, Carlo

    2011-08-01

    Diagenesis of ferrimagnetic minerals can alter the magnetic properties, erasing partially or entirely the original paleomagnetic and paleoclimatic signals, especially on continental margins where sedimentation rates are usually high. Understanding the mechanisms by which magnetic particles are affected by diagenesis is therefore critical for retrieving paleomagnetic and paleoclimatic information from sediments. High-resolution magnetic analysis was carried out on rapidly deposited (0.4-20 mm/year) Holocene sediments from the East China Sea (ECS) inner continental shelf. The primary magnetic mineral assemblage in the sediment core contains ferrimagnetic minerals, such as magnetite, with minor contributions from hematite. The magnetic properties vary down-core in two steps, due to post-depositional reductive diagenesis. The first occurs at depths of 0.15-1.1 m and is characterized by reduction of both magnetite and hematite in suboxic sediments. The suboxic-sulfate boundary (SSB) is therefore located at 1.1 m. We demonstrate that the depth of the SSB has negative relation to the average sedimentation rate in Chinese marginal seas. The second step change in magnetic properties occurs at 3.2-5.8 m, and contains two intervals with extremely low magnetic mineral content, each corresponding to dissolution fronts associated with the former and present position of the sulfate-methanic transition (SMT). These two intervals correlate well with abrupt changes in sedimentation rate and separate the anoxic zone into two parts: the sulfidic zone and the methanic zone. Our study suggests that sedimentation rate provides a dominant control on magnetic mineral diagenesis, at least in the Chinese marginal seas, which controls not only the type of redox zonation, but also the thicknesses of diagenetic zones.

  15. Wave climatological analysis in the East China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Dong, Changming; He, Yijun

    2016-06-01

    The ERA-40 and ERA-Interim datasets from ECMWF (European Centre for Medium-Range Weather Forecasts) are used to study the wave and wind climate in the East China Sea (ECS). The temporal and spatial variablities in the wave and wind fields on multiple scales from the intraseasonal to decadal are discussed in detail. The results show that the wave height and the wind speed are highly correlated, especially in winter. For interannual and decadal scale, the wind and wave in the ECS is strongly influenced by the ENSO and PDO with the negative correlation. The trend spatial distributions of the mean state and extreme events are presented with wave height increase by 0.005-0.01 m a-1 in most of the ECS from 1979 to 2014. The influence of typhoon on the extreme wave is significant. Vector empirical orthogonal function (VEOF) methods are used to analyze the primary three modes of wave and wind variability. Because the monthly values are filtered the fluctuation with period shorter than 14 months before VEOF analysis, the three modes presents interannual variations. The first mode is presented as the wind blowing from land to sea or from sea to land. The second mode reflects the asymmetry of winter and summer monsoon for wind and wave. And the third mode presents as a cyclone located near 28°N which caused by a cyclonic eddy existing in the north of the ECS. The waves are further categorized based on quasi-wave age. The wind waves and swell distributions display obvious differences in different seasons. The wind waves are found to be dominated in autumn and winter in the ECS.

  16. Antimony and arsenic biogeochemistry in the East China Sea

    NASA Astrophysics Data System (ADS)

    Ren, Jing-Ling; Zhang, Xu-Zhou; Sun, You-Xu; Liu, Su-Mei; Huang, Daji; Zhang, Jing

    2016-02-01

    The biogeochemical cycles of the metalloid elements arsenic and antimony in the East China Sea (ECS), one of the most important marginal seas for western Pacific, were examined in May 2011. Dissolved inorganic arsenic (As(V) and As(III)) and antimony (Sb(V) and Sb(III)) species were determined by selective hydride generation-atomic fluorescence spectrometry (HG-AFS). Results show that total dissolved inorganic arsenic (TDIAs; [TDIAs]=[As(V)]+[As(III)]) were moderately depleted in the surface water and enriched in the deep water. Arsenite (As(III)) showed different vertical profiles with that of TDIAs, with significant surface enrichment in the middle shelf region where the concentrations of phosphate were extremely low. Speciation of dissolved arsenic was subtly controlled by the stoichiometric molar ratio of arsenate (As(V)) to phosphate. The average As(V)/P ratio for the ECS in spring 2011 was 10.8×10-3, which is higher than previous results and indicates the arsenate stress. The concentrations of total dissolved inorganic antimony (TDISb; [TDISb]=[Sb(V)]+[Sb(III)]) were high near the Changjiang Estuary and the coastal area of Hangzhou Bay and decreased moderately off the coast. TDISb displayed moderate conservative behavior in the ECS that confirms by the correlations with salinity and dissolved aluminum. Different with that of As(III), antimonite (Sb(III)) concentrations were extremely lower in the ECS, with relative higher concentration appeared at the bottom layer which indicates the contribution from sediment-water interface. A preliminary box model was established to estimate the water-mass balance and antimony budgets for the ECS. Compared with other areas in the world, the concentrations of dissolved inorganic arsenic and antimony in the ECS remain at natural levels.

  17. Teaching West in the East: An American University in China

    ERIC Educational Resources Information Center

    Ozturgut, Osman

    2007-01-01

    Having closed its door to Western ideas for centuries, China has always presented itself as a puzzle both for academicians and politicians. Westerners, though, have always been attracted by the natural resources and human power that China offers to the capitalistic world. This study explores the entrance of Western ideas in China from an…

  18. Processes and mechanisms of persistent extreme precipitation events in East China

    NASA Astrophysics Data System (ADS)

    Zhai, Panmao; Chen, Yang

    2014-11-01

    This study mainly presents recent progresses on persistent extreme precipitation events (PEPEs) in East China. A definition focusing both persistence and extremity of daily precipitation is firstly proposed. An identification method for quasi-stationary regional PEPEs is then designed. By utilizing the identified PEPEs in East China, typical circulation configurations from the lower to the upper troposphere are confirmed, followed by investigations of synoptic precursors for key components with lead time of 1-2 weeks. Two characteristic circulation patterns responsible for PEPEs in East China are identified: a double blocking high type and a single blocking high type. They may account for occurrence of nearly 80% PEPEs during last 60 years. For double blocking high type, about two weeks prior to PEPEs, two blockings developed and progressed towards the Ural Mountains and the Sea of Okhotsk, respectively. A northwestward progressive anomalous anticyclone conveying abundant moisture and eastward-extended South Asia High favoring divergence can be detected about one week in advance. A dominant summertime teleconnection over East Asia, East Asia/ Pacific (EAP) pattern, is deemed as another typical regime inducing PEPEs in the East China. Key elements of the EAP pattern initiated westward movement since one week prior to PEPEs. Eastward energy dispersion and poleward energy dispersion contributed to early development and subsequent maintenance of this teleconnection pattern, respectively. These typical circulation patterns and significant precursors may offer local forecasters some useful clues in identifying and predicting such high-impact precipitation events about 1-2 weeks in advance.

  19. Distribution of the East China Sea continental shelf basins and depths of magnetic sources

    NASA Astrophysics Data System (ADS)

    Lin, J.-Y.; Sibuet, J.-C.; Hsu, S.-K.

    2005-11-01

    The acoustic basement map of the East China Sea, established by the Shanghai Offshore Petroleum Bureau with all available industry seismic data, shows the existence of a 30-km-wide, 10-km-deep basin, that we named the Ho Basin. The Ho Basin belongs to a series of elongated deep basins extending over 600 km east of the Taiwan-Sinzi Ridge and flanked to the East by a ridge named the Longwan Ridge in its northern part. This new system of basin and ridge was probably formed during middle Miocene, sometimes in between rifting episodes occurring in the Taipei Basin and Okinawa Trough. It complements the already defined system of five belts of backarc basins and associated arc volcanic ridges in the East China Sea, which are progressively younger from the Mainland China shoreline (late Cretaceous/early Tertiary) to the Okinawa Trough (Present). In order to determine the crustal thickness beneath the East China Sea continental shelf, we used a power spectrum method to calculate the depth of the top (Zt) and the centroid (Zo) of the magnetic basement by fitting a straight line through the high- and low-wave number portions of the power spectrum, respectively. Then, the depth of the base (Zb)is estimated from Zt and Zo. After optimizing the size of the data squares, we demonstrate that, except for basins more than 10 km deep, Zt corresponds to the basement depths and Zb, the depth of the Curie point, to the Moho depth. As wide-angle reflection and refraction data are scarce in the East China Sea, this method provides a way to characterize the crustal thickness of the East China Sea and to compute the theoretical heat flow values.

  20. Suspended sediment concentration mapping based on the MODIS satellite imagery in the East China inland, estuarine, and coastal waters

    NASA Astrophysics Data System (ADS)

    Yang, Xianping; Sokoletsky, Leonid; Wei, Xiaodao; Shen, Fang

    2016-04-01

    The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration (SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters. For this aim, three important tasks are formulated and solved: 1) an estimation of remote-sensing reflectance spectra R rs(λ) after atmospheric correction; 2) an estimation of R rs(λ) from the radiometric signals above the air-water surface; and 3) an estimation of SSC from R rs(λ). Six different models for radiometric R rs(λ) determination and 28 models for SSC versus R rs(λ) are analyzed based on the field observations made in the Changjiang River estuary and its adjacent coastal area. The SSC images based on the above-mentioned analysis are generated for the area.

  1. Future acidification of marginal seas: A comparative study of the Japan/East Sea and the South China Sea

    NASA Astrophysics Data System (ADS)

    Luo, Yiming; Boudreau, Bernard P.

    2016-06-01

    The response of marginal (peripheral) seas to ocean acidification on short and long time scales is not well established. Through modeling, we examine the future acidification of two adjacent marginal seas, the South China Sea (SCS) and the Japan/East Sea (J/ES). Our results illustrate the importance of unique features in determining their acidification. The J/ES basin will become completely undersaturated with regard to calcite rapidly in the next few decades, while the SCS basin will experience relatively slower acidification. During its acidification, the J/ES will continually act as a sink for atmospheric CO2, whereas the SCS will temporarily switch from a source to a sink during the peak pCO2 interval, only to return slowly to being a source again. Marginal sea acidification will be determined by multiple factors, including their connections with the open ocean and their unique physical and biogeochemical dynamics, in addition to the level of atmospheric CO2.

  2. Distinguishing Terrestrial Organic Carbon in Marginal Sediments of East China Sea and Northern South China Sea

    NASA Astrophysics Data System (ADS)

    Kandasamy, Selvaraj; Lin, Baozhi; Wang, Huawei; Liu, Qianqian; Liu, Zhifei; Lou, Jiann-Yuh; Chen, Chen-Tung Arthur; Mayer, Lawrence M.

    2016-04-01

    Knowledge about the sources, transport pathways and behavior of terrestrial organic carbon in continental margins adjoining to large rivers has improved in recent decades, but uncertainties and complications still exist with human-influenced coastal regions in densely populated wet tropics and subtropics. In these regions, the monsoon and other episodic weather events exert strong climatic control on mineral and particulate organic matter delivery to the marginal seas. Here we investigate elemental (TOC, TN and bromine-Br) and stable carbon isotopic (δ13C) compositions of organic matter (OM) in surface sediments and short cores collected from active (SW Taiwan) and passive margin (East China Sea) settings to understand the sources of OM that buried in these settings. We used sedimentary bromine to total organic carbon (Br/TOC) ratios to apportion terrigenous from marine organic matter, and find that Br/TOC may serve as an additional, reliable proxy for sedimentary provenance in both settings. Variations in Br/TOC are consistent with other provenance indicators in responding to short-lived terrigenous inputs. Because diagenetic alteration of Br is insignificant on shorter time scales, applying Br/TOC ratios as a proxy to identify organic matter source along with carbon isotope mixing models may provide additional constraints on the quantity and transformation of terrigenous organics in continental margins. We apply this combination of approaches to land-derived organic matter in different depositional environments of East Asian marginal seas.

  3. Response of Biogeochemical Cycles and Ecosystem in the East China Sea to Multi-stressors

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Huang, Daji; Xiao, Tian; Liu, Su Mei; Fang, Jianguang

    2016-02-01

    This editorial article introduces the research progress of IMBER-China Study on "Sustainability of Marine Ecosystem Production under Multi-stressors and Adaptive Management" (MEcoPAM), funded by the Ministry of Science and Technology of China (MoST-China No. 2011CB409800). There are 12 research articles in this Special Issue of Deep-Sea Research II on the "East China Sea", which provide the reader with snapshots of "Impact of Multi-stressors on the Structure and Function of Marine Ecosystems", one of research foci of MEcoPAM in the period of 2011-2015.

  4. Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000.

    SciTech Connect

    Lu, Z.; Streets, D. G.; Zhang, Q.; Wang, S.; Carmichael, G. R.; Cheng, Y. F.; Wei, C.; Chin, M.; Diehl, T.; Tan, Q.; Decision and Information Sciences; Tsinghua Univ.; Univ. of Iowa; NASA Goddard Space Flight Center

    2010-01-01

    With the rapid development of the economy, the sulfur dioxide (SO{sub 2}) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO{sub 2} emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO{sub 2} emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO{sub 2} in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of flue-gas desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO{sub 2} emission in China is consistent with the trends of SO{sub 2} concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO{sub 2} and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO{sub 2} concentration in Japan is found during 2000-2007, indicating that the decrease of urban SO{sub 2} is lower in areas close to the Asian continent. This implies that the transport of increasing SO{sub 2} from the Asian continent partially counteracts the local reduction of SO{sub 2} emission downwind. The aerosol optical depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the surface solar radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO{sub 2} emission in East Asia. The trends of AOD from both satellite retrievals and model over

  5. Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000

    NASA Astrophysics Data System (ADS)

    Lu, Z.; Streets, D. G.; Zhang, Q.; Wang, S.; Carmichael, G. R.; Cheng, Y. F.; Wei, C.; Chin, M.; Diehl, T.; Tan, Q.

    2010-04-01

    With the rapid development of the economy, the sulfur dioxide (SO2) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO2 emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO2 emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO2 in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of Flue-Gas Desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO2 emission in China is consistent with the trends of SO2 concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO2 and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO2 concentration in Japan is found during 2000-2007, indicating that the decrease of urban SO2 is lower in areas close to the Asian continent. This implies that the transport of increasing SO2 from the Asian continent partially counteracts the local reduction of SO2 emission downwind. The Aerosol Optical Depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the Surface Solar Radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO2 emission in East Asia. The trends of AOD from both satellite retrievals and model over East Asia are also consistent with the trend of SO2 emission in China

  6. Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000

    NASA Astrophysics Data System (ADS)

    Lu, Z.; Streets, D. G.; Zhang, Q.; Wang, S.; Carmichael, G. R.; Cheng, Y. F.; Wei, C.; Chin, M.; Diehl, T.; Tan, Q.

    2010-07-01

    With the rapid development of the economy, the sulfur dioxide (SO2) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO2 emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO2 emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO2 in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of flue-gas desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO2 emission in China is consistent with the trends of SO2 concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO2 and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO2 concentration in Japan is found during 2000-2007, indicating that the decrease of urban SO2 is lower in areas close to the Asian continent. This implies that the transport of increasing SO2 from the Asian continent partially counteracts the local reduction of SO2 emission downwind. The aerosol optical depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the surface solar radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO2 emission in East Asia. The trends of AOD from both satellite retrievals and model over East Asia are also consistent with the trend of SO2 emission in China

  7. East-China Geochemistry Database (ECGD):A New Networking Database for North China Craton

    NASA Astrophysics Data System (ADS)

    Wang, X.; Ma, W.

    2010-12-01

    North China Craton is one of the best natural laboratories that research some Earth Dynamic questions[1]. Scientists made much progress in research on this area, and got vast geochemistry data, which are essential for answering many fundamental questions about the age, composition, structure, and evolution of the East China area. But the geochemical data have long been accessible only through the scientific literature and theses where they have been widely dispersed, making it difficult for the broad Geosciences community to find, access and efficiently use the full range of available data[2]. How to effectively store, manage, share and reuse the existing geochemical data in the North China Craton area? East-China Geochemistry Database(ECGD) is a networking geochemical scientific database system that has been designed based on WebGIS and relational database for the structured storage and retrieval of geochemical data and geological map information. It is integrated the functions of data retrieval, spatial visualization and online analysis. ECGD focus on three areas: 1.Storage and retrieval of geochemical data and geological map information. Research on the characters of geochemical data, including its composing and connecting of each other, we designed a relational database, which based on geochemical relational data model, to store a variety of geological sample information such as sampling locality, age, sample characteristics, reference, major elements, rare earth elements, trace elements and isotope system et al. And a web-based user-friendly interface is provided for constructing queries. 2.Data view. ECGD is committed to online data visualization by different ways, especially to view data in digital map with dynamic way. Because ECGD was integrated WebGIS technology, the query results can be mapped on digital map, which can be zoomed, translation and dot selection. Besides of view and output query results data by html, txt or xls formats, researchers also can

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

    PubMed Central

    Lu, Xiaoling; Liu, Xiaoyu; Long, Cong; Wang, Guoxiang; Gao, Yun; Liu, Junhua; Jiao, Binghua

    2011-01-01

    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. PMID:21789045

  9. Characterization of carbonaceous aerosols over the East China Sea: The impact of the East Asian continental outflow

    NASA Astrophysics Data System (ADS)

    Wang, Fengwen; Guo, Zhigang; Lin, Tian; Hu, Limin; Chen, Yingjun; Zhu, Yifang

    2015-06-01

    Seventy-five paired PM2.5 (aerodynamic diameter less than 2.5 μm) and TSP (total suspended particle) samples collected from a pristine island in the East China Sea (ECS) between October 2011 and August 2012 were analyzed for organic carbon (OC), elemental carbon (EC), and n-alkanes. The island lies in the pathway of continental outflow from Mainland China to the northwest Pacific Ocean driven by the East Asian Monsoon. The concentrations of OC, EC (in μg/m3), and n-alkanes (in ng/m3) were highest in winter (means: 4.7, 1.3, 140.1, respectively) and lowest in summer (means: 1.1, 0.3, 17.0, respectively). PM2.5 contained approximately 88% of the OC, 80% of the EC, and 61% of the n-alkanes in TSP. Petroleum residue was the dominant contributor to the n-alkanes. C12-C22n-alkanes with strong even-to-odd predominance observed in winter were attributed to the microbial contribution from sea spray aerosol (SSA) driven by the higher wind speed. There was a higher secondary organic carbon (SOC)/OC ratio in warm seasons (summer and fall) than that in cold seasons (spring and winter). The dominance of primary organic carbon (POC) and EC in cold seasons was possibly mainly due to the influence of the East Asian continental outflow. Three episodes of high concentrations of carbonaceous aerosols were observed, and we focused on the impact of these pollutants from East Asia on the air quality over the ECS. Carbonaceous pollutants were more concentrated in PM2.5 during the fall episode triggered by biomass burning in East China. The winter haze associated with intensive indoor heating in North China brought substantial carbonaceous pollutants, with a minor influence on their size distribution. The dust episode in spring was related to coarse particles (i.e., TSP-PM2.5), yielding a distinctly different size distribution.

  10. Impact of East Asian Summer Monsoon on the Air Quality over China: View from space

    SciTech Connect

    Zhao, Chun; Wang, Yuhang; Yang, Qing; Fu, Rong; Cunnold, Derek; Choi, Yunsoo

    2010-05-04

    Tropospheric O3 columns retrieved from OMI and MLS measurements, CO columns from MOPITT, and tropospheric O3 and CO concentrations from TES from May to August in 2006 are analyzed using the Regional chEmical and trAnsport Model (REAM) to investigate the impact of the East Asian summer monsoon on the air quality over China. The observed and simulated migrations of O3 and CO are in good agreement, demonstrating that the summer monsoon significantly affects the air quality over southeastern China and this influence extends to central East China from June to July. Enhancements of CO and O3 over southeastern China disappear after the onset of the summer monsoon and re-emerge in August after the monsoon wanes. The pre-monsoon high O3 concentrations over southern China are due to photochemical production from pollutant emissions and the O3 transport from the stratosphere. In the summer monsoon season, the O3 concentrations are relatively low over monsoon-affected regions because of the transport of marine air masses and weak photochemical activity. We find that the monsoon system strongly modulates the pollution problem over a large portion of East China in summer, depending on its strength and tempo-spatial extension. Model results also suggest that transport from the stratosphere and long-range transport from East China and South/Central Asia all make significant contributions to O3 enhancements over West China. Satellite observations provide valuable information for investigating the monsoon impact on air quality, particularly for the regions with limited in situ measurements.

  11. A new species of Syndicus (s. str.) Motschulsky (Coleoptera, Staphylinidae, Scydmaeninae) from East China.

    PubMed

    Yin, Zi-Wei; Song, Xiao-Bin; Li, Li-Zhen

    2014-01-01

    Syndicus (s. str.) jaloszynskii Yin and Song, new species is described from Fujian and Zhejiang, East China. All material was collected in rotten woods. The habitus of both sexes, aedeagus, and spermatheca are illustrated. The new species can be readily separated from all known congeners by the strikingly large body size, the structure of aedeagal endophallus, and the form of spermatheca. This is the first species of the nominotypical subgenus of Syndicus known to occur in China. PMID:24943429

  12. Discussion on origin of Pn velocity variation in China and adjacent region

    NASA Astrophysics Data System (ADS)

    Pei, Shun-Ping; Xu, Zhong-Huai; Wang, Su-Yun

    2004-01-01

    Pn velocity lateral variation and anisotropy images were reconstructed by adding about 50 000 travel times from the regional seismic networks to the datum set of near 40 000 travel times from National Seismic Network of China used by WANG, et al. We discussed the relation of Pn velocity variation to Moho depth, Earth’s heat flow, distribution of Cenozoic volcanic rock and the result of rock experiment under high pressure and high temperature. The result of quantitative analysis indicates that Pn velocity is positively correlated with the crust thickness and negatively correlated with the Earth’s heat flow. Two linear regression equations, one between Pn velocity and crust thickness, and the other between Pn velocity and heat flow, were obtained. The rate of variation of Pn velocity ν p with pressure P, ∂ ν p/∂ P, estimated from the velocity variation with crust thickness, ∂ ν p/∂ H is close to the result obtained from the rock experiment under high pressure and high temperature. If the effect of crust thickness on Pn velocity is deducted from the velocity variation, then the low Pn velocity beneath Qinghai-Xizang plateau is more notable. The low Pn velocity regions well agree with the Cenozoic volcanic rock. In the several regions with significant anisotropy, the direction of fast Pn velocity is consistent with the orientation of maximum principal crustal compressive stress, and also with the direction of present-day crustal movement. It indicates that the fast Pn velocity direction may be related to the deformation or flow of top mantle material along the direction of maximum pressure.

  13. Nutrient dynamics from the Changjiang (Yangtze River) estuary to the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Su Mei; Qi, Xiao Hong; Li, Xiaona; Ye, Hao Ran; Wu, Ying; Ren, Jing Ling; Zhang, Jing; Xu, Wei Yi

    2016-02-01

    Water and sediment samples were collected from the Changjiang (Yangtze River) estuary and the adjacent East China Sea during impoundment of the river at the Three Gorges Dam. The concentrations of dissolved inorganic and organic nutrients, and particulate inorganic phosphorus and particulate organic phosphorus in the water column (PIP and POP, respectively) and sediments (SIP and SOP, respectively) were analyzed. The nutrient dynamics in salt marshes associated with the Changjiang estuary were also considered. In addition, river water samples were collected bimonthly in the lower reaches of the Changjiang. The concentrations of dissolved inorganic nutrients, PIP and POP showed temporal and spatial variations, which decreased from the coast to offshore areas. The dissolved organic nitrogen and phosphorus (P) concentrations showed patchy distributions, but were consistent with the distribution of phytoplankton biomass. Phosphorus is the major limiting element for phytoplankton growth. Among the various P forms, particulate P represented 38-52% of total P. The PIP and POP concentrations showed clear seasonal variations corresponding to the occurrence of the levels of suspended particulate matter. The P accumulation rates showed a decreasing trend from the coast to offshore areas, and high P burial efficiencies were found; the latter were related to a low benthic PO43 - flux and high sediment accumulation rates. The potential bioavailable P was estimated to be 65-70% of total P, of which more than two-thirds was regenerated in the water column. The salt marsh in the Changjiang estuary plays an important ecological role in nutrient transport from the river to offshore areas, and increased P limitation.

  14. Coastal Seafloor Observatory Of The East China Sea At Xiaoqushan And Its Primary Observations

    NASA Astrophysics Data System (ADS)

    Xu, H.; Xu, C.; Qin, R.; Zhang, Y.; Chen, H.

    2010-12-01

    The seafloor observation system becomes increasingly important infrastructure in ocean sciences, which transforms oceanic research from temporal investigation to long term observation. The East China Sea coastal seafloor observatory, located between 30°31'44"N,122°15'12"E and 30°31'34"N,122°14'40"E, is built near the Xiaoqushan island outside the Yangtze River estuary, on the inner East China Sea continental shelf. The East China Sea coastal seafloor observatory is part of the East China Sea seafloor observational network. The observatory consists of a composite power cable made of optical fiber and extending for more than 1 kilometer and a special junction box, which provide power and signal communication for different instruments. The special junction box, which has various waterproof plugs, connects to three different instruments installed in a trawl preventer. The submarine optical fiber composite power cable is landed on the platform by The East China Sea Branch, State Oceanic Administration of the People’s Republic of China, and the power is continuously supplied by the solar panels and solar battery on the top of the platform. The real time data are directly sent through the cable to the platform and are transmitted by CDMA wireless to the receiver at the State Key Laboratory of Marine Geology of Tongji University. Measurements at the observatory have been taken since 26 April, 2009. The observations include current speeds and their directions at different depths, suspended sediment concentration, temperature and salinity nearby the seabed. The more than one year preliminary results show that the current field and fine suspended sediment transport of East China Sea are complex and show considerable seasonal variation affected by the integrated influence of Changjiang diluted water, Taiwan warm current and the Yellow Sea coastal current. The successful establishment of the coastal seafloor observatory is the first step toward future development of the

  15. Accumulation of steroid hormones in soil and its adjacent aquatic environment from a typical intensive vegetable cultivation of North China.

    PubMed

    Zhang, Feng-Song; Xie, Yun-Feng; Li, Xue-Wen; Wang, Dai-Yi; Yang, Lin-Sheng; Nie, Zhi-Qiang

    2015-12-15

    Steroid hormones released from manure agricultural application are a matter of global concern. The residual levels of steroid hormones were studied in a typical intensive vegetable cultivation area in northeast China, with a long history of heavy manure application. Seven steroids (estrone, 17α-estradiol, 17β-estradiol, estriol, testosterone, androstendione and progesterone) were analyzed from soil sampled from vegetable greenhouses, from sediments and water from the adjacent drainage ditch and from the groundwater. The results showed that target steroids were detected in the soil samples, with detection frequencies varying from 3.13 to 100%. The steroid concentrations varied substantially in soils, ranging from below the detection limit to 109.7μg·kg(-1). Three steroids-progesterone, androstendione and estrone-were found to have relatively high residue concentrations in soil, with maximum concentrations of 109.7, 9.83 and 13.30μg·kg(-1), respectively. In adjacent groundwater, all the steroids, with the exception of estrone, were detected in one or more of the 13 groundwater samples. The concentrations of steroids in groundwater ranged from below the method detection limit to 2.38ng·L(-1). Six of the seven (excluding androstendione) were detected in drainage ditch water samples, with concentrations ranging from below the detection limit to 14ng·L(-1). Progesterone, androstendione and estrone accumulated relatively easily in soils; their concentrations in groundwater were lower than those of other steroids. The concentrations of testosterone and estriol were relatively low in soil, while in groundwater were higher than those of other steroids. The residual levels of steroids in soil and groundwater showed a clear spatial variation in the study area. The residual levels of steroid hormones in soil varied substantially between differently planted greenhouses. PMID:26318226

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

    PubMed

    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. PMID:24771973

  17. Time trends of polybrominated diphenyl ethers in East China Seas: Response to the booming of PBDE pollution industry in China.

    PubMed

    Li, Yuanyuan; Lin, Tian; Hu, Limin; Feng, Jialiang; Guo, Zhigang

    2016-01-01

    The East China Seas (ECSs) are the receptors of the land-based persistent organic pollutants (POPs), such as polybrominated diphenyl ethers (PBDEs) mainly from China through atmospheric deposition driven by the East Asian winter monsoon and fluvial discharge (e.g., Yangtze River and Yellow River), making the offshore sediments to be a good proxy to reconstruct history of those pollutants in China. In this work, four well-placed sediment cores were extracted from the mud areas in the ECSs, and the (210)Pb-dated cores were analyzed to yield historical concentration profiles of PBDEs in the area. The results showed that there was a persistent increase from 1970s and almost no clear sign in the decline of PBDEs until recently in China. More importantly, there was a faster increase of PBDEs from 1990s in China; while this period was just shown as gradually leveling off or even declining trends in developed countries. The persistently increasing trend of PBDEs in China since 1990s could be largely due to the booming of the manufacturing industry and unexpectedly transfer of PBDE pollution from developed countries to China. Besides, the relative high concentrations and fluxes of PBDEs in the core from coastal ECS located near a well-known electrical/electronic waste (e-waste) recycling area suggests an important contribution of PBDE emissions from recycling centers of e-waste in China. Although efforts in environmental monitoring of PBDE contamination have been substantially increased over the last decade, China is still lagging behind in terms of nationwide regulation of PBDE usage and treatment of disposal PBDE-containing products. PMID:27179303

  18. Meiofauna assemblages of the Condor Seamount (North-East Atlantic Ocean) and adjacent deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Zeppilli, Daniela; Bongiorni, Lucia; Cattaneo, Antonio; Danovaro, Roberto; Santos, Ricardo Serrão

    2013-12-01

    Seamounts are currently considered hotspots of biodiversity and biomass for macro- and megabenthic taxa, but knowledge of meiofauna is still limited. Studies have revealed the existence of highly diverse meiofauna assemblages; however most data are mainly qualitative or focused only on specific groups, thus preventing comparisons among seamounts and with other deep-sea areas. This study, conducted on Condor Seamount (Azores, North-East Atlantic Ocean), describes variation in abundance, biomass, community structure and biodiversity of benthic meiofauna from five sites located on the Condor Seamount: and one site away from the seamount. While the summit of the seamount hosted the highest alpha biodiversity, the flanks and the bases showed a rich meiofauna assemblage in terms of abundance and biomass. The observed marked differences in grain size composition of sediments reflected the oceanographic conditions impacting different sectors of the Condor seamount, and could play an important role in the spatial distribution of different meiofaunal taxa. Trophic conditions (biochemical composition of organic matter) explained 78% of the variability in the meiofauna biomass pattern while sediment grain influenced the vertical distribution of meiofauna and only partially explained meiofaunal taxa composition. This study provides a further advancement in the knowledge of meiofaunal communities of seamounts. Only a deeper understanding of the whole benthic communities (including meiofauna) will allow to elaborate effective management and conservation tools for seamount ecosystems.

  19. An integrated East China Sea-Changjiang Estuary model system with aim at resolving multi-scale regional-shelf-estuarine dynamics

    NASA Astrophysics Data System (ADS)

    Ge, Jianzhong; Ding, Pingxing; Chen, Changsheng; Hu, Song; Fu, Gui; Wu, Lunyu

    2013-08-01

    A high-resolution numerical model system is essential to resolve multi-scale coastal ocean dynamics. So a multi-scale unstructured grid-based finite-volume coastal ocean model (FVCOM) system has been established for the East China Sea and Changjiang Estuary (ECS-CE) with the aim at resolving coastal ocean dynamics and understanding different physical processes. The modeling system consists of a three-domain-nested weather research and forecasting model, FVCOM model with the inclusion of FVCOM surface wave model in order to understand the wave-current interactions. The ECS-CE system contains three different scale models: a shelf-scale model for the East China Sea, an estuarine-scale model for the Changjiang Estuary and adjacent region, and a fine-scale model for the deep waterway regions. These three FVCOM-based models guarantee the conservation of mass and momentum transferring from outer domain to inner domain using the one-way common-grid nesting procedure. The model system has been validated using data from various observation data, including surface wind, tides, currents, salinity, and wave to accurately reveal the multi-scale dynamics of the East China Sea and Changjiang Estuary. This modeling system has been demonstrated via application to the seasonal variations of Changjiang diluted water and the bottom saltwater intrusion in the North Passage, and it shows strong potential for estuarine and coastal ocean dynamics and operational forecasting.

  20. Effect of Blast-Induced Vibration from New Railway Tunnel on Existing Adjacent Railway Tunnel in Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Liang, Qingguo; Li, Jie; Li, Dewu; Ou, Erfeng

    2013-01-01

    The vibrations of existing service tunnels induced by blast-excavation of adjacent tunnels have attracted much attention from both academics and engineers during recent decades in China. The blasting vibration velocity (BVV) is the most widely used controlling index for in situ monitoring and safety assessment of existing lining structures. Although numerous in situ tests and simulations had been carried out to investigate blast-induced vibrations of existing tunnels due to excavation of new tunnels (mostly by bench excavation method), research on the overall dynamical response of existing service tunnels in terms of not only BVV but also stress/strain seemed limited for new tunnels excavated by the full-section blasting method. In this paper, the impacts of blast-induced vibrations from a new tunnel on an existing railway tunnel in Xinjiang, China were comprehensively investigated by using laboratory tests, in situ monitoring and numerical simulations. The measured data from laboratory tests and in situ monitoring were used to determine the parameters needed for numerical simulations, and were compared with the calculated results. Based on the results from in situ monitoring and numerical simulations, which were consistent with each other, the original blasting design and corresponding parameters were adjusted to reduce the maximum BVV, which proved to be effective and safe. The effect of both the static stress before blasting vibrations and the dynamic stress induced by blasting on the total stresses in the existing tunnel lining is also discussed. The methods and related results presented could be applied in projects with similar ground and distance between old and new tunnels if the new tunnel is to be excavated by the full-section blasting method.

  1. Distribution of polybrominated diphenyl ethers in sediments of the Pearl River Delta and adjacent South China Sea.

    PubMed

    Mai, Bixian; Chen, Shejun; Luo, Xiaojun; Chen, Laiguo; Yang, Qingshu; Sheng, Guoying; Peng, Pingan; Fu, Jiamo; Zeng, Eddy Y

    2005-05-15

    Spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs) in sediments of the Pearl River Delta (PRD) and adjacent South China Sea (SCS) of southern China were examined. A total of 66 surface sediment samples were collected and analyzed to determine the concentrations of 10 PBDE congeners (BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209). The concentrations of BDE-209 and SigmaPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) ranged from 0.4 to 7340 and from 0.04 to 94.7 ng/g, respectively. The SigmaPBDEs concentrations were mostly < 50 ng/g, within the range for riverine and coastal sediments around the world, whereas the BDE-209 concentrations at the most contaminated sites were at the high end of the worldwide figures. Congener compositions were dominated by BDE-209 (72.6 - 99.7%), with minor contributions from penta- and octa-BDEs. Slightly different PBDE compositions were observed among samples collected from different locations, attributable to possible decomposition of highly brominated congeners and/or redistribution between particles of various sizes during atmospheric or fluvial transportation. The PBDE patterns in the SCS and Pearl River Estuary sediments were similar to those in sediments of the Zhujiang and Dongjiang Rivers, reflecting the widespread influence from local inputs. Analyses of two short sediment cores collected from the Pearl River Estuary showed that concentrations of BDE-209 rapidly increased in the upper layers of both cores, coincident with the growth of the electronics manufacturing capacities in the PRD region. The major sources of PBDEs were probably waste discharges from the cities of Guangzhou, Dongguan, and Shenzhen, the three fastest growing urban centers in the PRD. PMID:15952354

  2. Spatial distribution and sources of polychlorinated biphenyls in surface sediments from the Zhoushan Archipelago and Xiangshan Harbor, East China Sea.

    PubMed

    Wang, Xiaoyan; Xu, Huanzhi; Zhou, Yongdong; Wu, Changwen; Kanchanopas-Barnette, Praparsiri

    2016-04-15

    This study investigated ambient concentrations and potential sources of polychlorinated biphenyls (PCBs) in surface sediments from the Zhoushan Archipelago and adjacent Xiangshan Harbor. The ∑18PCB (total 18 PCB) concentrations ranged between 1.48 and 7.94ng/g d.w., average at 4.20ng/g d.w., presenting a low adverse environmental risk. Penta-CB was the dominant congener, contributing 46.01%-86.44% of the total PCBs. Concentrations of PCBs were highest in the northeastern part of the Zhoushan Archipelago and Xiangshan Harbor. Principal component analysis (PCA) showed that PCBs have a mixed origin; atmospheric deposition and PCB dispersion from paint flakings being the main sources of PCB pollution. Aroclor 1245 and Clophen A50 were the potential PCB sources in all sampling sites. This paper provides the first intensive survey and statistical analyses of PCB distributions and sources in the Zhoushan Archipelago and adjacent Xiangshan Harbor. This study may provide a reference to environmental protection and monitoring of PCB pollution in the East China Sea. PMID:26892201

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

    NASA Astrophysics Data System (ADS)

    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.

  4. History Didactics in the Post Cold War World: Central Asia, the Middle East, and China.

    ERIC Educational Resources Information Center

    Forsyth, Louise; Gould, David; Lawrence, David

    2000-01-01

    Examines three key geographical regions, Central Asia, the Middle East, and China, discussing how the political changes resulting from the end of the Cold War have affected each area. Attempts to demonstrate how teachers can address these changes in their classrooms. (CMK)

  5. The Development of the Distance Education College of East China Normal University: A Case Study

    ERIC Educational Resources Information Center

    Ye, Lixin; Su, Xiaobing; Yan, Hanbing

    2009-01-01

    Purpose: This paper aims to present a picture of the past and the present status of the Distance Education College (DEC) of East China Normal University (ECNU). It describes what the DEC has achieved in each phase, and probes into some essential problems that the DEC has attempted to solve. Design/methodology/approach: This article provides a…

  6. Changes in Nematode Communities in Different Physiographic Sites of the Condor Seamount (North-East Atlantic Ocean) and Adjacent Sediments

    PubMed Central

    Zeppilli, Daniela; Bongiorni, Lucia; Serrão Santos, Ricardo; Vanreusel, Ann

    2014-01-01

    Several seamounts are known as ‘oases’ of high abundances and biomass and hotspots of biodiversity in contrast to the surrounding deep-sea environments. Recent studies have indicated that each single seamount can exhibit a high intricate habitat turnover. Information on alpha and beta diversity of single seamount is needed in order to fully understand seamounts contribution to regional and global biodiversity. However, while most of the seamount research has been focused on summits, studies considering the whole seamount structure are still rather poor. In the present study we analysed abundance, biomass and diversity of nematodes collected in distinct physiographic sites and surrounding sediments of the Condor Seamount (Azores, North-East Atlantic Ocean). Our study revealed higher nematode biomass in the seamount bases and values 10 times higher in the Condor sediments than in the far-field site. Although biodiversity indices did not showed significant differences comparing seamount sites and far-field sites, significant differences were observed in term of nematode composition. The Condor summit harboured a completely different nematode community when compared to the other seamount sites, with a high number of exclusive species and important differences in term of nematode trophic diversity. The oceanographic conditions observed around the Condor Seamount and the associated sediment mixing, together with the high quality of food resources available in seamount base could explain the observed patterns. Our results support the hypothesis that seamounts maintain high biodiversity through heightened beta diversity and showed that not only summits but also seamount bases can support rich benthic community in terms of standing stocks and diversity. Furthermore functional diversity of nematodes strongly depends on environmental conditions link to the local setting and seamount structure. This finding should be considered in future studies on seamounts, especially in

  7. Changes in nematode communities in different physiographic sites of the condor seamount (north-East atlantic ocean) and adjacent sediments.

    PubMed

    Zeppilli, Daniela; Bongiorni, Lucia; Serrão Santos, Ricardo; Vanreusel, Ann

    2014-01-01

    Several seamounts are known as 'oases' of high abundances and biomass and hotspots of biodiversity in contrast to the surrounding deep-sea environments. Recent studies have indicated that each single seamount can exhibit a high intricate habitat turnover. Information on alpha and beta diversity of single seamount is needed in order to fully understand seamounts contribution to regional and global biodiversity. However, while most of the seamount research has been focused on summits, studies considering the whole seamount structure are still rather poor. In the present study we analysed abundance, biomass and diversity of nematodes collected in distinct physiographic sites and surrounding sediments of the Condor Seamount (Azores, North-East Atlantic Ocean). Our study revealed higher nematode biomass in the seamount bases and values 10 times higher in the Condor sediments than in the far-field site. Although biodiversity indices did not showed significant differences comparing seamount sites and far-field sites, significant differences were observed in term of nematode composition. The Condor summit harboured a completely different nematode community when compared to the other seamount sites, with a high number of exclusive species and important differences in term of nematode trophic diversity. The oceanographic conditions observed around the Condor Seamount and the associated sediment mixing, together with the high quality of food resources available in seamount base could explain the observed patterns. Our results support the hypothesis that seamounts maintain high biodiversity through heightened beta diversity and showed that not only summits but also seamount bases can support rich benthic community in terms of standing stocks and diversity. Furthermore functional diversity of nematodes strongly depends on environmental conditions link to the local setting and seamount structure. This finding should be considered in future studies on seamounts, especially in

  8. Dynamics of the cross-shelf circulation in the Yellow and East China Seas in winter

    NASA Astrophysics Data System (ADS)

    Yuan, Dongliang; Hsueh, Ya

    2010-10-01

    A general ocean circulation model is used to study the dynamics of the cross-shelf circulation in the Yellow and East China Seas in winter. The model results show that the shelf circulation in winter is induced primarily by the northerly monsoonal winds. Compared with the wind-driven circulation, the Kuroshio-forced circulation over the shelf is very weak. The westward shift of the Yellow Sea Warm Current is produced by the northerly winds through the generation of a sea-level trough off the Subei coasts and a sea-level ridge along the center of the Yellow Sea topographic trough. The sea-level trough off the Subei coasts is produced because the sea level at the coast is tied to the depression in the northern Yellow Sea and is moderated by the surface Ekman transport of the northerly monsoon. The sea-level ridge along the center of the Yellow Sea topographic trough is produced because the sea level along both the east China and the west Korea coasts decreases. The structure of the sea level gives rise to a geostrophic intrusion against the wind along the western side of the Yellow Sea trough and southward movement of the Korean coastal currents along the eastern side of the trough. Under the northerly wind forcing, the currents over the East China Sea shelf flow southward in an opposite direction to the Yellow Sea Warm Current. The resulting divergence, therefore, forces the Yellow Sea Coastal Current to move offshore to form the East China Sea Current. At the head of the submarine canyon off the Changjiang mouth, a northward intrusion is produced by downwind pile-up of sea level and by the wind-curl forcing. The Yellow Sea Warm Current and the canyon intrusion then extend southward through the propagation of topographic Rossby waves to reverse the wind-driven currents over the East China Sea shelf, generating the offshore and inshore branches of the Taiwan Warm Current, both of which serve to raise the sea level over the East China Sea shelf. The final adjustment

  9. Assessment of the Impact of The East Asian Summer Monsoon on the Air Quality Over China

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Ding, Aijun; Safieddine, Sarah; Valks, Pieter; Clerbaux, Cathy; Trautmann, Thomas

    2016-04-01

    Air pollution is one of the most important environmental problems in developing Asian countries like China. In this region, studies showed that the East Asian monsoon plays a significant role in characterizing the temporal variation and spatial patterns of air pollution, since monsoon is a major atmospheric system affecting air mass transport, convection, and precipitation. Knowledge gaps still exist in the understanding of Asian monsoon impact on the air quality in China under the background of global climate change. For the first time satellite observations of tropospheric ozone and its precursors will be integrated with the ground-based, aircraft measurements of air pollutants and model simulations to study the impact of the East Asian monsoon on air quality in China. We apply multi-platform satellite observations by the GOME-2, IASI, and MOPITT instruments to analyze tropospheric ozone and CO, precursors of ozone (NO2, HCHO and CHOCHO) and other related trace gases over China. Two years measurements of air pollutants including NO2, HONO, SO2, HCHO and CHOCHO at a regional back-ground site in the western part of the Yangtze River Delta (YRD) in eastern China will be presented. The potential of using the current generation of satellite instruments, ground-based instruments and aircraft to monitor air quality changes caused by the East Asian monsoon circulation will be presented. Preliminary comparison results between satellite measurement and limited but valuable ground-based and aircraft measurements will also be showed.

  10. Spatial variability in the abundance, composition, and age of organic matter in surficial sediments of the East China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Ying; Eglinton, Timothy; Yang, Liyang; Deng, Bing; Montluçon, Daniel; Zhang, Jing

    2013-12-01

    the sources and fate of organic matter (OM) sequestered in continental margin sediments is of importance because the mode and efficiency of OM burial impact the carbon cycle and the regulation of atmospheric CO2 over long time scales. We carried out molecular (lignin-derived phenols from CuO oxidation), elemental, isotopic (δ13C, Δ14C), and sedimentological (grain size and mineral surface area) analyses in order to examine spatial variability in the abundance, source, age of surface sediments of the East China Sea. Higher terrigenous organic matter values were found in the main accumulating areas of fluvial sediments, including the Changjiang (Yangtze) Estuary and Zhejiang-Fujian coastal zone. Isotopic and biomarker data suggest that the sedimentary OM in the inner shelf region was dominated by aged (Δ14C = -423 ± 42‰) but relatively lignin-rich OM (Λ = 0.94 ± 0.57 mg/100 mg OC) associated with fine-grained sediments, suggesting important contributions from soils. In contrast, samples from the outer shelf, while of similar age (Δ14 C = -450 ± 99‰), are lignin poor (Λ = 0.25 ± 0.14 mg/100 mg OC) and associated with coarse-grained material. Regional variation of lignin phenols and OM ages indicates that OM content is fundamentally controlled by hydrodynamic sorting (especially, sediment redistribution and winnowing) and in situ primary production. Selective sorption of acid to aldehyde in clay fraction also modified the ratios of lignin phenols. The burial of lignin in East China Sea is estimated to be relatively efficient, possibly as a consequence of terrigenous OM recalcitrance and/or relatively high sedimentation rates in the Changjiang Estuary and the adjacent Zhejing-Fujian mud belt.

  11. East China Sea δ18O Record Detects Millennial-Scale Changes in the East Asian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Gleeman, E.; Clemens, S. C.; Lawman, A. E.; Kubota, Y.; Holbourn, A. E.; Martin, A.

    2015-12-01

    The East Asian Summer Monsoon (EASM) brings heavy summer rainfall to some of Asia's most densely-populated areas, impacting agricultural production and water resources. Sediment cores were recovered from International Ocean Drilling Program Site U1429 in the East China Sea (31° 37.04' N, 128° 59.50' E, 732 mbsl). This location receives runoff from the Yangtze River, which serves as a major drainage system for monsoon-induced precipitation. Hence, the δ18O record of planktonic foraminifera at Site U1429 reflects changes in regional, monsoon-driven salinity. The top 100 meters of core at Site U1429 were sampled at a preliminary resolution of 15 cm and processed to isolate the planktonic foraminifer Globigerinoides ruber for δ18O mass spectrometry analyses. Abrupt, millennial-scale regional climate variability in the EASM and its linkage to orbital forcings have been reconstructed using stratigraphic analysis of δ18O. The sub-orbital scale structure of the δ18O record over the past 400 kyr matches the structures of both the composite speleothem δ18O from eastern China (Sanbao and Hulu caves) and the planktonic δ18O record from northern South China Sea Site 1146. The similarities between these δ18O records indicate a strong regional response to monsoon forcing. Removal of the temperature component of the δ18O signal by using Mg/Ca (G. ruber) paleothermometry will provide a record of changes in the δ18O composition of seawater in response to Yangtze River runoff.

  12. Observation-based Understanding of the Cloud Properties over East China Region

    NASA Astrophysics Data System (ADS)

    Zhao, C.

    2015-12-01

    Cloud properties over East China are described based on observations from satellite (MODIS), ground site and aircraft. Based on satellite observations, 10-year averaged cloud fraction over the whole China region is around 66%, similar to the average value of global, with the largest cloud occurrence in Summer; the cloud fraction increases slightly during last 10 years; more clouds are found at southeast region than at northwest region; cloud droplet effective radius shows the smallest values around 10 um at mid-latitude regions and largest values at high latitude regions; further PDF analysis shows that cloud droplet effective radius demonstrates a bimodal distribution with maximum occurrences around 10-16 um. Ground site observations show that cloud fraction at Taihu site is around 65% for 2013, consistent with that found by MODIS at the closest grid to the site; more clouds are found at night than during day. In-situ aircraft observations over Huanghua city show that cloud droplet effective radius increases with height, with values from 3-5 um at low altitude, 7-9 um at mid altitude, to 10-13 um at high altitude. While the aircraft observation sample volume is limited, the in-situ observed cloud properties demonstrate that cloud droplet re increases with height, consistent with many findings by in-situ aircraft at other locations. The consistency of satellite observed cloud droplet re between East China and other regions is likely caused by the fact that the cloud properties observed by satellite is more representative of those clouds at high altitudes which are weakly affected by the aerosols within the boundary layers. On the other hand, the cloud droplet re at the cloud bases over East China is much smaller than those found at other locations, likely demonstrating the significant impacts by the heavy aerosol loadings at this region. Further studies with more site and aircraft observations over East China are needed.

  13. Occurrence and source apportionment of sulfonamides and their metabolites in Liaodong Bay and the adjacent Liao River basin, North China.

    PubMed

    Jia, Ai; Hu, Jianying; Wu, Xiaoqin; Peng, Hui; Wu, Shimin; Dong, Zhaomin

    2011-06-01

    The presence of antibiotics in the environment is of great concern because of their potential for resistance selection among pathogens. In the present study we investigated the occurrence of 19 sulfonamides, five N-acetylated sulfonamide metabolites, and trimethoprim in the Liao River basin and adjacent Liaodong Bay, China, as well as 10 human/agricultural source samples. Within the 35 river samples, 12 sulfonamides, four acetylated sulfonamides, and trimethoprim were detected, with the dominant being sulfamethoxazole (66.6 ng/L), N-acetylsulfamethoxazole (63.1 ng/L), trimethoprim (29.0 ng/L), sulfadiazine (14.0 ng/L), and sulfamonomethoxine (8.4 ng/L); within the 36 marine samples, 10 chemicals were detected, with the main contributions from sulfamethoxazole (25.2 ng/L) and N-acetylsulfamethoxazole (28.6 ng/L). Sulfamethoxazole (25.9%), N-acetylsulfamethoxazole (46.6%), trimethoprim (22.9%), and sulfapyridine (1.4%) were the main chemicals from human sources, while sulfamonomethoxine, sulfamethazine, sulfaquinoxaline, sulfaguanidine, sulfadiazine, sulfanilamide, and sulfamethoxypyridazine were dominant in the animal husbandry sources, specifically, swine and poultry farms, and sulfamethoxazole (91%) was dominant in the mariculture source. A principal component analysis with multiple linear regression was performed to evaluate the source apportionment of total sulfonamides in Liaodong Bay. It was found that animal husbandry contributed 15.2% of total sulfonamides, while human sources contributed 28.5%, and combined human and mariculture sources contributed 56.3%. In addition, the mariculture contribution was 24.1% of total sulfonamides into the sea based on mass flux estimation. The present study is the first report that the environmental levels of sulfonamide metabolites were comparable to the corresponding parents; therefore, we should pay attention to their environmental occurrence. Source apportionment showed human discharge (60.7%) significantly

  14. Holocene environmental change inferred from the loess-palaeosol sequences adjacent to the floodplain of the Yellow River, China

    NASA Astrophysics Data System (ADS)

    Huang, Chun Chang; Pang, Jiangli; Su, Hongxia; Li, Shengli; Ge, Benwei

    2009-12-01

    Chinese loess deposits are generally considered to be the product of dust storms and dust falls from the central Asia arid zones that were transported across China by the northwesterly continental monsoon. In contrast, the Zhengzhou Loess found southeast of the Loess Plateau, adjacent to the floodplain of the Yellow River, records a different eolian regime and dust source. The Zhengzhou Loess was investigated by field observations, measurements of magnetic susceptibility, particle-size distribution, loss-on-ignition, CaCO 3 and chemical contents. Both field observations and the laboratory results indicate that, during the last glacial, the Zhengzhou Loess was supplied by two different eolian regimes and dust sources, one was from the fresh flood deposits of the Yellow River driven by the northeast winds from the low-lying floodplain, and the other was from the dust storms and dust falls that traveled across the Loess Plateau driven by the northwesterly continental monsoon from the central Asian arid lands. The early Holocene, 11,500-8500 a BP, was a transition during the change in eolian regime and dust source because of the weakened northwesterly monsoon along with the global climatic amelioration. Following the retreat of the northwesterly monsoon from the onset of the mid-Holocene Climatic Optimum at 8500 a BP, dust supply from the drifting sand zone on the Yellow River floodplain became dominant because of the intensified strength of the northeast winds from the Bohai Sea. From 3100 a BP onwards, climatic aridity and extensive human disturbance have resulted in intensive eolian processes causing the incursion of the drifting sand into the Zhengzhou Loess zone. These results show that loess accumulation is more complex than traditionally assumed. The origin of loess deposits elsewhere outside the Loess Plateau may be related to dust sources derived from alluvial sediments of major river systems.

  15. Modern transport and deposition of settling particles in the northern South China Sea: Sediment trap evidence adjacent to Xisha Trough

    NASA Astrophysics Data System (ADS)

    Liu, Jianguo; Clift, Peter D.; Yan, Wen; Chen, Zhong; Chen, Han; Xiang, Rong; Wang, Dongxiao

    2014-11-01

    Studies on modern sediment transport and deposition, especially studies analyzing settling particles collected with sediment traps, have rarely been carried out in the northern South China Sea. Using sediment trap time series data from Site XS1 (17°24.5‧N, 110°55.0‧E, water depth 1690 m) adjacent to the Xisha Trough, variations in sediment source through time have been reconstructed. These observations include total particle flux (TPF) and current data, grain size distributions, and clay mineral compositions obtained from two sediment traps deployed in 500 m and 1500 m water depth, respectively. Time series records at Site XS1 changed seasonally for both sampled layers. TPF in the lower layer (426 mg/m2/d) was several times that of the upper layer (113 mg/m2/d) and is affected by lateral transport. However, mean grain size (Mz) of the upper layer is greater that of the lower layer (29 vs10 μm) due to contributions from biogenic materials. There are no clear seasonal changes in clay mineral assemblage in either the upper or lower layers. The annual percentages of four main clay minerals were 82-83% illite, 7-9% kaolinite, 6-8% chlorite and 1-3% smectite. Taiwan was the dominant sediment source (42-74%), while sediment contributions from the Red River and Annamite Chain account for 23-53% and 0-15%, respectively. Sediment supply from Taiwan could be explained by deep water current flow, while coastal currents may aid sediment transport from the Red River and small mountainous rivers of central Vietnam.

  16. Distributions and sources of petroleum, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Bohai Bay and its adjacent river, China.

    PubMed

    Wang, Min; Wang, Chuanyuan; Hu, Xiaoke; Zhang, Haijiang; He, Shijie; Lv, Shuangyan

    2015-01-15

    Surface sediment samples from Bohai Bay and its adjacent river, China, were analyzed for aliphatic hydrocarbon, PAHs and biomarkers in order to determine the distribution, composition and source of organic matter in a coastal environment. Results suggested that the input of organic matter from anthropogenic activities has a more significant influence on its distribution than that from natural processes. Petroleum contamination, mainly from offshore oil exploration and discharge of pollutants from rivers, was the main source of n-alkanes. PAHs were mostly of pyrogenic origin; while some sites in Yellow River Estuary were derived mainly from the petrogenic sources. The toxic assessment suggested that the PAHs in surface sediments will not cause immediately adverse biological effects in sediments from Bohai Bay and its adjacent river, China. PMID:25499964

  17. Abrupt change of the mid-summer climate in central east China by the influence of atmospheric pollution

    NASA Astrophysics Data System (ADS)

    Xu, Qun

    Following the great flooding of summer 1998, the mid-lower Yangtze Basin further suffered from another large flooding in summer 1999. Successive droughts through 3 recent summers (1997-1999) appeared in north China in addition, leading to an abnormal summer climate pattern of "north drought with south flooding". Such southward move of the summer monsoon rainy belt in east China started in the late 1970s-early 1980s. Its main cause may not be a purely natural climate change, but the acceleration of industrialization in east China could play a major role by emitting large volumes of SO 2, especially from the rapidly growing rural factories of east China. The annual release of SO 2 in China exceeded 20 Tg during 1992-1998, so dense sulfate aerosols covered the central east China which significantly reduced the sunlight. Although present estimates for the changes of clear sky global solar radiation may include some error, they show that the negative radiative forcing of sulfate aerosols in central east China by far exceeds the effect of greenhouse warming in summer. Hence the mid-summer monsoon rainy belt of east China has a trend moving southward in 21 recent years (1979-1999), showing the very sensitive characteristic of the summer monsoon system to the change in heat equilibrium of the land surface. The occurrence rate of summer climate pattern of "north drought with south flooding" in east China during 21 recent years is the largest since AD 950; such anomalous climate has brought large losses to China. The only possible way to reverse this southward trend of summer monsoon rainy belt is to significantly reduce air pollution by using more clean energy. Recently, the PRC has paid serious attention to this problem by adopting a series of countermeasures.

  18. Regional climate simulations of summer diurnal rainfall variations over East Asia and Southeast China

    NASA Astrophysics Data System (ADS)

    Huang, Wan-Ru; Chan, Johnny C. L.; Au-Yeung, Andie Y. M.

    2013-04-01

    This study evaluates the performance of RegCM3 (Regional Climate Model Version 3) in simulating the East Asian rainfall, with emphasis on the diurnal variations of rainfall over Southeast China during the 1998-2002 summer (June-August) seasons. The evaluation focuses on the sensitivity of the choice of cumulus parameterizations and model domain. With the right setup, the spatial and temporal evolution of diurnal rainfall over Southeast China, which has not been well simulated by past studies, can be accurately simulated by RegCM3. Results show that the Emanuel cumulus scheme has a more realistic simulation of summer mean rainfall in East Asia, while the GFC (Grell scheme with the Frisch-Chappell convective closure assumption) scheme is better in simulating the diurnal variations of rainfall over Southeast China. The better performance of these two schemes [relative to the other two schemes in RegCM3: the Kuo scheme and the GAS (Grell scheme with the Arakawa-Schubert closure assumption) scheme] can be attributed to the reasonable reproduction of the major formation mechanism of rainfall—the moisture flux convergence—over Southeast China. Furthermore, when the simulation domain covers the entire Tibetan Plateau, the diurnal variations of rainfall over Southeast China are found to exhibit a noticeable improvement without changes in the physics schemes.

  19. A diagnostic model of summer circulation on the northwest shelf of the East China sea

    NASA Astrophysics Data System (ADS)

    Yaochu, Yuan; Jilan, Su; Sangyun, Xia

    Hydrographic data and moored current meter records collected during a cruise of the China-U.S. Joint Study in August 1981 were used to compute the circulation in the East China Sea. A steady state, linear diagnostic model with a constant vertical eddy viscosity was developed. Lateral friction was ignored. The Taiwan Warm Current plays a dominant role in the survey area. Both the Huanghai Warm Current and the cyclonic cold water gyre southwest of Cheju Island are closely related to the Taiwan Warm Current.

  20. Variations of picoplankton abundances during blooms in the East China Sea

    NASA Astrophysics Data System (ADS)

    Zhao, Yuan; Zhao, Li; Zhang, Wuchang; Sun, Jun; Huang, Lingfeng; Li, Jia; Zhai, Hongchang; Liu, Sumei; Xiao, Tian

    2016-02-01

    The picoplankton distribution in the East China Sea was investigated during bloom events occurred in spring (June) and summer (August) 2011. In spring, there was no significant difference in picoplankton abundances between areas where bloom conditions were or were not established. In the bloom area, Synechococcus, picoeukaryotes and heterotrophic prokaryotes exhibited at only some stations that abundances were higher than those within the non-bloom area. In summer, the abundances of Synechococcus and picoeukaryotes were significantly higher inside the bloom area than outside. Among the picoplankton components, heterotrophic prokaryotes represented the highest carbon biomass. Factors that most influenced picoplankton distribution under bloom conditions in the East China Sea varied with season. In spring, ciliates and salinity tended to be the main factors, whereas in summer, this role was played by temperature and chlorophyll a concentration.

  1. Two new eunicellin diterpenoids from the East China Sea gorgonian Muricella sp.

    PubMed

    Zhao, Chuan; Wang, Jia; Jin, De-Jun; Duan, Hong-Quan; Xing, Guo-Sheng; Tang, Sheng-An

    2016-09-01

    A phytochemical investigation on gorgonian Muricella sp. from East China Sea resulted in the isolation of eight eunicellin diterpenoids including two new ones, muricellins A-B (1, 2). Chemical structures of these compounds were elucidated by spectroscopic techniques (1D and 2D NMR and MS) and by comparison with data reported in the literature. Anti-rheumatoid arthritis activities of 1, 3, 4, and 6 have been evaluated. PMID:27004724

  2. Evidence of a Cooler Continental Climate in East China during the Warm Early Cenozoic

    PubMed Central

    Zhang, Qian-Qian; Smith, Thierry; Yang, Jian; Li, Cheng-Sen

    2016-01-01

    The early Cenozoic was characterized by a very warm climate especially during the Early Eocene. To understand climatic changes in eastern Asia, we reconstructed the Early Eocene vegetation and climate based on palynological data of a borehole from Wutu coal mine, East China and evaluated the climatic differences between eastern Asia and Central Europe. The Wutu palynological assemblages indicated a warm temperate vegetation succession comprising mixed needle- and broad-leaved forests. Three periods of vegetation succession over time were recognized. The changes of palynomorph relative abundance indicated that period 1 was warm and humid, period 2 was relatively warmer and wetter, and period 3 was cooler and drier again. The climatic parameters estimated by the coexistence approach (CA) suggested that the Early Eocene climate in Wutu was warmer and wetter. Mean annual temperature (MAT) was approximately 16°C and mean annual precipitation (MAP) was 800–1400 mm. Comparison of the Early Eocene climatic parameters of Wutu with those of 39 other fossil floras of different age in East China, reveals that 1) the climate became gradually cooler during the last 65 million years, with MAT dropping by 9.3°C. This cooling trend coincided with the ocean temperature changes but with weaker amplitude; 2) the Early Eocene climate was cooler in East China than in Central Europe; 3) the cooling trend in East China (MAT dropped by 6.9°C) was gentler than in Central Europe (MAT dropped by 13°C) during the last 45 million years. PMID:27196048

  3. Variability of Cross-shelf Penetrating Fronts in the East China Sea

    NASA Astrophysics Data System (ADS)

    He, Lei; Li, Yao; Zhou, Hui; Yuan, Dongliang

    2010-10-01

    Images of 8-day mean chlorophyll- a concentrations of the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard of Aqua Satellite from 2002 to 2007 and of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite from 1998 to 2007 are used to study the variability of the cross-shelf penetrating fronts (CPFs) in the East China Sea. The analysis suggests that the generation of the CPFs has strong seasonal-to-interannual variations, with more CPFs in summer and winter than in spring and fall. Each CPF lasts for a few days to a month. The majority of the fronts are triangle-shaped with their broad bases nearby the coast and their sharp heads penetrating into the middle shelf. There are over 40 CPFs with penetrating distances exceeding 100 km over the East China Sea during the past 10 years of the satellite era, with the maximum ones reaching the Kuroshio at the edge of the continental shelf. Of all the low cloud scenes of the satellite images, more than 25% contain at least one CPF. The high-frequency occurrence of the CPFs suggests that the CPFs play an important role in cross-shelf transport of heat, effluent, and land-derived materials in the East China Sea. The generation of the CPF is found to be influenced by winds and by intrinsic oceanic variability. In particular, the collision of wind-forced coastal jet with the Taiwan Warm Current is suggested as one of the mechanisms that generate the CPFs in the East China Sea.

  4. Evidence of a Cooler Continental Climate in East China during the Warm Early Cenozoic.

    PubMed

    Zhang, Qian-Qian; Smith, Thierry; Yang, Jian; Li, Cheng-Sen

    2016-01-01

    The early Cenozoic was characterized by a very warm climate especially during the Early Eocene. To understand climatic changes in eastern Asia, we reconstructed the Early Eocene vegetation and climate based on palynological data of a borehole from Wutu coal mine, East China and evaluated the climatic differences between eastern Asia and Central Europe. The Wutu palynological assemblages indicated a warm temperate vegetation succession comprising mixed needle- and broad-leaved forests. Three periods of vegetation succession over time were recognized. The changes of palynomorph relative abundance indicated that period 1 was warm and humid, period 2 was relatively warmer and wetter, and period 3 was cooler and drier again. The climatic parameters estimated by the coexistence approach (CA) suggested that the Early Eocene climate in Wutu was warmer and wetter. Mean annual temperature (MAT) was approximately 16°C and mean annual precipitation (MAP) was 800-1400 mm. Comparison of the Early Eocene climatic parameters of Wutu with those of 39 other fossil floras of different age in East China, reveals that 1) the climate became gradually cooler during the last 65 million years, with MAT dropping by 9.3°C. This cooling trend coincided with the ocean temperature changes but with weaker amplitude; 2) the Early Eocene climate was cooler in East China than in Central Europe; 3) the cooling trend in East China (MAT dropped by 6.9°C) was gentler than in Central Europe (MAT dropped by 13°C) during the last 45 million years. PMID:27196048

  5. Impacts of the East Asian Monsoon on springtime dust concentrations over China

    NASA Astrophysics Data System (ADS)

    Lou, Sijia; Russell, Lynn M.; Yang, Yang; Xu, Li; Lamjiri, Maryam A.; DeFlorio, Michael J.; Miller, Arthur J.; Ghan, Steven J.; Liu, Ying; Singh, Balwinder

    2016-07-01

    We use 150 year preindustrial simulations of the Community Earth System Model to quantify the impacts of the East Asian Monsoon strength on interannual variations of springtime dust concentrations over China. The simulated interannual variations in March-April-May (MAM) dust column concentrations range between 20-40% and 10-60% over eastern and western China, respectively. The dust concentrations over eastern China correlate negatively with the East Asian Monsoon (EAM) index, which represents the strength of monsoon, with a regionally averaged correlation coefficient of -0.64. Relative to the strongest EAM years, MAM dust concentrations in the weakest EAM years are higher over China, with regional relative differences of 55.6%, 29.6%, and 13.9% in the run with emissions calculated interactively and of 33.8%, 10.3%, and 8.2% over eastern, central, and western China, respectively, in the run with prescribed emissions. Both interactive run and prescribed emission run show the similar pattern of climate change between the weakest and strongest EAM years. Strong anomalous northwesterly and westerly winds over the Gobi and Taklamakan deserts during the weakest EAM years result in larger transport fluxes, and thereby increase the dust concentrations over China. These differences in dust concentrations between the weakest and strongest EAM years (weakest-strongest) lead to the change in the net radiative forcing by up to -8 and -3 W m-2 at the surface, compared to -2.4 and +1.2 W m-2 at the top of the atmosphere over eastern and western China, respectively.

  6. Genetic diversity and temporal dynamics of phytoplankton viruses in East Lake, China.

    PubMed

    Wang, Mei-Niang; Ge, Xing-Yi; Wu, Yong-Quan; Yang, Xing-Lou; Tan, Bing; Zhang, Yu-Ji; Shi, Zheng-Li

    2015-08-01

    Phytoplankton viruses are important components of aquatic ecosystems. However, their prevalence and genetic diversity in marine and freshwater systems are largely under estimated owing to the immense size of water bodies and limitations in virus discovery techniques. In this study, we conducted a 1-year survey of phytoplankton virus communities by collecting surface water monthly from an inland lake (East Lake) in China between May 2012 and April 2013. We examined four phytoplankton viruses, i.e., myoviruses, podoviruses, siphoviruses, and phycodnaviruses, and seven sets of primers were used to target conserved genes within these four species. In this year-long investigation, a total of 358 different virus-related sequences from four virus families were obtained. All virus families were detected in all months, except for cyanopodoviruses, which were only identified during eight of the 12 months surveyed. Moreover, virus abundance and diversity changed dynamically over time. Phylogenetic analysis revealed that the majority of viral sequences from East Lake, China displayed distinct clustering patterns compared with published sequences. These results supported the existence of a highly diverse and unique phytoplankton virus community in East Lake, China. PMID:26248585

  7. [Water environment adaptability and ecological groups of hydroidomedusae in East China Sea].

    PubMed

    Xu, Zhao-li

    2009-01-01

    Based on the data of four seasonal oceanographic censuses in East China Sea (23 degrees 30' - 33 degrees 00' N, 118 degrees 30' - 128 degrees 00' E) in 1997-2000, the optimal water temperature and salinity and the ecological groups of Hydroidomedusae were studied by curve fitting, mathematical model forming, and geographic distribution analyzing. The results showed that Hydroidomedusae could live in the waters with different temperature and salinity. 15 species of Hydroidomedusae had an optimal water temperature of <20 degrees C, 8 species at 20 degrees C - 25 degrees C, 12 species at 22.5 degrees C - 25 degrees C, and 17 species at > or =25 degrees C. 32 species of Hydroidomedusae had an optimal salinity of 32-34, 13 species at 34, 6 species at 30-32, and only 2 species at <30. The weak adaptability of most Hydroidomedusae species to the variation of water salinity made them have low density and limited distribution in East China Sea. Sugiura chengshanense and Clytia hemisphaerica were of nearshore warm temperate water species, Cunina octonaria and other 12 species were of offshore warm temperate water species, 8 species represented by Ectopleura latitaeniata were of nearshore subtropical water species, 5 species represented by Aglaura hemistoma showed some oceanic tropical features, while 25 species represented by Liriope tetraphylla were of offshore subtropical species. Some Hydroidomedusae species could be used as an important bio-indicator of water mass in East China Sea. PMID:19449583

  8. Tectonic entities connection between West Junggar (NW China) and East Kazakhstan

    NASA Astrophysics Data System (ADS)

    Zhao, Lei; He, Guoqi

    2013-08-01

    West Junggar (NW China) and East Kazakhstan are situated in the southwest of the Central Asian orogenic belt (CAOB). Tectonic entities in the two areas share the same tectonic evolution history and make up the famous horseshoe-shaped orocline in Central Asia. This paper presents a newly compiled cross-border tectonic sketch map of West Junggar and East Kazakhstan and proposes the extension of the Chingiz-Tarbagatai belt and the North Balkhash-West Junggar belt. The Chingiz-Tarbagatai Belt in East Kazakhstan consists mainly of Middle-Late Ordovician differentiated volcanic rocks, pyroclastic sediments and flysch; while in the Tarbagatai Mountain in China, Tarbagatai (Kujibai) ophiolite is newly found with zircon (gabbro) age of 478 ± 3 Ma and the Ordovician flysch metamorphosed to a greenschist facies is distinguished from Devonian-Carboniferous rock associations. Therefore, the Early Paleozoic Chingiz-Tarbagatai belt of East Kazakhstan evidently extends to the northern part of West Junggar along the Tarbagatai orogenic belt. The North Balkhash-West Junggar belt lying south to the Chingiz-Tarbagatai belt is separated by the EW-trending Baiyanghe-Heshituoluogai depression in West Junggar. Early Ordovician-Early Silurian ophiolitic fragments and related pyroclastic sediments are widely exposed in Tekturmas, North Balkhash and Agadyr of East Kazashtan. Similarly, Early Paleozoic ophiolites have also been verified in Tangbale, Mayile, Baerluke, Darbut and Karamay of West Junggar in recent years. Therefore, nearly all ophiolites in West Junggar and East Kazakhstan are proved to have formed in Early Paleozoic, which suggests that the evolution of the paleo-ocean in the two areas reached its peak in the Early Paleozoic. Based on the ages of the Tangbale, Karamay and Hongguleleng ophiolites, an Early Paleozoic continental accretionary belt extending from Tangbale to Hongguleleng is determined at the NW margin of the Junggar basin for the first time. According to

  9. The Effects of Black Carbon and Sulfate Aerosols in ChinaRegions on East Asia Monsoons

    SciTech Connect

    Yang, Bai; Liu, Yu; Sun, Jiaren

    2009-01-01

    In this paper we examine the direct effects of sulfate and black carbon aerosols in China on East Asia monsoons and its precipitation processes by using the CAM3.0 model. It is demonstrated that sulfate and black carbon aerosols in China both have the effects to weaken East Asia monsoons in both summer and winter seasons. However, they certainly differ from each other in affecting vertical structures of temperature and atmospheric circulations. Their differences are expected because of their distinct optical properties, i.e., scattering vs. absorbing. Even for a single type of aerosol, its effects on temperature structures and atmospheric circulations are largely season-dependent. Applications of T-test on our results indicate that forcing from black carbon aerosols over China is relatively weak and limited. It is also evident from our results that the effects of synthetic aerosols (sulfate and black carbon together) on monsoons are not simply a linear summation between these two types of aerosols. Instead, they are determined by their integrated optical properties. Synthetic aerosols to a large degree resemble effects of sulfate aerosols. This implies a likely scattering property for the integration of black carbon and sulfate aerosols in China.

  10. Investigation of Anthrax Cases in North-East China, 2010-2014

    PubMed Central

    Zhou, Wei; Sun, Yang; Zhu, Lingwei; Zhou, Bo; Liu, Jun; Ji, Xue; Wang, Xiaofeng; Wang, Nan; Gu, Guibo; Feng, Shuzhang; Qian, Jun; Guo, Xuejun

    2015-01-01

    We determined the genotypes of seven Bacillus anthracis strains that were recovered from nine anthrax outbreaks in North-East China from 2010 to 2014, and two approved vaccine strains that are currently in use in China. The causes of these cases were partly due to local farmers being unaware of the presence of anthrax, and butchers with open wounds having direct contact with anthrax-contaminated meat products. The genotype of five of the seven recovered strains was A.Br.001/002 sub-lineage, which was concordant with previously published research. The remaining two cases belongs to the A.Br.Ames sub-lineage. Both of these strains displayed an identical SNR pattern, which was the first time that this genotype was identified in North-East China. Strengthening education in remote villages of rural China is an important activity aimed at fostering attempts to prevent and control anthrax. The genotype of the vaccine strain Anthrax Spore Vaccine No.II was A.Br.008/009 and A.Br.001/002 for the vaccine strain Anthrax Spore Vaccine Non-capsulated. Further studies of their characteristics are clearly warranted. PMID:26308449

  11. Investigation of Anthrax Cases in North-East China, 2010-2014.

    PubMed

    Zhou, Wei; Sun, Yang; Zhu, Lingwei; Zhou, Bo; Liu, Jun; Ji, Xue; Wang, Xiaofeng; Wang, Nan; Gu, Guibo; Feng, Shuzhang; Qian, Jun; Guo, Xuejun

    2015-01-01

    We determined the genotypes of seven Bacillus anthracis strains that were recovered from nine anthrax outbreaks in North-East China from 2010 to 2014, and two approved vaccine strains that are currently in use in China. The causes of these cases were partly due to local farmers being unaware of the presence of anthrax, and butchers with open wounds having direct contact with anthrax-contaminated meat products. The genotype of five of the seven recovered strains was A.Br.001/002 sub-lineage, which was concordant with previously published research. The remaining two cases belongs to the A.Br.Ames sub-lineage. Both of these strains displayed an identical SNR pattern, which was the first time that this genotype was identified in North-East China. Strengthening education in remote villages of rural China is an important activity aimed at fostering attempts to prevent and control anthrax. The genotype of the vaccine strain Anthrax Spore Vaccine No.II was A.Br.008/009 and A.Br.001/002 for the vaccine strain Anthrax Spore Vaccine Non-capsulated. Further studies of their characteristics are clearly warranted. PMID:26308449

  12. Kuroshio front in the East China Sea: Joint analysis of oceanographic data, RADARSAT-1 SAR and multi-sensor imagery

    NASA Astrophysics Data System (ADS)

    Litovchenko, K.; Ivanov, A.; He, M. X.

    2003-04-01

    The unique RADARSAT-1 synthetic aperture radar (SAR) (ScanSAR Narrow A mode) image in the East China Sea covering of the Kuroshio frontal zone from the Luson Strait (Taiwan) to Cheju Island (Korea) has been acquired on November 19, 2000. In addition, 2 ERS-2 SAR.PRI images covering the adjacent areas have been acquired in November 2000. On the basis of the in situ observations and satellite remote sensing data the surface manifestations visible on the SAR images are analyzed. To support image analysis of the signature of the Kuroshio front a multi-sensor approach has been applied and available data/measurements in this area have been collected and used. Topex-Poseidon data, monthly averaged sea surface temperature (SST) field from NOAA satellites and SeaWiFS-based chlorophyll-a distribution have been additionally used. Imagery from space was also accompanied by measurements of the standard oceanographic and meteorological parameters, wind and surface wave characteristic records available from the oceanographic databases of China and Japan, as well as data/measurements collected by the ships crossing the frontal zone. Satellite imagery and in situ data also document the existence of the frontal zone with pronounced western boundary coinciding with the SAR image signature. SAR signatures of oceanic fronts are considered are a result of action of a number of physical mechanisms changing the sea surface roughness, among them are: (1) surface wave-current interaction modulated spectrum of surface waves; (2) difference in atmospheric boundary layer stability due to air-sea differences causing changes in radar backscatter, and (3) damping short waves due to oil films accumulation in convergent zones. By comparing and analyzing all available data, it’s concluded that the SAR signature of the Kuroshio front is a result, mainly, of surface wave-current interaction at observed winds more than of 10-12 m/s. The surface roughness responsible for backscatter contrast (up to 5

  13. Lung cancer among women in north-east China.

    PubMed Central

    Wu-Williams, A. H.; Dai, X. D.; Blot, W.; Xu, Z. Y.; Sun, X. W.; Xiao, H. P.; Stone, B. J.; Yu, S. F.; Feng, Y. P.; Ershow, A. G.

    1990-01-01

    A case-control study of lung cancer involving interviews with 965 female patients and 959 controls in Shenyang and Harbin, two industrial cities which have among the highest rates of lung cancer in China, revealed that cigarette smoking is the main causal factor and accounted for about 35% of the tumours among women. Although the amount smoked was low (the cases averaged eight cigarettes per day), the percentage of smokers among women over age 50 in these cities was nearly double the national average. Air pollution from coal burning stoves was implicated, as risks of lung cancer increased in proportion to years of exposure to 'Kang' and other heating devices indigenous to the region. In addition, the number of meals cooked by deep frying and the frequency of smokiness during cooking were associated with risk of lung cancer. More cases than controls reported workplace exposures to coal dust and to smoke from burning fuel. Elevated risks were observed for smelter workers and decreased risks for textile workers. Prior chronic bronchitis/emphysema, pneumonia, and recent tuberculosis contributed significantly to lung cancer risk, as did a history of tuberculosis and lung cancer in family members. Higher intake of carotene-rich vegetables was not protective against lung cancer in this population. The findings were qualitatively similar across the major cell types of lung cancer, except that the associations with smoking and previous lung diseases were stronger for squamous/oat cell cancers than for adenocarcinoma of the lung. PMID:2257230

  14. Atmospheric Transport and Deposition of Nitrogen Compounds From the Asian Continent Over the East China Sea

    NASA Astrophysics Data System (ADS)

    Uematsu, M.; Nakamura, T.; Endo, M.; Narita, Y.

    2004-12-01

    The growth of economy and population is rapid among in the east Asian countries. Within two decades, emission from east Asia could roughly account for half of the nitrogen released to the atmosphere from all anthropogenic sources worldwide. The Asia/western Pacific region has a unique mixture of aerosols and trace gases because of these distinctive patterns of emissions in combination with the local meteorological conditions affecting the region. Continental outflows can alter bilogical and chemical processes along the coastal Asia and, therefore, modify biogeochemical fluxes and feedbacks that may have serious implications to human health and climate implications. We made atmospheric measurements on board R/V Hakuho Maru over the western North Pacific and the East China Sea from 26 September to 9 October 2002 (the KH02-3 Cruise) in the autumn and from 4 to 20 March 2004 (the KH04-1 Cruise) in the spring. The atmospheric deposition fluxes of nitrogen compounds (ammonium, nitrate, and organic N) to the marine environment were investigated as a part of the IGBP/SOLAS project. Size segregated ambient aerosols (d<2.5μ m and d>2.5μ m) were collected at every 4-12 hours intervals on a PTFE fiber filter by using a high-volume dichotomous virtual impactor air sampler. Atmospheric average total ammonium concentration over the East China Sea was 2.3 μ g N m-3, and that of nitrate was 0.48 μ g N m-3. However, >90 percent of paticulate ammonium occurred in the fine fraction whereas >80 percent of particulate nitrate was in the coarse fraction. By using empirical dry deposition velocities for two size categories, we estimated the ammonium and nitrate dry deposition fluxes over the East China Sea to be 160 Gg N yr-1 and 270 Gg N yr-1, respectively. Our results clearly show that particle size is critical for different components and flux estimation. The atmospheric inputs of the nitrogen compounds to the East China Sea are found to be comparable to their fluxes of 190 Gg N yr

  15. The China Medical Board and Medical Libraries in the Far East *

    PubMed Central

    Fukudome, Takao

    1968-01-01

    The China Medical Board was created in 1914 to support the development of a medical college in Peking, China. However, its activity had to be discontinued due to the political change in China in late 1950, and the Board's new plans expanded into the whole area of the Far East in 1951. The primary program is to assist financially in the development of medical and nursing education and research; the library is one of the major concerns of the program. The assistance to libraries is categorized as follows: construction and equipment, books and journals, fellowships, and other items. An attempt is made to describe the actual status of medical libraries in the area since World War II from the point of view of the program of the Board. PMID:5644799

  16. Bioavailability of dissolved organic carbon linked with the regional carbon cycle in the East China Sea

    NASA Astrophysics Data System (ADS)

    Gan, Shuchai; Wu, Ying; Zhang, Jing

    2016-02-01

    The regional carbon cycle on continental shelves has created great interest recently due to the enigma of whether these areas are a carbon sink or a source. It is vital for a precise carbon cycle model to take the bioavailability of dissolved organic carbon (DOC) into account, as it impacts the sink and source capacity, especially on dynamic shelves such as the East China Sea. Nine bio-decomposition experiments were carried out to assess differences in the bioavailability of DOC. Samples were collected from different water masses in the East China Sea, such as the Coastal Current, the Taiwan Current, and the Kuroshio Current, as well as from the Changjiang (Yangtze River), the main contributor of terrestrial DOC in the East China Sea. This study aimed to quantify and qualify bioavailable DOC (BDOC) in the East China Sea. Both the degradation constant of BDOC and the carbon output from microorganisms have been quantitatively evaluated. Qualitatively, excitation-emission matrix fluorescence spectra (EEMs) were used to evaluate the intrinsic reasons for BDOC variation. By using EEMs in conjunction with parallel factor analysis (PARAFAC), five individual fluorescent components were identified in this study: three humic-like and two protein-like components (P1, P2). The highest P1 and P2 fluorescence intensities were recorded in the coastal water during a phytoplankton algal bloom, while the lowest intensities were recorded in the Changjiang estuary. Quantitatively, BDOC observed during the incubation ranged from 0 to 26.1 μM. The DOC degradation rate constant varied from 0 to 0.027 (d-1), and was lowest in the Changjiang and highest in algal bloom water and warm shelf water (the Taiwan current). The Taiwan Current and mixed shelf water were the major contributors of BDOC flux to the open ocean, and the East China Sea was a net source of BDOC to the ocean. The results verified the importance of BDOC in regional carbon cycle modeling. Combining the data of BDOC and EEMs

  17. Internal structures and developing mechanisms of tidal sand ridges in the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Z.

    2004-12-01

    *Abstract:* The internal structures of the tidal sand ridges in the East China Sea are characterized by the southwest-dipping beddings and several erosion surfaces, which resulted in young sand ridges overlying old ones and forming a unique multi-layer complex structure. These characteristics reveal the multi-phase development of the tidal sand ridges, and their multi-repetitive forming history of accumulation, erosion and accumulation. There are two mechanisms interpreting the migration and evolution of these sand ridges. One mechanism concerns the evolution tidal sand ridge itself. The tidal current difference along two flanks of a ridge makes the sediments migrate toward the side with lower current speed. This is so-called auto-cyclic process of sand ridge developing. For the tidal sand ridges in the East China Sea, one side is dominated by flood currents in a NW direction, the other side is dominated by ebb current in a SE direction. Due to the influences of topography gradient of the continental shelf and the runoff from Chinese main land, the velocity of the ebb currents is larger than that of the flood currents, so the sediment is transported to southwest continuously, and it is a certainty for the sand ridges migrate toward SW and form the beddings inclining toward SW. The other mechanism is allo-cyclic process, which relates to global or regional hydrodynamic changes, such as sea-level fluctuations or storm waves. The post-glacial sea level rose rapidly in a stepwise pattern caused by the four postglacial melting water pulses (MWP-1A, 1B, 1C, 1D) (Liu et al., 2004) and it should play an important role in this mechanism. Both mechanisms exist in the development of the tidal sand ridges in the East China Sea, so there is some difficulties to distinguish them clearly. It is obvious that the tidal sand ridges of the East China Sea have evolved continuously since the postglacial period; four stages of sand ridges have formed in sequence: younger ridges overlaid

  18. Innovation in the Educational Technology Course for Pre-Service Student Teachers in East China Normal University

    ERIC Educational Resources Information Center

    Yan, Hanbing; Xiao, Yumin; Wang, Qiyun

    2012-01-01

    Modern Educational Technology is a common course in many normal universities in China. The Modern Educational Technology Center (METC) of East China Normal University (ECNU) decided to improve the course for pre-service teachers at the end of 2010. The enhanced course has some additional features, such as emphasising knowledge and skills transfer,…

  19. Petrology, geochemistry and isotope data on a ultrahigh-pressure jadeite quartzite from Shuanghe, Dabie Mountains, East-central China

    NASA Astrophysics Data System (ADS)

    Liou, J. G.; Zhang, R. Y.; Jahn, Bor-ming

    1997-08-01

    In the Dabie ultrahigh-pressure terrane of east-central China, coesite-bearing jadeite quartzites occur locally as intercalated layers with marble and mafic eclogite. This rock assemblage is, in turn, enclosed within quartzofeldspathic gneisses. Metamorphic parageneses and kelyphitic textures reveal a multistage metamorphic evolution and complex exhumation history. The primary peak metamorphic assemblage consists of jadeite + garnet + coesite + rutile ± apatite. Minor coesite and coesite pseudomorphs occur as inclusions in jadeite and garnet. Three stages of retrograde assemblages are observed in the jadeite quartzites. Stage A is represented by the polymorphic transformation of coesite to quartz aggregates. Stage B is characterized by formation of coronas around jadeite porphyroblasts consisting of an inner layer of oligoclase + amphibole and an outer layer of albite ± aegirine—augite. The last stage (stage C) involved total replacement of jadeite and most garnets by taramitic amphibole + albite + aegirine-augite. Peak metamorphic P-T conditions were > 26 kbar at 660°C and are consistent with the estimates from the adjacent coesite-bearing eclogites. The jadeite quartzites display clockwise P-T path that matches those of the adjacent eclogites. Major and trace element data suggest that the protolith of the jadeite quartzite could have been an albitized siltstone enriched in Na and depleted in K and Ca. The highly negative present-day ɛNd value (-24.7) indicates a very old age for the protolith. Its late Archean model age (TDM) of 2.58 Ga is among the oldest so far identified for rocks from the Dabie UHPM terrane. Concordant field relations and petrogenetic considerations suggest that all mafic, politic, carbonate and gneissic rocks have experienced in-situ UHP metamorphism during Triassic continental collision between the Sino-Korean and Yangtze cratons.

  20. Mantle dynamics and Cretaceous magmatism in east-central China: Insight from teleseismic tomograms

    NASA Astrophysics Data System (ADS)

    Jiang, Guoming; Zhang, Guibin; Zhao, Dapeng; Lü, Qingtian; Li, Hongyi; Li, Xinfu

    2015-11-01

    Both the rich mineralization in the Lower Yangtze Block (LYB) and the post-collisional mafic rocks in the Dabie Orogen (DBO) are closely related to the Cretaceous magmatism in east-central China. Various geodynamic models have been proposed for explaining the mechanism of the Cretaceous magmatism, but these models are controversial and even contradictory with each other, especially on the mechanism of adakites. A unified geodynamic model is required for explaining the magmatism in east-central China, in particular, the spatial and temporal correlations of magmatic activity in the DBO and that in the LYB. For this purpose, we apply teleseismic tomography to study P-wave velocity structure down to 800 km depth beneath east-central China. A modified multiple-channel cross-correlation method is used to collect 28,805 high-quality P-wave arrival-time data from seismograms of distant earthquakes recorded by permanent seismic stations and our temporary stations in the study region. To remove the influence of crustal heterogeneity on the mantle tomography, we used the CRUST1.0 model to correct the teleseismic relative residuals. Our tomography revealed distinct high-velocity (high-V) anomalies beneath the DBO and two flanks of the LYB, and low-velocity (low-V) anomalies above the high-V zones. Combining our tomographic images with previous geological, geochemical and geophysical results, we infer that these high-V and low-V anomalies reflect the detached lithosphere and upwelling asthenospheric materials, respectively, which are associated with the Late Mesozoic dynamic process and the Cretaceous magmatism. We propose a double-slab subduction model that a ridge subduction yielded the adakitic rocks in the LYB during 150-135 Ma and the subsequent Pacific Plate subduction played a crucial role in not only the formation of igneous rocks in the LYB but also remelting of the subducted South China Block beneath the DBO during 135-101 Ma.

  1. A historical perspective of the extremely hot 2013 summer in East-central China

    NASA Astrophysics Data System (ADS)

    Liu, Qi; Fu, Congbin; Mao, Huiting

    2016-04-01

    An extreme hot summer occurred over East-central China in 2013. Its duration of continuous, highest temperature anomalies was the longest on record for the time period of 1948-2013. Several modeling studies have attempted to identify the causes and did not obtain conclusive findings, in large part due to their limited scopes of the problem. Here, we conducted a multi-scale and multi-factor analysis of this extreme event using observational data of 600 monitoring stations over China and global reanalysis data for the period of 1981-2013. Our results suggested that the number of heatwave days (NHD) (defined as a day with daily maximum temperature ≥ 35°C) over East-central China experienced an increasing trend of 3.44 days per decade since 1981 and reached the record maximum (34.1 days) in 2013, with significant inter-annual variability superimposed on the trend. It should be noted that this increasing trend in NHD was consistent with that of the intensity of the Western Pacific Subtropical High (WPSH) linked to global warming as suggested in the literature. There were also strong correlations between NHD over East-central China, WPSH, and global mean temperature (GT) on interannual scales. The extremely hot 2013 summer could not be explained by global warming and associated enhanced WPSH alone as GT and WPSH intensity were not record high in that summer. Further analysis suggested that large scale air-sea interaction over the Pacific region could have played a critical role. Specifically, enhanced convection over the Philippine Sea and along Indonesian islands in summer 2013 appeared to be strongest for the study period. This convection could cause a strong local feedback among precipitation, cloud cover, and net radiation, which could further weaken upper- and lower-level circulation via the tropical-extratropical teleconnection and Rossby wave propagation. This feedback was likely the direct cause of the extremely hot 2013 summer.

  2. Continuous surface seawater surveillance on poly aromatic hydrocarbons (PAHs) and mutagenicity of East and South China Seas

    NASA Astrophysics Data System (ADS)

    Ren, Huifeng; Kawagoe, Tsubasa; Jia, Huijuan; Endo, Hideaki; Kitazawa, Akira; Goto, Sumio; Hayashi, Tetsuhito

    2010-02-01

    Poly aromatic hydrocarbons (PAHs) and mutagenic compounds were adsorbed on Blue Rayon (BR) to monitor the pollution level of the surface seawater of the East and South China Seas by continuous sampling of seawater along the ship lane of our research and training vessel Umitaka-Maru. Eluted PAHs from BR were quantitatively determined by HPLC and their total amount in each sample ranged between 30.40 and 120.29 ng per liter of seawater, showing a difference of about 4 times among 8 samples. Acenaphthylene, naphthalene, and benz(a)anthracene were the most common PAHs found in the East and South China Seas, however, no big difference was observed in the concentrations of PAHs distributed throughout those two closed seas. Mutagenicity was detected as pseudo-positive from three samples. Among them, one sample collected along the east edge of the East China Sea showed a strong direct cytotoxicity which interrupted the mutagenicity test.

  3. Magnetic investigation of heavy metals contamination in urban topsoils around the East Lake, Wuhan, China

    NASA Astrophysics Data System (ADS)

    Yang, Tao; Liu, Qingsheng; Chan, Lungsang; Cao, Guodong

    2007-11-01

    Magnetic measurements and heavy metal analyses were performed on 133 samples from the urban soils around the East Lake in Wuhan, China. Samples were collected from four areas with different environmental settings: a heavy industrial area well known for thermal power generation and steel works; villages located in the downwind area of the industrial area; a main road with heavy traffic and roads around the East Lake. Results show that concentrations of magnetic particle and heavy metals in urban topsoils are significantly elevated due to the input of coarser-grained magnetite from industrial (e.g. power generation and steel production) and other anthropogenic activities (e.g. vehicle emissions). Concentration-related magnetic parameters, for example, magnetic susceptibility, saturation isothermal remanent magnetization and anhysteretic remanent magnetization, significantly correlate with the concentration of heavy metals. Moreover, in terms of grain sizes, the magnetic particles of different origins can be efficiently discriminated at the studied region. Therefore, magnetic measurements provide a basis for discrimination and identification of different contamination sources, and can be used as an economic alternative to chemical analysis when mapping heavy metal contamination in urban soil around the East Lake region, Wuhan, China.

  4. Numerical modeling of Late Miocene tectonic inversion in the Xihu Sag, East China Sea Shelf Basin, China

    NASA Astrophysics Data System (ADS)

    Dai, Liming; Li, Sanzhong; Lou, Da; Liu, Xin; Suo, Yanhui; Yu, Shan

    2014-06-01

    The East China Sea Shelf Basin is an important oil- and gas-bearing basin in the West Pacific continental margin. This region was affected by subduction of the Pacific Plate and the Philippine Plate in Cenozoic and experienced multi-stage tectonic inversions. This paper presents results from a numerical simulation by finite element method to the Xihu Sag in the East China Sea Shelf Basin and neighboring areas in an attempt to evaluate the WNW-directed compression on the sag during Late Miocene. Based on comprehensive structural analysis of a large number of seismic profiles, we determine the structural geometry of the sag, including the basement of the basin, the sedimentary cover, and 29 major faults in the Xihu Sag. Simulation results show that under continuous WNW-directed compression, tectonic inversion occurred firstly in the Longjing and Yuquan tectonic zones in the sag. Based on quantitative analysis of vertical displacement field of the Xihu Sag and peripheral areas and its stress intensity evolution, we identify a compressional regime in the Longjing Anticline Zone with a gradually propagated uplifting from south to north; whereas the propagation of uplifting in the Yuquan Anticline Zone is from north to south. The inversion intensity decreases from north to south. The formation of the tectonic inversion zone in the Xihu Sag is not only correlated to the direction of compression and fault patterns in the basin, but also closely related to the spatial configuration of fault surfaces of the Xihu-Jilong Fault in the Xihu Sag.

  5. Overview of ASIAEX field experiments in the South and East China Seas

    NASA Astrophysics Data System (ADS)

    Lynch, James F.; Dahl, Peter H.

    2002-11-01

    In the spring of 2001 the Asian Seas International Acoustics Experiment (ASIAEX) was performed in the South and East China Seas. The ASIAEX program originated from the Office of Naval Research's initiative to develop a Sino-American cooperation in the field of ocean acoustics, and expanded to involve Taiwan, Korea, Singapore, and Japan. In the South China Sea, the emphasis was on lower frequency (50-600 Hz) acoustic propagation through complex oceanography along and across the shelfbreak. The oceanographic variability was driven at the mesoscale by the monsoonal wind stress, buoyancy fluxes from the Chinese coast, and by occasional Kuroshio intrusions through the Luzon Strait. Large, nonlinear internal waves also significantly affected the acoustics. In the East China Sea the emphasis was on low- to- midfrequency acoustic interaction with, and reverberation from, the sea floor and sea surface. The experimental site was chosen for flatness, to minimize the influence of bathymetric trends, and emphasize bottom roughness and subbottom structures, in the measurements. This talk will describe the scope of the ASIAEX experimental program, including the ocean acoustic and environmental characterization of the seafloor, sea surface, and water column. Results from various measurement programs will be described in separate papers.

  6. Airborne Measurements of Trace Gases and Aerosols in Northern China: EAST-AIRE IOP 2005

    NASA Astrophysics Data System (ADS)

    Li, C.; Dickerson, R. R.; Li, Z.; Stehr, J. W.; Chen, H.; Marufu, L. T.

    2005-12-01

    To characterize the emission, transport and removal of pollutants and aerosols emitted from East Asia, a US-China joint field campaign was conducted from February to April in China under the EAST-AIRE project. Surface and airborne measurements of trace gases and aerosols were made at different locations in northern China. In early April, eight research flights were conducted around Shenyang, an industrialized city with a population of about 6 million, 600 km northeast of Beijing. Parameters measured include SO2, CO, O3, aerosol size distribution, aerosol scattering and absorption coefficients. During 4 of the 8 flights, the research aircraft made spirals over two suburban locations (~50 km south and north of the downtown area of Shenyang) to determine the detailed vertical distribution of trace gases and aerosols. Various weather patterns were encountered, allowing an examination of the roles of atmospheric circulation in transporting local pollutants to much larger areas. For example, the flights made ahead of the cold front showed fairly high concentrations of pollutants above the planetary boundary layer, probably lifted by the upward motion associated with the approaching cold fronts. On the other hand, much lower pollutant levels were found for the flights made behind the cold front. Also observed in one cold-sector flight is a level (~3000 m) with enhanced aerosol scattering but almost undetectable SO2. Back trajectory analysis using NOAA-HYSPLIT model suggests possible dust transport from source regions.

  7. Spatial variability of dissolved phosphorous concentrations and alkaline phosphatase activity in the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, H.; Chang, J.; Ho, T.; Gong, G.

    2010-12-01

    The concentrations of dissolved inorganic phosphorus (DIP) and alkaline phosphatase activity (APA) have been determined at about 25 sampling stations in the East China Sea since 2003. The stations are mainly distributed from the Changjiang river mouth to northern Taiwan and east to the shelf break. In addition to the Changjiang discharge, we have found a specific nutrient source around a coastal site (122° 2’30’’ E, 28° 40’ N). Elevated DIP and nitrate concentrations have been constantly observed around the sampling station for 8 years, where the surface DIP concentrations are generally around 0.3 µM. The nutrient source may either originate from ground water discharge or coastal upwelling, where lower temperature has been observed in the water column around the station. In general, APA has been negatively correlated with DIP concentrations in the studies sites, with lowest APA around the high DIP station and the Changjiang river mouth.

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

    NASA Astrophysics Data System (ADS)

    Song, G. D.; Liu, S. M.; Marchant, H.; Kuypers, M. M. M.; Lavik, G.

    2013-03-01

    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-loss as N2 was the main pathway

  9. A new species of Praebebalia (Crustacea: Brachyura: Leucosiidae) from East China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Hui-Lian; Fang, Shao-Hua

    2000-12-01

    A new species of the genus Praebebalia from the East China Sea, belonging to the subfamily Ebaliinae Stimpson, 1871, is described. It is characterized by carapace being broader than long, the dorsal surface without sharp granules near borders, the median part of anterolateral borders with a notch, the junction of anterolateral and posterolateral borders with a tubercle, the posterior border with a triangular tubercle on each side, the propodi of anterior 3 pairs of ambulatory legs with a tubercle and the fingers of chelipeds being longer than palm.

  10. Polychlorinated biphenyl (PCB) congeners in Mussel and other mollusc from Da Chen Island, East China Sea

    SciTech Connect

    Chu, S.G.; Xi, Z.Q.; Xu, X.B

    1995-11-01

    Polychlorinated biphenyls (PCBs) are among the most persistent and toxic pollutants in environment. Determination of these contaminants in fish, shellfish and other mollusc is very important, not only because these aquatics are important food for mankind, but also because they can bioconcentrate contaminants preferentially in their adipose tissue, and serve as biomarker of the aquatic pollution. Mussels and oysters have been widely used to monitor the pollution in the coastal environment. The aim of the study was to investigate the concentrations and the main source of PCBs in mussels and other mollusca from the coastal areas of East China Sea. 10 refs., 3 figs., 2 tabs.

  11. A new species of Lataxiena Jousseaume, 1883 (Gastropoda: Muricidae) from the East and South China Seas

    NASA Astrophysics Data System (ADS)

    Zhang, Suping; Zhang, Shuqian

    2015-03-01

    A new muricid gastropod species, Lataxiena lutescena sp. nov., is described and illustrated. The new species was recognized during reidentification of the Muricidae collection in the Marine Biological Museum, Chinese Academy of Sciences, Qingdao. The specimens of the new species were collected from the East and South China Seas off Fujian, Guangdong, and Hainan Provinces. Lataxiena lutescena sp. nov. is similar to Lataxiena blosvillei (Deshayes, 1832) in general shape, but can be distinguished from the latter by the shell sculpture and radular characteristics. Lataxiena lutescena sp. nov. also resembles Lataxiena bombayana (Melvill, 1893), but differs from that species in the shell shape and anal notches and in lacking short spines on the shell.

  12. China upgrades surveillance and control measures of Middle East respiratory syndrome (MERS).

    PubMed

    Gao, Jianjun; Song, Peipei

    2015-06-01

    Three years after the identification of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia, the first case of MERS in China was reported on May 29, 2015. Although the Chinese government issued the MERS Prevention and Control Plan in 2013, a novel edition was released on June 5, 2015 to better cope with the current epidemic situation. The revised Plan refines the descriptions in case-finding and establishment of case-monitoring systems. In addition, tougher regulations on close contacts of confirmed patients and suspected cases are introduced in this new Plan. It is expected these countermeasures will play a greater role in surveilling and controlling MERS in China. PMID:26063202

  13. Distribution characteristics of marine litter on the sea bed of the East China Sea and the South Sea of Korea

    NASA Astrophysics Data System (ADS)

    Lee, Dae-In; Cho, Hyeon-Seo; Jeong, Sun-Beom

    2006-10-01

    The types, quantities, and distribution of marine litter found on the sea bed of the East China Sea and the South Sea of Korea are surveyed. Surveys were evaluated using bottom trawl nets during 1996-2005 cruises. Mean distribution densities were high in coastal seas, especially in the South Sea of Korea offshore from Yeosu, with 109.8 kg km -2, and low in the East China Sea, with densities of 30.6 kg km -2. Fishing gear, such as pots, nets, octopus jars, and fishing lines, accounted for about 42-72% and 37-62% of litter items in the East China Sea and the South Sea of Korea, respectively, whereas the contributions of rubber, vinyl, metal, plastic, glass, wood, and clothing were below 30% mainly. Rope and drum composition fluctuated greatly, between 54% and 0%. Eel and net pots dominated the marine debris of the South Sea of Korea, and some vinyl, plastics, and fishing gear made in Korea, China, and Japan were collected in abundance in the East China Sea. Fishing gear was probably discarded into the sea, deliberately or inadvertently, by fishing operations. A comprehensive joint approach by Korea, China, and Japan is needed for the continuous monitoring of input sources, the actual conditions, and the behavior of marine litter for protection against litter pollution and fisheries resource management in this area.

  14. Impacts of interannual variation of the East Asian winter monsoon on aerosol concentrations over eastern China

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Liao, H.; Li, J.; Feng, J.

    2012-04-01

    China has been experiencing increased concentrations of aerosols, commonly attributed to the large increases in emissions associated with the rapid economic development. We apply a global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) driven by the NASA/GEOS-4 assimilated meteorological data to quantify the impacts of East Asian winter monsoon (EAWM) on the aerosol concentrations over eastern China. We found that the simulated aerosol concentrations over eastern China have strong interannual variation and negative correlations with the strength of EAWM. Model results show that, accounting for sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols, the winter surface layer PM2.5 concentration averaged over eastern China (110°-125°E, 20°-45°N) can be 17.97% (4.78 µg m-3) higher in the weak monsoon years than that in the strong monsoon years. Regionally, the weakening of EAWM is shown to be able to increase PM2.5 concentration in the middle and lower reach of the Yellow River by 12 µg m-3. This point indicates that climate change associated with variation of EAWM has an essential influence on worsening air quality over eastern China. The possible causes of higher aerosol concentrations in the weak monsoon years may be attributed to the changing in wind fields and planetary boundary layer height between the weak and strong monsoon years. Sensitivity studies are performed to identify the role of chemical reaction associated with temperature and humidity on the higher aerosol concentrations in the weak monsoon years over eastern China.

  15. Long-Term Evolution of the East Asian Monsoon and Impact on Erosion and Weathering Around the South China Sea

    NASA Astrophysics Data System (ADS)

    Clift, P. D.

    2014-12-01

    Deep-water sediment records in the South China Sea have the potential to allow environment in the adjacent landmasses to be reconstructed since the Eocene rifting of the basin if the effects of provenance and drainage capture can be quantified and accounted for. The rifted margin of South China, fed by the Pearl River, likely holds the simplest record, as until the uplift of Taiwan after ~5 Ma the sediment must be dominantly derived from southern China, which is relatively tectonically quiescent. Provenance data suggest that the Pearl River was likely not involved in the major drainage capture events that affect the Yangtze, Red and Mekong Rivers. Choosing the right monsoon proxy is difficult because heavier rain provides moisture, potentially increasing alteration of sediment, yet greater run-off also causes faster transport, which reduces the time available for alteration to occur. The Middle Miocene is generally identified as the time during which the most altered sediment accumulated, while seismic data also finger this period as one with the fastest sediment delivery rates, indicating rapid erosion onshore. Prior to 22 Ma and during the Mid Miocene Climatic Optimum (15.5-17.0 Ma) conditions were wet and tropical but not very seasonal, i.e. the summer monsoon was weak. Chemical weathering traced by clay minerals and geochemical proxies such as K/Al decreased as the Neogene advanced, likely reflecting falling global temperatures rather than weaker summer rainfall. Weathering decreased even faster between 10 and 8 Ma, when the summer monsoon is inferred to have weakened until 5 Ma, consistent with falling sediment delivery rates to the continental margin. Records after that time are more variable, but are also complicated by sediment flux from Taiwan. The onset of Northern Hemispheric Glaciation appears to be linked to short-lived periods of stronger and weaker monsoon. No simple relationship can be inferred between the intensity of the East Asian Monsoon and the

  16. Unusual distribution of floating seaweeds in the East China Sea in the early spring of 2012.

    PubMed

    Komatsu, Teruhisa; Mizuno, Shizuha; Natheer, Alabsi; Kantachumpoo, Attachai; Tanaka, Kiyoshi; Morimoto, Akihiko; Hsiao, Sheng-Tai; Rothäusler, Eva A; Shishidou, Hirotoshi; Aoki, Masakazu; Ajisaka, Tetsuro

    2014-01-01

    Floating seaweeds play important ecological roles in offshore waters. Recently, large amounts of rafting seaweed have been observed in the East China Sea. In early spring, juveniles of commercially important fish such as yellowtail accompany these seaweed rafts. Because the spatial distributions of seaweed rafts in the spring are poorly understood, research cruises were undertaken to investigate them in 2010, 2011, and 2012. Floating seaweed samples collected from the East China Sea during the three surveys contained only Sargassum horneri. In 2010 and 2011, seaweed rafts were distributed only in the continental shelf and the Kuroshio Front because they had become trapped in the convergence zone of the Kuroshio Front. However, in 2012, seaweed was also distributed in the Kuroshio Current and its outer waters, and massive strandings of seaweed rafts were observed on the northern coast of Taiwan and on Tarama Island in the Ryukyu Archipelago. Environmental data (wind, currents, and sea surface height) were compared among the surveys of 2010, 2011, and 2012. Two factors are speculated to have caused the unusual distribution in 2012. First, a continuous strong north wind produced an Ekman drift current that transported seaweed southwestward to the continental shelf and eventually stranded seaweed rafts on the coast of Taiwan. Second, an anticyclonic eddy covering northeast Taiwan and the Kuroshio Current west of Taiwan generated a geostrophic current that crossed the Kuroshio Current and transported the rafts to the Kuroshio Current and its outer waters. Such unusual seaweed distributions may influence the distribution of fauna accompanying the rafts. PMID:24771974

  17. Structural evolution of the northern East China Sea Shelf Basin interpreted from cross-section restoration

    NASA Astrophysics Data System (ADS)

    Cukur, Deniz; Horozal, Senay; Lee, Gwang H.; Kim, Dae C.; Han, Hyun C.; Kang, Moo H.

    2011-09-01

    The northern East China Sea Shelf Basin consists of three depressions (the Domi, Jeju, and Socotra Depressions), separated by basement highs or rises. Reconstruction of depth-converted seismic reflection profiles from these depressions reveals that the northern East China Sea Shelf Basin experienced two phases of rifting, followed by regional subsidence. Initial rifting in the Late Cretaceous was driven by the NW-SE crustal stretching of the Eurasian plate, caused by the subduction of the Pacific plate beneath the plate margin. Major extension (~15 km) took place during the early phase of basin formation. The initial rifting was terminated by regional uplift in the Late Eocene-Early Oligocene, which was probably due to reorganization of plate boundaries. Rifting resumed in the Early Oligocene; the magnitude of extension was mild (<1 km) during this period. A second phase of uplift in the Early Miocene terminated the rifting, marking the transition to the postrift phase of regional subsidence. Up to 2,600 m of sediments and basement rock were removed by erosion during and after the second phase of uplift. An inversion in the Late Miocene interrupted the postrift subsidence, resulting in an extensive thrust-fold belt in the eastern part of the area. Subsequent erosion removed about 900 m of sediments. The regional subsidence has dominated the area since the Late Miocene.

  18. Geotechnical properties of surface and near-surface deposits in the East China Sea

    NASA Astrophysics Data System (ADS)

    Keller, George H.; Yincan, Ye

    Shelf deposits in the East China Sea are primarily relict sands with overlying fine-grained cohesive deposits occurring along the innermost shelf and as a more or less isolated deposit on the midshelf. Considering these surface and near-surface (0 to 1.5 m) cohesive deposits as a unit, the innermost shelf sediments are slightly coarser (more silt) than those of the midshelf which commonly contain more clay-size material. The inner shelf sediments also display higher mean wet bulk densities (1.48 to 1.88 mg m -3) and shear strengths (4.0 to 9.8 kPa), but lower water contents (64 to 81%) and porosities (62 to 66%) than those found associated with the midshelf deposits. Available data indicate that the midshelf mud deposit is primarily derived from the reworking of Huanghe (Yellow River) coastal deposits that were laid down at a time when the river debouched into the Yellow Sea to the north of the Changjiang. Some portion of the midshelf mud may be derived from the Changjiang. These midshelf 'fines' apparently are caught up in a large circulation gyre over the shelf which accounts for their isolated nature. Strong bottom and near-bottom currents, as well as winter storm wave activity, are primary mechanisms resulting in both suspended sediment and bedload transport on the shelf of the East China Sea.

  19. The distribution of dissolved aluminum in the Yellow and East China Seas

    NASA Astrophysics Data System (ADS)

    Li, Jianbing; Ren, Jingling; Zhang, Jing; Liu, Sumei

    2008-02-01

    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 μmolL-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 Al 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.

  20. Eutrophication-Driven Hypoxia in the East China Sea off the Changjiang Estuary.

    PubMed

    Wang, Hongjie; Dai, Minhan; Liu, Jinwen; Kao, Shuh-Ji; Zhang, Chao; Cai, Wei-Jun; Wang, Guizhi; Qian, Wei; Zhao, Meixun; Sun, Zhenyu

    2016-03-01

    Coastal hypoxia is an increasingly recognized environmental issue of global concern to both the scientific community and the general public. We assessed the relative contributions from marine and terrestrially sourced organic matter that were responsible for oxygen consumption in a well-studied seasonal coastal hypoxic zone, the East China Sea off the Changjiang Estuary. Our fieldwork was conducted in August 2011 during reinstatement of a subsurface hypoxia, when we observed a continuous decline of dissolved oxygen along with production of dissolved inorganic carbon resulting from organic carbon remineralization. On the basis of a three end-member mixing model and determinations of the stable isotopic compositions of dissolved inorganic carbon (δ(13)CDIC), the end product of particulate organic carbon (POC) degradation, we quantified the δ(13)C value of the remineralized organic carbon (δ(13)COCx), which was -18.5 ± 1.0‰. This isotopic composition was very similar to the δ(13)C of marine sourced POC produced in situ (-18.5 ± 0.3‰) rather than that of the terrestrially sourced POC (-24.4 ± 0.2‰). We concluded that marine-sourced organic matter, formed by eutrophication-induced marine primary production, was the dominant oxygen consumer in the subsurface hypoxic zone in the East China Sea off the Changjiang Estuary. PMID:26824328

  1. Detecting the red tide based on remote sensing data in optically complex East China Sea

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohui; Pan, Delu; Mao, Zhihua; Tao, Bangyi; Liu, Qiong

    2012-09-01

    Red tide not only destroys marine fishery production, deteriorates the marine environment, affects coastal tourist industry, but also causes human poison, even death by eating toxic seafood contaminated by red tide organisms. Remote sensing technology has the characteristics of large-scale, synchronized, rapid monitoring, so it is one of the most important and most effective means of red tide monitoring. This paper selects the high frequency red tides areas of the East China Sea as study area, MODIS/Aqua L2 data as the data source, analysis and compares the spectral differences in the red tide water bodies and non-red tide water bodies of many historical events. Based on the spectral differences, this paper develops the algorithm of Rrs555/Rrs488> 1.5 to extract the red tide information. Apply the algorithm on red tide event happened in the East China Sea on May 28, 2009 to extract the information of red tide, and found that the method can determine effectively the location of the occurrence of red tide; there is a good corresponding relationship between red tide extraction result and chlorophyll a concentration extracted by remote sensing, shows that these algorithm can determine effectively the location and extract the red tide information.

  2. Internal wave damping in the East China in late summer 2014

    NASA Astrophysics Data System (ADS)

    Kuh Kang, Sok; Lee, Jae Hak; Park, Jae-Hun; Kim, Eun Jin; Hong, Chang Su

    2016-04-01

    A field measurement was carried out to observe generation, propagation and damping of the internal waves on the continental shelf around 31N in the East China Sea during September 16-27, 2014. Two trawl-resistant bottom mount ADCPs (M1, M2) were deployed along 126.5oE with 10 km apart. Over the 10 km distance the dominant frequency internal wave group with periods around 500 s is estimated to dissipate its energy by about 30%. The damping process appears to be partly related with the higher-mode evolution at the downward station M1, compared with the 1st-mode dominancy at the upstream station (M2). Our observations suggest that the damping processes of internal waves on the continental shelf of the East China Sea occur by rather complicated manners than by the simple process due to frictional decaying. This work was partially supported by KIOST projects (PE99396)and this research has been performed as collaborative research project of project No (Development of HPC-based management system againstnational scale disaster) and supported by the KOREA INSTITUTE of SCIENCE and TECHNOLOGY INFORMATION (KISTI).

  3. Vertical distribution and indications of lipids biomarkers in the sediment core from East China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Rui; Wang, Jiangtao; Li, Feng; Yang, Shu; Tan, Liju

    2016-07-01

    To study the distribution and indications of lipids biomarkers in the mud areas of the East China Sea shelf, a sediment core was collected. Lipids were determined to find the origination of different organic matter (fatty acids and sterols) inputs. The results demonstrated that the distribution of fatty acids and sterols indicated the organic matter derived from the mixed allochthonous and autochthonous sources, but mainly autochthonous. The total fatty acids concentrations ranged from 29.08 μg g-1 to 303.92 μg g-1 and exhibited unimodal distribution with the predominance of C16-fatty acid. Neutral lipid concentrations ranged from 1.77 μg g-1 to 4.65 μg g-1. Furthermore, the distribution patterns of sterols varied with depth, and were dominated by C27-sterol and C29-sterol in the top and bottom sediments respectively. Although bacterial lipids were recruited during diagenesis, the refractory terrestrial lipids were usually preferentially preserved. This records dated from the 1980s suggested that the phytoplankton community was mainly influenced by eutrophication in the East China Sea and this variation may be recorded by lipid biomarkers deposited in the sediment.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Diurnal variation of surface ozone in mountainous areas: Case study of Mt. Huang, East China.

    PubMed

    Zhang, Lei; Jin, Lianji; Zhao, Tianliang; Yin, Yan; Zhu, Bin; Shan, Yunpeng; Guo, Xiaomei; Tan, Chenghao; Gao, Jinhui; Wang, Haoliang

    2015-12-15

    To explore the variations in atmospheric environment over mountainous areas, measurements were made from an intensive field observation at the summit of Mt. Huang (30.13°N, 118.15°E, 1841m above sea level), a rural site located in East China, from June to August 2011. The measurements revealed a diurnal change of surface O3 with low concentrations during the daytime and high concentrations during the nighttime. The causes of diurnal O3 variations over the mountain peak in East China were investigated by using a fairly comprehensive WRF-Chem and HYSPLIT4 modeling approach with observational analysis. By varying model inputs and comparing the results to a baseline modeling and actual air quality observations, it is found that nearby ozone urban/anthropogenic emission sources were contributing to a nighttime increase in mountaintop ozone levels due to a regional transport lag and residual layer effects. Positive correlation of measured O3 and CO concentrations suggested that O3 was associated with anthropogenic emissions. Sensitivity modeling experiments indicated that local anthropogenic emissions had little impact on the diurnal pattern of O3. The diurnal pattern of O3 was mainly influenced by regional O3 transport from the surrounding urban areas located 100-150km away from the summit, with a lag time of 10h for transport. PMID:26318811

  6. Infection prevalence and phylogenetic analysis of Perkinsus olseni in Ruditapes philippinarum from East China.

    PubMed

    Wu, Shao-Qiang; Wang, Cai-Xia; Lin, Xiang-Mei; Wang, Zong-Xiang; Li, Xiao-Fei; Liu, Jian; Deng, Jun-Hua; Qiu, Song-Yin

    2011-08-29

    The prevalence of Perkinsus sp. infection in Manila clam Ruditapes philippinarum was investigated in the coastal areas of east China. Thirteen groups of clams were collected from 5 sites: Dandong and Qingdao Bays (Yellow Sea), Weifang Bay (Bohai Sea), and Ningbo and Fuzhou Bays (East China Sea). The clams were tested for perkinsosis infection using Ray's fluid thioglycollate medium culture assay. Perkinsus sp. was found in samples from all 5 sites from May 2008 to May 2009. Infection prevalence ranged from 43.75 to 95.83%, and was significantly higher in October than in May. The only 3 uninfected groups of clams were collected from Weifang Bay, the site farthest from the ocean. There was no difference in the prevalence of infection among the remaining 4 sites. The conserved internal transcribed spacer regions of the ribosomal RNA gene complex in each of the Perkinsus sp. isolates were amplified by PCR. The resulting amplicons were sequenced and phylogenetically analyzed. All the Perkinsus isolates were identified as Perkinsus olseni. PMID:21991665

  7. Late paleozoic base and precious metal deposits, East Tianshan, Xinjiang, China: Characteristics and geodynamic setting

    USGS Publications Warehouse

    Mao, J.; Goldfarb, R.J.; Wang, Y.; Hart, C.J.; Wang, Z.; Yang, J.

    2005-01-01

    The East Tianshan is a remote Gobi area located in eastern Xinjiang, northwestern China. In the past several years, a number of gold, porphyry copper, and Fe(-Cu) and Cu-Ag-Pb-Zn skarn deposits have been discovered there and are attracting exploration interest. The East Tianshan is located between the Junggar block to the north and early Paleozoic terranes of the Middle Tianshan to the south. It is part of a Hercynian orogen with three distinct E-W-trending tectonic belts: the Devonian-Early Carboniferous Tousuquan-Dananhu island arc on the north and the Carboniferous Aqishan - Yamansu rift basin to the south, which are separated by rocks of the Kanggurtag shear zone. The porphyry deposits, dated at 322 Ma, are related to the late evolutionary stages of a subduction-related oceanic or continental margin arc. In contrast, the skarn, gold, and magmatic Ni-Cu deposits are associated with post-collisional tectonics at ca. 290-270 Ma. These Late Carboniferous - Early Permian deposits are associated with large-scale emplacement and eruption of magmas possibly caused by lithosphere delamination and rifting within the East Tianshan.

  8. Structural evolution of the East China Sea and the relationship with oil and gas

    SciTech Connect

    Wu, Xianghong; Duan, Chang

    1995-12-31

    The East China Sea (ECH) is a Cenozoic sedimentary basin, lying on the Pre-Cretaceous basement. During Cenozoic Era, the basin went through three development stages: the half-graben, domnwarping depression, and regional subsidence. Analyzed the data from gravity, magnetism, reflection seismology measurements, the structural pattern of the ECS can be decided: east-west zone of the NE-or NNE-trending structural belts and a south-north differentiation of structural blocks. From west to east the structural belts are the Zhe-min uplift, the shelf basin, Diaoyu island uplift, Okinawa trough basin and Ryukyu islands. This structural pattern is controlled by the activity of the Eurasia plate and the Pacific plate, which can be interpreted from the data of the earthquake and the structural stress field. Calculating of Moho and Curie, and 2-D modeling of gravity and magnetism data help constrain the seismic interpretation and understood the faults and structure. Modeling of sedimentary and thermal history help find the region of generation oil.

  9. Crustal structure of China and adjacent areas: a final report of the detailed compilation of data and results

    SciTech Connect

    Mooney, W D

    1998-06-04

    In geophysical terms, China is a ''data rich'' country. However it is often very difficult for Western scientists to access the available information or identify individuals responsible for program development. The USGS has largely bypassed this bottleneck by virtue of more than two decades of collaborative research based on an official Protocol Agreement.

  10. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    NASA Astrophysics Data System (ADS)

    Guo, X. Y.; Zhu, X.-H.; Long, Y.; Huang, D. J.

    2013-04-01

    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.

  11. An optimal index for measuring the effect of East Asian winter monsoon on China winter temperature

    NASA Astrophysics Data System (ADS)

    Hu, Chundi; Yang, Song; Wu, Qigang

    2015-11-01

    Extreme cold events occur frequently in China. The authors define a representative yet simple index to reveal the monthly changes in China winter temperature associated with the East Asian winter monsoon (EAWM), which is represented by both the leading empirical orthogonal function (EOF) mode and the country-mean temperature index of Chinese 160 gauge stations. A combined technique of correlation and multivariate EOF (Corr-MVEOF) analyses is applied to capture the dominant coupled patterns of EAWM circulation system. Based on the atmospheric circulation features captured by the leading Corr-MVEOF mode, a new EAWM index referred to as CNWMI is derived by using a stepwise regression analysis. The CNWMI highlights the importance of (1) the Mongolia-Siberian High (MSH) and its southward expansion and (2) the Asia-wide meridional dipole anomaly of 500 hPa geopotential height. Compared with the 27 existing EAWM indices, the CNWMI not only best represents the leading modes of both EAWM circulation system and China winter temperature, but also reasonably tracks the intraseasonal-to-interdecadal variations of EAWM so that the monthly intensity of EAWM can be monitored conveniently. In particular, the Aleutian low (AL) is not strongly related to the MSH and may not be responsible for the variability of EAWM/MSH. Moreover, the indices that are highly correlated with the temperature over southern East Asia do not show significant relationships with the AL, which is different from the conventional concept that a strong EAWM/MSH is linked to a deepened AL. In contrast, the anomalous Australia-Maritime Continent low is in good agreement with the variation of EAWM/MSH.

  12. Temporal trends of nonylphenol and bisphenol A contamination in the Pearl River Estuary and the adjacent South China Sea recorded by dated sedimentary cores.

    PubMed

    Peng, Xianzhi; Wang, Zhendi; Mai, Bixian; Chen, Fanrong; Chen, Shejun; Tan, Jianhua; Yu, Yiyi; Tang, Caiming; Li, Kechang; Zhang, Gan; Yang, Chun

    2007-10-01

    Three dated sedimentary cores were collected for the investigation of temporal trends and the environmental loadings of nonylphenol (NP) and bisphenol A (BPA) in recent decades in the Pearl River Estuary (PRE), South China and the adjacent South China Sea (SCS). The peak fluxes of NP and BPA occurred in the mid-1980s in the PRE, coincident with the rapid economic growth in China. The decline of NP and BPA fluxes is attributable to the implementation of sewage treatment in the late 1980s in the Pearl River Delta (PRD). Multi-model distributions were observed for the fluxes of NP and BPA in the SCS with the peak fluxes occurring in the late 1950s and the mid-1970s respectively. The fluxes of NP and BPA have increased since the 1990s due to the lack of adequate wastewater treatment facilities and the constant economic growth. Nonylphenol was quantifiably detected in sediments predating its widespread application (1940s), suggesting the downward penetration of NP in the sediment columns. The characterization results revealed that NP and BPA were preserved well and the isomer-selective degradation of NP did not occur significantly in the sediment cores. The environmental loadings of NP and BPA in the PRE sediments were roughly estimated to be 124 t and 1.7 t respectively over the past 30 years. PMID:17618676

  13. A dynamic sediment model based on satellite-measured concentration of the surface suspended matter in the East China Sea

    NASA Astrophysics Data System (ADS)

    Mao, Zhihua; Pan, Delu; Tang, Charles L.; Tao, Bangyi; Chen, Jianyu; Bai, Yan; Chen, Peng; He, Xianqiang; Hao, Zengzhou; Huang, Haiqing; Zhu, Qiankun

    2016-04-01

    The concentration of total suspended matter (TSM) at the sea surface is derived from satellite data using a complex proxy TSM model in East China Sea from 1997 to 2008. The structure of the mean TSM image is similar to that of the topography, indicating that the distribution of the surface concentration is strongly related to the water depth. A dynamic sediment model (DSM) is constructed to relate the TSM concentration at the sea surface with suspended sediment at the benthic boundary layer, the Rouse number, and the water depth. The DSM model is improved through iteration with a convergence identified by the mean relative difference between two adjacent bottom TSM images which becomes smaller with the more iterations and the value is less than 1% after 50 iterations. The performance of the DSM model is validated by satellite-measured concentration with a mean relative error of 5.2% for the monthly mean images. The DSM model is used to deduce the bottom TSM concentration at the benthic boundary layer and the distribution of the Rouse number. The spatial distribution of the sea surface TSM concentration is determined predominately by both the bottom suspended sediment concentration and water depth. The temporal variation of the sea surface concentration mainly depends upon the Rouse number in the water column. Our result shows that the discharge of the Changjiang River can change the distribution of the Rouse number to form a band-shaped region in the Changjiang Estuary. The DSM model provides a framework for understanding some of the mechanisms of the formation and variation of the primary TSM plume and the secondary plume in the ECS. The primary TSM plume corresponds approximately to the region with depth shallower than 20 m and the secondary plume corresponds to the region with depths between 20 and 50 m.

  14. Monitoring schistosomiasis risk in East China over space and time using a Bayesian hierarchical modeling approach.

    PubMed

    Hu, Yi; Ward, Michael P; Xia, Congcong; Li, Rui; Sun, Liqian; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu

    2016-01-01

    Schistosomiasis remains a major public health problem and causes substantial economic impact in east China, particularly along the Yangtze River Basin. Disease forecasting and surveillance can assist in the development and implementation of more effective intervention measures to control disease. In this study, we applied a Bayesian hierarchical spatio-temporal model to describe trends in schistosomiasis risk in Anhui Province, China, using annual parasitological and environmental data for the period 1997-2010. A computationally efficient approach-Integrated Nested Laplace Approximation-was used for model inference. A zero-inflated, negative binomial model best described the spatio-temporal dynamics of schistosomiasis risk. It predicted that the disease risk would generally be low and stable except for some specific, local areas during the period 2011-2014. High-risk counties were identified in the forecasting maps: three in which the risk remained high, and two in which risk would become high. The results indicated that schistosomiasis risk has been reduced to consistently low levels throughout much of this region of China; however, some counties were identified in which progress in schistosomiasis control was less than satisfactory. Whilst maintaining overall control, specific interventions in the future should focus on these refractive counties as part of a strategy to eliminate schistosomiasis from this region. PMID:27053447

  15. Monitoring schistosomiasis risk in East China over space and time using a Bayesian hierarchical modeling approach

    PubMed Central

    Hu, Yi; Ward, Michael P.; Xia, Congcong; Li, Rui; Sun, Liqian; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu

    2016-01-01

    Schistosomiasis remains a major public health problem and causes substantial economic impact in east China, particularly along the Yangtze River Basin. Disease forecasting and surveillance can assist in the development and implementation of more effective intervention measures to control disease. In this study, we applied a Bayesian hierarchical spatio-temporal model to describe trends in schistosomiasis risk in Anhui Province, China, using annual parasitological and environmental data for the period 1997–2010. A computationally efficient approach–Integrated Nested Laplace Approximation–was used for model inference. A zero-inflated, negative binomial model best described the spatio-temporal dynamics of schistosomiasis risk. It predicted that the disease risk would generally be low and stable except for some specific, local areas during the period 2011–2014. High-risk counties were identified in the forecasting maps: three in which the risk remained high, and two in which risk would become high. The results indicated that schistosomiasis risk has been reduced to consistently low levels throughout much of this region of China; however, some counties were identified in which progress in schistosomiasis control was less than satisfactory. Whilst maintaining overall control, specific interventions in the future should focus on these refractive counties as part of a strategy to eliminate schistosomiasis from this region. PMID:27053447

  16. Spatial and seasonal patterns of ichthyoplankton assemblages in the Haizhou Bay and its adjacent waters of China

    NASA Astrophysics Data System (ADS)

    Li, Zengguang; Ye, Zhenjiang; Wan, Rong

    2015-12-01

    Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages (near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring <20 m, and the middle bay assemblage generally occurred in the middle of bay, with depths measuring 20 to 40 m. Spatial and seasonal variations in ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay.

  17. Summer and winter living coccolithophores in the Yellow Sea and the East China Sea

    NASA Astrophysics Data System (ADS)

    Gu, X. Y.; Feng, Y. Y.; Jin, S. F.; Jiang, W. S.; Jin, H. Y.; Chen, J. F.; Sun, J.

    2013-05-01

    To date, very little information on living coccolithophores species composition and distribution, especially the vertical profile has been reported around the world. This paper tries to fill this gap by descripting on living coccolithophores (LCs) distribution in the Yellow Sea and the East China Sea in summer and winter time in detail, and its relationship among enviromental factors by canonical correspondence analysis (CCA). We carried out the investigations on LC distribution in the Yellow Sea and the East China Sea in July and December 2011. 210 samples from different depths were collected from 44 stations in summer and 217 samples were collected from 45 stations in winter. Totally 20 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1000 × magnification. The dominant species of the two seasons were Gephyrocapsa oceanica, Emiliania huxleyi, Helicosphaera carteri, and Algirosphaera robusta. In summer the abundance of cells and coccoliths ranged 0 ~ 176.40 cells mL-1, and 0 ~ 2144.98 coccoliths mL-1, with the average values of 8.45 cells mL-1, and 265.42 coccoliths mL-1, respectively. And in winter the abundance of cells and coccoliths ranged 0 ~ 71.66 cells mL-1, and 0 ~ 4698.99 coccoliths mL-1, with the average values of 13.91 cells mL-1 and 872.56 coccoliths mL-1 respectively. In summer the LCs in surface layer were mainly observed on the coastal belt and southern part of the survey area. The highest abundance was found at the bloom station. In winter the LCs in surface layer had high value in the continental shelf area of section P. The comparison among section A, section F, section P and section E indicated lower species diversity and less abundance in the Yellow Sea than those of the East China Sea in both seasons. Temperature and the nitrate concentration may be the major environmental factors controlling the distribution and species composition of LCs in the studying area based on CCA.

  18. The influences of East Asian Monsoon on summer precipitation in Northeast China

    NASA Astrophysics Data System (ADS)

    Sun, Li; Shen, Baizhu; Sui, Bo; Huang, Bohua

    2016-05-01

    A unique dataset of 53-year (1961-2013) rainfall measurements from 104 stations uniformly distributed in the Northeast China, combined with the observation-based NCEP/NCAR atmospheric reanalysis, is used to analyze the precipitation anomalies in Northeast China during late boreal summer (July-August) and their relationship with the anomalous moisture transport associated with the fluctuations of the East Asian Summer Monsoon (EASM) circulation. Based on this analysis, a new EASM influence index (I EASM ) is proposed to quantify the EASM effects on the Northeast China summer precipitation. The relationship between the IEASM variations and patterns of the anomalous regional atmospheric circulation is demonstrated. The characteristics of several precursors that lead to the major fluctuations of the I EASM index are also explored. The results show that the EASM influence index is closely linked to the anomalous rainfall in Northeast China and can be used as a major factor to measure the physical processes that affect the regional dry and wet conditions. The I EASM index responds to the large-scale anomalies of the atmospheric circulation sensitively. Specifically, the high I EASM values are associated with the intensified Mongolia cyclone, blocking developing near the Ural Mountains and a northwestward shift of subtropical high over the western Pacific. The low I EASM values are associated with a reversed pattern of these features. The I EASM anomalous fluctuation has some precursors. A major high (low) index during the summer is likely preceded with the pattern of the sea surface temperature anomalies of an El Niño (La Niña) event in the Pacific from the previous early fall to early winter.

  19. Pore water nutrient characteristics and the fluxes across the sediment in the Pearl River estuary and adjacent waters, China

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Wang, Lu; Yin, Kedong; Lü, Ying; Zhang, Derong; Yang, Yongqiang; Huang, Xiaoping

    2013-11-01

    Spatio-temporal distribution of pore water nutrients and the fluxes at the sediment-water interface (SWI) were investigated to probe into the geochemical behavior of nutrients associated with early diagenesis of organic matter (OM), and to study the accumulation and transformation processes of nutrients at the SWI, as well as to discuss the impact of riverine inputs on nutrients in the Pearl River estuary (PRE) and adjacent offshore areas. Nutrient concentrations decreased from the upper to the lower reaches of the estuary, suggesting that there was a high input of anthropogenic nutrients and the estuary was acting as a nutrient sink. Dissolved inorganic nitrogen (DIN: the sum of NH4-N, NO3-N and NO2-N) concentrations in the water column and the pore water were higher in the estuary than at offshore areas due to the riverine discharge and the high accumulation rate in the estuary. NO3-N concentration was the highest of the three forms of DIN in the overlying water and showed a sharp decrease from the surficial sediment with increasing sediment depth, indicating that there was strong denitrification at the SWI. NH4-N, mainly deriving from the anaerobic degradation of OM, was the main form of DIN in the pore water and increased with depth. Negative NO3-N fluxes (into the sediment) and positive NH4-N fluxes (from the sediment) were commonly observed from incubation experiments, indicating the denitrification occurred at the SWI. DIN flux suggested that the sediment was a sink of DIN in spring, however, the sediment was the source of DIN in summer and winter. Nutrients dominantly diffused out of the sediment, suggesting that the sediment was the source of nutrients in spring at adjacent offshore areas. The fluxes directed that PO4-P mainly diffused into the sediment while SiO4-Si mainly diffused out of the sediment.

  20. Quantification of lincomycin resistance genes associated with lincomycin residues in waters and soils adjacent to representative swine farms in China

    PubMed Central

    Li, Liang; Sun, Jian; Liu, Baotao; Zhao, Donghao; Ma, Jun; Deng, Hui; Li, Xue; Hu, Fengyang; Liao, Xiaoping; Liu, Yahong

    2013-01-01

    Lincomycin is commonly used on swine farms for growth promotion as well as disease treatment and control. Consequently, lincomycin may accumulate in the environment adjacent to the swine farms in many ways, thereby influencing antibiotic resistance in the environment. Levels of lincomycin-resistance genes and lincomycin residues in water and soil samples collected from multiple sites near wastewater discharge areas were investigated in this study. Sixteen lincomycin-resistance and 16S rRNA genes were detected using real-time PCR. Three genes, lnu(F), erm(A), and erm(B), were detected in all water and soil samples except control samples. Lincomycin residues were determined by rapid resolution liquid chromatography-tandem mass spectrometry, with concentrations detected as high as 9.29 ng/mL in water and 0.97 ng/g in soil. A gradual reduction in the levels of lincomycin-resistance genes and lincomycin residues in the waters and soils were detected from multiple sites along the path of wastewater discharging to the surrounding environment from the swine farms. Significant correlations were found between levels of lincomycin-resistance genes in paired water and soil samples (r = 0.885, p = 0.019), and between lincomycin-resistance genes and lincomycin residues (r = 0.975, p < 0.01). This study emphasized the potential risk of dissemination of lincomycin-resistance genes such as lnu(F), erm(A), and erm(B), associated with lincomycin residues in surrounding environments adjacent to swine farms. PMID:24348472

  1. Urban Community Development and Private Education Dilemma: Based on a Field Study of a City in East China

    ERIC Educational Resources Information Center

    Qian, Li; Anlei, Jing

    2014-01-01

    Urbanization is an issue of universal concern today distinctly affecting the supply, content, and orientation of education. Based on a field study in a city in East China, the article argues that rural-urban migration in the process of urbanization created private sectors in education enterprises that were in sync with the urban community…

  2. Revision of the genus Acanthaspis Amyot & Serville (Hemiptera: Heteroptera: Reduviidae: Reduviinae) from China, with new records of species to adjacent countries.

    PubMed

    Cao, Liangming; Rédei, Dávid; Li, Hu; Cai, Wanzhi

    2014-01-01

    The assassin bugs of the genus Acanthaspis Amyot & Serville (Reduviinae) from China are revised. Fourteen species are recognized, described or redescribed and illustrated. Three species, A. fulviconnexa, A. melanota, and A. octoguttata, are described as new to science. Acanthaspis subinermis Hsiao 1976 is synonymized with A. laoensis Distant 1919. A key for the identification of Chinese species of Acanthaspis is provided. The biology of A. cincticrus Stål is briefly noted. The following species are newly recorded from adjacent countries: A. collaris Hsiao from Laos and Thailand, A. geniculata Hsiao from Vietnam, A. picta Hsiao from Laos, Myanmar and Thailand, A. quinquespinosa (Fabricius) from Nepal, A. ruficeps Hsiao from Laos, Thailand and Vietnam, and A. laoensis Distant  from Thailand.  PMID:25544374

  3. Basin modeling of the Parang (Socotra) Basin, northern East China Sea shelf: Implications for hydrocarbon potential

    NASA Astrophysics Data System (ADS)

    Kim, H.; Moon, S.; Lee, G.; Yoon, Y.; Kim, H.

    2013-12-01

    The hydrocarbon potential of the Parang (Socotra) Basin in the northern East China Sea shelf has remained poorly understood. We performed one-dimensional basin modeling for a dummy well located in the depocenter of the northern part of the Parang Basin to investigate the timings of hydrocarbon generation and expulsion. First, a depth-converted seismic profile crossing the dummy well was restored by backstripping and decompaction for eight regional and subregional unconformities, including the top of the acoustic basement, to reconstruct the subsidence history and to determine the timing of trap formation. The basin modeling, assuming rifting heat-flow model and source rocks with type III kerogen, suggests that the main phase of hydrocarbon (mostly gas) expulsion peaked in the Late Eocene, predating the inversion that created traps in the early Middle to latest Middle Eocene. Thus, the potential for large hydrocarbon accumulations in the northern Parang Basin is probably limited.

  4. Investigation of atmospheric aerosols and gases at an East China Station. Technical memo

    SciTech Connect

    Parungo, F.; Nagamoto, C.; Kopcewicz, B.; Li, X.; Yang, D.

    1993-04-01

    From August to October of 1991, when the West Pacific Exploratory Mission (PEM-west) airborne expedition was conducted, ground-level measurements of gases and aerosols were carried out at Lin-an station near the east coast of China. Meteorological parameters such as temperature, pressure, humidity, solar radiation, wind direction, and wind speed were recorded continuously. Concentrations of SO[sub 2], NO[sub 2], O[sub 3], and black carbon were monitored in situ intermittently. Aerosol samples were collected and later analyzed in laboratories. A transmission electron microscope was used to analyze particle concentration, morphology, and size distribution. Elemental compositions of aerosol samples, collected on filters, were determined with an neutron activation analyzer and with a proton induced x-ray energy spectrometer. The water soluble portions of the aerosols were analyzed by ion chromatography.

  5. Increased zooplankton PAH concentrations across hydrographic fronts in the East China Sea.

    PubMed

    Hung, Chin-Chang; Ko, Fung-Chi; Gong, Gwo-Ching; Chen, Kuo-Shu; Wu, Jian-Ming; Chiang, Hsin-Lun; Peng, Sen-Chueh; Santschi, Peter H

    2014-06-15

    The Changjiang has transported large quantities of polycyclic aromatic hydrocarbons (PAHs) to the East China Sea (ECS), but information of these pollutants in zooplankton is limited. To understand PAHs pollution in zooplankton in the ECS, total concentrations of PAHs in zooplankton from surface waters were measured. Values of PAHs ranged from 2 to 3500 ng m(-3) in the ECS, with highest PAHs levels located at the salinity front between the Changjiang Diluted Water (CDW) and the mid-shelf waters. In contrast, concentrations of zooplankton PAHs in the mid-shelf and outer-shelf waters were significantly lower (2-23 ng m(-3)) than those in the CDW. These results demonstrate that PAHs are conspicuously accumulated in zooplankton at the salinity front between the CDW and the mid-shelf waters. These higher levels of PAHs in zooplankton at the salinity front may be further biomagnified in marine organisms of higher trophic levels through their feeding activities. PMID:24775063

  6. Data-Model Comparisons for Sea Surface Waves from the ASIAEX East China Sea Experiment

    NASA Astrophysics Data System (ADS)

    Yang, Jie; Zhou, Ji-Xun; Rogers, Peter H.

    2010-09-01

    During ASIAEX, surface directional wave spectra were recorded for nine consecutive days. Data are analyzed in this paper to show the characteristics of the surface wave field in the East China Sea. Three surface spectrum models, Pierson-Moskowitz, JONSWAP, and Toba, are evaluated and compared with the ASIAEX RMS surface wave height data. The data-model comparisons show that the JONSWAP-Mitsuyasu model is the best fit to the experimental results. Model performance can be improved by a combined model, JONSWAP-Mitsuyasu for U/cp<0.8 and Toba-Donelan for U/cp>0.8. The preliminary results suggest that locally measured wave age can be used to find the most appropriate surface model for acoustic prediction purposes.

  7. Investigation of the clinical features in filamentary keratitis in Hangzhou, east of China

    PubMed Central

    Chen, Siming; Ruan, Yimeng; Jin, Xiuming

    2016-01-01

    Abstract Filamentary keratitis (FK) is a chronic and recurrent disorder of the cornea. FK is reportedly associated with various kinds of ocular surface diseases or conditions. Until now, there have been lacks of studies based on quantitative sample analysis concerning FK incidence regularity and inducement characteristics at different ages. This was a retrospective study of 147 patients (162 eyes) with FK who had been continuously and completely recorded from August 2012 to August 2015 at the Second Affiliated Hospital of Zhejiang University in Hangzhou, east of China. Our results suggest that the causative factors of FK varied at different ages and the distribution of filaments on the corneal surface was also diverse with different inducements. By exploring the frequency and clinical features of FK, we believe that the findings from our research will be clinically significant and aid in the early prevention and treatment guidance of the disease. PMID:27583881

  8. Responses of phytoplankton community to the input of different aerosols in the East China Sea

    NASA Astrophysics Data System (ADS)

    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.

  9. Spatial variation, fractionation and sedimentary records of mercury in the East China Sea.

    PubMed

    Duan, Li-Qin; Song, Jin-Ming; Yu, Yu; Yuan, Hua-Mao; Li, Xue-Gang; Li, Ning

    2015-12-15

    Surface and core sediments were collected to study distributions, phases and potential environmental risk of Hg and to reconstruct anthropogenic Hg change over the past one hundred years in the East China Sea (ECS). Hg contents in surface sediments displayed a decreasing gradient from the Changjiang Estuary to the outer sea. Sequential extraction analysis showed that Hg mainly existed as residual fraction (70.18% of total), and while organic matter fraction (22.96% of total) was the main component of labile fraction, indicating the strong adsorption of organic matters on Hg. Enrichment factor and sediment quality guidelines suggested that Hg in sediments of ECS were at minor enrichment and low adverse effect. Temporal distributions of total Hg content, labile fraction, burial flux and anthropogenic Hg flux showed that anthropogenic Hg input increased since the 1960s, which was related to riverine input and atmospheric transport. PMID:26475021

  10. Pseudolella major sp. nov. (Axonolaimidae, Nematoda) from the intertidal zone of the East China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Chunming; Huang, Yong

    2016-03-01

    A new species of free-living nematode, Pseudolella major sp. nov. is described from the intertidal mudflats of Ximen Island in the East China Sea. Pseudolella major sp. nov. is characterized as follows: body length ~1 300 μm; short cephalic setae, 2-3 μm long; amphidial fovea loop-shaped with elongated ventral branch; ventral branch 50-60 μm long and extending past the base of buccal cavity; buccal cavity cylindrical with arching or spherical base; three heavy outwardly-curving odontia with blunt tips located at anterior of buccal cavity; pharynx short with posterior bulb; ventral gland cell elongate oval-shaped, located posterior to pharyngo-intestinal junction; excretory pore situated at the level of the middle of buccal cavity; tail conical to cylindrical; spicules arched, with double-cephalate proximal end; gubernaculum with a strong dorsal caudal apophysis.

  11. Free polyamine content during algal bloom succession in the East China Sea in spring 2010

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Zhao, Weihong; Li, Caiyan; Miao, Hui

    2016-03-01

    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.

  12. Investigation of the clinical features in filamentary keratitis in Hangzhou, east of China.

    PubMed

    Chen, Siming; Ruan, Yimeng; Jin, Xiuming

    2016-08-01

    Filamentary keratitis (FK) is a chronic and recurrent disorder of the cornea. FK is reportedly associated with various kinds of ocular surface diseases or conditions. Until now, there have been lacks of studies based on quantitative sample analysis concerning FK incidence regularity and inducement characteristics at different ages. This was a retrospective study of 147 patients (162 eyes) with FK who had been continuously and completely recorded from August 2012 to August 2015 at the Second Affiliated Hospital of Zhejiang University in Hangzhou, east of China. Our results suggest that the causative factors of FK varied at different ages and the distribution of filaments on the corneal surface was also diverse with different inducements.By exploring the frequency and clinical features of FK, we believe that the findings from our research will be clinically significant and aid in the early prevention and treatment guidance of the disease. PMID:27583881

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Toxicological studies of Karlodinium micrum (Dinophyceae) isolated from East China Sea.

    PubMed

    Zhou, Chengxu; Fernández, Nuria; Chen, Haiming; You, Yurong; Yan, Xiaojun

    2011-01-01

    Karlodinium micrum (Strain NMBjah047) was isolated from the water samples of East China Sea (ECS). The hemolytic, ichthyotoxic, and cytotoxic activities of the algae was characterized. Embryotoxicity of both intra and extracellular extracts were also tested on a local sea urchin species. The algal intracellular hemolytic toxicity averaged about 87.5% at different algal growth phases. However, extracellular hemolytic activity depended on the population growth phase. The toxicity increased with the increase in the population size, reaching the highest hemolytic activity during the stationary phase, and maintained a relatively high activity even when the population declined. Time and density dependent ichthyotoxicity to Lateolabrax maculates juveniles was also detected. The LD(50) in 24 h was 1.1 × 10(5) cells/mL. Inhibition of the fertilized egg hatching was also observed and estimated the IC(50) in 40 h with 3.5 × 10(4) cells/mL. Extracellular extracts of K. micrum dense culture also showed significant cytotoxic activity on HUVEC (IC(50) = 70.8 μg/mL). A dose dependent acute toxicity to embryos of sea urchin was also determined. The algal intracellular and extracellular extracts delayed or even restricted the embryological development of the sea urchin, illustrating the potential toxicity of K. micrum not only to vertebrates, but also to marine invertebrates. The hemolytic compounds in the ECS strain were extracted and analyzed. At least two fractions had significant hemolytic activities. A lipid-like compound, named Digalactosyldiacylglycerol (DGDG), was suggested to be responsible for the hemolytic activity in one of these fractions. From the results of the present studies, this strain of K. micrum isolated from the East China Sea might be considered a toxic strain with hemolytic activity, ichthyotoxicity, cytotoxicity and embryotoxicity. PMID:20858509

  15. Epidemiologic study of human parvovirus B19 infection in East China.

    PubMed

    Zhang, Lahong; Cai, Chengsong; Pan, Feng; Hong, Liquan; Luo, Xian; Hu, Sha; Xu, Jiali; Chen, Zhaojun

    2016-07-01

    Human parvovirus B19 (B19V) infection causes a number of diseases in humans, and, in some circumstances, can be life threatening. To understand the epidemiology of B19V infection in the greater metropolitan area of Hangzhou, East China, we performed surveys of IgM and IgG antibodies against B19V and quantification of B19V DNA, by using enzyme-linked immunosorbent assay and quantitative PCR, respectively, in plasma samples from diverse groups. These groups included anemia patients, Mycoplasma pneumonia- and Treponema pallidum-infected patients, HIV-positive individuals, and healthy blood donor volunteers. Our results demonstrated a low level of B19V IgG antibody presence, ranging from 21.9% to 41.8% in all the groups tested, suggesting a low prevalence of B19V infection in the area. Of note, we found that two healthy blood donors and one Mycoplasma pneumonia-infected patient had B19V IgM antibody among 1,290 plasma samples tested. The Mycoplasma pneumonia-infected patient had viremia with viral genome copies of 2.86 × 10(6) per ml of plasma. We detected a high rate of B19V DNA (7.1%) in HIV-positive injection drug users. Importantly, an amino acid mutation of P558S in the large non-structural protein NS1 was identified to be conserved among 14 B19V isolates from the HIV-positive group but not in the B19V isolate of the Mycoplasma pneumonia-infected patient, representing a hallmark of B19V isolates that circulate in HIV1-positive patients in the greater metropolitan area of Hangzhou, East China. PMID:26705119

  16. Five Sarsiellidae ostracods (Crustacea: Myodocopida) from the South Coast of Korea (East China Sea).

    PubMed

    Karanovic, Ivana; Soh, Ho-Young

    2015-01-01

    The East China Sea is part of the Warm Temperate Northwest Pacific zoogeographic province and, as such, has a high biodiversity and many tropical and subtropical biotic elements. Nevertheless, many invertebrate groups from this area remain poorly studied. Ostracods are one of them, especially those belonging to the subclass Myodocopa. In this paper we provide the first data on a diverse myodocopid family, Sarsiellidae, not only for the East China Sea, but also for Korea. Five species are reported in this paper from three Korean islands (Jeju, Chuja, and Maemul), and they are only a part of the ostracods collected during this study, indicating a high diversity of the group in this region. Three new species, Eurypylus koreanus sp. nov., Eusarsiella hanguk sp. nov., and Sarsiella nereis sp. nov., clearly stand apart from their respective congeners, mostly by prominent shell characters but also by details of the soft part morphology. Their affinity though clearly indicates a close connection of the region with the more southern zoogeographical realms, especially Central Indo Pacific and partly Temperate Australasia. Two species previously known from Japan (north part of the Sea of Japan and southeastern part of the Pacific Coast of Japan), Sarsiella japonica Hiruta, 1977 and S. misakiensis Kajiyama, 1912, are redescribed. Based on 11 newly obtained COI sequences we construct a preliminary phylogenetic tree, which supports previous hypotheses based on the morphological data, that Eusarsiella Cohen & Kornicker, 1975 is a polyphyletic taxon. With the maps of species distribution provided for each of the three genera, we give an overview of their current zoogeography, and clearly indicate areas that have no data, mostly due to the lack of investigation. PMID:25947749

  17. Effects of urban land-use change in East China on the East Asian summer monsoon based on the CAM5.1 model

    NASA Astrophysics Data System (ADS)

    Ma, Hongyun; Jiang, Zhihong; Song, Jie; Dai, Aiguo; Yang, Xiuqun; Huo, Fei

    2016-05-01

    The effects of urban land-use change in East China on the East Asian summer monsoon (EASM) are investigated using a Community Atmosphere Model Version 5.1. The results show that the urban land-use change in East China causes spatially-varying changes in surface net radiation and heat fluxes, atmospheric circulation, and water budgets. It results in significant surface warming (cooling) and precipitation decrease (increase) in a large region north (south) of 30°N. Urban expansion agglomerated in (29°-41°N, 110°-122°E) alters the surface energy budget and warms the surface, resulting in strengthened southwesterly airflow south of 25°N and increased convergence below the mid-troposphere between 20° and 30°N. A concomitant northward downdraft associated with the increased convection generates an anomalous high pressure north of 30°N. Meanwhile, the downdraft not only produces adiabatic warming but also inhibits the dynamic condition for precipitation formation. The anomalous high pressure formed in North China prevents the southwesterly airflow from advancing northward, leading to increase the convergence and precipitation in South China. These changes reduce the meridional temperature gradient in the mid-lower troposphere and weaken the westerly airflow near 30°N. In addition, horizontal transport of vorticity north of 35°N weakens significantly, which leads to an anomalous barotropic structure of anticyclonic there. As a result, the anomalous anticyclonic circulation and descent north of 30°N are strengthened. At the same time, the anomalous cyclonic circulation and ascent south of 30°N are enhanced. These process induced by the thermal state changes due to urbanization weakens the EASM.

  18. The contribution of anthropogenic sources to the aerosols over East China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Fujiang; Chen, Ying; Meng, Xi; Fu, Jiangping; Wang, Bo

    2016-02-01

    Total suspended particulate (TSP) samples were collected at a pristine island (Huaniao) in northern East China Sea (ECS) between Mar. 2011 and Jan. 2013 and analyzed for the concentrations of major ions and trace elements. Aerosol sources and the distribution of source regions are identified using positive matrix factorization (PMF) and potential source contribution function (PSCF) methods. It is found that aerosols over Huaniao Island are contributed by six main factors including primary industrial emissions (11.3%), secondary aerosol (22%), oxalate-associated aerosol (15.7%), sea salt (36.7%), ship emission (6.3%) and mineral dust (8.1%). Anthropogenic source contribution to the resolved aerosol mass reached the highest (76.6%) and lowest (18%) values in January 2013 and August 2012 respectively, strongly influenced by the prevailing winds of East Asian monsoon. The main source regions of secondary aerosol are southeastern Hebei and Shandong, which is consistent with the most intensive distribution of coal-fired power plants and the largest emission of precursors in this area. Oxalate-associated aerosol is produced primarily along the coastal line. Primary industrial emissions mainly originate from southwestern Shandong and Yangtze River Delta.

  19. Regional Climate Simulations of Summer Diurnal Rainfall Variations over East Asia and Southeast China

    NASA Astrophysics Data System (ADS)

    Huang, W.-R.; Chan, J. C. L.

    2012-04-01

    This study evaluates the simulations of summer (June-August) precipitation over East Asia by the Regional Climate Model Version 3 (RegCM3), with emphasis on the diurnal variations of precipitation over Southeast China (PSEC) during the 1998-2002 summer seasons. The evaluation focuses on the maintenance mechanisms of the diurnal variations in PSEC as proposed by previous observational studies. It is found that the diurnal variations of PSEC are sensitive to the choice of cumulus parameterization schemes (CPSs). In particular, the Grell scheme with the Frisch-Chappell convective closure assumption (GFC) produces reasonable diurnal variations of PSEC. Other CPSs such as the Emanuel scheme produces a weaker late-afternoon maximum of PSEC, and the Kuo scheme as well as the Grell scheme with the Arakawa-Schubert closure assumption (GAS) is unable to simulate the occurrence of the late-afternoon maximum of PSEC. The simulations show that the adoption of the GFC scheme reproduces the large-scale land-sea breeze circulation and the moisture flux convergence that have been documented by previous studies as the maintenance mechanisms of the diurnal variations of PSEC. This feature illustrates the importance of convective cloud feedback at the diurnal timescale in maintaining the large-scale circulation. Furthermore, when the simulation domain covers the entire Tibetan Plateau, the diurnal variations of precipitation over East Asia are found to exhibit a noticeable improvement without changes in the physics schemes.

  20. Spatial variations of the Kuroshio nutrient stream from the East China Sea to South of Japan

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao-Hua; Guo, Xinyu; Long, Yu; Li, Bo

    2013-04-01

    Based on velocity calculated from hydrographic data obtained from 39 cruises during from 2000 to 2009 and nitrate concentration data observed from 1964 to 2011, we calculated nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over a section) through 5 sections along the Kuroshio path from the East China Sea (Sections PN and TK) to south of Japan (Sections ASUKA and 137E). In addition, Section OK east of the Ryukyu Islands was also examined. The nitrate flux showed a subsurface maximum core with a value of 9, 10, 6, 11 and 11 mol/m^2/s at Sections PN, TK, OK, ASUKA, 137E, respectively. The depth of subsurface maximum core changes at five sections and was about 400, 500, 800, 500, and 400 m at Sections PN, TK, OK, ASUKA, 137E, respectively. The eastward nitrate transport was 171, 167, 351, 942, 1444 k mol/s at Sections PN, TK, OK, ASUKA, 137E, respectively. The difference between nitrate transport through Section ASUKA and the sum of transports through Sections TK and OK, as well as the difference of nitrate transport between Sections ASUKA and 137E, suggest that the Kuroshio recirculation south of Shikoku can significantly intensify the eastward nitrate transport by the Kuroshio and therefore play an important role in the nitrate transport in the Kuroshio region.

  1. Human remains from Zhirendong, South China, and modern human emergence in East Asia

    PubMed Central

    Liu, Wu; Jin, Chang-Zhu; Zhang, Ying-Qi; Cai, Yan-Jun; Xing, Song; Wu, Xiu-Jie; Cheng, Hai; Edwards, R. Lawrence; Pan, Wen-Shi; Qin, Da-Gong; An, Zhi-Sheng; Trinkaus, Erik; Wu, Xin-Zhi

    2010-01-01

    The 2007 discovery of fragmentary human remains (two molars and an anterior mandible) at Zhirendong (Zhiren Cave) in South China provides insight in the processes involved in the establishment of modern humans in eastern Eurasia. The human remains are securely dated by U-series on overlying flowstones and a rich associated faunal sample to the initial Late Pleistocene, >100 kya. As such, they are the oldest modern human fossils in East Asia and predate by >60,000 y the oldest previously known modern human remains in the region. The Zhiren 3 mandible in particular presents derived modern human anterior symphyseal morphology, with a projecting tuber symphyseos, distinct mental fossae, modest lateral tubercles, and a vertical symphysis; it is separate from any known late archaic human mandible. However, it also exhibits a lingual symphyseal morphology and corpus robustness that place it close to later Pleistocene archaic humans. The age and morphology of the Zhiren Cave human remains support a modern human emergence scenario for East Asia involving dispersal with assimilation or populational continuity with gene flow. It also places the Late Pleistocene Asian emergence of modern humans in a pre-Upper Paleolithic context and raises issues concerning the long-term Late Pleistocene coexistence of late archaic and early modern humans across Eurasia. PMID:20974952

  2. Multi-Scale Interactions Associated with the Monsoon Onset Over South China Sea and Adjacent Regions during SCSMEX-98

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Li, X.; Wu, H.-T.

    1999-01-01

    Using data collected during The South China Sea Monsoon Experiment (SCSMEX) (1998) as well as from the TRMM Microwave-Imager (TMI) and precipitation radar (PR), we have studied the multi-scale interactions (meso-synoptic-intraseasonal) associated with monsoon onset over South China Sea (SCS) and its subsequent evolution. Results show that the monsoon onset (defined by development of steady wind direction and heavy precipitation) over the northern SCS occurred around May 15 -17. Prevailing southerlies and southwesterlies developed over the central SCS after May 20. Shortly after, monsoon convection developed over the whole SCS region around May 23-27. The entire onset process appeared to be delayed by about a week to 10 days compared with climatology. During late spring of 1998, mid-latitude frontal systems were particularly active. These systems strongly impacted the northern SCS convection and may have been instrumental in triggering the onset of the SCS monsoon. The Tropical Oceans and Global Atmosphere (TOGA) and Bureau of Meteorology Research Centre (BMRC) radar showed a wide variety of convective systems over the Intensive Flux Array, from frontal bands to shear-banded structure, deep convection, pop-corn type shallow convection, slow moving "fine lines" to water spout. Analysis of SSM/I wind and moisture data suggested that the delayed convective activity over the SCS may be linked to the weakened northward propagation of monsoon rain band, hence contributing to a persistence of the rainband south of the Yangtze River and the disastrous flood that occurred over this region during mid to late June, 1998.

  3. Macrobenthic assemblages of the Changjiang River estuary (Yangtze River, China) and adjacent continental shelf relative to mild summer hypoxia

    NASA Astrophysics Data System (ADS)

    Liao, Yibo; Shou, Lu; Tang, Yanbin; Zeng, Jiangning; Gao, Aigen; Chen, Quanzhen; Yan, Xiaojun

    2016-06-01

    To assess the effects of hypoxia, macrobenthic communities along an estuarine gradient of the Changjiang estuary and adjacent continental shelf were analyzed. This revealed spatial variations in the communities and relationships with environmental variables during periods of reduced dissolved oxygen (DO) concentration in summer. Statistical analyses revealed significant differences in macrobenthic community composition among the three zones: estuarine zone (EZ), mildly hypoxic zone (MHZ) in the continental shelf, and normoxic zone (NZ) in the continental shelf (Global R =0.206, P =0.002). Pairwise tests showed that the macrobenthic community composition of the EZ was significantly different from the MHZ (pairwise test R =0.305, P =0.001) and the NZ (pairwise test R =0.259, P =0.001). There was no significant difference in macrobenthic communities between the MHZ and the NZ (pairwise test R =0.062, P =0.114). The taxa included small and typically opportunistic polychaetes, which made the greatest contribution to the dissimilarity between the zones. The effects of mild hypoxia on the macrobenthic communities are a result not only of reduced DO concentration but also of differences in environmental variables such as temperature, salinity, and nutrient concentrations caused by stratification.

  4. Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China.

    PubMed

    Liu, Lusan; Zhou, Juan; Zheng, Binghui; Cai, Wenqian; Lin, Kuixuan; Tang, Jingliang

    2013-07-15

    Between 1972 and 2009, evidence of red tide outbreaks in the Yangtze River Estuary and adjacent waters was collected. A geographic information system (GIS) was used to analyze the temporal and spatial distribution of these red tides, and it was subsequently used to map the distribution of these events. The results show that the following findings. (1) There were three red tide-prone areas: outside the Yangtze River Estuary and the eastern coast of Sheshan, the Huaniaoshan-Shengshan-Gouqi waters, and the Zhoushan areas and eastern coast of Zhujiajian. In these areas, red tides occurred 174 total times, 25 of which were larger than 1000 km(2) in areal extent. After 2000, the frequency of red tide outbreaks increased significantly. (2) During the months of May and June, the red tide occurrence in these areas was 51% and 20%, respectively. (3) Outbreaks of the dominant red tide plankton species Prorocentrum dong-haiense, Skeletonema costatum, Prorocentrum dantatum, and Noctiluca scientillan occurred 38, 35, 15, and 10 times, respectively, during the study interval. PMID:23628547

  5. Polycyclic aromatic hydrocarbons in suspended particulate matter and sediments from the Pearl River Estuary and adjacent coastal areas, China.

    PubMed

    Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian; Yang, Qing-Shu; Sheng, Guo-Ying; Fu, Jia-Mo

    2006-01-01

    The spatial distribution, composition, and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments and suspended particulate matter (SPM) from the Pearl River Estuary and adjacent coastal areas were examined. Total PAH concentrations varied from 189 to 637 ng/g in sediments and 422 to 1,850 ng/g in SPM. PAHs were dominated by 5,6-ring compounds in sediments and by 2,3-ring compounds in SPM samples. Assessment of PAH sources suggested that biomass and coal combustion is the major PAH source to the outer part of the estuary sediments and that petroleum combustion is the major PAH source to the inner part of estuary sediments. As for SPM samples, PAH isomer pair ratios indicated multiple (petroleum, petroleum combustion, and biomass and coal combustion) PAH sources, and significant temporal variations could exist for the sources of water column PAHs in the study area. The distribution of perylene in SPM samples indicated that the river was the dominant source of perylene in SPM and that perylene could be taken as an index to assess the contribution of river inflow to the total PAHs in SPM samples. The high concentration of perylene in the sediment was indicative of an in situ biogenic origin. PMID:15996803

  6. Particulate organic matter in the northwest East China Sea: Implications from amino acids enantiomers

    NASA Astrophysics Data System (ADS)

    Zhu, Z. Y.; Zhang, J.; Wu, Y.; Shao, L.

    2012-04-01

    The north west East China Sea along the main land coast of China is an important region under the strong influence of the Changjiang (Yangtze) River. It is a main pathway for the particulate matter of the Changjiang travelling to the open ocean. An investigation was carried out in this interesting region north in May, 2007. Besides common parameters such as pH, nutrients, organic carbon and particulate nitrogen (PN), particulate amino acids enantiomers (PAA) were analyzed for all the surface samples and two typical sections. As influenced by strong terrestrial input, nutrients (e.g. dissolved inorganic nitrogen) in the surface increased much when closing the river mouth. Total suspended matter (TSM) concentrated in region close to the river mouth and around Zhoushan Archipelago, which then quickly decreased seawards. PN and PAA ranged from 0.6-7.8 μmol/L and 0.46-5.53 μmol/L, respectively. Elevated PAA concentration can be found along TSM front area. Asx, Glx and Gly were the main amino acids contributors. D-enantiomers accounts for 2%-7.6% of total PAA, indicating the activities of microbial activities. Relatively higher Degradation index (DI) suggests that particulate matter in this region is fresh, relative to other regions in the world.

  7. Learning cities in East Asia: Japan, the Republic of Korea and China

    NASA Astrophysics Data System (ADS)

    Han, SoongHee; Makino, Atsushi

    2013-09-01

    Lifelong learning cities emerged in Japan in the 1980s and 1990s; in the Republic of Korea in the 2000s and 2010s; and in China mostly from 2000 onwards. They were a countermeasure to the increasing challenges of global as well as post-industrial uncertainties at the turn of the century, when cities were trying to find governmental instruments to engage in cultural processes, community building and personal development as the new way of urban life. Learning was perceived to be a panacea to solve the social problems occurring in overwhelming processes of modernisation and industrialisation. The authors of this paper assert that the practice of and research on learning cities, especially in the East Asian region, need to go beyond the technical rationalities which are guiding government tools, and explain the realities to which they are meant to be applied. In order to do this, the authors investigated three separate but inter-connected scenes found in Japan, the Republic of Korea and China, revealing that the learning city is a phenomenon which reflects complex social dynamics and the interaction of many minds. While the cases in this region are distinctive, they do share some common characteristics. The authors place these within what they term a "community relations model", which they contrast with the "individual competence model" which is usually found in initiatives of the Organisation for Economic Co-operation and Development (OECD) and schemes implemented in the area of the European Union (EU).

  8. DDTs and HCHs in sediment cores from the coastal East China Sea.

    PubMed

    Lin, Tian; Nizzetto, Luca; Guo, Zhigang; Li, Yuanyuan; Li, Jun; Zhang, Gan

    2016-01-01

    Four sediment cores were collected along the Yangtze-derived sediment transport pathway in the inner shelf of the East China Sea (ECS) for OCP analysis. The sediment records of HCHs and DDTs in estuarine environment reflected remobilization of chemicals from enhanced soil erosion associated to extreme flood events or large scale land use transformation. The sediment records in the open sea, instead, reflected long-term historical trends of OCP application in the source region. Unlike the so-called mud wedge distribution of sediment, inventories of HCHs and DDTs slightly increased from the mouth of Yangtze River alongshore toward south, suggesting the sediment deposition rate was one of factors on the exposure of chemicals within the inner shelf of the ECS. Re-suspension and transport of the Yangtze-derived sediment and consequent fractionation in grain size and TOC were also responsible for the spatial variation of inventories of catchment derived OCPs in a major repository area of the Yangtze suspended sediment. The total burdens of HCHs and DDTs in the inner shelf of the ECS were 35tons and 110tons, respectively. After 1983 (year of the official ban in China), those values were 13tons and 50tons, respectively. It appears that the Yangtze still delivers relatively high inputs of DDTs more than 30years after the official ban. High proportions of DDD+DDE and β-HCH suggested those OCPs mainly originated from historical usage in the catchment recent years. PMID:26372941

  9. Historic climate variability of wetness in East China (960-1992): A wavelet analysis

    SciTech Connect

    Jianmin Jiang; Zhang, De`er; Fraedrich, K.

    1997-11-01

    In this paper, a dataset of historic wetness is analyzed with the wavelet transform technique. A previous dataset was derived from historic documents, and consists of annual dryness/wetness grades from 1 to 5 at 120 stations in the China mainland for the period from 1470 to 1979. This dataset was extended back to AD 960 for six regions in East China in a previous study, and the extended dataset is used in this paper. The Mexican Hat wavelet transform technique and descriptive statistical analysis were used to analyze each of the six regional time series. The wavelet analysis of climatic fluctuation displayed variations of different time scales at particular time points, as well as persistent anomalies. The climatic variations occuring on longer time scales may cover a larger area; these are the outstanding persistent dry and wet stages during the last 1033 years. The variations on longer time scales coincide roughly with those previously identified. On shorter time scales, some synchronous fluctations are also observed but in fewer years. 8 refs., 4 figs.

  10. Precipitation chemistry and corresponding transport patterns of influencing air masses at Huangshan Mountain in East China

    NASA Astrophysics Data System (ADS)

    Shi, ChunE; Deng, Xueliang; Yang, Yuanjian; Huang, Xiangrong; Wu, Biwen

    2014-09-01

    One hundred and ten samples of rainwater were collected for chemical analysis at the summit of Huangshan Mountain, a high-altitude site in East China, from July 2010 to June 2011. The volume-weighted-mean (VWM) pH for the whole sampling period was 5.03. SO{4/2-} and Ca2+ were the most abundant anion and cation, respectively. The ionic concentrations varied monthly with the highest concentrations in winter/spring and the lowest in summer. Evident inter-correlations were found among most ions, indicating the common sources for some species and fully mixing characteristics of the alpine precipitation chemistry. The VWM ratio of [SO{4/2-}]/[NO{3/-}] was 2.54, suggesting the acidity of rainwater comes from both nitric and sulfuric acids. Compared with contemporary observations at other alpine continental sites in China, the precipitation at Huangshan Mountain was the least polluted, with the lowest ionic concentrations. Trajectories to Huangshan Mountain on rainy days could be classified into six groups. The rainwater with influencing air masses originating in Mongolia was the most polluted with limited effect. The emissions of Jiangxi, Anhui, Zhejiang and Jiangsu provinces had a strong influence on the overall rain chemistry at Huangshan Mountain. The rainwater with influencing air masses from Inner Mongolia was heavily polluted by anthropogenic pollutants.

  11. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    NASA Astrophysics Data System (ADS)

    Guo, X. Y.; Zhu, X.-H.; Long, Y.; Huang, D. J.

    2013-10-01

    Based on absolute geostrophic velocity, which was calculated using repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured in the same areas from 1964 to 2009, we obtained the temporally averaged nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over one section) of four sections across the Kuroshio from the East China Sea (sections PN and TK) to an area south of Japan (sections ASUKA and 137E). In addition, we examined section OK east of the Ryukyu Islands in order to understand how the Ryukyu Current contributes to the transport of nutrients by the Kuroshio south of Japan. The mean nitrate flux shows a subsurface maximum core with values of 9.6, 10.6, 11.2, 10.5, and 5.7 mol m-2 s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The depth of the subsurface maximum core changes among these 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 204.8, 165.8, 879.3, 1230.4, and 338.6 kmol s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The transport of nutrients in these sections suggests the presence of the Kuroshio nutrient stream from its upstream to downstream regions. The deep current structure of the Ryukyu Current (section OK) contributes to the same order of nitrate transport as does the Kuroshio from the East China Sea (section TK) to the area south of Japan; however, the former only has one-fifth the volume transport of the latter. A budget calculation suggests that the downstream increase of transported nitrate along the Kuroshio is mainly caused by the recirculation of nitrate into the Kuroshio. This conclusion, however, depends on water depth. In the upper layers (< 26.5σθ), the downstream change of nitrate concentration along the Kuroshio and that from the recirculation of nitrate has a significant contribution to the downstream

  12. Impact assessment of ammonia emissions on inorganic aerosols in East China using response surface modeling technique.

    PubMed

    Wang, Shuxiao; Xing, Jia; Jang, Carey; Zhu, Yun; Fu, Joshua S; Hao, Jiming

    2011-11-01

    Ammonia (NH(3)) is one important precursor of inorganic fine particles; however, knowledge of the impacts of NH(3) emissions on aerosol formation in China is very limited. In this study, we have developed China's NH(3) emission inventory for 2005 and applied the Response Surface Modeling (RSM) technique upon a widely used regional air quality model, the Community Multi-Scale Air Quality Model (CMAQ). The purpose was to analyze the impacts of NH(3) emissions on fine particles for January, April, July, and October over east China, especially those most developed regions including the North China Plain (NCP), Yangtze River delta (YRD), and the Pearl River delta (PRD). The results indicate that NH(3) emissions contribute to 8-11% of PM(2.5) concentrations in these three regions, comparable with the contributions of SO(2) (9-11%) and NO(x) (5-11%) emissions. However, NH(3), SO(2), and NO(x) emissions present significant nonlinear impacts; the PM(2.5) responses to their emissions increase when more control efforts are taken mainly because of the transition between NH(3)-rich and NH(3)-poor conditions. Nitrate aerosol (NO(3)(-)) concentration is more sensitive to NO(x) emissions in NCP and YRD because of the abundant NH(3) emissions in the two regions, but it is equally or even more sensitive to NH(3) emissions in the PRD. In high NO(3)(-) pollution areas such as NCP and YRD, NH(3) is sufficiently abundant to neutralize extra nitric acid produced by an additional 25% of NO(x) emissions. The 90% increase of NH(3) emissions during 1990-2005 resulted in about 50-60% increases of NO(3)(-) and SO(4)(2-) aerosol concentrations. If no control measures are taken for NH(3) emissions, NO(3)(-) will be further enhanced in the future. Control of NH(3) emissions in winter, spring, and fall will benefit PM(2.5) reduction for most regions. However, to improve regional air quality and avoid exacerbating the acidity of aerosols, a more effective pathway is to adopt a multipollutant

  13. Temporal and spatial variations of sea surface temperature in the East China Sea

    NASA Astrophysics Data System (ADS)

    Tseng, Chente; Lin, Chiyuan; Chen, Shihchin; Shyu, Chungzen

    2000-03-01

    Sea surface temperature of the East China Sea (ECS) were analyzed using the NOAA/AVHRR SST images. These satellite images reveal surface features of ECS including mainly the Kuroshio Current, Kuroshio Branch Current, Taiwan Warm Current, China coastal water, Changjiang diluted water and Yellow Sea mixed cold water. The SST of ECS ranges from 27 to 29°C in summer; some cold eddies were found off northeast Taiwan and to the south of Changjiang mouth. SST anomalies at the center of these eddies were about 2-5°C. The strongest front usually occurs in May each year and its temperature gradient is about 5-6°C over a cross-shelf distance of 30 nautical miles. The Yellow Sea mixed cold water also provides a contrast from China Coastal waters shoreward of the 50 m isobath; cross-shore temperature gradient is about 6-8°C over 30 nautical miles. The Kuroshio intrudes into ECS preferably at two locations. The first is off northeast Taiwan; the subsurface water of Kuroshio is upwelled onto the shelf while the main current is deflected seaward. The second site is located at 31°N and 128°E, which is generally considered as the origin of the Tsushima Warm Current. More quantitatively, a 2-year time series of monthly SST images is examined using EOF analysis to determine the spatial and temporal variations in the northwestern portion of ECS. The first spatial EOF mode accounts for 47.4% of total spatial variance and reveals the Changjiang plume and coastal cold waters off China. The second and third EOF modes account for 16.4 and 9.6% of total variance, respectively, and their eigenvector images show the intrusion of Yellow Sea mixed cold waters and the China coastal water. The fourth EOF mode accounts for 5.4% of total variance and reveals cold eddies around Chusan Islands. The temporal variance EOF analysis is less revealing in this study area.

  14. Fish community diversity in the middle continental shelf of the East China Sea

    NASA Astrophysics Data System (ADS)

    Shan, Xiujuan; Jin, Xianshi; Zhou, Zhipeng; Dai, Fangqun

    2011-11-01

    The status of fishery stocks in the coastal waters of China is far from ideal, mainly due to climate change and the impacts of human activities (e.g., pollution and overfishing). Thus, the restoration and protection of fishery resources have become critical and complex. The stability and balanced structure of the fish community is a basic foundation for the protection of fishery resources. Based on data collected from bottom trawls by the R/V Beidou in continental shelf of the East China Sea in November 2006 and February 2007, changes in the composition and diversity of fish species and functional groups were analyzed. The research area was divided into offshore waters and inshore waters by the two-way indicator species analysis (TWIA). The results showed that the dominant species were different between offshore waters and inshore waters and also varied with the survey time. The most abundant family was Sciaenidae and Teraponidae in November 2006, Sciaenidae, Engraulidae and Triglidae were most abundant in February 2007. The species belonged mainly to mobile piscivores (G6), benthivores/piscivores (G4), benthivores (G3) and planktivores (G1), and the dominant species in November 2006 were commercial species (e.g. Larimichthys polyactis and Trichiurus japonicus), but small-sized species were dominant in February 2007 (e.g., Harpadon nehereus, Benthosema pterotum, Champsodon capensis, and Acropoma japonicum). The species diversity showed a similar trend as the functional group diversity. Stations with higher diversity were mainly distributed in inshore waters in February 2007, whereas higher diversity was found in offshore waters in November 2006. The highest biomass and species number were found in G6 group, followed by the G4, G5 and G1 groups. The distribution of the number of individuals of each functional group showed the opposite trend as that of the biomass distribution. In addition, the size spectra were mainly concentrated around 3-29 cm, and the individual

  15. Classification of typical summer rainfall patterns in the East China monsoon region and their association with the East Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Zhao, Junhu; Feng, Guolin

    2016-06-01

    In this study, the summer rainfall patterns in the East China monsoon region during 1951-2015 were objectively classified into four typical categories: the northern China rainfall pattern (NCP), the intermediate rainfall pattern (IRP), the Yangtze River rainfall pattern (YRP), and the South China rainfall pattern (SCP). The periods of the four patterns show significant decadal characteristics. The NCP occurred mainly between the late 1950s and the early 1980s, and the IRP in the late 1950s to the early 1970s and the 2000s. The YRP occurred mainly between the 1980s and the 1990s, and the SCP between the mid-1990s and the early 21st century. The relationship between the East Asian summer monsoon index (EASM I WF) and the four rainfall patterns was comparatively analyzed. The results confirmed that the four rainfall patterns have obvious differences in the EASM. In the NCP, IRP, or SCP years, the EASM I WF primarily showed a positive phase and a strong summer monsoon; in the YRP years, the EASM I WF primarily showed a negative phase and a weak summer monsoon.

  16. Double SST fronts observed from MODIS data in the East China Sea off the Zhejiang-Fujian coast, China

    NASA Astrophysics Data System (ADS)

    He, Shuangyan; Huang, Daji; Zeng, Dingyong

    2016-02-01

    We report a double coastal front system off the Zhejiang (Zhe) and Fujian (Min) Provinces in the East China Sea in winter. In addition to the well-known Zhe-Min offshore coastal front along 50 m isobath, a secondary near-shore coastal thermal front along 20 m isobath is also apparent in December and January. The fronts were observed by Moderate Resolution Imaging Spectroradiometer (MODIS) at monthly mean nighttime sea surface temperature (SST) during 2000-2013 in terms of SST gradients. Our results showed temporal and spatial variations of the two fronts as follows: (1) both offshore front and near-shore front often co-exist between 26.5°N and 29.5°N in December and between 28.0°N and 29.5°N in January. However, only the offshore front is apparent in November and February. (2) The near-shore front is narrow (4-16 km), while the offshore front is three to four times wider (16-48 km). (3) In contrast to the well-known offshore front which exists throughout the winter with a strong intensity, the near-shore front has a shorter lifetime with a weak intensity, and has been overlooked by previous studies. Finally, we proposed that the bottom bathymetric gradients may play an important role in the frontogenesis of the double fronts.

  17. Variation of the ratio of nitrate to non-seasalt sulfate in precipitation over East Asia with emissions from China

    NASA Astrophysics Data System (ADS)

    Itahashi, Syuichi; Uno, Itsushi; Hayami, Hiroshi; Fujita, Shin-ichi

    2015-10-01

    Changes in anthropogenic emissions in East Asia will cause substantial variations in the precipitation chemistry. In particular, the effects of changes in China, where NOx emissions have been rising continuously and SO2 emissions peaked in 2005-2006, are important. The absolute chemical concentration in precipitation is inherently linked to the amount of precipitation; therefore, in this work we used the ratio of nitrate (NO3-) to non-seasalt sulfate nss-SO42- concentration in precipitation on an equivalent basis (hereinafter, Ratio). Here, we extend the method in our previous study (Itahashi et al., 2014a) to Korea and China. We analyzed the long-term behavior of Ratio in precipitation during 2000-2011 and investigated the factors responsible for variations of Ratio in precipitation by using a model simulation with sensitivity analysis for emission changes in China. Ratio over Japan, Korea, and China decreased slightly or remained constant during 2000-2005 (first 6 years of 2000-2011) and subsequently increased during 2006-2011 (last 6 years of 2000-2011). Linear regression analysis of the observations showed significant increases in Ratio during 2006-2011: +3.4 ± 1.0%/year, +13.2 ± 4.1%/year, and +9.8 ± 2.5%/year for Japan, Korea, and China, respectively (each p < 0.05). These variations in Ratio corresponded closely to the changes in the NOx/SO2 emission ratio in China. This suggests that anthropogenic emissions from China were responsible for most of the variation in precipitation chemistry in East Asia. Model simulations for 2000-2011 and their reproducibility were validated by comparison with the observation dataset, and they captured the observed features well. Sensitivity analysis of emissions from China in the model simulation for 2009-2011 clarified that the increase in NOx emissions from China contributed to 55-60% of the increase in Ratio in China and around 50-55% in Korea and Japan; the contribution of the increase in NOx emissions was smaller in

  18. Rapid East Asian Monsoon change during the Last Interglacial in the Bohai Sea Coastal Zone, China

    NASA Astrophysics Data System (ADS)

    Du, S.; Li, B.; Chen, M.; Zhang, D.; Xiang, R.; Niu, D.

    2013-12-01

    The Bohai Sea coastal zone of China faces the Pacific Ocean to the east and the Eurasian continent to the west, hence, this region is influenced by both the ocean and continental landmasses. The Bohai Sea coastal zone has significant monsoon climate characteristics and a strong sensitivity to climate change. The Miaodao stratigraphical section (MDS) contains historical information about climate features in the region, especially the high-frequency variations during the last interglacial, sea level changes, and the evolution of the East Asian monsoon. By analyzing the ages of different sedimentary facies in combination with proxy paleoclimatic indices (i.e., grain <63 μm fraction, average grain size (Mz), clay + silt/sand content (SC/D), magnetic susceptibility, and the ratios of Na2O/Al2O3 and (Al2O3+TOFe)/SiO2, in the fifth segments of the MDS from the last-interglacial (MDS5), we conclude that subsections 5a, 5c, and 5e were controlled by summer monsoons, whereas subsections 5b and 5d were formed when winter monsoons prevailed. These results were similar to oxygen isotope analyses from previous studies including the Spectral Mapping Project (SPECMAP) and the North Greenland Ice Core Project (NorthGRIP). Five and a half comparable oscillations in proxy indices that were dated to ca. 116.1, 118.3, 121.2, 122.7, 125.9, and 128.7 ka occurred within the MDS 5e subsection when winter monsoon winds strengthened. This millennial-scale climate variability during the Eemian period may have reached up to ten and a half oscillations with a quasi-periodicity of approximately a 1,470 year cycle during the late glacial period. This rapid period of climate change has been recorded in northern and central Europe, central Asia, as well as in East Asia. The climate forming mechanism was probably initiated by changes in solar activity, and driven by the East Asian monsoon and sea level oscillations. Comparison of Miaodao section records with other paleoclimatic records during the

  19. Assessment of satellite ocean color products of MERIS, MODIS and SeaWiFS along the East China Coast (in the Yellow Sea and East China Sea)

    NASA Astrophysics Data System (ADS)

    Cui, Tingwei; Zhang, Jie; Tang, Junwu; Sathyendranath, Shubha; Groom, Steve; Ma, Yi; Zhao, Wei; Song, Qingjun

    2014-01-01

    The validation of satellite ocean-color products is an important task of ocean-color missions. The uncertainties of these products are poorly quantified in the Yellow Sea (YS) and East China Sea (ECS), which are well known for their optical complexity and turbidity in terms of both oceanic and atmospheric optical properties. The objective of this paper is to evaluate the primary ocean-color products from three major ocean-color satellites, namely the Moderate Resolution Imaging Spectroradiometer (MODIS), Medium Resolution Imaging Spectrometer (MERIS), and Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Through match-up analysis with in situ data, it is found that satellite retrievals of the spectral remote sensing reflectance Rrs(λ) at the blue-green and green bands from MERIS, MODIS and SeaWiFS have the lowest uncertainties with a median of the absolute percentage of difference (APDm) of 15-27% and root-mean-square-error (RMS) of 0.0021-0.0039 sr-1, whereas the Rrs(λ) uncertainty at 412 nm is the highest (APDm 47-62%, RMS 0.0027-0.0041 sr-1). The uncertainties of the aerosol optical thickness (AOT) τa, diffuse attenuation coefficient for downward irradiance at 490 nm Kd(490), concentrations of suspended particulate sediment concentration (SPM) and Chlorophyll a (Chl-a) were also quantified. It is demonstrated that with appropriate in-water algorithms specifically developed for turbid waters rather than the standard ones adopted in the operational satellite data processing chain, the uncertainties of satellite-derived properties of Kd(490), SPM, and Chl-a may decrease significantly to the level of 20-30%, which is true for the majority of the study area. This validation activity advocates for (1) the improvement of the atmosphere correction algorithms with the regional aerosol optical model, (2) switching to regional in-water algorithms over turbid coastal waters, and (3) continuous support of the dedicated in situ data collection effort for the validation task.

  20. Merging aerosol optical depth data from multiple satellite missions to view agricultural biomass burning in Central and East China

    NASA Astrophysics Data System (ADS)

    Xue, Y.; Xu, H.; Mei, L.; Guang, J.; Guo, J.; Li, Y.; Hou, T.; Li, C.; Yang, L.; He, X.

    2012-04-01

    Agricultural biomass burning (ABB) in Central and East China occurs every year from May to October and peaks in June. The biomass burning event in June 2007 was very strong. During the period from 26 May to 16 June 2007, ABB occurred mainly in Anhui, Henan, Jiangsu and Shandong provinces. A comprehensive set of aerosol optical depth (AOD) data, produced by a merger of AOD product data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging Spectroradiometer (MIRS), is used to study the spatial and temporal distribution of agricultural biomass aerosols in Central and East China combining with ground observations from both AErosol RObotic NETwork (AERONET) and China Aerosol Remote Sensing NETwork (CARSNET) measurements. We compared merged AOD data with single-sensor single-algorithm AOD data (MODIS Dark Target AOD data, MODIS Deep Blue AOD data, SRAP-MODIS AOD data and MISR AOD data). In this comparison, we found merged AOD products can improve the quality of AOD products from single-sensor single-algorithm data sets by expanding the spatial coverage of the study area and keeping the statistical confidence in AOD parameters. There existed high correlation (0.8479) between the merged AOD data and AERONET measurements. Our merged AOD data make use of synergetic information conveyed in all of the available satellite data. The merged AOD data were used for the analysis of the biomass burning event from 26 May to 16 June 2007 together with meteorological data. The merged AOD products and the ground observations from China suggest that biomass burning in Central and East China has had great impact on AOD over China. Influenced by this ABB, the highest AOD value in Beijing on 12 June 2007 reached 5.71.

  1. High-resolution depositional records of polycyclic aromatic hydrocarbons in the central continental shelf mud of the East China Sea

    SciTech Connect

    Zhigang Guo; Tian Lin; Gan Zhang; Zuosheng Yang; Ming Fang

    2006-09-01

    A well-placed {sup 210}Pb-dated sediment core extracted from the distal mud in the central continental shelf of the East China Sea is used to reconstruct the high-resolution atmospheric depositional record of polycyclic aromatic hydrocarbons (PAHs), believed to be transported mainly from China in the past 200 years due to the East Asian Monsoon. Total PAHs (TPAHs), based on the 16 USEPA priority PAHs, range from 27 in 1788 to 132 ng g{sup -1} in 2001. TPAH variation in the core reflects energy usage changes and follows closely the historical economic development in China. PAHs in the core are dominantly pyrogenic in source, i.e., they are mainly from the incomplete combustion of coal and biomass burning. Several individual PAHs suggest that contribution from incomplete petroleum combustion has increased during recent years. Analysis of the 2 + 3 ring and the 5 + 6 ring PAHs and principle component analysis provide more evidence in the change in the energy structure, especially after 1978 when China embarked on the 'Reform and Open' Policy, indicating the transformation from an agricultural to an industrial economy of China. The historical profile of PAH distribution in the study area is obviously different from the United States and Europe due to their difference in energy structure and economic development stages. 39 refs., 5 figs.

  2. Assessment of the Impact of The East Asian Summer Monsoon on the Air Quality Over China from space

    NASA Astrophysics Data System (ADS)

    Hao, N.; Ding, A.; Valks, P.; Safieddine, S.; Clerbaux, C.; Trautmann, T.

    2013-12-01

    Air pollution is one of the most important environmental problems in developing Asian countries like China. Due to huge consumption of fossil fuels and rapid increase of traffic emissions in the past decades, many regions in China have been experiencing heavy air pollution. In China, studies showed that the East Asian monsoon plays a significant role in characterizing the temporal variation and spatial patterns of air pollution, since monsoon is a major atmospheric system affecting air mass transport, convection, and precipitation. Publicly available in situ observations cannot provide sufficient spatial coverage and high consistence in data quality for a long-term period. Therefore, knowledge gaps still exist in the understanding of Asian monsoon impact on the air quality in China under the background of global climate change. Satellite retrievals with high spatial coverage and high consistence for a long period can well document the change of air pollution with monsoon. We apply multi-platform satellite observations by the GOME, SCIAMACHY, GOME-2, IASI, GOMOS, MIPAS and MOPITT instruments to analyze tropospheric ozone and CO, precursors of ozone (NOx, HCHO and CH4) and other related trace gases over China. The potential of using the current generation of satellite instruments to monitor air quality changes caused by the East Asian monsoon circulation will be presented. Preliminary comparison results between satellite measurement and limited but valuable ground-based and aircraft measurements will also be showed.

  3. Modeling of soil erosion and sediment transport in the East River Basin in southern China.

    PubMed

    Wu, Yiping; Chen, Ji

    2012-12-15

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide. PMID:23137981

  4. Influence of Typhoon Matsa on Phytoplankton Chlorophyll-a off East China

    PubMed Central

    Shao, Jinchao; Han, Guoqi; Yang, Dezhou

    2015-01-01

    Typhoons can cause strong disturbance, mixing, and upwelling in the upper layer of the oceans. Rich nutrients from the subsurface layer can be brought to the euphotic layer, which will induce the phytoplankton to breed and grow rapidly. In this paper, we investigate the impact of an intense and fast moving tropical storm, Typhoon Matsa, on phytoplankton chlorophyll-a (Chl-a) concentration off East China. By using satellite remote sensing data, we analyze the changes of Chl-a concentration, Sea Surface Temperature (SST) and wind speed in the pre- and post-typhoon periods. We also give a preliminary discussion on the different responses of the Chl-a concentration between nearshore and offshore waters. In nearshore/coastal regions where nutrients are generally rich, the Chl-a maximum occurs usually at the surface or at the layer close to the surface. And, in offshore tropical oligotrophic oceans, the subsurface maxima of Chl-a exist usually in the stratified water column. In an offshore area east of Taiwan, the Chl-a concentration rose gradually in about two weeks after the typhoon. However, in a coastal area north of Taiwan high Chl-a concentration decreased sharply before landfall, rebounded quickly to some degree after landfall, and restored gradually to the pre-typhoon level in about two weeks. The Chl-a concentration presented a negative correlation with the wind speed in the nearshore area during the typhoon, which is opposite to the response in the offshore waters. The phenomena may be attributable to onshore advection of low Chl-a water, coastal downwelling and intensified mixing, which together bring pre-typhoon surface Chl-a downward in the coastal area. In the offshore area, the typhoon may trigger increase of Chl-a concentration through uptake of nutrients by typhoon-induced upwelling and entrainment mixing. PMID:26407324

  5. Influence of Typhoon Matsa on Phytoplankton Chlorophyll-a off East China.

    PubMed

    Zhao, Hui; Shao, Jinchao; Han, Guoqi; Yang, Dezhou; Lv, Jianhai

    2015-01-01

    Typhoons can cause strong disturbance, mixing, and upwelling in the upper layer of the oceans. Rich nutrients from the subsurface layer can be brought to the euphotic layer, which will induce the phytoplankton to breed and grow rapidly. In this paper, we investigate the impact of an intense and fast moving tropical storm, Typhoon Matsa, on phytoplankton chlorophyll-a (Chl-a) concentration off East China. By using satellite remote sensing data, we analyze the changes of Chl-a concentration, Sea Surface Temperature (SST) and wind speed in the pre- and post-typhoon periods. We also give a preliminary discussion on the different responses of the Chl-a concentration between nearshore and offshore waters. In nearshore/coastal regions where nutrients are generally rich, the Chl-a maximum occurs usually at the surface or at the layer close to the surface. And, in offshore tropical oligotrophic oceans, the subsurface maxima of Chl-a exist usually in the stratified water column. In an offshore area east of Taiwan, the Chl-a concentration rose gradually in about two weeks after the typhoon. However, in a coastal area north of Taiwan high Chl-a concentration decreased sharply before landfall, rebounded quickly to some degree after landfall, and restored gradually to the pre-typhoon level in about two weeks. The Chl-a concentration presented a negative correlation with the wind speed in the nearshore area during the typhoon, which is opposite to the response in the offshore waters. The phenomena may be attributable to onshore advection of low Chl-a water, coastal downwelling and intensified mixing, which together bring pre-typhoon surface Chl-a downward in the coastal area. In the offshore area, the typhoon may trigger increase of Chl-a concentration through uptake of nutrients by typhoon-induced upwelling and entrainment mixing. PMID:26407324

  6. Metamorphic Core Complex dynamics and structural development: Field evidences from the Liaodong Peninsula (China, East Asia)

    NASA Astrophysics Data System (ADS)

    Charles, Nicolas; Gumiaux, Charles; Augier, Romain; Chen, Yan; Faure, Michel; Lin, Wei; Zhu, Rixiang

    2012-08-01

    Metamorphic Core Complexes (MCC) constitute remarkable features within wide rifts. Based on analogue and numerical modelling, MCC dynamics and structural development are mainly controlled by first geothermal gradient, second the compositional layering, and after the strain rate and partial melting. In the Late Mesozoic, continental extension occurred in East Asia leading to the development of MCC, magmatism and extensional sedimentary basins. Based on an integrated study (i.e. structural and finite strain analysis, petrofabrics, Anisotropy of Magnetic Susceptibility (AMS) and U/Pb on zircon dating), this paper aims at constraining the tectonic evolution and deformation mechanisms in the South Liaodong Peninsula (NE China). The Gudaoling massif is identified as a "migmatitic" MCC developed from Upper Jurassic (ca. 157-154 Ma) to Early Cretaceous (ca. 128-113 Ma). Intrusion of the Yinmawanshan synkinematic pluton (Early Cretaceous) to the south of the dome marks out the final stages of shearing along the Gudaoling detachment zone and of exhumation of the MCC into the upper crust. The Gudaoling MCC and the Yinmawanshan pluton stay in line with the coeval South Liaodong MCC, to the south, all making a ~ 140 × 30 km wide extensional band formed during a regional E-W to NW-SE crustal stretching. The area shows a bi-phased development with a "slow" and a "fast" stage which corresponds to (1) crustal necking and (2) dome amplification/exhumation stages according to published thermo-mechanical modelling results. Finally, the Gudaoling MCC lower unit almost exclusively displays migmatites and anatectic granitoids of Late Jurassic and Early Cretaceous, respectively. Occurrence of partial melting during earlier stages of extension seems controlling the initiation of MCC (as a soft anomaly within the lower crust). In East Asia, a regional-scale thermal event, during Jurassic-Cretaceous times, may have significantly reduced the bulk lithosphere strength and locally induced

  7. Factors controlling the CCN number concentrations at north of East China Sea in spring 2005

    NASA Astrophysics Data System (ADS)

    Koike, M.; Kuwata, M.; Kondo, Y.; Miyazaki, Y.; Kodama, D.; Yum, S. S.; Tanimoto, H.; Matsueda, H.

    2006-12-01

    Ground based measurement of Cloud Condensation Nuclei (CCN) was made at Gosan station on Jeju Island, Korea, which is located at north of East China Sea during the Atmospheric Brown Cloud/East Asian Regional Experiment 2005 (ABC/EAREX2005) campaign conducted in March/April 2005. An averaged CCN number concentration was 3600 cm-3 at super-saturation S = 1.0%, which is higher than previously-reported CCN concentrations in the maritime (less than 1000 cm-3) and continental (about 2000 cm-3) air, and is as high as the CCN concentration measured in air influenced by large- scale biomass burning in southern Africa and Amazon. When air parcels which had been strongly affected by anthropogenic emissions over Asian continent were transported, CCN concentrations increased by a factor of 2-6. While the CCN concentrations at S = 1.0 and 0.6% are primarily explained by the temporal change in aerosol total number concentrations, the aerosol size distribution becomes more important for the CCN concentration at S = 0.3 and 0.1%. For S = 1.0%, in addition to transport of anthropogenic aerosols from over the Asian continent, the new particle formation resulted from anthropogenic precursor gases and their subsequent growth are likely important to increase CCN number concentrations. For S = 0.1%, CCN number concentration generally correlated with CO concentration, and more than 80% of these aerosols contained refractory-core, suggesting that many of these CCN had been transported from over the Asian continent. These aerosols are considered to grow to the critical dry diameter of 130 nm through condensation of precursor gases and/or coagulation of aerosols.

  8. Case study of absorption aerosol optical depth closure of black carbon over the East China Sea

    NASA Astrophysics Data System (ADS)

    Koike, M.; Moteki, N.; Khatri, P.; Takamura, T.; Takegawa, N.; Kondo, Y.; Hashioka, H.; Matsui, H.; Shimizu, A.; Sugimoto, N.

    2014-01-01

    aerosol optical depth (AAOD) measurements made by sun-sky photometers are currently the only constraint available for estimates of the global radiative forcing of black carbon (BC), but their validation studies are limited. In this paper, we report the first attempt to compare AAODs derived from single-particle soot photometer (SP2) and ground-based sun-sky photometer (sky radiometer, SKYNET) measurements. During the Aerosol Radiative Forcing in East Asia (A-FORCE) experiments, BC size distribution and mixing state vertical profiles were measured using an SP2 on board a research aircraft near the Fukue Observatory (32.8°N, 128.7°E) over the East China Sea in spring 2009 and late winter 2013. The aerosol extinction coefficients (bext) and single scattering albedo (SSA) at 500 nm were calculated based on aerosol size distribution and detailed BC mixing state information. The calculated aerosol optical depth (AOD) agreed well with the sky radiometer measurements (2 ± 6%) when dust loadings were low (lidar-derived nonspherical particle contribution to AOD less than 20%). However, under these low-dust conditions, the AAODs obtained from sky radiometer measurements were only half of the in situ estimates. When dust loadings were high, the sky radiometer measurements showed systematically higher AAODs even when all coarse particles were assumed to be dust for in situ measurements. These results indicate that there are considerable uncertainties in AAOD measurements. Uncertainties in the BC refractive index, optical calculations from in situ data, and sky radiometer retrieval analyses are discussed.

  9. Aerial observation of nitrogen compounds over the East China Sea in 2009 and 2010

    NASA Astrophysics Data System (ADS)

    Fujiwara, Hiroshi; Sadanaga, Yasuhiro; Urata, Junki; Masui, Yoshihiko; Bandow, Hiroshi; Ikeda, Keisuke; Hanaoka, Sayuri; Watanabe, Izumi; Arakaki, Takemitsu; Kato, Shungo; Kajii, Yoshizumi; Zhang, Daizhou; Hara, Kazutaka; Fujimoto, Toshiyuki; Seto, Takafumi; Okuyama, Kikuo; Ogi, Takashi; Takami, Akinori; Shimizu, Atsushi; Hatakeyama, Shiro

    2014-11-01

    Aerial observations of atmospheric pollutants were made over the East China Sea to analyze the transport of air pollutants, especially nitrogen oxides, from East Asia. Three flights each were conducted in October 2009 (autumn) and December 2010 (winter). Onboard measurements of gaseous total odd nitrogen species, gaseous nitric acid (HNO3(g)), O3, SO2, CO and black carbon were made and particles were collected on filters for ionic and metal component analyses. The NO3-(p)/T.NO3 (T.NO3 = HNO3(g) + NO3-(p); NO3-(p) indicates particulate nitrate) ratios were less than 0.5 in most cases. Exceptions were 17 October and 11 December, when high concentrations of dust particles (Kosa) were transported. The average T.NO3/NOy (NOy indicates total odd nitrogen species) ratio in winter was 0.59, and that in autumn was 0.71. In addition, positive and negative correlations between NOy - T.NO3 and ozone were observed in autumn and winter, respectively. These results indicate that the main components of NOy - T.NO3 are NOx and its descendant photochemical products, such as peroxyacyl nitrates and alkyl nitrates, in winter and autumn, respectively. Ratios of Na+ to Cl- + NO3- in particles were close to the seawater ratio for observations in both autumn and winter, save for the Kosa events. The main NO3-(p) formation process was the reaction of HNO3(g) with sea salt aerosols during autumn and winter. On the other hand, NO3-(p) was generated by the reaction of HNO3(g) with dust particles and sea salt during the Kosa events. The fraction of NH4NO3 in NO3-(p) was very small.

  10. Seasonal variation of organochlorine pesticides in the gaseous phase and aerosols over the East China Sea

    NASA Astrophysics Data System (ADS)

    Ji, Tianyi; Lin, Tian; Wang, Fengwen; Li, Yuanyuan; Guo, Zhigang

    2015-05-01

    Eighty paired gaseous phase and PM2.5 (particulate matter < 2.5 μm in diameter) samples, covering four seasons from October 2011 to August 2012 were collected simultaneously from a remote island in the East China Sea (ECS). The samples were analyzed for organochlorine pesticides (OCPs) to determine their seasonal variation and potential sources over the coastal marine environment. The concentrations of individual OCPs in the PM2.5 samples were higher in winter and lower in summer, and the reverse trend was observed for the measured OCP compounds (except hexachlorocyclohexanes, HCHs) in the gaseous phase. Principal component analysis revealed one trend that contributed 40% to PM2.5-bound OCPs characterized by β-HCH, α-HCH, p,p‧-dichlorodiphenyldichloroethane (p,p‧-DDD), p,p‧-dichlorodiphenyldichloroethylene (p,p‧-DDE), and chlordanes; whereas two seasonal trends, represented by dichlorodiphenyltrichloroethanes (DDTs) or chlordanes and HCHs, were responsible for 38% and 23% of the gaseous OCPs, respectively. Continental outflow driven by the East Asian monsoon brought large quantities of particulate OCPs to the ECS, especially in winter. Possible fresh sources or net volatilization from the Yangtze River induced by both higher ambient temperature and higher discharge rates caused the higher gaseous DDT and chlordane levels observed in summer. However, the lower concentrations of gaseous HCHs observed in summer suggested that net volatilization had a relatively limited impact on gaseous HCHs due to the long-term prohibition of their use and their low residual levels in the catchment, whereas the elevated concentrations of gaseous HCHs in winter controlled by gas-particle partitioning, resulted from increased particulate HCHs producing a partial shift to gaseous HCHs over ECS.

  11. Modeling of soil erosion and sediment transport in the East River Basin in southern China

    USGS Publications Warehouse

    Wu, Yping; Chen, Ji

    2012-01-01

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide.

  12. Sea surface salinity variability in the East China Sea observed by the Aquarius instrument

    NASA Astrophysics Data System (ADS)

    Kim, S.; Lee, J. H.; de Matthaeis, P.; Yueh, S. H.; Hong, C. S.; Pang, I.; Lagerloef, G. S. E.

    2014-12-01

    This study demonstrates that the spaceborne Aquarius instrument is able to monitor the sea surface salinity (SSS) variations in the East China Sea (ECS), where routine observations are difficult. The two geophysical contaminants enter the sidelobes of the Aquarius antenna and bias the coastal SSS low: the emission from the land surface and the radiofrequency interference (RFI). Away from about one Aquarius pixel (150 km) from the coastline, the Aquarius SSS is fairly insensitive (less than about 0.2 psu) to the radiometric details of the method to correct for the land emission. The ascending orbits appear to be affected by unfiltered RFI much less than the descending tracks. The Aquarius SSS along the ascending tracks is low over the ECS by 0.40 to 0.93 psu (with respect to the in situ data during the two separate 7-day periods) and is biased low by 0.41 to 1.07 psu (accuracy, or the time-mean of difference from the regional model along three Aquarius tracks over a 18-month period). The presence of the ascending and descending differences in the Aquarius SSS, and the spatially widespread bias suggest that the bias is attributed to the unfiltered RFI originating from strong point sources (rather than to the land contamination from weak distributed sources, or to other seasonally-varying geophysical contaminants). Despite the bias, the Aquarius data describe well the temporal and spatial variability of the ECS SSS. The temporal trend and magnitude of salinity changes agree remarkably between Aquarius and a regional numerical model, during both the freshwater discharge season from the Yangtze river and the rest of the year. The river discharge rate correlates with the Aquarius SSS with the coefficient of 0.71 on a seasonal scale with the discharge leading the SSS changes. The Aquarius SSS increases away from the coast, in response to the river outflow. The interannual changes in the Aquarius SSS capture the effect of the regional drought in summer 2013. Kim et al., in

  13. Using stable isotopes to determine the submarine groundwater discharge in the East China Sea

    NASA Astrophysics Data System (ADS)

    Lian, E.; Yang, S.; Yang, C.; Li, C.

    2013-12-01

    Over the last decade the flux of submarine groundwater discharge (SGD) to global ocean has been well investigated, which reaches 12, 000km3/yr, about 10~50% of the total riverine discharge into the ocean. The large uncertainty of the estimation of SGD flux lies in poor data in large river deltas and adjoining coastal areas. As a typical river-dominated epicontinental sea, the East China Sea is characterized by wide continental shelf and huge terrestrial input mostly from the Changjiang (Yangtze River). The Changjiang River exerts a significant role on sedimentological and biogeochemical processes in the East China Sea by delivering an enormous amount of dissolved and particulate materials. In this contribution, the riverwater and seawater samples were collected in dry and flood seasons in 2012 and 2013 for the measurements of stable H-O isotopes, with a major aim to examine the contribution of SGD off the Changjiang Estuary and on the coastal shelf. The results show that the values of δD and δ18O exhibit regular variations with seasons, controlled by the monsoon-induced rainfall and anthropogenic activities in the large Changjiang catchment. The δD and δ18O values in the groundwater samples from the boreholes in the Changjiang Delta fluctuate between -48.0 and -51.5‰ and between -5.9 and -7.55‰, respectively, while relatively positive values were observed in the seawater samples, ranging from -2.82 to 0.16‰ for δD and -0.54 to -0.26‰ for δ18O. Some of the offshore samples (about 50 km off the coast, 11-15 m below the sea surface) bear relatively negative isotopic values (δD: -11.21~ -3.25‰; δ18O: -1.55 ~ -0.23‰). The H-O isotopic compositions of these samples fall on a mixing line between those of groundwater and seawater samples, which probably reflects the SGD contribution. Based on the isotopic equilibrium calculation, it is estimated that about 18.7~23.1% of fresh groundwater resource flowing into the Changjiang estuarine and shelf areas is

  14. Burial history and thermal maturity, Rocky Mountain front ranges, foothills, and foreland, east-central British Columbia and adjacent Alberta, Canada

    SciTech Connect

    Kalkreuth, W.; McMechan, M.

    1988-11-01

    The regional pattern of maturation of Cretaceous strata in the study area was determined from vitrinite-reflectance measurements. Maturation increases from west to east across the Foothills to a maximum near the eastern limit of Foothills deformation and decreases farther east. Maturation along the eastern limit of deformation also decreases northward significantly. Reflectance measurements from Carboniferous strata exposed in the Front Ranges are much lower than values from the Lower Cretaceous near the eastern limit of deformation. Modeling using burial history curves indicates the regional maturation pattern largely reflects variations in the depth and/or duration of burial beneath Maastrichtian-Eocene foredeep deposits. However, differential vertical movements associated with the Peace River arch/embayment in the Carboniferous, Triassic, Early Cretaceous and Maastrichtian-Eocene had an important effect on the maturation pattern. Determined and estimated maturation levels for reservoir strata are consistent with the known occurrences of gas fields and oil pools, except along the relatively unexplored western margin of the study area. There, moderate maturation levels indicate a potential for wet-gas or oil preservation in shallow structures containing Triassic and Lower Carboniferous carbonates in the south. In the north, structures in the western Foothills deforming Triassic strata with lower levels of maturation are breached. 15 figures.

  15. Chain response of microbial loop to the decay of a diatom bloom in the East China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Linnan; Lin, Shiquan; Huang, Lingfeng; Lu, Jiachang; Chen, Wenzhao; Guo, Weidong; Zhang, Wuchang; Xiao, Tian; Sun, Jun

    2016-02-01

    Algal bloom has been regarded as one of the key causes for the summer hypoxia phenomena in the bottom water adjacent to the Yangtze River estuary in the East China Sea. Although a series of biological processes within microbial loop are involved in the development of oxygen depletion during the bloom decay, little has been known about the dynamics of microorganisms in response to the decaying process of the bloom through trophic interaction context. Here, we report some preliminary results of our observations about the response of microbial loop to the bloom decay, based on the onboard incubation experiments for 10 days during a diatom bloom near the Yangtze River estuary in August, 2011. Light and dark incubations were conducted to simulate the bloom decay inside and below the euphotic layer, respectively. In the first stage of bloom decay (Day 0 to Day 4), rapid response was found in heterotrophic bacteria (HB) and ciliate growth, which was in accordance with the decrease of total Chl a, indicating a "bottom-up" control at the early stage of bloom decay. However, the increase of heterotrophic nanoflagellates (HNF) abundance was rather inconspicuous, suggesting predation pressure on HNF from ciliate or other predator at this stage. In the second stage (Day 4 to Day 8), HB and ciliate decreased rapidly with the increase of HNF, revealing the release of HNF form ciliate predation, which suggested a "top-down" control. In the last stage of our experiment (Day 8 to Day 10), the trophic interactions were more complex, but it also implied a "top-down" control within the microbial loop. Meanwhile, virus had been monitored in the whole process of our incubations. It was found that virus lysed microalgae at the first stage, and lysed HB at the second stage. In addition, the bacterial mortality was principally caused by HNF grazing in the light-sufficient incubations and by viral lysis in the light-insufficient incubations. Our results suggest tight trophic interactions

  16. Numerical Analysis of Secondary Undulations in Urauchi Bay Caused by an Eastward Pressure Wave over the East China Sea

    NASA Astrophysics Data System (ADS)

    Saita, T.; Asano, T.

    2012-12-01

    Background and Methods Seiches, called abiki in Japanese, are frequently observed along the west coast of Kyushu Island, Japan. In 2009, an abiki of almost 3 m in total height occurred in Urauchi Bay at the Koshiki Islands located off Kyushu Island. The Seiches in the bay have been attributed to a meteorological disturbance over the East China Sea. Here, the response of the East China Sea to propagating pressure waves and the resulting oscillations in Urauchi Bay are evaluated by numerical analysis. The computational domains are the East China Sea (Domain I) and Urauchi Bay (Domain II). The primitive equations are a continuity equation and nonlinear shallow-water equations, taking into account the effect of an atmospheric pressure gradient at the sea surface. Results (1) Development of long-period waves in the East China Sea The water surface undulations generated by pressure waves propagating eastward over the East China Sea are evaluated. In the calculations, the shapes of pressure waves are simplified such that barometric pressure changes along the east-west direction only. The pressure is constant along the meridional direction. The pressure waves move from west to east in Domain I at a constant speed. Calculations are executed under 891 conditions where the wave lengths L, amplitude Pmax, and phase velocity Cp of the pressure waves are changed in the ranges of 10-140 km, 1-3 hPa, and 60-210 km/h, respectively. Eastward pressure waves over the East China Sea generate water level fluctuations of sufficient duration to put Urauchi Bay into resonance. For Cp of 80-140 km/h, surface wave heights become especially large. The increase in wave height is attributed to Proudman resonance because Cp is close to 88.3 km/h which is the propagation speed of a surface wave estimated for the mean water depth in the western area of the Okinawa Trough. A smaller L increases the amplitude of water level fluctuations and shortens their period. L of 10-40 km leads to fluctuations

  17. Phthalic Acid Esters in Soils from Vegetable Greenhouses in Shandong Peninsula, East China

    PubMed Central

    Chai, Chao; Cheng, Hongzhen; Ge, Wei; Ma, Dong; Shi, Yanxi

    2014-01-01

    Soils at depths of 0 cm to 10 cm, 10 cm to 20 cm, and 20 cm to 40 cm from 37 vegetable greenhouses in Shandong Peninsula, East China, were collected, and 16 phthalic acid esters (PAEs) were detected using gas chromatography-mass spectrometry (GC-MS). All 16 PAEs could be detected in soils from vegetable greenhouses. The total of 16 PAEs (Σ16PAEs) ranged from 1.939 mg/kg to 35.442 mg/kg, with an average of 6.748 mg/kg. Among four areas, including Qingdao, Weihai, Weifang, and Yantai, the average and maximum concentrations of Σ16PAEs in soils at depths of 0 cm to 10 cm appeared in Weifang, which has a long history of vegetable production and is famous for extensive greenhouse cultivation. Despite the different concentrations of Σ16PAEs, the PAE compositions were comparable. Among the 16 PAEs, di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), di-n-butyl phthalate (DnBP), and diisobutyl phthalate (DiBP) were the most abundant. Compared with the results on agricultural soils in China, soils that are being used or were used for vegetable greenhouses had higher PAE concentrations. Among PAEs, dimethyl phthalate (DMP), diethyl phthalate (DEP) and DnBP exceeded soil allowable concentrations (in US) in more than 90% of the samples, and DnOP in more than 20%. Shandong Peninsula has the highest PAE contents, which suggests that this area is severely contaminated by PAEs. PMID:24747982

  18. Processing and interpretation of data from a sonobouy refraction seismic section in the East China Sea shelf marginal ridge

    NASA Astrophysics Data System (ADS)

    Lou, Qing-Yuan; Yu, Pu-Zhi; Chen, Zuo-Lin

    1998-03-01

    Refraction seismic data obtained from a sonobuoy (SB7) in the East China Sea shelf marginal ridge was processed and interpreted. Intercept times and layer velocities were used to set up a one-dimension depth-velocity model based on which a two-dimenssion depth-velocity crustal model was established through two-dimension ray-tracing. The computation results showed that the upper crustal depth-velocity model beneath lineSB7 is composed of four layers with primary wave velocities of 1.80 2.20, 2.85 2.90, 3.24 3.34 and 4.55 6.00 m/s respectively. Neighbouring reflection seismic data and data on the East China Sea (ECS) regional geology were used to study the relationship between the velocities and their formation ages and also the contact relationship between the velocity boundaries.

  19. A fine grid two-dimensional M{sub 2} tidal model of the East China Sea

    SciTech Connect

    Han, K.M.; Choi, B.H.

    1993-12-31

    The previous two-dimensional non-linear tidal model of the East China Sea (Chung, 1986) has been further refined to resolve the flow over the continental shelf in more detail. The mesh resolution of the present finite-difference grid system used is 4 minutes latitude by 5 minutes longitude over the entire shelf. The developed fine grid two-dimensional model was utilized to reproduce the M{sub 2} tide and M{sub 4} tide for the East China Sea continental shelf. There is general agreement between the model results and the current observation made in the Eastern Yellow Sea, which supports the calculated tidal regime over the shelf. Some preliminary results on maximum bottom stress and tidally-induced residual current were also examined and discussed.

  20. Arsenic fractionation and contamination assessment in sediments of thirteen lakes from the East Plain and Yungui Plateau Ecoregions, China.

    PubMed

    Zan, Fengyu; Huo, Shouliang; Zhang, Jingtian; Zhang, Li; Xi, Beidou; Zhang, Lieyu

    2014-10-01

    Arsenic (As) fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment samples of lakes of the East Plain Lake Ecoregion are higher than those of Yungui Plateau Lake Ecoregion. Residual As is the main fraction in sediment samples of lakes from both ecoregions, followed by reducible As and soluble or oxidizable As. The total As is correlated to oxidizable As and residual As in sediment samples from both lake ecoregions. As distribution in sediment samples of lakes of the East Plain Ecoregion appears to be affected by human activity, while the As origin mainly comes from natural sources in sediment samples of lakes in the Yungui Plateau Ecoregion. The potential ecological risk index and geoaccumulation index values suggest "low to moderate" risk degree and "unpolluted to moderately polluted" for As in the studied lake sediments. PMID:25288540

  1. Variations of atmospheric CH4, N2O and SF6 over Japan and the East China Sea

    NASA Astrophysics Data System (ADS)

    Ishijima, K.; Goto, D.; Ishidoya, S.; Yashiro, H.; Umezawa, T.; Sugawara, S.; Patra, P. K.; Muromachi, A.; Elkins, J. W.; Dutton, G. S.; Dlugokencky, E. J.; Morimoto, S.; Aoki, S.; Nakazawa, T.

    2013-12-01

    East Asia is one of the most important regions for anthropogenic sources of both short-lived air pollutants and long-lived greenhouse gases (GHGs). According to recent estimates from an emission database, China has become the largest emitter of long-lived GHGs. Since Japan and the East China Sea are located at the east end of Eurasia, atmospheric species emitted from the continent are transported over them throughout the year. Particularly in winter to spring, outflow of the emitted species is enhanced over the East China Sea due to the East Asian Monsoon. To monitor temporal and spatial variability of atmospheric GHGs in the East Asian region, we conducted systematic GHG observations during 2003-2012 from flask samples collected onboard four different commercial ferry boats, which connected between Wakkanai and Rishiri islands (WAK ; 45.4°N, 141.5°E), between Sakaiminato and Oki islands (OKI ; 35.8°N, 133.2°E), between Kagoshima and Okinawa islands (RYU ; 30.0°N, 130.0°E), and between Ishigaki and Hateruma islands (HTR ; 24.0°N, 124.0°E). Air samples were collected almost weekly, and they were sent to Tohoku University and analyzed for GHGs and related gases. In this study, we present analyses of observed CH4, N2O and SF6 concentrations in comparison with simulations by the Atmospheric general circulation model-based Chemistry Transport model (ACTM). The observed three species predictably show higher concentrations than those observed at Cape Kumukahi (KUM), which is a NOAA air sampling site located in the Central Pacific, reflecting strong outflow of the species from East Asia. Annual mean latitudinal gradients found from the four locations as well as decrease toward KUM are generally reproduced by the ACTM. This is mostly because of reasonable spatial distributions in GHG emissions given in the ACTM. The three species also show discernible seasonal cycles. ACTM simulates seasonal cycles of CH4 and SF6 relatively well, but not for N2O, suggesting

  2. Spatial and temporal variation of the Synechococcus population in the East China Sea and its contribution to phytoplankton biomass

    NASA Astrophysics Data System (ADS)

    Chiang, Kuo-Ping; Kuo, Min-Chieh; Chang, Jeng; Wang, Ru-Huey; Gong, Gwo-Ching

    2002-01-01

    Variations in the spatial and temporal distribution of the Synechococcus population in the East China Sea were investigated in five cruises of the R/V Ocean Research I between May 1996 and October 1998. On the continental shelf, a two-phased (warm >20°C; and cold <20°C) seasonal cycle with 10-fold variation was found in the Synechococcus population. In the cold season (winter to late spring), when temperature is probably a limiting factor, a low density Synechococcus population was homogeneously distributed over the entire continental shelf. A dome-type spatial distribution pattern appeared in summer, that is, population densities were high toward the middle of the sea. This area of higher density moved toward the outer shelf in fall. No seasonal variation was found in the Coastal Water, probably because in summer the low transmission means that light is limited below the surface. The average carbon biomass of Synechococcus in the East China Sea ranged from 0.09 (early spring) to 0.90 gC m -2 (fall). Based on carbon biomass, Synechococcus accounted for less than 25% of the total photosynthetic plankton in cold season and about 50% in the warm season. Our results suggest that the cyanobacterium Synechococcus is a major contributor to the seasonal variation of phytoplankton in the East China Sea.

  3. [Construction of individual-based ecological model for Scomber japonicas at its early growth stages in East China Sea].

    PubMed

    Li, Yue-Song; Chen, Xin-Jun; Yang, Hong

    2012-06-01

    By adopting FVCOM-simulated 3-D physical field and based on the biological processes of chub mackerel (Scomber japonicas) in its early life history from the individual-based biological model, the individual-based ecological model for S. japonicas at its early growth stages in the East China Sea was constructed through coupling the physical field in March-July with the biological model by the method of Lagrange particle tracking. The model constructed could well simulate the transport process and abundance distribution of S. japonicas eggs and larvae. The Taiwan Warm Current, Kuroshio, and Tsushima Strait Warm Current directly affected the transport process and distribution of the eggs and larvae, and indirectly affected the growth and survive of the eggs and larvae through the transport to the nursery grounds with different water temperature and foods. The spawning grounds in southern East China Sea made more contributions to the recruitment to the fishing grounds in northeast East China Sea, but less to the Yangtze estuary and Zhoushan Island. The northwestern and southwestern parts of spawning grounds had strong connectivity with the nursery grounds of Cheju and Tsushima Straits, whereas the northeastern and southeastern parts of the spawning ground had strong connectivity with the nursery grounds of Kyushu and Pacific Ocean. PMID:22937663

  4. Distribution of inorganic phosphorus in profiles and particle fractions of Anthrosols across an established riparian buffer and adjacent cropped area at the Dian lake (China)

    NASA Astrophysics Data System (ADS)

    Zhang, Guo Sheng; Cha Li, Jian

    2016-02-01

    Riparian buffers can trap sediment and nutrients sourced from upper cropland, minimizing the eutrophication risk of water quality. This study aimed to investigate the distributions of soil inorganic phosphorus (Pi) forms among profile and particle-size fractions in an established riparian buffer and adjacent cropped area at the Dian lake, southwestern China. The Ca-bound fraction (62 %) was the major proportion of the Pi in the riparian soils. After 3 years' restoration, buffer rehabilitation from cropped area had a limited impact on total phosphorus (TP) concentrations, but has contributed to a change in Pi forms. In the 0-20 cm soil layer, levels of the Olsen-P, non-occluded, Ca-bound, and total Pi were lower in the buffer than the cropped area; however, the Pi distribution between the cropped area and the buffer did not differ significantly as depth increased. The clay fraction corresponded to 57 % of TP and seemed to be both a sink for highly recalcitrant Pi and a source for labile Pi. The lower concentration of Pi forms in the silt and sand particle fraction in the surface soil was observed in the buffer area, which indicated that the Pi distribution in coarse particle fraction had sensitively responded to land use changes.

  5. Impact of temperature variation between adjacent days on childhood hand, foot and mouth disease during April and July in urban and rural Hefei, China

    NASA Astrophysics Data System (ADS)

    Cheng, Jian; Zhu, Rui; Xu, Zhiwei; Wu, Jinju; Wang, Xu; Li, Kesheng; Wen, Liying; Yang, Huihui; Su, Hong

    2016-06-01

    Previous studies have found that both high temperature and low temperature increase the risk of childhood hand, foot and mouth disease (HFMD). However, little is known about whether temperature variation between neighboring days has any effects on childhood HFMD. A Poisson generalized linear regression model, combined with a distributed lag non-linear model, was applied to examine the relationship between temperature change and childhood HFMD in Hefei, China, from 1st January 2010 to 31st December 2012. Temperature change was defined as the difference of current day's mean temperature and previous day's mean temperature. Late spring and early summer (April-July) were chosen as the main study period due to it having the highest childhood HFMD incidence. There was a statistical association between temperature change between neighboring days and childhood HFMD. The effects of temperature change on childhood HFMD increased below a temperature change of 0 °C (temperature drop). The temperature change has the greatest adverse effect on childhood HFMD at 7 days lag, with 4 % (95 % confidence interval 2-7 %) increase per 3 °C drop of temperature. Male children and urban children appeared to be more vulnerable to the effects of temperature change. Temperature change between adjacent days might be an alternative temperature indictor for exploring the temperature-HFMD relationship.

  6. Population genetic diversity of the northern snakehead (Channa argus) in China based on the mitochondrial DNA control region and adjacent regions sequences.

    PubMed

    Zhou, Aiguo; Zhuo, Xiaolei; Zou, Qing; Chen, Jintao; Zou, Jixing

    2015-06-01

    Genetic variation and population structure of northern snakehead (Channa argus) from eight locations in China were investigated using mitochondrial DNA control region and adjacent regions sequences. Sequence analysis showed that there were 105 haplotypes in 260 individuals, 48 unique haplotypes and 57 shared haplotypes, but no common haplotype shared by all populations. As a whole, the haplotype diversity was high (h=0.989), while the nucleotide diversity was low (π=0.00482). AMOVA analysis detected significant genetic differentiation among all eight populations (FST=0.328, p<0.01) and 66.17% of the total variance was resulted from intra-population differentiation. UPGMA analysis indicated that the eight populations could be divided into four major clusters, which was consistent with that the eight sampled locations were belonged to four isolated river systems. The neutrality and mismatch distribution tests suggested that the eight populations of C. argus in the sampling locations underwent recent population expansion. Among the eight populations, the Erhai Lake population may represent a unique genetic resource and therefore needs to be conserved. PMID:24724976

  7. Impact of temperature variation between adjacent days on childhood hand, foot and mouth disease during April and July in urban and rural Hefei, China.

    PubMed

    Cheng, Jian; Zhu, Rui; Xu, Zhiwei; Wu, Jinju; Wang, Xu; Li, Kesheng; Wen, Liying; Yang, Huihui; Su, Hong

    2016-06-01

    Previous studies have found that both high temperature and low temperature increase the risk of childhood hand, foot and mouth disease (HFMD). However, little is known about whether temperature variation between neighboring days has any effects on childhood HFMD. A Poisson generalized linear regression model, combined with a distributed lag non-linear model, was applied to examine the relationship between temperature change and childhood HFMD in Hefei, China, from 1st January 2010 to 31st December 2012. Temperature change was defined as the difference of current day's mean temperature and previous day's mean temperature. Late spring and early summer (April-July) were chosen as the main study period due to it having the highest childhood HFMD incidence. There was a statistical association between temperature change between neighboring days and childhood HFMD. The effects of temperature change on childhood HFMD increased below a temperature change of 0 °C (temperature drop). The temperature change has the greatest adverse effect on childhood HFMD at 7 days lag, with 4 % (95 % confidence interval 2-7 %) increase per 3 °C drop of temperature. Male children and urban children appeared to be more vulnerable to the effects of temperature change. Temperature change between adjacent days might be an alternative temperature indictor for exploring the temperature-HFMD relationship. PMID:26493199

  8. Impact of temperature variation between adjacent days on childhood hand, foot and mouth disease during April and July in urban and rural Hefei, China

    NASA Astrophysics Data System (ADS)

    Cheng, Jian; Zhu, Rui; Xu, Zhiwei; Wu, Jinju; Wang, Xu; Li, Kesheng; Wen, Liying; Yang, Huihui; Su, Hong

    2015-10-01

    Previous studies have found that both high temperature and low temperature increase the risk of childhood hand, foot and mouth disease (HFMD). However, little is known about whether temperature variation between neighboring days has any effects on childhood HFMD. A Poisson generalized linear regression model, combined with a distributed lag non-linear model, was applied to examine the relationship between temperature change and childhood HFMD in Hefei, China, from 1st January 2010 to 31st December 2012. Temperature change was defined as the difference of current day's mean temperature and previous day's mean temperature. Late spring and early summer (April-July) were chosen as the main study period due to it having the highest childhood HFMD incidence. There was a statistical association between temperature change between neighboring days and childhood HFMD. The effects of temperature change on childhood HFMD increased below a temperature change of 0 °C (temperature drop). The temperature change has the greatest adverse effect on childhood HFMD at 7 days lag, with 4 % (95 % confidence interval 2-7 %) increase per 3 °C drop of temperature. Male children and urban children appeared to be more vulnerable to the effects of temperature change. Temperature change between adjacent days might be an alternative temperature indictor for exploring the temperature-HFMD relationship.

  9. Microbial biomarkers from the East China Sea and implications for paleoenvironmental reconstructions

    NASA Astrophysics Data System (ADS)

    Zhao, M.; Hu, W. J.; Duan, S. S.; Cao, L. Y.; Wang, Y. Y.; Zhao, S. Z.; Xing, L.

    2015-12-01

    We report the vertical and spatial distributions of isoprenoid glycerol dibiphytanyl glycerol tetraethers (GDGTs), ladderanes and phytoplankton biomarkers in suspended particulates from the East China Sea (ECS) to evaluate the living habitat and environments of the planktonic archaea Thaumarchaeota and anaerobic ammonium oxidation (anammox) bacteria, respectively. Maximum GDGT concentration mostly occurred in bottom waters while maximum phytoplankton biomarker concentration occurred in the surface layers; and these results from the ECS provides further evidence for the use of the TEX86 index as a proxy for bottom water temperature in shallow shelf sea environments. Ladderanes were detected in both surface and subsurface particulates, suggesting that anammox activity was widespread in both the hypoxia zone near the Changjiang Estuary and in the mid-shelf of the ECS. Thus, anaerobic condition is not a requirement for anammox bacteria; however, ladderane-derived anammox activity was higher in lower oxygen environments, confirming ladderanes as useful proxies for reconstructing hypoxia changes. Statistical analysis will be presented to assess the link between archaea (Thaumarchaeota) performing aerobic ammonia oxidation and bacteria (anammox) performing anaerobic ammonium oxidation in the ECS, the implications for both carbon and nitrogen cycles.

  10. Study on the storm surges induced by cold waves in the Northern East China Sea

    NASA Astrophysics Data System (ADS)

    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.

  11. Geologic evolution and aspects of the petroleum geology of the northern East China Sea shelf basin

    SciTech Connect

    Lee, G.H.; Kim, B.Y.; Shin, K.S.; Sunwoo, D.

    2006-02-15

    Analysis of multichannel seismic reflection profiles reveals that the northern East China Sea shelf basin experienced two phases of rifting, followed by regional subsidence. The initial rifting in the Late Cretaceous created a series of grabens and half grabens, filled by alluvial and fluviolacustrine deposits. Regional uplift and folding (Yuquan movement) in the late Eocene-early Oligocene terminated the initial rifting. Rifting resumed in the early Oligocene, while alluvial and fluviolacustrine deposition continued to prevail. A second phase of uplift in the early Miocene terminated the rifting, marking the transition to the postrift phase. The early postrift phase (early Miocene-late Miocene) is characterized by regional subsidence and westward and northwestward marine transgression. Inversion (Longjing movement) in the late Miocene interrupted the postrift subsidence, resulting in an extensive thrust-fold belt in the eastern part of the area. The entire area entered a stage of regional subsidence again and has become a broad continental shelf. Source rocks include synrift lacustrine facies, fluvial shales, and coal beds. Synrift fluvial, lacustrine, and deltaic deposits, postrift littoral and/or shallow-marine sandstones, and fractured basement have the potential to provide reservoirs. Various types of hydrocarbon traps (e.g., faulted anticlines, overthrusts, rollover anticlines, faults, unconformity traps, combination structural-stratigraphic traps, weathered basement, and stratigraphic traps) are recognized, but many of these traps have not been tested.

  12. Paleo-environment from isotopes and hydrochemistry of groundwater in East Junggar Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Li, Jie; Pang, Zhonghe; Froehlich, Klaus; Huang, Tianming; Kong, Yanlong; Song, Wenhui; Yun, Hongxiang

    2015-10-01

    Isotopic and geochemical evidence of paleoclimatic conditions from the Pleistocene (∼30ka BP) has been obtained from groundwater in a non-monsoon area in the East Junggar Basin, NW China. The major ion chemistry of groundwater is controlled by some processes including ion exchange in clay minerals and dissolution of gypsum as well as other evaporites in the desert groundwater, while carbonate minerals seem to be essentially absent in the aquifers. The water chemistry, oxygen and deuterium, deuterium excess, and stable carbon isotopes of groundwater show distinctive excursions inferred to be related to environmental variations such as air temperature and land cover change. Shallow groundwater bears an isotopic signature similar to that of the mean annual rainfall in Urumqi, suggesting recharge under warm climate conditions in the Holocene. Deep groundwater in the central part of the basin is characterized by depleted heavy isotopes, lower deuterium excess and low 14C content, indicating lower air temperature in the late Pleistocene, after correction for altitude effect. Old groundwater with enriched 13C indicates the higher proportion of C4 species in the late Pleistocene.

  13. Viral and nanoflagellate control of bacterial production in the East China Sea summer 2011

    NASA Astrophysics Data System (ADS)

    Tsai, An-Yi; Gong, Gwo-Ching; Huang, Jun-Kai; Lin, Yun-Chi

    2013-03-01

    This study investigated spatial patterns in bacterial, viral, nanoflagellate abundance and the loss of bacterial production due to viral lysis and nanoflagellate grazing across the surface water of East China Sea (ECS) during the summer (1-12 July) of 2011. Abundance of bacteria ranged from 1.3 × 105 to 12.4 × 105 cells mL-1, with the highest value found in surface coastal waters, coinciding with a peak in Chl a concentrations. Spatial variations in bacterial growth rates ranged from 0.029 to 0.071 h-1, the highest growth rate near the river mouth of the Changjiang River. Nanoflagellate grazing was responsible for most of the bacterial mortality, accounting for 59% of total mortality within the plume (salinity <31) and 66% outside the plume (salinity >31) on average. Variation in viral lysis was associated with environmental gradients and bacterial abundance. We found a balance budget between bacterial losses due to both bacterivory and viral infection and production, which suggests strong top-down control of bacteria in the ECS during the summer.

  14. Impact of Typhoon Morakot on suspended matter size distributions on the East China Sea inner shelf

    NASA Astrophysics Data System (ADS)

    Li, Yunhai; Li, Dongyi; Fang, Jianyong; Yin, Xijie; Li, Haidong; Hu, Wenye; Chen, Jian

    2015-06-01

    Two surveys were conducted on the East China Sea inner shelf before and after the passage of Typhoon Morakot in 2009. The typhoon-induced variations in the size distributions of suspended matters were studied based on the data collected by a Laser In Situ Scattering Transmissometer (LISST). A comparison of the measurements from the two surveys revealed significant changes in seafloor sediment grain size, suspended matter volume concentration and size distribution due to Typhoon Morakot. The mean seafloor sediment grain size increased generally, while the sorting coefficient decreased after the typhoon. Before the typhoon, suspended matter size was generally >100 μm, which was significantly reduced to between 20-50 μm after the typhoon. The single-grain fraction with sizes <36 μm and microflocs with sizes between 36-133 μm significantly increased in volume concentrations and percentage after the typhoon. On the other hand, the volume concentration of macroflocs (with sizes >133 μm) were largely reduced from >40% before the typhoon to <20% after the typhoon in the entire water body. Our analyzes suggest that the dynamic process of the typhoon caused the seafloor sediment resuspension, which significantly increased the suspended matter volume concentration in addition to the increase of terrigenous materials due to high-intensity rainfall accompanying the typhoon. The typhoon process also decreased the suspended matter size and macrofloc (>133 μm) concentration by strong disturbance of water column and the temporary demise of plankton under heavy cloudy condition.

  15. Causes of endocrine disrupting potencies in surface water in East China.

    PubMed

    Shi, Wei; Deng, Dongyang; Wang, Yuting; Hu, Guanjiu; Guo, Jing; Zhang, Xiaowei; Wang, Xinru; Giesy, John P; Yu, Hongxia; Wang, Ziheng

    2016-02-01

    Surface water is essential for human health and ecological diversity, but some endocrine disrupting chemicals are detectable. Both thyroid receptor (TR) and androgen receptor (AR) agonistic/antagonistic potencies in grade II surface water in East China were investigated using reporter gene assays. While none of the water exhibited agonistic potency, significant AR and TR antagonistic potencies were detectable. TR antagonistic equivalents (TR-AntEQ) and AR antagonistic equivalents (AR-AntEQ) ranged from 3.6 to 76.1 μg dibutyl phthalate/L and from 2.3 to 242.6 μg flutamide/L, respectively. The TR and AR antagonistic potencies in the Yangtze River watershed were highlighted, with equivalents greater than the lowest observable effect concentration (LOEC) of dibutyl phthalate and flutamide, respectively. Phthalate esters (PAEs) being the most abundant explained most of the TR antagonistic potency, contributing more than 65% of the TR-AntEQ and diisobutyl phthalate (DiBP) was the major contributor. In most surface waters studied, PAEs contributed little of the AR-AntEQ, but the frequently detected octylphenol, nonylphenol and benzo[a]pyrene might be responsible. PMID:26495828

  16. Diversity of Cronobacter spp. isolates from the vegetables in the middle-east coastline of China.

    PubMed

    Chen, Wanyi; Yang, Jielin; You, Chunping; Liu, Zhenmin

    2016-06-01

    Cronobacter spp. has caused life-threatening neonatal infections mainly resulted from consumption of contaminated powdered infant formula. A total of 102 vegetable samples from retail markets were evaluated for the presence of Cronobacter spp. Thirty-five presumptive Cronobacter isolates were isolated and identified using API 20E and 16S rDNA sequencing analyses. All isolates and type strains were characterized using enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), and genetic profiles of cluster analysis from this molecular typing test clearly showed that there were differences among isolates from different vegetables. A polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) based on the amplification of the gyrB gene (1258 bp) was developed to differentiate among Cronobacter species. A new PCR-RFLP assay based on the amplification of the gyrB gene using Alu I and Hinf I endonuclease combination is established and it has been confirmed an accurate and rapid subtyping method to differentiate Cronobacter species. Sequence analysis of the gyrB gene was proven to be suitable for the phylogenetic analysis of the Cronobacter strains, which has much better resolution based on SNPs in the identification of Cronobacter species specificity than PCR-RFLP and ERIC-PCR. Our study further confirmed that vegetables are one of the most common habitats or sources of Cronobacter spp. contamination in the middle-east coastline of China. PMID:27116956

  17. Effects of the Changjiang (Yangtze) River discharge on planktonic community respiration in the East China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Chung-Chi; Shiah, Fuh-Kwo; Chiang, Kuo-Ping; Gong, Gwo-Ching; Kemp, W. Michael

    2009-03-01

    Planktonic communities tend to flourish on the western margins of the East China Sea (ECS) fueled by substrates delivered largely from the Changjiang River, the fifth largest river in the world. To study the effects of the Changjiang River discharge on planktonic community respiration (CR), physical-chemical variables and key processes were measured in three consecutive summers in the ECS. Results showed that concentrations of nitrate and Chl a, protozoan biomass, bacterial production, as well as CR in the surface water were all negatively correlated with sea surface salinity, reflecting the strong influence of river discharge on the ECS shelf ecosystem. Moreover, mean values of nitrate, Chl a concentrations, and CR rates were proportionally related to the area of Changjiang diluted water (CDW; salinity ≤31.0 practical salinity units (psu)), an index of river discharge rate. Presumably, higher river flow delivers higher nutrient concentrations which stimulate phytoplankton growth, which in turn fuels CR. CR exhibited significant monthly and interannual variability, and rates appear to be dominated by bacteria and phytoplankton. Although the plankton community was relatively productive (mean = 0.8 mg C m-2 d-1) in the CDW, the mean ratio of production to respiration was low (0.42). This suggests that the heterotrophic processes regulating CR were supported by riverine organic carbon input in addition to in situ autotrophic production.

  18. Two new species of Chromadoridae (Chromadorida: Nematoda) from the East China Sea.

    PubMed

    Huang, Yong; Gao, Qun

    2016-01-01

    Two new species of Chromadoridae, a family of free-living marine nematodes, are described from intertidal sediments of the East China Sea. Ptycholaimellus pirus sp. nov. is characterized by having a cuticle with six longitudinal rows of double dots and long somatic setae, relatively long cephalic setae, a pear-shaped terminal pharyngeal bulb occupying less than 30% of pharyngeal length, and an elongate conical tail. The new species is distinguished from all related species by the unique character of the cuticle, with six longitudinal rows of horizontal double dots, and the pear-shaped terminal pharyngeal bulb. Hypodontolaimus ventrapophyses sp. nov. is characterized by having a cylindrical body with a slightly expanded anterior end and a conical tail, a homogeneous cuticle with lateral differentiation of two longitudinal rows of larger dots, a well developed pharynx with oval-shaped buccal bulb and terminal bulb, and a large ventral gland. Males have slender, strongly curved spicules and a gubernaculum with a ventral apophysis, and precloacal supplements are absent. The new species differs from all related species in this genus by the structure of the gubernaculum, which has a ventral apophysis. PMID:27470838

  19. A new species of Parodontophora (Nematoda: Axonolaimidae) from the intertidal zone of the East China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Haixia; Huang, Yong

    2016-02-01

    This study described a new species of free-living nematode discovered in the intertidal mudflat of Ximen Island, East China Sea. The new species, designated Parodontophora longiamphidata sp. nov., was characterized by a cylindrical body with tapering extremeties; cuticle smooth without somatic setae; four short cephalic setae; cylindrical buccal cavity with six clawlike teeth at the top of stoma; pharynx cylindrical with widened base; amphidial fovea crook-shaped with elongated scalariform branch extending past level of base of pharynx and ventral gland; ventral gland cell long-oval shaped located posterior to pharyngo-intestinal junction; excretory pore at level of middle of buccal cavity; tail conico-cylindrical with enlarged tip; three caudal gland cells, male spicules arched with cephalic proximal end and tapered distal end; gubernaculum with dorso-caudal apophysis; female with two opposed outstretched ovaries; and vulva at slightly post-midpoint of body length. This new species was close to P. wuleidaowanensis Zhang, 2005 and P. polita Gerlach, 1955 in terms of long amphidial fovea branch. The newly found species was easily distinguishable from the two documented; its amphidial fovea branch (255-290 µm versus 72-106 and 125-150 µm) was obviously longer. Key to the Parodontophora species with a longer amphidial fovea branch was given.

  20. Aerosol deposition favors red tide phytoplankton in the East China Sea

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Chinese marginal seas support vast fisheries and vital economies, but their productivity is threatened by eutrophication from runoff and atmospheric deposition. The East China Sea is inundated with nitrogen from the Yangtze River and anthropogenic emissions, leading to elevated N:P ratios. We show that aerosol additions approximating one week of moderate deposition to offshore waters favor the growth of red tide phytoplankton, such as Skeletonema costatum, by providing nutrients and trace metals (iron and zinc) needed for growth. In contrast toxin-producing Pseudonitzchia does not benefit from aerosols in this region, possibly due to its preference for lower N:P ratios. A dose-dependent toxic response was observed in Synechococcus at high aerosol loads approximating a week of heavy deposition in the region. In contrast, phytoplankton growth at an onshore station was light limited, and aerosol additions did not have an appreciable effect on phytoplankton growth. Aerosol and chlorophyll observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite have the potential to explore the effect of aerosols on phytoplankton blooms over longer time scales and seasons. This study shows the potential for aerosols to control N:P ratios in offshore waters and to shape the phytoplankton community through fertilization and toxicity, contributing to the occurrence of red tides.

  1. The impact of atmospheric deposition of cadmium on dominant algal species in the East China Sea

    NASA Astrophysics Data System (ADS)

    Quan, Qiwei; Chen, Ying; Ma, Qingwei; Wang, Fujiang; Meng, Xi; Wang, Bo

    2016-04-01

    Cadmium (Cd) mainly derived from anthropogenic emissions can be transported through atmospheric pathway to marine ecosystem, affecting the phytoplankton community and primary productivity. In this study, we identified the toxicity threshold of Cd for phytoplankton under seawater conditions of the coastal East China Sea (ECS) through both laboratory and in situ mesocosm incubation experiments. The mesocosm experiment showed that Cd in low concentration (0.003 μg per μg chl a) was conducive to the growth of natural community and increased chl a productivity. In high concentration (0.03 μg per μg chl a) Cd acted as an inhibiting factor which decreased the total chl a productivity. The diatom community was found to be more sensitive to Cd toxicity than dinoflagellate, as the low concentration Cd showed toxicity to diatom but enhanced dinoflagellate growth. We noticed that the soluble Cd estimated from atmosphere deposition to the coastal ECS was below the toxicity threshold and the Cd deposition might promote phytoplankton growth in this region. In our laboratory experiments, adding Cd, similar to aerosol deposition, stimulated the growth of both dominant algal species Prorocentrum donghaiense Lu (dinoflagellate) and Skeletonema costatum (diatom). Adding Cd on a higher level inhibited the growth of both the species, but Skeletonema costatum seemed obviously more sensitive to toxicity. This indicates the potential impact of atmospheric deposition Cd on phytoplankton community succession in the ECS.

  2. [Diversity and enzyme-producing activity of culturable halophilic bacteria in Daishan Saltern of East China].

    PubMed

    Yang, Dan-Dan; Li, Qian; Huang, Jing-Jing; Chen, Min

    2012-11-01

    Soil and saline water samples were collected from the Daishan Saltern of East China, and the halophilic bacteria were isolated and cultured by using selective media, aimed to investigate the diversity and enzyme-producing activity of culturable halophilic bacteria in saltern environment. A total of 181 strains were isolated by culture-dependent method. Specific primers were used to amplify the 16S rRNA gene of bacteria and archaea. The operation taxonomy units (OTUs) were determined by ARDRA method, and the representative strain of each OTU was sequenced. The phylogenetic position of all the isolated strains was determined by 16S rRNA sequencing. The results showed that the isolated 181 strains displayed 21 operational taxonomic units (OTUs), of which, 12 OTUs belonged to halophilic bacteria, and the others belonged to halophilic archaea. Phylogenetic analysis indicated that there were 7 genera presented among the halophilic bacteria group, and 4 genera presented among the halophilic archaea group. The dominant halophilic strains were of Halomonas and Haloarcula, with 46.8% in halophilic bacteria and 49.1% in halophilic archaea group, respectively. Enzyme-producing analysis indicated that most strains displayed enzyme-producing activity, including the activities of producing amylase, proteinase and lipase, and the dominant strains capable of enzyme-producing were of Haloarcula. Our results showed that in the environment of Daishan Saltern, there existed a higher diversity of halophilic bacteria, being a source sink for screening enzyme-producing bacterial strains. PMID:23431797

  3. The potential drivers in forming avian biodiversity hotspots in the East Himalaya Mountains of Southwest China.

    PubMed

    Lei, Fumin; Qu, Yanhua; Song, Gang; Alström, Per; Fjeldså, Jon

    2015-03-01

    Little has been published to describe or interpret Asian biodiversity hotspots, including those in the East Himalayan Mountains of Southwest China (HMSC), thus making necessary a review of the current knowledge. The Pliocene and Pleistocene geological and glacial histories of the Asian continent differ from those of Europe and North America, suggesting different mechanisms of speciation and extinction, and, thus, different responses to climate changes during the Quaternary glaciations. This short review summarizes potential drivers in shaping and maintaining high species richness and endemism of birds in the HMSC. The geographical location at the junction of different biogeographical realms, the wide range of habitats and climates along the extensive elevational range, the complex topography and the distinct geological history of this region have probably contributed to the evolution of an exceptionally species-rich and endemic-rich, specialized montane avian fauna. The Mountain systems in the HMSC may have provided refugia where species survived during the glacial periods and barriers for preventing species dispersal after the glacial periods. More studies are required to further test this refugia hypothesis by comparing more cold-tolerent and warm-tolerent species. PMID:25316284

  4. Seasonal and interannual changes of the Kuroshio intrusion onto the East China Sea Shelf

    NASA Astrophysics Data System (ADS)

    Wu, Chau-Ron; Hsin, Yi-Chia; Chiang, Tzu-Ling; Lin, Yong-Fu; Tsui, I.-Fong

    2014-08-01

    An advanced artificial neural network classification algorithm is applied to 20 years of multisatellite geostrophic velocity data to study the Kuroshio intrusion onto the southern shelf of the East China Sea. The results suggest that the on-shelf intrusion may occur year round, but winter intrusion events are more frequent than summer events. Both stronger intrusion (which is closely correlated to surface heat flux gradient) and weaker intrusion (which is correlated to wind forcing) occur during wintertime, but the former dominates in late winter while the latter prevails in early winter. There is a significant year-to-year variation of the winter on-shelf intrusion. Although on-shelf intrusion is the major characteristic of the region during wintertime, seldom intrusion events have been identified in the winters of 1997-1998 and 2002-2003. Two conditions are responsible for the cause of the nonintrusion events. During the two nonintrusion winters, the upstream Kuroshio transport anomaly is insignificant (the Kuroshio is not weakened) and no significant winter cooling off northeast Taiwan. Thus, the Kuroshio tends to flow along the shelf break following the 200 m isobath and on-shelf intrusion ceases. Those two nonintrusion events take place during the winters when both the Niño 3.4 index and the PDO index are large and positive.

  5. Physical mechanisms for the offshore detachment of the Changjiang Diluted Water in the East China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Changsheng; Xue, Pengfei; Ding, Pingxing; Beardsley, R. C.; Xu, Qichun; Mao, Xianmou; Gao, Guoping; Qi, Jiahua; Li, Chunyan; Lin, Huichan; Cowles, Geoffrey; Shi, Maochong

    2008-02-01

    Physical mechanisms for the summertime offshore detachment of the Changjiang Diluted Water (CDW) into the East China Sea are examined using the high-resolution, unstructured-grid, Finite-Volume Coastal Ocean Model (FVCOM). The model results suggest that isolated low salinity water lens detected west of Cheju Island can be formed by (1) a large-scale adjustment of the flow field to the Changjiang discharge and (2) the detachment of anticyclonic eddies as a result of baroclinic instability of the CDW front. Adding the Changjiang discharge intensifies the clockwise vorticity of the subsurface current (originating from the Taiwan Warm Current) flowing along the 50-m isobath and thus drives the low-salinity water in the northern coastal area of the Changjiang mouth offshore over a submerged plateau that extends toward Cheju Island. Given a model horizontal resolution of less than 1.0 km, the CDW front becomes baroclinically unstable and forms a chain of anticyclonic and cyclonic eddies. The offshore detachment of anticyclonic eddies can carry the CDW offshore. This process is enhanced under northward winds as a result of the spatially nonuniform interaction of wind-induced Ekman flow and eddy-generated frontal density currents. Characteristics of the model-predicted eddy field are consistent with previous theoretical studies of baroclinic instability of buoyancy-driven coastal density currents and existing satellite imagery. The plume stability is controlled by the horizontal Ekman number. In the Changjiang, this number is much smaller than the criterion suggested by a theoretical analysis.

  6. Effects of an artificial oyster shell reef on macrobenthic communities in Rongcheng Bay, East China

    NASA Astrophysics Data System (ADS)

    Xu, Qinzeng; Zhang, Libin; Zhang, Tao; Zhou, Yi; Xia, Sudong; Liu, Hui; Yang, Hongsheng

    2014-01-01

    An artificial oyster shell reef was deployed in Rongcheng Bay, East China. However, the effects of this reef on the surrounding macrobenthic communities were unknown. We compared sedimentary factors, macrobenthic biomass, abundance, and community composition and ecological indicators between the reef and non-reef areas over a one year period. The mean values for chlorophyll a (Chl a), total organic matter (TOM), total organic carbon (TOC), and total nitrogen (TN) content in surface sediments in the reef area were slightly higher than those in the non-reef area. The Chl a levels differed significantly between the two areas, but the TOM, TOC, and TN were not significantly different. The abundance of crustaceans was significantly different between the two areas, but the abundance and biomass of polychaetes, echinoderms, mollusk did not differ significantly. The permutational multivariate analysis of variance (PERMANOVA) revealed that the macrobenthic community differed significantly through time and analysis of similarity multivariate analyses (ANOSIM) revealed that the macrobenthic community differed significantly in some months. The ecological indicators revealed that the environmental quality of the reef area was slightly better than that of the non-reef area. Overall, our results suggest that the artificial oyster shell reef may change the macrobenthic community and the quality of the environment. Despite the lack of an effect in the short term, long-term monitoring is still needed to evaluate the effects of artificial oyster shell reefs on macrobenthic communities.

  7. Characteristics of turbulent kinetic energy dissipation rate and turbidity near the coast of East China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Yanwei; Xu, Huiping; Qin, Rufu; Xu, Changwei; Fan, Daidu

    2016-01-01

    The East China Sea (ECS) has a high suspended-sediment concentration because of the influence of the Changjiang River, indicated by high turbidity in the water. Considering the islands offthe coast and the complex topography, and the strong influence of tides and wind, the coast offthe ECS is a typical region with strong oceanic mixing processes. The changes in the dynamic processes near the bottom play an important role in the control of water turbidity. The turbulent kinetic energy dissipation rate ( ɛ ) is a parameter that shows the strength of ocean mixing. This is estimated based on a structure method using current velocity that is measured by a high-frequency Acoustic Doppler Current Profiler (ADCP) from a seafloor observatory in the ECS. The results indicate strong ocean mixing processes with a mean ɛ value of 5.7×10-5 W/kg and distinct tidal variations in the dissipation rate. Conversely, the variation of the water turbidity leads to changes in the water dynamical structure near the bottom. Comparing the dissipation rate with the turbidity near the bottom boundary layer, we find that the high turbidity mimics strong ocean mixing.

  8. Uncertainty analysis in future extreme flow projections in Jinhua River Basin, East China

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Tian, Y.; Booij, M.

    2013-12-01

    Uncertainties in extreme high flows originating from greenhouse gas emission scenarios, hydrological model structures and their parameters for the Jinhua River basin, East China are assessed. The baseline (1961-1990) and future (2011-2040) climates for A1B, A2 and B2 scenarios are downscaled from the General Circulation Model (GCM) using the PRECIS Regional Climate Model with a spatial resolution of 50km×50km. A distribution-based bias correction method is applied to bias correct the PRECIS -derived temperature and precipitation. The bias corrected precipitation and temperature are then used as inputs for three hydrological models (GR4J, HBV and Xinanjiang) to simulate extreme high flows in the study area. The parameter uncertainty is quantified by means of the Generalized Likelihood Uncertainty Estimation (GLUE) method for each hydrological model for three emission scenarios. It is found that compared with the baseline period, the extreme high flows tend to decrease under scenario A1B, A2 and B2. The largest uncertainty is observed in the HBV model and the GR4J model has the smallest uncertainty. It is found that the major source of uncertainty in this study is from parameters, followed by the uncertainties from the hydrological model structure and the emission scenarios have the smallest uncertainty contribution to extreme high flows in this study. 90% confidence intervals of 50-year extreme hight flows under scenarios A1B, A2 and B2

  9. Effects of climate change on hydrology and hydraulics of Qu River Basin, East China.

    NASA Astrophysics Data System (ADS)

    Gao, C.; Zhu, Q.; Zhao, Z.; Pan, S.; Xu, Y. P.

    2015-12-01

    The impacts of climate change on regional hydrological extreme events have attracted much attention in recent years. This paper aims to provide a general overview of changes on future runoffs and water levels in the Qu River Basin, upper reaches of Qiantang River, East China by combining future climate scenarios, hydrological model and 1D hydraulic model. The outputs of four GCMs BCC, BNU, CanESM and CSIRO under two scenarios RCP4.5 and RCP8.5 for 2021-2050 are chosen to represent future climate change projections. The LARS-WG statistical downscaling method is used to downscale the coarse GCM outputs and generate 50 years of synthetic precipitation and maximum and minimum temperatures to drive the GR4J hydrological model and the 1D hydraulic model for the baseline period 1971-2000 and the future period 2021-2050. Finally the POT (Peaks Over Threshold) method is applied to analyze the change of extreme events in the study area. The results show that design runoffs and water levels all indicate an increasing trend in the future period for Changshangang River, Jiangshangang River and Qu River at most cases, especially for small return periods(≤20), and for Qu River the increase becomes larger, which suggests that the risk of flooding will probably become greater and appropriate adaptation measures need to be taken.

  10. Characteristics of turbulent kinetic energy dissipation rate and turbidity near the coast of East China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Yanwei; Xu, Huiping; Qin, Rufu; Xu, Changwei; Fan, Daidu

    2016-09-01

    The East China Sea (ECS) has a high suspended-sediment concentration because of the influence of the Changjiang River, indicated by high turbidity in the water. Considering the islands offthe coast and the complex topography, and the strong influence of tides and wind, the coast offthe ECS is a typical region with strong oceanic mixing processes. The changes in the dynamic processes near the bottom play an important role in the control of water turbidity. The turbulent kinetic energy dissipation rate ( ɛ ) is a parameter that shows the strength of ocean mixing. This is estimated based on a structure method using current velocity that is measured by a high-frequency Acoustic Doppler Current Profiler (ADCP) from a seafloor observatory in the ECS. The results indicate strong ocean mixing processes with a mean ɛ value of 5.7×10-5 W/kg and distinct tidal variations in the dissipation rate. Conversely, the variation of the water turbidity leads to changes in the water dynamical structure near the bottom. Comparing the dissipation rate with the turbidity near the bottom boundary layer, we find that the high turbidity mimics strong ocean mixing.

  11. Regional sea level variability in the Bohai Sea, Yellow Sea, and East China Sea

    NASA Astrophysics Data System (ADS)

    Cheng, Yongcun; Plag, Hans-Peter; Hamlington, Benjamin D.; Xu, Qing; He, Yijun

    2015-12-01

    The regional sea level variability in the Bohai Sea (BS), Yellow Sea (YS) and East China Sea (ECS) is investigated based on tide gauge, satellite altimeter data and an independent oceanic general circulation model for the Earth Simulator (OFES) model outputs. It is found that atmospheric forcing significantly affects local sea level variability in the BS and YS and local sea level variability at the Southern ECS is highly correlated with along-shore currents. Particularly, the annual sea level fluctuations potentially change inundation risk and the frequency and magnitude of flooding in regions with high annual sea level. Hence, the cyclostationary empirical orthogonal function (CSEOF) analysis is carried out to investigate the variations of annual sea level cycle amplitude. Similar spatial distribution characteristics of annual sea level amplitude fluctuations are presented from satellite altimeter data and model outputs. The variability of annual sea level amplitude estimated from the satellite altimeter data agrees well with that from the tide gauge data, and positively (negatively) correlates with Southern Oscillation Index (Pacific Decadal Oscillation). The OFES model, however, underestimates the fluctuation of the annual cycle. After removing the annual signal, the low-passed (i.e., 13-month running mean) tide gauge data shows high correlations with SOI and PDO on time scales over 8 years in the BS and ECS.

  12. Determinants of Childhood Immunization Uptake among Socio-Economically Disadvantaged Migrants in East China

    PubMed Central

    Hu, Yu; Li, Qian; Chen, Enfu; Chen, Yaping; Qi, Xiaohua

    2013-01-01

    Objective: To determine the coverage of childhood immunization appropriate for age among socio-economically disadvantaged recent migrants living in East China and to identify the determinants of full immunization uptake among these migrant children. Methods: This is a cross-sectional survey of 1,426 migrant mothers with a child aged ≤24 months, who were interviewed with a pretested questionnaire. Various vaccines, migration history and some other social-demographic and income details were collected. Single-level logistic regression analyses were applied to identify the determinants of full immunization status. Results: Immunization coverage rates are lower among migrants and even lower among recent migrants. The likelihood of a child receiving full immunization rise with parents’ educational level and the frequency of mother’s utilization of health care. Higher household income also significantly increase the likelihood of full immunization, as dose post-natal visits by a health worker. Conclusions: Recent migrant status favours low immunization uptake, particularly in the vulnerability context of alienation and livelihood insecurity. Services must be delivered with a focus on recent migrants. Investments are needed in education, socio-economic development and secure livelihoods to improve and sustain equitable health care services. PMID:23839061

  13. Spatiotemporal variation characteristics and related affecting factors of dissolved carbohydrates in the East China Sea

    NASA Astrophysics Data System (ADS)

    He, Zhen; Wang, Qi; Yang, Gui-Peng; Gao, Xian-Chi; Wu, Guan-Wei

    2015-10-01

    Carbohydrates are the largest identified fraction of dissolved organic carbon and play an important role in biogeochemical cycling in the ocean. Seawater samples were collected from the East China Sea (ECS) during June and October 2012 to study the spatiotemporal distributions of total dissolved carbohydrates (TCHOs) constituents, including dissolved monosaccharides (MCHOs) and polysaccharides (PCHOs). The concentrations of TCHOs, MCHOs and PCHOs showed significant differences between summer and autumn 2012, and exhibited an evident diurnal variation, with high values occurring in the daytime. Phytoplankton biomass was identified as the primary factor responsible for seasonal and diurnal variations of dissolved carbohydrates in the ECS. The TCHOs, MCHOs and PCHOs distributions in the study area displayed similar distribution patterns, with high concentrations appearing in the coastal water. The influences of chlorophyll-a, salinity and nutrients on the distributions of these carbohydrates were examined. A carbohydrate enrichment in the near-bottom water was found at some stations, implying that there might be an important source of carbohydrate in the deep water or bottom sediment.

  14. Future potential evapotranspiration changes and contribution analysis in Zhejiang Province, East China

    NASA Astrophysics Data System (ADS)

    Xu, Yue-Ping; Pan, Suli; Fu, Guangtao; Tian, Ye; Zhang, Xujie

    2014-03-01

    Potential evapotranspiration is an important component of hydrological modeling. In this study, the objective is to project potential evapotranspiration in the future period 2011-2040 and understand their changes in Zhejiang Province, East China. The sensitivity of potential evapotranspiration to five climatic variables (solar radiation, daily minimum and maximum air temperature, relative humidity, and wind speed) is analyzed based on observation data from 1955-2008 using a global sensitivity analysis method, Sobol's method. The changes in potential evapotranspiration during the future period are generated using one regional climate model, Providing Regional Climates for Impacts Studies, with two global climate models, ECHAM5 and Hadley Centre Coupled Model version 3, and their causes are analyzed based on sensitivity analysis results. Global sensitivity analysis results reveal substantial spatial-temporal variations in the sensitivity of potential evapotranspiration to climatic variables and unignorable interactions among climatic variables. Rather similar spatial change patterns of annual mean potential evapotranspiration (PET) are generated for both general circulation models; however, seasonal or monthly changes are very different due to different spatial-temporal changes in climatic variables. Different contributory sources to potential evapotranspiration changes are identified at different months and stations; the PET changes in 2011-2040 are mainly due to three climatic variables including solar radiation, relative humidity, and daily minimum temperature.

  15. Amalgamation of East Eurasia Since Late Paleozoic: Constraints from the Apparent Polar Wander Paths of the Major China Blocks

    NASA Astrophysics Data System (ADS)

    Wu, L.; Kravchinsky, V. A.; Potter, D. K.

    2014-12-01

    It has been a longstanding challenge in the last few decades to quantitatively reconstruct the paleogeographic evolution of East Eurasia because of its great tectonic complexities. As the core region, the major China cratons including North China Block, South China Block and Tarim Block hold the key clues for the understanding of the amalgamation history, tectonic activities and biological affinity among the component blocks and terranes in East Eurasia. Compared with the major Gondwana and Laurentia plates, however, the apparent polar wander paths of China are not well constrained due to the outdated paleomagnetic database and relatively loose pole selection process. With the recruitment of the new high-fidelity poles published in the last decade, the rejection of the low quality data and the strict implementation of Voo's grading scheme, we build an updated paleomagnetic database for the three blocks from which three types of apparent polar wander paths (APWP) are computed. Version 1 running mean paths are constructed during the pole selection and compared with those from the previous publications. Version 2 running mean and spline paths with different sliding time windows are computed from the thoroughly examined poles to find the optimal paths with the steady trend, reasonable speed for the polar drift and plate rotation. The spline paths are recommended for the plate reconstructions, however, considering the poor data coverage during certain periods. Our new China APWPs, together with the latest European reference path, the geological, geochronological and biological evidence from the studied Asian plates allow us to reevaluate the paleogeographic and tectonic history of East Eurasia.

  16. Wet deposition of acidifying substances in different regions of China and the rest of East Asia: modeling with updated NAQPMS.

    PubMed

    Ge, B Z; Wang, Z F; Xu, X B; Wu, J B; Yu, X L; Li, J

    2014-04-01

    The traditional way to study Sources-Receptor Relationships (SRRs) of wet deposition is based on sensitivity simulation, which has weakness in dealing with the non-linear secondary formation pollutants (e.g. ozone and nitrate). An on-line source tracking method has been developed in the Nested Air Quality Prediction Modeling System (NAQPMS) coupled with cloud-process module for the first time. The new model can not only quantify the total volume of the sulfate, nitrate and ammonium wet deposition with more accuracy, but also trace these acidic species to their emitted precursors. Compared with previous studies, our result clearly shows: (1) East China and Central China, which are the two primary export regions, have 15-30% and 10% effect on wet deposition in other areas, respectively; (2) Besides the above two regions, the total acid deposition in Southwestern and Northeastern China have reached or exceeded the critical loads under their own environmental conditions. PMID:24418974

  17. The Impact of Sea Surface Temperature Front on Stratus-Sea Fog over the Yellow and East China Seas

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Li, M.; Liu, F.

    2013-12-01

    A stratus-sea fog event occurred on 3 June 2011 over the Yellow and East China Seas (as shown in figure) is investigated observationally and numerically. Emphasis is put on the influences of the sea surface temperature front (SSTF) and of the synoptic circulations on the transition of stratus to sea fog. The southerly winds from a synoptic high pressure transport water vapor from the East China Sea to the Yellow Sea, while the subsidence induced by the high contributes to the formation of the temperature inversion on the top of the stratus or stratocumulus that appears mainly over the warm flank of a sea surface temperature front in the East China Sea. Forced by the SSTF, there is a secondary cell within the atmospheric boundary layer (ABL), with a sinking branch on the cold flank and a rising one on the warm flank of the SSTF. This sinking branch, in phase with the synoptic subsidence, forces the stratus or stratocumulus to lower in the elevation getting close to the sea surface as these clouds move northward driven by the southerly winds. The cloud droplets can either reach to the sea surface directly or evaporate into water vapor that may condense again when coming close to the cold sea surface to form fog. In this later case, the stratus and fog may separate. The cooling effect of cold sea surface counteracts the adiabatic heating induced by the subsidence and thus helps the transition of stratus to sea fog in the southern Yellow Sea. By smoothing the SSTF in the numerical experiment, the secondary cell weakens and the sea fog patches shrink obviously over the cold flank of the SSTF though the synoptic subsidence and moist advection still exist. A conceptual model is suggested for the transition of stratus to sea fog in the Yellow and East China Seas, which is helpful for the forecast of sea fog over these areas. The satellite visible image of the stratus-fog event. The fog appears in the Yellow Sea and the stratocumulus in the East China Sea.

  18. Contribution of the phase transition of Pacific Decadal Oscillation to the late 1990s' shift in East China summer rainfall

    NASA Astrophysics Data System (ADS)

    zhu, yali

    2016-04-01

    Based on our previous study, the interdecadal changes in summer rainfall over East China in the late 1990s are further explored here. The increased local rising motion is implicated as the dominant factor of increased rainfall in the lower Huang-Huai River valley (LHR). Both the observation and numerical experiments using Community Atmosphere Model, version 4 suggest that the negative Pacific Decadal Oscillation (PDO) mode can result in rising anomalies and thus more rainfall in the LHR. The East Asian westerly jet stream (EAWJS) is suggested as a bridge to link the Pacific sea surface temperature anomalies and East Asian summer rainfall. Model results reveal that the negative PDO mode can lead to significant easterly anomalies over East Asia. As a result, the EAWJS is weakened and shifts poleward, which coincides with observed changes in EAWJS after the late 1990s. In addition, weakened and poleward shifted EAWJS can result in an anomalous ascending motion to its south (in the LHR) by modulating the jet-related secondary meridional-vertical circulation. Consequently, rainfall increased in the LHR after the late 1990s. Besides, the positive Atlantic Meridional Oscillation can only induce insignificant changes over East Asia and partly counteract the negative PDO effect there.

  19. Holocene temperature records from the East China sea mud area southwest of the Cheju Island reconstructed by the U{37/K'} and TEX86 paleothermometers

    NASA Astrophysics Data System (ADS)

    Xing, Lei; Jiang, Yiqing; Yuan, Zineng; Zhang, Hailong; Li, Li; Zhou, Liping; Zhao, Meixun

    2013-12-01

    As an important marginal sea under the influences of both the Changjiang River and the Kuroshio, the East China Sea (ECS) environment is sensitive to both continental and oceanic forcing. Paleoenvironmental records are essential for understanding the long-term environmental evolution of the ECS and adjacent areas. However, paleo-temperature records from the ECS shelf are currently very limited. In this study, the U{37/K'} and TEX86 paleothermometers were used to reconstruct surface and subsurface temperature changes of the mud area southwest of the Cheju Island (Site F10B) in the ECS during the Holocene. The results indicate that temperature changes of F10B during the early Holocene (11.6-6.2 kyr) are associated with global climate change. During the period of 6.2-2.5 kyr, the similar variability trends of smoothing average of ΔT (the difference between surface and subsurface temperature) of Site F10B and the strength of the Kuroshio suggest that the Kuroshio influence on the site started around 6.2 kyr when the Kuroshio entered the Yellow Sea and continued to 2.5 kyr. During the late Holocene (2.5-1.45 kyr), apparent decreases of U{37/K'} sea surface temperature (SST) and ΔT imply that the direct influence of the Kuroshio was reduced while cold eddy induced by the Kuroshio gradually controlled hydrological conditions of this region around 2.5 kyr.

  20. Palaeoclimatic implications of aeolian sediments on the Miaodao Islands, Bohai Sea, East China, based on OSL dating and proxies

    NASA Astrophysics Data System (ADS)

    Xu, Shujian; Ding, Xinchao; Yu, Lupeng; Ni, Zhichao

    2015-12-01

    The loess-paleosol sequences in Shandong Province, East China, is an important aeolian archive, which can provide information for aeolian activity, palaeoclimatic change and sea level change in eastern coast of China since the last interglacial period. However, for so long, most of the studies about loess have been focused on the Chinese Loess Plateau, remaining many questions and disputes about the loess in East China. The Xianjingyuan (XJY) section on the TIA, Bohai Sea, is a representative aeolian section for islands off the eastern coast of China. In this study, optically stimulated luminescence (OSL) dating, particle size and magnetic susceptibility were applied to date and analysis the loess-paleosol sequences in this section. The results show that: (1) The OSL ages at the depths of 0.8 m, 2.5 m, and 3.9 m are 12.6 ± 1.0 ka, 19.2 ± 1.1 ka and 56.9 ± 2.6 ka, respectively, and the loess started to accumulate at ca. 86.5 ka according to the depositional rates (2) The loess accumulated mainly during the Marine Isotope Stage (MIS) 2, i.e., Last glacial maximum and deglaciation, MIS4 and MIS3b with higher depositional rate, coarser grain size, and higher magnetic susceptibility; while paleosol mainly developed during MIS3a, MIS3c and MIS5 with lower depositional rate, finer grain size and lower magnetic susceptibility. (3) The palaeoclimatic changes and aeolian sediments evolution were mainly controlled by the changes of East Asian summer monsoon and sea levels.

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

    NASA Astrophysics Data System (ADS)

    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

  2. Source attribution and process analysis for atmospheric mercury in East China simulated by CMAQ-Hg

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Wang, T.; Bieser, J.; Matthias, V.

    2015-04-01

    The contribution from different emission sources and atmospheric processes to gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), particulate bound mercury (PBM) and mercury deposition in East China were quantified using the Community Multi-scale Air Quality (CMAQ-Hg) modeling system run with nested grid resolution of 27 km. Natural source (NAT) and six categories of anthropogenic mercury sources (ANTH) including cement production (CEM), domestic life (DOM), industrial boilers (IND), metal production (MET), coal-fired power plants (PP) and traffic (TRA) were considered for source apportionment. NAT was responsible for 36.6% of annual averaged GEM concentration which was regard as the most important source for GEM in spite of obvious seasonal variation. Among ANTH, the influence of MET and PP on GEM were most evident especially in winter. ANTH dominated the variations of GOM and PBM concentration with a contribution of 86.7 and 79.1% respectively. Among ANTH, IND was the largest contributor for GOM (57.5%) and PBM (34.4%) so that most mercury deposition came from IND. The effect of mercury emitted from out of China was indicated by > 30% contribution to GEM concentration and wet deposition. The contribution from nine processes consisting of emissions (EMIS), gas-phase chemical production/loss (CHEM), horizontal advection (HADV), vertical advection (ZADV), horizontal advection (HDIF), vertical diffusion (VDIF), dry deposition (DDEP), cloud processes (CLDS) and aerosol processes (AERO) were calculated for processes analysis with their comparison in urban and non-urban regions of Yangtze River Delta (YRD). EMIS and VDIF affected surface GEM and PBM concentration most and tended to compensate each other all the time in both urban and non-urban areas. However, DDEP was the most important removal process for GOM with 7.3 and 2.9 ng m-3 reduced in the surface of urban and non-urban areas respectively in a whole day. Diurnal profile variation of processes

  3. Tidal cooling effect on SST and its influence on typhoon simulation over the East China Sea

    NASA Astrophysics Data System (ADS)

    Zong, H.; WU, H.

    2013-12-01

    Each summer, tropical cyclones (including typhoon) frequently travel across the East China Sea (ECS), beating the surrounding regions with massive damages. Therefore, it is very important to predict their intensities and tracks by using numerical models, so as to advise people to evacuate from the possible affected area. Unfortunately, forecasting the typhoon is still a big challenge since a couple of reasons. To numerically predict the typhoons, an atmosphere-ocean coupling model is often required. Researchers have done many efforts on the atmosphere part to improve the accuracy, while the ocean part was often treated simply. For example, many operational forecasting models simply set the SST as climatological values. As the ocean motion is energetic and the sea conditions vary significantly with time, this brief setting could result in some error. Some other models include an ocean model that considering the air-sea exchange of heat and momentum, as well as large-scale ocean motions like circulation. However, in the shallow coastal oceans like the ECS, tidal forcing also plays an important role that modulate the vertical exchange to adjust the SST. So far no atmosphere-ocean coupling model in this region consider the tide. In this study, we have found that 1) Accuracy of SST is essential to correctly predict the intensity and track of typhoons; 2) It is important to include the tide to correctly simulate the SST in the shallow oceans like the ECS. We setup an Advanced Research Hurricane WRF (WRF-AHW) model in the ECS and simulated typhoon Muifa (No. 201109). The 6-hourly data of the NCEP FNL Global Analyses was used as the initial and lateral boundary conditions in the model. Firstly, We run the model only with NCEP FNL Global Analyses data. The simulated track was very similar to China forecasted one, which was more than 200 kilometers far from the Joint Typhoon Warning Center (JTWC) provided typhoon location at 0:00 am, 6 August, 2011. Then, We run the model

  4. Distribution and ecological risk assessment of polycyclic aromatic hydrocarbons in water, suspended particulate matter and sediment from Daliao River estuary and the adjacent area, China.

    PubMed

    Zheng, Binghui; Wang, Liping; Lei, Kun; Nan, Bingxu

    2016-04-01

    Polycyclic aromatic hydrocarbons (PAHs) contamination was investigated in concurrently sampled surface water, suspended particulate matter (SPM) and sediment of Daliao River estuary and the adjacent area, China. The total concentrations of PAHs ranged from 71.12 to 4255.43 ng/L in water, from 1969.95 to 11612.21 ng/L in SPM, and from 374.84 to 11588.85 ng/g dry weight (dw) in sediment. Although the 2-3 ring PAHs were main PAH congeners in water and SPM, the 4-6 ring PAHs were also detected and their distribution was site-specific, indicating a very recent PAHs input around the area since they were hydrophobic. The PAHs pollution was identified as mixed combustion and petroleum sources. Based on species sensitivity distribution (SSD), the ecological risk in SPM from 82% stations was found to be higher obviously than that in water. The risk in water was basically ranked as medium, while the risk in SPM was ranked as high. Analysis with sediment quality guidelines (SQGs) indicated that negative eco-risk occasionally occurred in about 50% stations, while negative eco-risk frequently occurred in about 3% stations only caused by Phenanthrene(Phe) and Dibenzo(a,h)anthracene(DBA). Here freshwater acute effects data together with saltwater data were used for SSD model. And this method could quickly give the rational risk information, and achieved our objective that compared the spatial difference of risk levels among three compartments. The results confirmed that the use of freshwater acute effects data from the ECOTOX database together with saltwater effects data is acceptable for risk assessment purposes in estuary. PMID:26855211

  5. Lithospheric structure beneath the central and western North China Craton and the adjacent Qilian orogenic belt from Rayleigh wave dispersion analysis

    NASA Astrophysics Data System (ADS)

    Wei, Zigen; Chen, Ling; Jiang, Mingming; Ling, Yuan

    2015-04-01

    We used surface wave tomography to image the lithospheric S-wave velocity structure along a linear seismic array across the central and western North China Craton (NCC) and the adjacent Qilian orogenic belt (QB). Using waveform data from 8 earthquakes collected at 60 broadband stations, Rayleigh wave phase velocities were measured at periods of 20-120 s and subsequently inverted for reliable S-wave velocities from 60 to 200 km depth. Distinct lithospheric structures and marked lateral variations were revealed beneath the study region, correlating well with regional geological and tectonic features. The average S-wave velocity from 60 to 200 km depth beneath the array is ~ 4.45 km/s, ~ 1% lower than that in model AK135. High velocities of > 4.45 km/s are most pronounced beneath the stable Ordos Block (western NCC). However, the depth to which the observed high velocity body extends varies significantly laterally. It is deepest (~ 200 km) under eastern Ordos, and becomes shallower on both sides along the array. The maximum depth of the high velocity body gradually shallows westward and reaches ~ 110 km near the western edge of Ordos. This depth variation suggests a coexistence of both preserved and modified lithosphere in Ordos. The depth of high velocities decreases rapidly eastward by > 80 km over a lateral distance of < 200 km across the North-south Gravity Lineament (NSGL) in central NCC, supporting the speculation that the NSGL represents a major continental-lithospheric boundary. A stratified lithospheric mantle was revealed beneath QB, the ~ 2% low velocity anomaly above 100 km depth may be attributed partially to a higher temperature here. Our study revealed rapid lithospheric structural variations beneath NSGL and the boundary zone between Ordos and QB, probably reflecting long-lived, inherited weaknesses in lithosphere that may have been enhanced by episodic tectonic reactivations during the evolution of NCC.

  6. [Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

    PubMed

    Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

    2014-09-01

    The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb < Cu < Cd < Cr < As < Zn. The heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd < Cu < As < Cr

  7. Estimating dissolved organic carbon inventories in the East China Sea using remote-sensing data

    NASA Astrophysics Data System (ADS)

    Liu, Qiong; Pan, Delu; Bai, Yan; Wu, Kai; Chen, Chen-Tung Authur; Liu, Zhiliang; Zhang, Lin

    2014-10-01

    The coastal ocean is characterized by a high dissolved organic carbon (DOC) concentration due to large terrestrial inputs and high primary production. Monitoring the dynamic variation of DOC inventories in coastal oceans provide more information on carbon flux, but is very challenging in practice. We propose a method of estimating DOC inventories in the East China Sea (ECS) by integrating the surface DOC distribution with a vertical model of the DOC profile via satellite data. Surface DOC concentration was retrieved from satellite-derived chromophoric dissolved organic matter and chlorophyll concentration. Two vertical DOC profile models (uniform model and stratified model) were established based on water-density profiles, and the usage of these two models was corresponded to water mass classification determined by a water mass index. The average bias of the satellite-derived DOC inventory, in the euphotic layer was 23.8% in spring, 24.8% in autumn and 14.7% in winter, and in the water column was 15.6% in spring, 12.3% in autumn, and 10.2% in winter. The total satellite-derived DOC inventory integrated in the water column was about 31.84, 31.96, 28.59, and 31.18 Tg in four seasons in the ECS (5.84 × 105 km2). Sensitivity analysis indicated that the remote-sensing method of estimating DOC inventory is stable and reliable. The available long-term and large-scale satellite-derived DOC inventories in marginal sea would provide us basic information on carbon cycle, and the difference between the seasonal DOC inventories would help to understand the DOC export and relative biogeochemical processes in the ECS.

  8. Sources, behaviors and degradation of dissolved organic matter in the East China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Yang, Gui-Peng; Liu, Li; Zhang, Peng-Yan; Leng, Wei-Song

    2016-03-01

    Concentrations of dissolved organic carbon (DOC), dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON) and its major compound classes-total hydrolysable amino acids (THAA) were measured at 4 cross-shelf transects of the East China Sea in July 2011. Surface concentrations of DOC, DIN, DON and THAA at the nearshore stations were mostly in excess of those found at the offshore sites, indicating either substantial autochthonous production or allochthonous inputs from the Changjiang River. The vertical distributions of DOC, DON and THAA showed similar trends with higher values in the surface layer, whereas the elevated concentrations of DIN were observed in the bottom layer. Major constituents of THAA presented in the study area were glycine, serine, alanine, glutamic acid, aspartic acid and valine. The mole percentages of neutral amino acids increased from surface water to bottom water, whereas acidic and hydroxy amino acids decreased with the water depth. Concentrations of DOC and THAA were negatively correlated to the ΔDIN values (the difference between the real concentration and theoretical concentration), respectively, indicating the coupling relation between dissolved organic matter (DOM) remineralization and nutrient regeneration in the water column. The C/N ratios in the water column exhibited different characteristics with elevated values appearing in the surface and bottom layers. Box and whisker plots showed that both degradation index (DI) values and THAA yields displayed a decreasing trend from the surface layer to the bottom layer, implying increasing degradation with the water depth. Our data revealed that glycine and alanine increased in relative abundance with decreasing DI, while tyrosine, valine, phenylalanine and isoleucine increased with increasing DI.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Impact of two typhoons on the marine environment in the Yellow Sea and East China Sea

    NASA Astrophysics Data System (ADS)

    Fu, Dongyang; Luan, Hong; Pan, Delu; Zhang, Ying; Wang, Li'an; Liu, Dazhao; Ding, Youzhuan; Li, Xue

    2016-07-01

    This study investigated the effects of two typhoons (Nari and Wipha) on sea surface temperature (SST) and chlorophyll- a (Chl- a) concentration. Typhoons Nari and Wipha passed through the Yellow Sea on September 13, 2007 and the East China Sea (ECS) on September 16, 2007, respectively. The SST and Chl- a data were obtained from the Aqua/Terra MODIS and NOAA18, respectively, and the temperature and salinity in the southeast of the study area were observed in situ from Argo. The average SST within the study area dropped from 26.33°C on September 10 to a minimum of 22.79°C on September 16. Without the usual phenomenon of `right bias', the most striking response of SST was in the middle of the typhoons' tracks, near to coastal waters. Strong cooling of the upper layers of the water column was probably due to increased vertical mixing, discharge from the Changjiang River estuary, and heavy rainfall. During the typhoons, average Chl- a increased by 11.54% within the study area and by 21.69% in the offshore area near to the southeast ECS. From September 1 to 13, average Chl- a was only 0.10 mg/m3 in the offshore waters but it reached a peak of >0.17 mg/m3 on September 18. This large increase in Chl- a concentration in offshore waters might have been triggered by strong vertical mixing, upwelling induced by strong typhoons, and sedimentation and nutrient influx following heavy rainfall.

  11. Impacts of South East Biomass Burning on local air quality in South China Sea

    NASA Astrophysics Data System (ADS)

    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.

  12. Interaction between neritic and warm water tintinnids in surface waters of East China Sea

    NASA Astrophysics Data System (ADS)

    Li, H.; Zhao, Y.; Chen, X.; Zhang, W.; Xu, J.; Li, J.; Xiao, T.

    2016-02-01

    Tintinnid are important microzooplankton in marine pelagic habitats. In the temperate shelf area, tintinnid could be divided into neritic, warm-water and cosmopolitan biogeographical types. Up to now, there is no understanding in the interaction between neritic and warm-water genera in shelf waters. Here we studied the interaction of neritic and warm-water tintinnids in East China Sea during three cruises (May, August and October) in 2013. Our hypothesis were (1) that the factors influencing the expansion of neritic and warm-water genera were different and (2) that different genera within each biogeographical type had different adaptation abilities in the process of expansion. Totally 94 species in 36 genera were identified in three cruises. According to the distribution of each tintinnid genus in the three cruises, tintinnid genera were divided into three biogeographical types: neritic, warm-water and cosmopolitan. The data confirmed our hypothesis. The factor influencing neritic tintinnid species richness and abundance was water depth while salinity was the factor influencing species richness and abundance of warm-water tintinnids. According to the difference in their expansion ability, neritic and warm-water genera could be divided into core genera and pioneer genera. In the case of neritic genera, core and pioneer neritic genera stayed together in May and August while pioneer neritic genera expanded a lot out to the oceanic water in October. In the case of warm-water genera, the pioneer genera always expanded a lot out to the coast in all three cruises. In May and August, the pioneers of neritic and warm-water genera did not meet. However, in October, the cores of neritic and warm-water genera collided. Our data clearly showed that the core and pioneer of both neritic and warm-water genera interacted in different modes in different months. Whether the cores of neritic and warm-water genera will further mixed in winter is an open question.

  13. Performance evaluation of operational atmospheric correction algorithms over the East China Seas

    NASA Astrophysics Data System (ADS)

    He, Shuangyan; He, Mingxia; Fischer, Jürgen

    2016-04-01

    To acquire high-quality operational data products for Chinese in-orbit and scheduled ocean color sensors, the performances of two operational atmospheric correction (AC) algorithms (ESA MEGS 7.4.1 and NASA SeaDAS 6.1) were evaluated over the East China Seas (ECS) using MERIS data. The spectral remote sensing reflectance R rs(λ), aerosol optical thickness (AOT), and Ångström exponent (α) retrieved using the two algorithms were validated using in situ measurements obtained between May 2002 and October 2009. Match-ups of R rs, AOT, and α between the in situ and MERIS data were obtained through strict exclusion criteria. Statistical analysis of R rs(λ) showed a mean percentage difference (MPD) of 9%-13% in the 490-560 nm spectral range, and significant overestimation was observed at 413 nm (MPD>72%). The AOTs were overestimated (MPD>32%), and although the ESA algorithm outperformed the NASA algorithm in the blue-green bands, the situation was reversed in the red-near-infrared bands. The value of α was obviously underestimated by the ESA algorithm (MPD=41%) but not by the NASA algorithm (MPD=35%). To clarify why the NASA algorithm performed better in the retrieval of α, scatter plots of the α single scattering albedo (SSA) density were prepared. These α-SSA density scatter plots showed that the applicability of the aerosol models used by the NASA algorithm over the ECS is better than that used by the ESA algorithm, although neither aerosol model is suitable for the ECS region. The results of this study provide a reference to both data users and data agencies regarding the use of operational data products and the investigation into the improvement of current AC schemes over the ECS.

  14. Phenotypic Characters and Molecular Epidemiology of Campylobacter Jejuni in East China.

    PubMed

    Zeng, Dexin; Zhang, Xiaoping; Xue, Feng; Wang, Yanhong; Jiang, Luyan; Jiang, Yuan

    2016-01-01

    In this study, we investigated the distribution, phenotypic and molecular typing characters of Campylobacter jejuni in domestic fowl, and livestock populations in East China, to provide some reference for researches on its molecular epidemiology. A total of 1250 samples were collected from different animal sources, and C. jejuni strains were then isolated and tested for antibiotic sensitivity. Antibiotics-resistance gene and pathogenic genes were detected by polymerase chain reaction. Phylogenic analysis on the C. jejuni strains was performed by multilocus sequence typing (MLST) method. The results showed that 108 out of the 1250 samples (mean 8.64%) were C. jejuni positive. These 108 C. jejuni strains were highly sensitive to antibiotics such as chloramphenicol, amoxicillin, amikacin, cefotaxime, and azithromycin, whereas they were highly resistant to antibiotics such as cefoperazone, cotrimoxazole, cefamandole, sulfamethoxazole, and cefradine. Pathogenicity related gene identification indicated that the mean carrying rate of adhesion related gene cadF and racR, flagellin gene flaA, toxin regulating gene cdtA, cdtB, cdtC, wlaN and virB11, heat shock proteins and transferring proteins related genes dnaJ and ceuE, CiaB and pldA were 92.45%, 38.69%, 73.58%, 71.70%, 52.83%, 96.23%, 12.26%, 1.89%, 0.94%, 65.09%, 39.62% and 9.43%, respectively. A total of 58.82% of these strains contained more than 6 pathogenicity-related genes. MLST typed 58 ST types from the 108 isolated C. jejuni strains, including 24 new types, and ST-21 was the major type, accounting for 39.3% of the total strains. PMID:26565657

  15. Trichoderma Biodiversity of Agricultural Fields in East China Reveals a Gradient Distribution of Species

    PubMed Central

    Chen, Jing; Mao, Li-Juan; Feng, Xiao-Xiao; Zhang, Chu-Long; Lin, Fu-Cheng

    2016-01-01

    We surveyed the Trichoderma (Hypocreales, Ascomycota) biodiversity in agricultural fields in four major agricultural provinces of East China. Trichoderma strains were identified based on molecular approaches and morphological characteristics. In three sampled seasons (spring, summer and autumn), 2078 strains were isolated and identified to 17 known species: T. harzianum (429 isolates), T. asperellum (425), T. hamatum (397), T. virens (340), T. koningiopsis (248), T. brevicompactum (73), T. atroviride (73), T. fertile (26), T. longibrachiatum (22), T. pleuroticola (16), T. erinaceum (16), T. oblongisporum (2), T. polysporum (2), T. spirale (2), T. capillare (2), T. velutinum (2), and T. saturnisporum (1). T. harzianum, T. asperellum, T. hamatum, and T. virens were identified as the dominant species with dominance (Y) values of 0.057, 0.052, 0.048, and 0.039, respectively. The species amount, isolate numbers and the dominant species of Trichoderma varied between provinces. Zhejiang Province has shown the highest diversity, which was reflected in the highest species amount (14) and the highest Shannon–Wiener diversity index of Trichoderma haplotypes (1.46). We observed that relative frequencies of T. hamatum and T. koningiopsis under rice soil were higher than those under wheat and maize soil, indicating the preference of Trichoderma to different crops. Remarkable seasonal variation was shown, with summer exhibiting the highest biodiversity of the studied seasons. These results show that Trichoderma biodiversity in agricultural fields varies by region, crop, and season. Zhejiang Province (the southernmost province in the investigated area) had more T. hamatum than Shandong Province (the northernmost province), not only in isolate amounts but also in haplotype amounts. Furthermore, at haplotype level, only T. hamatum showed a gradient distribution from south to north in correspondence analysis among the four dominant species. The above results would contribute to the

  16. A new approach to discriminate dinoflagellate from diatom blooms from space in the East China Sea

    NASA Astrophysics Data System (ADS)

    Shang, Shaoling; Wu, Jingyu; Huang, Bangqin; Lin, Gong; Lee, Zhongping; Liu, James; Shang, Shaoping

    2014-07-01

    Dinoflagellate and diatom blooms often occur in the East China Sea (ECS) during spring and summer. Some of the dinoflagellate blooms are toxic, resulting in widespread economic damage. In order to mitigate the negative impacts, remote-sensing methods that can effectively and accurately discriminate between bloom types are demanded for early warning and continuous monitoring of bloom events at large scales. An in situ bio-optical data set collected from diatom and dinoflagellate blooming waters indicates that the two types of blooms exhibited distinctive differences in the shapes and magnitudes of remote-sensing reflectance (Rrs). The ratio of in situ measured Rrs spectral slopes at two spectral ranges (443-488 and 531-555 nm, bands available with the moderate resolution imaging spectrometer (MODIS) sensor), abbreviated as BI (representing bloom index), was found effective in differentiating dinoflagellates from diatoms. Reflectance model simulations, which were carried out using in situ and algal culture data as input, provided consistent results. A classification approach for separating dinoflagellate from diatom blooms in the ECS was then developed: When fluorescence line height (FLH) is doubled over the background level and total absorption coefficient at 443 nm ≥ 0.5 m-1, if 0.0 < BI ≤ 0.3, it suggests a dinoflagellate bloom; if 0.3 < BI ≤ 1.0, it suggests a diatom bloom. Finally, the approach was applied to MODIS measurements over the ECS, and a series of diatom and dinoflagellate bloom events during April-June 2005 and 2011 were successfully identified, suggesting that the proposed approach is generally valid for the ECS.

  17. Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands, East China Sea

    NASA Astrophysics Data System (ADS)

    Jiang, Tao; Xu, Yixiao; Li, Yang; Qi, Yuzao; Jiang, Tianjiu; Wu, Feng; Zhang, Fan

    2014-01-01

    A 12-month program of monitoring potentially toxic microalgae (that produce lipophilic shellfish toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identified, and D. caudata was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×102 cells/L in surface water and 1.25×102 cells/L in bottom water (<10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid (OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit (20 μg OA eq./100 g meat). Ten out of fifteen wild samples (66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat (more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities (80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.

  18. Chlorinated and brominated organic pollutants in shellfish from the Yellow Sea and East China Sea.

    PubMed

    Yin, Ge; Asplund, Lillemor; Qiu, Yanling; Zhou, Yihui; Wang, Hua; Yao, Zongli; Jiang, Jianbin; Bergman, Åke

    2015-02-01

    The global contamination with persistent organic pollutants (POPs), or compounds with similar characteristics, is well known. Still there are data gaps for POP concentrations from many areas in the world. The aim of the present study is to assess several legacies POPs and also hexabromocyclododecane (HBCDD) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in shellfish from three locations in the Yellow Sea and East China Sea. The sources of the contaminants are discussed. Pooled samples were treated by liquid-liquid extraction and acid and column cleanup prior to analysis by gas chromatogram equipped with electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). The by far most abundant environmental contaminant originates from dichlorodiphenyltrichloroethane (DDT), independent of species analyzed or sampling site. The results indicate ongoing or at least recent discharges of DDT. The second highest concentrations were reported for HBCDD (21-40 ng/g fat) in the shellfish, independent of sampling sites. The two natural products, 6-MeO-BDE-47 and 2'-MeO-BDE-68, were also present in the shellfish (1.3-22 and 1-14 ng/g fat, respectively). The polychlorinated biphenyl (PCB) congener CB-153 (0.8-6.5 ng/g fat), hexachlorobenzene (HCB) (1.1-3.6 ng/g fat), and β-hexachlorocyclohexane (β-HCH) (2.3-4.9 ng/g fat) were all higher than the concentrations of other HCH isomers, β-endosulfan, PBDE congeners, and mirex. Apart from the DDTs and HBCDDs, it is evident that the pollution of shellfish was similar to, or lower than, the contamination of shellfish in other parts of the world. PMID:24958534

  19. [Litter decomposition and its main affecting factors in tidal marshes of Minjiang River Estuary, East China].

    PubMed

    Zhang, Lin-Hai; Zeng, Cong-Sheng; Zhang, Wen-Juan; Wang, Tian-E; Tong, Chuan

    2012-09-01

    By using litterbag method, this paper studied the decomposition of the leaf- and flower litters of two emergent macrophytes, native species Phragmites australis and invasive species Spartina alterniflora, and related affecting factors in the Minjiang River estuary of East China. In the decomposition process of the litters, the decay of standing litter (0-90 days) was an important period, and the loss rate of the flower- and leaf litters dry mass of P. australis and S. alterniflora was 15.0 +/- 3.5% and 13.3 +/- 1.1%, and 31.9 +/- 1.1% and 20.8 +/- 1.4%, respectively. During lodging decay period (91-210 days), the loss rate of the flower- and leaf litters dry mass of P. australis and S. alterniflora was 69.5 +/- 0.6% and 71.5 +/- 2.5%, and 76.8 +/- 1.9% and 67.5 +/- 2.1%, respectively. In standing decay period, the decomposition rate of the two plants litters was positively correlated with the litters C/N but negatively correlated to the litters N/P, and the litters P was an important factor limiting the litters decay. In lodging decay period, the effects of the litters C/N, C/P, and N/P decreased, while the environment factors (climate, soil moisture, soil acidity and salinity, and sediment properties) acted more important roles. The differences in the factors affecting the decay of the litters in different decomposition periods were mainly related to the micro-environment and tidal process for the two plant communities. PMID:23285995

  20. Occurrence and distribution of organochlorine pesticides (HCH and DDT) in sediments collected from East China Sea.

    PubMed

    Yang, Rui-qiang; Jiang, Gui-bin; Zhou, Qun-fang; Yuan, Chun-gang; Shi, Jian-bo

    2005-08-01

    Sediments used in this study were collected from different depths of eight sites in East China Sea in November 2002. The levels and distribution patterns of the selected organochlorine pesticides (OCPs=p,p'-DDT, o,p'-DDT, p,p'-DDE, p,p'-DDD, alpha-, beta-, gamma- and delta-HCH) in samples were investigated by the technique of sonication extraction followed by the analysis of gas chromatography (GC) coupled with a micro-electron capture detector (muECD). The concentrations of SigmaHCH and SigmaDDT in the surface sediments were in the range of <0.05-1.45 ng/g (mean 0.76 ng/g), <0.06-6.04 ng/g (mean 3.05 ng/g) based on dry weight (dw), respectively. In the vertical distributions, the SigmaHCH and SigmaDDT were in the range of <0.05-2.52 ng/g, <0.06-10.94 ng/g dw, respectively. Residues of OCPs varied significantly with different sampling sites. SigmaDDT in the surface sediments was correlated well with total organic carbon (TOC) content (r2=0.71), while SigmaHCH showed no obvious correlation. The distribution showed that the sediments from the vicinity estuary or near shore had higher TOC contents, and higher OCPs concentrations. The contamination record indicated an extensive use of OCPs in the catchments from Yangtze River in the past might greatly affect the OCP residues. PMID:16024080

  1. Effects of aerosol-radiation interaction on precipitation during biomass-burning season in East China

    NASA Astrophysics Data System (ADS)

    Huang, Xin; Ding, Aijun; Liu, Lixia; Liu, Qiang; Ding, Ke; Niu, Xiaorui; Nie, Wei; Xu, Zheng; Chi, Xuguang; Wang, Minghuai; Sun, Jianning; Guo, Weidong; Fu, Congbin

    2016-08-01

    Biomass burning is a main source for primary carbonaceous particles in the atmosphere and acts as a crucial factor that alters Earth's energy budget and balance. It is also an important factor influencing air quality, regional climate and sustainability in the domain of Pan-Eurasian Experiment (PEEX). During the exceptionally intense agricultural fire season in mid-June 2012, accompanied by rapidly deteriorating air quality, a series of meteorological anomalies was observed, including a large decline in near-surface air temperature, spatial shifts and changes in precipitation in Jiangsu province of East China. To explore the underlying processes that link air pollution to weather modification, we conducted a numerical study with parallel simulations using the fully coupled meteorology-chemistry model WRF-Chem with a high-resolution emission inventory for agricultural fires. Evaluation of the modeling results with available ground-based measurements and satellite retrievals showed that this model was able to reproduce the magnitude and spatial variations of fire-induced air pollution. During the biomass-burning event in mid-June 2012, intensive emission of absorbing aerosols trapped a considerable part of solar radiation in the atmosphere and reduced incident radiation reaching the surface on a regional scale, followed by lowered surface sensible and latent heat fluxes. The perturbed energy balance and re-allocation gave rise to substantial adjustments in vertical temperature stratification, namely surface cooling and upper-air heating. Furthermore, an intimate link between temperature profile and small-scale processes like turbulent mixing and entrainment led to distinct changes in precipitation. On the one hand, by stabilizing the atmosphere below and reducing the surface flux, black carbon-laden plumes tended to dissipate daytime cloud and suppress the convective precipitation over Nanjing. On the other hand, heating aloft increased upper-level convective

  2. Quaternary seismic stratigraphy and paleoenvironments on the continental shelf of the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Zhen-Xia; Berne, Serge; Saito, Yoshiki; Lericolais, G.; Marsset, T.

    2000-08-01

    Paleoenvironments and stratigraphy have been interpreted from 4380 km of seismic profiling collected during a geological and geophysical cruise on the continental shelf of the East China Sea (ECS) undertaken in 1996. The geophysical data are correlated with a borehole situated on the outer shelf obtained by Shanghai Marine Geology Bureau, indicating that six seismic units have been preserved since oxygen-isotope stage 6, including four regressive-transgressive cycles. Seismic units U2, U3+U4+U5, U6, and U7 are interpreted to correspond respectively to oxygen-isotope stages 1, 3, 5, and 6, implying that sediment partitioning and sequence architecture in the ECS have been controlled by glacio-eustasy and global climate changes. Alternating continental and marine strata corresponding to glaciation and interglaciation are well preserved on the outer shelf of the ECS. Most of the cold environment strata, which formed on the outer shelf during oxygen-isotope stages 2 and 4, are too thin to be recognized on SIG 600J because of resolution, but corresponding erosion surfaces exist. Seismic unit U7 is widespread over the shelf, extending to the continental edge and showing little variation in thickness, as the regression was pronounced and lasted a long time. Thus, U7 can be used as a marker layer for correlation of Quaternary strata on the shelf of the ECS. Post-glacial transgression is obvious in the ECS. Marine strata with varied thickness were developed in the shallow sea of the inner shelf, thinning toward the outer shelf. The continental shelf of the ECS has been influenced by Pacific tide-wave systems for a long time, forming tidal sand-ridge sequences, developed during transgressions, corresponding to oxygen-isotope stages 7 (or 9), 5, 3 and 1.

  3. Internal architecture and mobility of tidal sand ridges in the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Zhenxia; Berné, Serge; Saito, Yoshiki; Yu, Hua; Trentesaux, Alain; Uehara, Katsuto; Yin, Ping; Paul Liu, J.; Li, Chaoxing; Hu, Guanghai; Wang, Xiangqin

    2007-07-01

    On the basis of bathymetric and seismic data and data from piston cores collected by the Chinese-French marine geology and geophysics investigation of 1996, we discuss the internal architecture and mobility of tidal sand ridges in the East China Sea (ECS). We characterized the sand ridges on the middle to outer shelf of the ECS as tide-dominated sand ridges with southwest dipping beds, indicating that the regional net sediment transport is toward the southwest. As the sand ridges gradually migrate toward the southwest, new sand ridges are continually replacing old ones, and several generations of sand ridges have developed in the study area. High-resolution seismic data, acoustic Doppler current profiler data, and two 14C-dated piston cores, DGKS9614 and DGKS9612—from a sand ridge swale and crest, respectively—show that these sand ridges, which are at water depths of 90-100 m, have been migrating for the last ca. 2-3 kyr at least, though these ridges have previously been interpreted as moribund or relict. Sequence stratigraphic interpretation of seismic profiles and core data show that tidal ridges in the ECS evolved from muddier sand ridges formed during the last transgression to sandier shelf sand ridges in response to the shoreline retreat, which resulted in a decrease of riverine muddy sediments and recycling of sandy materials by tidal currents. Most active sand ridge formation occurred during the last transgression, but the present sand ridges on the middle to outer shelf are still being influenced by the modern hydrodynamics. Therefore, these sand ridges on the ECS shelf should be referred to as "quasi-active sand ridges" rather than as moribund or relict sand ridges.

  4. The East Asian monsoon during MIS 2 expressed in a speleothem δ 18O record from Jintanwan Cave, Hunan, China

    NASA Astrophysics Data System (ADS)

    Cosford, Jason; Qing, Hairuo; Lin, Yin; Eglington, Bruce; Mattey, Dave; Chen, Yue Gau; Zhang, Meiliang; Cheng, Hai

    2010-05-01

    Stalagmite J1 from Jintanwan Cave, Hunan, China, provides a precisely dated, decadally resolved δ 18O proxy record of paleoclimatic changes associated with the East Asian monsoon from ˜29.5 to 14.7 ka and from ˜12.9 to 11.0 ka. At the time of the last glacial maximum (LGM), the East Asian summer monsoon weakened and then strengthened in response to changes in Northern Hemisphere insolation. As the ice sheets retreated the East Asian summer monsoon weakened, especially during Heinrich event H1, when atmospheric and oceanic teleconnections transferred the climatic changes around the North Atlantic to the monsoonal regions of Eastern Asia. A depositional hiatus between ˜14.7 and 12.9 ka leaves the deglacial record incomplete, but an abrupt shift in δ 18O values at ˜11.5 ka marks the end of the Younger Dryas and the transition into the Holocene. Comparisons of the J1 record to other Chinese speleothem records indicate synchronous climatic changes throughout monsoonal China. Further comparisons to a speleothem record from western Asia (Socotra Island) and to Greenland ice cores support hemispherical-scale paleoclimatic change. Spectral and wavelet analyses reveal centennial- and decadal-scale periodicities that correspond to solar frequencies and to oscillations in atmospheric and oceanic circulation.

  5. Novel early flood warning in the Huaihe River basin in east-central China using the TIGGE database

    NASA Astrophysics Data System (ADS)

    He, Y.; Cloke, H.; Li, Z.; Wetterhall, F.; Pappenberger, F.

    2009-04-01

    Flooding is a wide spread and devastating natural disaster worldwide. Floods that took place in the last decade in China were ranked the worst amongst recorded floods worldwide in terms of the number of human fatalities and economic losses (Munich Re-Insurance). Rapid economic development and population expansion into low lying flood plains has worsened the situation. The last decade has seen an increase in flood preparedness across all levels of society in China. Current conventional flood prediction systems in China are neither suited to the perceptible climate variability nor the rapid pace of urbanization sweeping the country. Flood prediction systems from short-term (a few hours) to medium-term (a few days) need to be revisited and adapted to changing socio-economic and hydro-climatic realities. The latest technology requires implementation of multiple numerical weather prediction systems. The availability of a number of global ensemble weather prediction systems through the ‘THORPEX Interactive Grand Global Ensemble' (TIGGE) offers a good opportunity for an effective state-of-the-art early forecasting system. A prototype of a Novel Flood Early Warning System (NEWS) using the TIGGE database is tested in the Huai River basin located in east-central China. It is the first early flood warning system in China that uses the massive TIGGE database cascaded with river catchment models, the Xinanjiang model and a 1-D hydraulic model, to predict river discharge and flood inundation. Results from selected flood events will be presented.

  6. Spatio-temporal variability of aerosols over East China inferred by merged visibility-GEOS-Chem aerosol optical depth

    NASA Astrophysics Data System (ADS)

    Lin, Jintai; Li, Jing

    2016-05-01

    Long-term visibility measurements offer useful information for aerosol and climate change studies. Recently, a new technique to converting visibility measurements to aerosol optical depth (AOD) has been developed on a station-to-station basis (Lin et al., 2014). However, factors such as human observation differences and local meteorological conditions often impair the spatial consistency of the visibility converted AOD dataset. Here we further adopt AOD spatial information from a chemical transport model GEOS-Chem, and merge visibility inferred and modeled early-afternoon AOD over East China on a 0.667° long. × 0.5° lat. grid for 2005-2012. Comparisons with MODIS/Aqua retrieved AOD and subsequent spectral decomposition analyses show that the merged dataset successfully corrects the low bias in the model while preserving its spatial pattern, resulting in very good agreement with MODIS in both magnitude and spatio-temporal variability. The low bias is reduced from 0.10 in GEOS-Chem AOD to 0.04 in the merged data averaged over East China, and the correlation in the seasonal and interannual variability between MODIS and merged AOD is well above 0.75 for most regions. Comparisons between the merged and AERONET data also show an overall small bias and high correlation. The merged dataset reveals four major pollution hot spots in China, including the North China Plain, the Yangtze River Delta, the Pearl River Delta and the Sichuan Basin, consistent with previous works. AOD peaks in spring-summer over the North China Plain and Yangtze River Delta and in spring over the Pearl River Delta, with no distinct seasonal cycle over the Sichuan Basin. The merged AOD has the largest difference from MODIS over the Sichuan Basin. We also discuss possible benefits of visibility based AOD data that correct the sampling bias in MODIS retrievals related to cloud-free sampling and misclassified heavy haze conditions.

  7. Spatio-temporal variability of aerosols over East China inferred by merged visibility-GEOS-Chem aerosol optical depth

    NASA Astrophysics Data System (ADS)

    Lin, Jintai; Li, Jing

    2016-05-01

    Long-term visibility measurements offer useful information for aerosol and climate change studies. Recently, a new technique to converting visibility measurements to aerosol optical depth (AOD) has been developed on a station-to-station basis (Lin et al., 2014). However, factors such as human observation differences and local meteorological conditions often impair the spatial consistency of the visibility converted AOD dataset. Here we further adopt AOD spatial information from a chemical transport model GEOS-Chem, and merge visibility inferred and modeled early-afternoon AOD over East China on a 0.667° long. × 0.5° lat. grid for 2005-2012. Comparisons with MODIS/Aqua retrieved AOD and subsequent spectral decomposition analyses show that the merged dataset successfully corrects the low bias in the model while preserving its spatial pattern, resulting in very good agreement with MODIS in both magnitude and spatio-temporal variability. The low bias is reduced from 0.10 in GEOS-Chem AOD to 0.04 in the merged data averaged over East China, and the correlation in the seasonal and interannual variability between MODIS and merged AOD is well above 0.75 for most regions. Comparisons between the merged and AERONET data also show an overall small bias and high correlation. The merged dataset reveals four major pollution hot spots in China, including the North China Plain, the Yangtze River Delta, the Pearl River Delta and the Sichuan Basin, consistent with previous works. AOD peaks in spring-summer over the North China Plain and Yangtze River Delta and in spring over the Pearl River Delta, with no distinct seasonal cycle over the Sichuan Basin. The merged AOD has the largest difference from MODIS over the Sichuan Basin. We also discuss possible benefits of visibility based AOD data that correct the sampling bias in MODIS retrievals related to cloud-free sampling and misclassified heavy haze conditions.

  8. Holocene East Asian summer monsoon records in northern China and their inconsistency with Chinese stalagmite δ18O records

    NASA Astrophysics Data System (ADS)

    Liu, Jianbao; Chen, Jianhui; Zhang, Xiaojian; Chen, Fahu

    2016-04-01

    Monsoon precipitation over China exhibits large spatial differences. It has been found that a significantly enhanced East Asian summer monsoon (EASM) is characterized by increased rainfall in northern China and by reduced rainfall in southern China, and this relationship occurs on different time scales during the Holocene. This study presents results from a diverse range of proxy paleoclimatic records from northern China where precipitation variability is traditionally considered as an EASM proxy. Our aim is to evaluate the evolution of the EASM during the Holocene and to compare it with all of the published stalagmite δ18O records from the Asian Monsoon region in order to explore the potential mechanism(s) controlling the Chinese stalagmite δ18O. We found that the intensity of the EASM during the Holocene recorded by the traditional EASM proxy of moisture (or precipitation) records from northern China are significantly different from the Chinese stalagmite δ18O records. The EASM maximum occurred during the mid-Holocene, challenging the prevailing view of an early Holocene EASM maximum mainly inferred from stalagmite δ18O records in eastern China. In addition, all of the well-dated Holocene stalagmite δ18O records, covering a broad geographical region, exhibit a remarkably similar trend of variation and are statistically well-correlated on different time scales, thus indicating a common signal. However, in contrast with the clear consistency in the δ18O values in all of the cave records, both instrumental and paleoclimatic records exhibit significant spatial variations in rainfall on decadal-to- centennial time scales over eastern China. In addition, both paleoclimatic records and modeling results suggest that Holocene East Asian summer monsoon precipitation reached a maximum at different periods in different regions of China. Thus the stalagmite δ18O records from the EASM region should not be regarded as a reliable indicator of the strength of the East

  9. Characteristics and potential sources of atmospheric mercury at a subtropical near-coastal site in East China

    NASA Astrophysics Data System (ADS)

    Yu, Ben; Wang, Xun; Lin, Che-Jen; Fu, Xuewu; Zhang, Hui; Shang, Lihai; Feng, Xinbin

    2015-08-01

    To evaluate the impact of regional mercury (Hg) emissions and understand possible source regions of atmospheric Hg in Eastern China, 2 year observation for speciated atmospheric Hg was conducted at the Dameishan Atmospheric Observatory, a mountain site near the east coast of China. The observed concentration of total gaseous Hg (TGM) was 3.3 ± 1.4 ng m-3. During the sampling period, gaseous oxidized Hg and particulate bound Hg were 6.7 ± 4.3 pg m-3 and 180 ± 110 pg m-3 in winter and 5.9 ± 3.4 pg m-3 and 130 ± 100 pg m-3 in spring, respectively. The relatively high mean concentration of TGM was mainly caused by regional anthropogenic emissions and occasional long-range transport from domestic source regions. Seasonal variation in the TGM concentration was observed with lower values in the wet monsoon season (from May to September) and higher values in the dry monsoon season (from October to April). Backward trajectories and potential source contribution function analysis suggested that anthropogenic Hg emission from coal combustion in the Yangtze River Delta region was the most likely cause for the elevated TGM concentrations. Relatively clean air originating from the East China Sea was the most possible cause for the observed low TGM concentrations. Positive correlation between TGM concentration and air quality index suggests that emissions that influenced regional air quality contributed to the elevated TGM concentrations.

  10. Genetic diversity and population structure of Eleutheronema rhadinum in the East and South China Seas revealed in mitochondrial COI sequences

    NASA Astrophysics Data System (ADS)

    Sun, Xinxu; Xu, Dongdong; Lou, Bao; Zhang, Tao; Xin, Jian; Guo, Yaoshi; Ma, Shilei

    2013-11-01

    Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. A total of 76 specimens were collected from three localities around the East (Qidong and Zhoushan) and South China Seas (Zhuhai). Among these individuals, nine polymorphic sites were detected and 11 distinct haplotypes were defined. High levels of haplotype diversity ( h =0.759±0.035) and low levels of nucleotide diversity ( π= 0.001 98±0.003 26) were observed in these populations. Hierarchical analysis of molecular variance (AMOVA) indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant ( φ st=0.032 85, P<0.01). These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.

  11. Increasing zooplankton size diversity enhances the strength of top-down control on phytoplankton in the East China Sea

    NASA Astrophysics Data System (ADS)

    Ye, L.; Chang, C.; García-Comas, C.; Gong, G.; Hsieh, C.

    2012-12-01

    Body size is one of the fundamental characteristics of organisms linking many ecosystem properties and functions. Recent studies suggest that environmental changes alter the size structure of pelagic food webs; however, ecosystem consequences of such changes remain unclear. Here we tested our main hypothesis that increasing zooplankton size diversity enhances top-down control on phytoplankton in the East China Sea (H1), as well as five conventional hypotheses explaining the top-down control: shallower zooplankton size spectrum enhances the strength of top-down control (H2); nutrient enrichment lessens the strength of top-down control (H3); increasing zooplankton taxonomic diversity enhances the strength of top-down control (H4); increasing fish predation is linked to decreasing the strength of top-down control of zooplankton on phytoplankton (H5); increasing temperature intensifies the strength of top-down control (H6). While the results of our univariate analyses support H1, H2, H3, and H4, more in depth analyses indicate that zooplankton size diversity is the most important factor in determining the strength of top-down control on phytoplankton in East China Sea. Our results suggest a new potential mechanism that increasing predator size diversity enhances the strength of top-down control on prey through diet niche partitioning. This mechanism can be explained by the concept of optimal predator-prey body-mass ratio concept. Suppose each size group of zooplankton predators has its own optimal phytoplankton prey size, increasing size diversity of zooplankton would promote diet niche partitioning of predators and thus elevates the top-down control.Fig. 1 Scatter plots the relationship between zooplankton/phytoplankton biomass ratio versus (A) zooplankton size diversity, (B) slope of zooplankton size spectrum, (C) Zoolankton Shannon diversity, (D) NO3, (E) PO4, (F) SiO3, (G) water temperature, and (H) fish larvae density in the East China Sea. Table 1. Results of the

  12. Characteristics of Flow Field in Relation to transportation of Eggs and Larvae of Pelagic Fish in the East China Sea

    NASA Astrophysics Data System (ADS)

    Morinaga, K.

    2003-12-01

    Jack mackerel (Trachurus japonicus), one of the most familiar pelagic fishes in the East China Sea was been spawned between winter and spring, estimating from temporal and spatial distributions of fishing grounds near the Kyushu coast. Recently, from result of distributions of larvae collected during February to March, it was reported that main spawning grounds had been formed in the southern part of the East China Sea. These eggs and larvae are transported from spawning grounds by the Kuroshio, and a part of them branches northward at northwest of the Amami Oshima Island. This portion is considered to be distributed to the Sea of Japan by the origin of the Tsushima warm current. However, it is difficult to estimate the amount of eggs and larvae, since there is little information about the branched flow from northern edge of the Kuroshio to the Tsushima warm current during winter season. In this paper, in order to make it clear that how eggs and larvae are transported to the Pacific Ocean or the Sea of Japan from the southern East China Sea, the flow pattern in the East China Sea is to be described. Especially a flow that branches from the Kuroshio at northwest of the Amami Oshima Island is described in detail. Using many infrared imagery obtained by NOAA satellite, we detected both the frontal waves generated at the northern edge of the Kuroshio and the path of warm water branched from the frontal waves. These results revealed important information to measure the volume transport of the Tsushima warm current efficiently. Frontal waves are to be broken on the northern edge of the Kuroshio and became the origins of the Tsushima warm current. We carried out ADCP measurement in and around a breaking frontal wave, by using the quadrireciprocal method which requires four round trip surveys along a transect during a diurnal tidal period of 24 hours and 50 minutes in order to remove a tidal current. We were able to acquire a detailed information about a fine structure of

  13. Riding over the Kuroshio from the South to the East China Sea: Mixing and transport of DIC

    NASA Astrophysics Data System (ADS)

    Sheu, David D.; Chou, Wen-Chen; Chen, C. T. Arthur; Wei, Ching-Ling; Hsieh, Hsiu-Ling; Hou, Wei-Ping; Dai, Minhan

    2009-04-01

    Export of dissolved inorganic carbon (DIC) to adjoining oceans enhances the potential of CO2 sequestration in marginal seas. By using a series of measured DIC depth profiles and reported flow transports, we estimated that the intermediate outflow (100-600 m) from the South China Sea is capable of transporting 6.5 ± 4.1 Tg (1 Tg = 1012g) of biologically mediated carbon (DICbio) annually to the East China Sea (ECS) via the northwardly flowing Kuroshio current. The mixing and transport of these DIC-rich waters would raise 3% and 16% of DIC/TA ratio and the Revelle factor of the adjoining seawaters, respectively. Upon upwelling onto the ECS shelf, these DIC-rich waters would counteract the potential of CO2 uptake of shelf waters that might have been enhanced by the accompanying increase in nutrient inputs, thus complicating assessment of the ECS as a net CO2 source or sink.

  14. Study on the linear sand ridges on shelf of the East China Sea

    NASA Astrophysics Data System (ADS)

    WU, Z.; Jin, X.; Li, M.; Shang, J.; Li, S.

    2013-12-01

    The linear sand ridges (LSR) revealed by newest multi-beam echo soundings bathymetric data (MBES) are distributed extensively on shelf of the East China Sea (ECS). It is not only a kind of ubiquitous geological phenomenon on tide-dominated shelf but also a key step in paleo-environment evolvement history of the ECS. Based on the MBES, high-resolution single-channel seismic profiles, analyzed results of boreholes and numerical simulation of paleo-tidal current fields, the distribution, 3D fine structures , space-time spreading regulars and developing tendencies of the LSR on ECS shelf were studied by quantitative synthetic statistical analysis method. The relationship between LSR and paleo-tidal current field, sea-level curve and the evolution stages of LSR such as formation, growth and buried stages were discussed. The strikes of LSR on ECS shelf emerge at a normal distribution. The azimuth of N155°E is the central point and the azimuth of N125°E,N130°E,N140°E and N180°E are convergent points respectively for the normal distribution. The LSR are aggregating in the centre part of ECS shelf, rarefying at the north and south part, dispersing and bifurcating to the east, aggregating and converging to the west. The LSR on ECS shelf are distributed landward to the isobath of 60m, and seaward to the water depth of 120m at northeast and 150m at southwest. Immature LSR are firstly observed at water depth of 130-180m in the southwestern depressions. Lithology analysis and dating of 4 boreholes and 12 cores have indicated that the widely distributed transgressive sand layers with high content of shell debris which formed in the early to middle Holocene are the main compositions of the LSR on the ECS shelf. The top boundaries of buried LSR in unit 14 are distinguished, and a 3D map of these buried LSR in local area is reconstructed. The features such as length, width, height and strikes of these buried LSR are analyzed quantitatively and compared with those of LSR in unit

  15. Paleogene Rift Basins along East China Sea: Tectonic Evolution of Penghu Basin

    NASA Astrophysics Data System (ADS)

    Yang, Tzu-Ruei; Yang, Kenn-Ming; Kuo, Yong-Chein; Lee, Chang-Ji

    2013-04-01

    Prior to the orogeny, Taiwan is located at the passive continental margin. Two extensional events in Tertiary resulted in Paleogene and Neogene basins. The Paleogene rift basins along East China Sea and Taiwan Straight - Tungyintao, Nanjihtao, Penghu basins, from north to south, respectively, comprise a left-lateral and en echelon array rift system. Previous wellbore data revealed that these basins are filled with Paleocene and Eocence sediments, which were controlled by the NE-SW trending growth normal faults. Moreover, Penghu basin is composed of two sub-basins separated by lateral fault which induced a regional volcanic uplift. The seismic profiles indicate that it represents a typical half-graben basin with wedge-shaped synrift deposits thickening toward the main boundary fault. Five wells in the Penghu basin show that Penghu basin began to form during the Late Pliocene with shallow marine deposition. The mid-Eocene shale sequences in northwestern side are interbedded with some layers of basic lava flow, which indicate that the normal faults induced the volcanism. Data used in this study consist of: (1) multi-channel seismic data, (2) seven wellbore data acquired by CPC, Taiwan (Chinese Petroleum Corporation, Taiwan). Seismic profiles were interpreted by Kingdom Suite. Afterwards, integrate synthetic seismogram to generate depth-converted profiles, and import them to 2Dmove for cross-section restoration. Three regional unconformities and four sequence units are delineated in this area. Seismic profile interpretations also infer that the main faults dominantly oriented NE-SW, and the formation of Penghu basin is mostly due to the normal fault in the southeastern side, which is NE-SW trending in the north, and gradually changes to nearly E-W trending. These normal faults are separated by some lateral faults. Restoration of representive cross sections suggest three phases of basin development in the Penghu basin. Regarding to the stratigraphy framework according

  16. [Distributions of inorganic nitrogen species in atmospheric aerosols over the East China Sea].

    PubMed

    Shi, Jin-Hui; Zhang, Yun; Li, Rui-Peng; Gao, Hui-Wang; Zhang, Jing

    2010-12-01

    33 total suspended particle samples and 7 size-segregated particle samples were collected over the East China Sea from Nov. to Dec., 2006, Feb. to Mar., 2007 and May. to Jun., 2008. Concentrations of ammonium, nitrate and nitrite in aerosols were measured to investigate their seasonal variation and size distribution. The concentrations of ammonium in aerosols ranged from 2.6 to 646.9 nmol x m(-3) ,with the higher values observed in winter and spring, and the lower values in summer. Nitrate concentrations were from 5.5 to 281.5 nmol x m(-3), presenting the seasonal trend of winter > spring approximately summer. The concentrations of nitrite were very low, less than 0.5 nmol x m(-3). The relative contributions of nitrogen species to total nitrogen varied seasonally in some extent. The contribution of nitrate was comparable with that of ammonium in winter, while the contribution of ammonium was the predominant in spring and summer. The size distribution of nitrate presented clear monthly changes. Most of nitrate existed in the fine particles less than 2.1 microm in Nov. to Dec., and it predominated in the coarse particles with the size of 1.1-4.7 microm and 2.1-7.0 microm, respectively, in Feb. to Mar. and May. to Jun. The size distributions of ammonium in different months were similar, with one peak presenting in the < 1.1 microm fine particles. The air mass back trajectories analysis indicated that the distributions of inorganic nitrogen in aerosols were significantly influenced by the sources and transport pathways of air mass. Both high nitrogen concentration per unit atmospheric volume (nmol x m(-3)) and per unit mass particle (micromol x g(-1)) occurred when the air mass passed over severe pollution region. Both low concentration in atmosphere and particle occurred when the air mass came from clean marine atmosphere. Lower concentration in atmosphere and higher concentration in particle occurred when the air mass originated from the continent and transported

  17. Distribution, sources and budgets of particulate phosphorus and nitrogen in the East China Sea

    NASA Astrophysics Data System (ADS)

    Yu, Yu; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning

    2012-07-01

    Suspended particles were collected from the northern East China Sea (ECS) in four spring and autumn cruises to study the sources and biogeochemical behavior of particulate inorganic and organic phosphorus and nitrogen (PIP, POP, PIN, and PON). PIP and PON were dominant forms of particulate P and N, accounting for 57.2% of TPP and 78.2% of TPN, respectively. PIP and POP concentrations decreased seaward from the estuary, and had high values near Zhoushan Islands and in the northern ECS. It was indicated that the Changjiang dilute water (CDW) and the Jiangsu coastal currents (JCC), which were rich in particulate phosphorus were the major sources of PIP and POP. PIN and PON concentrations exhibited decreasing trend from the middle shelf toward land and offshore, suggesting the dilution effect of N-depleted riverine particles on particulate nitrogen in coastal waters. The highest concentrations of PIN and PON were observed in the coast of Zhejiang and in the northern ECS, which were two productive areas in the ECS. PON and PIN were primarily of marine source and POP was also influenced by phytoplankton productivity. The concentrations, compositions and distribution of particulate nutrients varied between spring and autumn, in response to the seasonal variations of phytoplankton productivity and terrestrial input. Budget calculation demonstrated that the sediment flux of Changjiang accounted for 88% of total input flux in spring and summer, indicating that the Changjiang River was the major particle source in the ECS. Particulate P was mainly from phytoplankton and the input of the Changjiang River, while the major source of particulate N was phytoplankton. Phytoplankton production contributed 70% of TPP input flux and 95% of TPN input flux in spring and summer, while 64% of TPP input and 89% of TPN input in autumn and winter. It was shown that riverine particles were enriched in inorganic P, whereas marine particles had high organic P and N content, which suggested that

  18. Anammox, denitrification and dissimilatory nitrate reduction to ammonium in the East China Sea sediment

    NASA Astrophysics Data System (ADS)

    Song, G. D.; Liu, S. M.; Marchant, H.; Kuypers, M. M. M.; Lavik, G.

    2013-11-01

    Benthic nitrogen transformation pathways were investigated in the sediment of the East China Sea (ECS) 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 intracellular nitrate release occurred in the ECS sediments. These four processes did not exist independently, nitrate release therefore diluted the 15N labeling fraction of NO3-, and 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 Thamdrup and Dalsgaard (2002), denitrification rates were slightly underestimated by an 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. The significant correlation between potential denitrification rate and sediment organic matter content (r = 0.68, p < 0.001, Pearson) indicated that denitrification was regulated by organic matter, while, no such correlations were found for anammox and DNRA. 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, implying the significant role of anammox in benthic nitrogen cycling in the ECS sediments, especially on the outer shelf. N-loss as N2 was the main pathway, while DNRA was also an important pathway accounting for 20-31% of benthic nitrate

  19. Mechanistic controls on diverse fates of terrestrial organic components in the East China Sea

    NASA Astrophysics Data System (ADS)

    Zhu, Chun; Wagner, Thomas; Talbot, Helen M.; Weijers, Johan W. H.; Pan, Jian-Ming; Pancost, Richard D.

    2013-09-01

    Terrestrial carbon transferred from the land to sea is a critical component of the global carbon cycle. A range of geochemical proxies has been developed to fingerprint the fate of terrestrial organic matter (TOM) in marine sediments. However, discrepancies among different proxies limit our ability to quantify and interpret the terrestrial signals in marine sediments, with consequences for the investigation of both the modern carbon cycle and past environmental change. To mechanistically understand these discrepancies, we examined the distributions of a range of terrestrial proxies and their aquatic counterparts (i.e. marine proxies) in the Yangtze river-East China Sea (YR-ECS) shelf system, where TOM experiences extensive modification during transport and burial. TOM proxies in the YR-ECS system collectively fit a power-law model but with distinct attenuation rates (the a∗ values) for individual molecular proxy groups. Among a range of TOM proxies, the modeled a∗ values decrease in the order: soil-marker BHPs > triterpenols > lignin > HMW n-alkanols > branched GDGTs > HMW n-alkanes for biomarkers; and Rsoil > BIT > %TOMiso for proxies tracing %TOM. Rapid loss of TOM components through dissociation in the narrow estuary, followed by oxidation over the wide open shelf, are best described by power curves. Inherent chemical reactivity (i.e. the number of functional groups), responses to hydraulic sorting, and in situ production regulate the individual attenuation rates. Of them, chemical reactivity plays the most important role on proxy behavior, supported by a strong correlation between a∗ values and standard molal Gibbs energies. Both, physical protection and chemical reactivity fundamentally control the overall behavior of TOM components, with the relative importance being setting-dependant: The former is relatively important in the estuary, whereas the later is the primary control over the open shelf. Moreover, regional variation of different marine

  20. Sea surface salinity variability in the East China Sea observed by the Aquarius instrument

    NASA Astrophysics Data System (ADS)

    Kim, Seung-bum; Lee, Jae Hak; de Matthaeis, Paolo; Yueh, Simon; Hong, Chang-Su; Lee, Joon-Ho; Lagerloef, Gary

    2014-10-01

    This study demonstrates that the spaceborne Aquarius instrument is able to monitor the sea surface salinity (SSS) variations in the East China Sea (ECS) with the spatial resolution of about 150 km at 7 day interval, where routine observations are difficult. The two geophysical contaminants enter the sidelobes of the Aquarius antenna and bias the coastal SSS low: the emission from the land surface and the radiofrequency interference (RFI). Away from about one Aquarius pixel (150 km) from the coastline, the Aquarius SSS is fairly insensitive (less than about 0.2 psu) to the radiometric details of the method to correct for the land emission. The ascending orbits appear to be affected by unfiltered RFI much less than the descending tracks. The Aquarius SSS along the ascending tracks is low over the ECS by 0.40-0.93 psu (with respect to the in situ data during the two separate 7 day periods) and is biased low by 0.41-1.07 psu (accuracy, or the time-mean of difference from the regional model along three Aquarius tracks over a 18 month period). The presence of the ascending and descending differences in the Aquarius SSS, and the spatially widespread bias suggest that the bias is attributed to the unfiltered RFI originating from strong point sources (rather than to the land contamination from weak distributed sources, or to other seasonally varying geophysical contaminants). Despite the bias, the Aquarius data describe well the temporal and spatial variability of the ECS SSS. The temporal trend and magnitude of salinity changes agree remarkably between Aquarius and a regional numerical model, during both the freshwater discharge season from the Yangtze river and the rest of the year. The precision of the Aquarius observation in the ECS is comparable with the Aquarius mission requirement (0.2 psu one-sigma for a monthly average over the open ocean). The river discharge rate correlates with the Aquarius SSS with the coefficient of 0.71 on a seasonal scale with the discharge

  1. Geochemical forms and seasonal variations of phosphorus in surface sediments of the East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Zhou, Fengxia; Gao, Xuelu; Yuan, Huamao; Song, Jinming; Chen, Chen-Tung Arthur; Lui, Hon-Kit; Zhang, Yong

    2016-07-01

    Geochemical characteristics of phosphorus (P) in the surface sediments of the East China Sea shelf (ECSS) were studied in spring and autumn, 2014. Distributions, seasonal variations, transformations and their influencing factors were discussed. Besides, burial fluxes of P in different seasons were also calculated. Five operationally defined forms of P, namely exchangeable or loosely sorbed P (Ads-P), iron-bound P (Fe-P), authigenic P (Au-P), detrital apatite plus other inorganic P (De-P) and organic P (OP), were obtained using a sequential extraction procedure. Generally, the concentrations of Ads-P, Fe-P, Au-P and OP decreased seaward and the concentrations of De-P increased seaward in both seasons. In spring, the average concentrations of Ads-P, Fe-P, Au-P, De-P and OP were 13.8 ± 5.0, 21.9 ± 7.6, 148.5 ± 44.5, 153.1 ± 55.8 and 91.7 ± 21.5 μg g- 1, respectively. The corresponding concentrations in autumn were 11.4 ± 4.3, 20.0 ± 10.9, 170.4 ± 53.6, 225.6 ± 101.7 and 77.1 ± 33.9 μg g- 1, respectively. The average percentages of P fractions in total P (TP) in spring and autumn were both in the order: De-P > Au-P > OP > Fe-P > Ads-P. The average concentrations of Bio-available P (Bio-P) were 127.4 ± 31.4 μg g- 1 in spring and 108.5 ± 47.2 μg g- 1 in autumn, accounting for 29.8% ± 7.3% and 21.5% ± 8.2% of corresponding TP, respectively. Seasonal variations of the primary production, hydrodynamic conditions, hypoxia and other environmental conditions were responsible for the seasonal variations of different phosphorus forms. The calculation of burial fluxes reflected that, in most parts of the studied area, TP had relative high burial fluxes in autumn, while Bio-P had relatively high burial fluxes in spring. The burial fluxes of other phosphorus forms also showed different seasonal variations in different parts of the studied area.

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

    PubMed

    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. PMID:26975003

  3. Dynamics of Autotrophic Marine Planktonic Thaumarchaeota in the East China Sea

    PubMed Central

    Hu, Anyi; Yang, Zao; Yu, Chang-Ping; Jiao, Nianzhi

    2013-01-01

    The ubiquitous and abundant distribution of ammonia-oxidizing Thaumarchaeota in marine environments is now well documented, and their crucial role in the global nitrogen cycle has been highlighted. However, the potential contribution of Thaumarchaeota in the carbon cycle remains poorly understood. Here we present for the first time a seasonal investigation on the shelf region (bathymetry≤200 m) of the East China Sea (ECS) involving analysis of both thaumarchaeal 16S rRNA and autotrophy-related genes (acetyl-CoA carboxylase gene, accA). Quantitative PCR results clearly showed a higher abundance of thaumarchaeal 16S and accA genes in late-autumn (November) than summer (August), whereas the diversity and community structure of autotrophic Thaumarchaeota showed no statistically significant difference between different seasons as revealed by thaumarchaeal accA gene clone libraries. Phylogenetic analysis indicated that shallow ecotypes dominated the autotrophic Thaumarchaeota in the ECS shelf (86.3% of total sequences), while a novel non-marine thaumarchaeal accA lineage was identified in the Changjiang estuary in summer (when freshwater plumes become larger) but not in autumn, implying that Changjiang freshwater discharge played a certain role in transporting terrestrial microorganisms to the ECS. Multivariate statistical analysis indicated that the biogeography of the autotrophic Thaumarchaeota in the shelf water of the ECS was influenced by complex hydrographic conditions. However, an in silico comparative analysis suggested that the diversity and abundance of the autotrophic Thaumarchaeota might be biased by the ‘universal’ thaumarchaeal accA gene primers Cren529F/Cren981R since this primer set is likely to miss some members within particular phylogenetic groups. Collectively, this study improved our understanding of the biogeographic patterns of the autotrophic Thaumarchaeota in temperate coastal waters, and suggested that new accA primers with improved

  4. [Ecological characteristics of zooplankton in frequent HAB areas of the East China Sea in spring].

    PubMed

    Xu, Zhaoli; Hong, Bo; Zhu, Mingyuan; Chen, Yaqu

    2003-07-01

    A comprehensive oceanographic survey was made in the East China Sea (122 degrees-123 degrees 30'E, 29 degrees-32 degrees N) during April to May, 2002, and the zooplankton samples were collected by zooplankton net (mesh size 0.567 mm). Analyses on the ecological characteristics of zooplankton such as its quantity, community characteristics, species composition and dominant species showed that 128 species of diet zooplankton were identified (16 pelagic larvae and fish juveniles were not involved). Among them, copepods occupied dominant position, including 40 species, composing 31.25% of diet zooplankton. The community was divided into 3 ecological types, in which, eurythermy and euryhalinity occupied dominant position. Key species, Calanus sinicus, was the first dominant species (142.10 ind.m-3, composing 68.09% of diet zooplankton abundance). The average biomass of zooplankton was 243.80 mg.m-3 (55.53-773.92 mg.m-3), and the highest density (> 500 mg.m-3) was found in the estuary area of the Yangtze River (30 degrees 45'-31 degrees 15'N, 122 degrees 45'-123 degrees 15'E). The average biomass of diet zooplankton was 195.96 mg.m-3 (55.53-496.09 mg.m-3). It was also showed that the biomass value of the estuary area of the Yangtze River (the north of 30 degrees 30'N) was higher than that of the southwest of Zhoushan waters, and that of the offshore of the estuary area of the Yangtze River (122 degrees 45'E) was higher than that of coastal waters. The mean value of diversity index (H') was 2.12 (1.09-3.73), and the stations having low H' (< 2) occupied 37.03%. The index of diversity, evenness and richness in the estuary area of the Yangtze River were low, but dominance was high. These results showed that the community structure of zooplankton in studied areas was not stable. Regression analysis results showed that main factors in relation to the characteristic distribution of zooplankton were temperature, diatom abundance, and dinoflagellate abundance. PMID:14587326

  5. Crustal and upper-mantle Seismic Tomography beneath the Helan-Liupan-Ordos's western margin structural belt and its adjacent region in central China

    NASA Astrophysics Data System (ADS)

    Cheng, S.; Cheng, B.; Zhang, G.; Zhao, D.

    2013-12-01

    Abstract We determined high-resolution 3-D P-wave velocity and anisotropic structures under the Helan-Liupan-Ordos's western margin (H-L-O) structural belt and its adjacent region using 13,506 P-wave high-quality arrival times from 2,666 regional earthquakes recorded by 87 seismic stations distributed in Northwestern China during 1980 to 2008. The results indicate that the prominent low-Vp anomalies widely exist in the lower crust beneath the study region and extend to the uppermost mantle in local area, which suggest that the lower crust contains relative high-temperature materials and/or fluids. The major fault zones especial the large boundary faults are distributed in the edge portion of the low-Vp anomalies or a transitional zone between the low- and high-Vp anomalies in the upper crust, and the obvious low-Vp anomalies are revealed in the lower crust even uppermost mantle under most of the faults. Most of the large historical earthquakes are located in the boundary zones where P-wave velocity changes drastically in a short distance. The prominent low-Vp zones are visible in the lower crust even uppermost mantle beneath the large historical earthquakes and most of the regional earthquakes. The anisotropic patterns in the upper crust is good consistent with the surface structures. In the lower crust and uppermost mantle, the predominant fast velocity direction has the NNE-SSW under the Yinchuan Graben and NWW-SEE or NW-SE beneath the Corridor transitional zone, Qilian Orogenic Belt and Western Qinling Orogenic Belt with about NE-SW in local region such as eastern Qilian Orogenic Belt, respectively, being caused by the LPO of lower crustal minerals which may be result from the ductile flow of the lower crust with varied flow directions. Another velocity feature is being zonation with low- and high-velocity S-N strike and segments along S-N within the Crust. The present results shed new light on the structural heterogeneities and seismic anisotropy in the crust

  6. Climatology of the oceanography in the northern South China Sea Shelf-sea (NoSoCS) and adjacent waters: Observations from satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Pan, X.; Wong, G. T.; Tai, J.; Ho, T.

    2013-12-01

    By using the observations from multiple satellite sensors, the climatology of the oceanography, including the surface wind vector, sea surface temperature (SST), surface chlorophyll a concentration (Chl_a), and vertically integrated net primary production (PPeu), in the northern South China Sea Shelf-sea (NoSoCS) and adjacent waters is evaluated. Regional and sub-regional mechanisms in driving the coastal processes, which influence the spatial and temporal distributional patterns in water component, are assessed. Seasonal vertical convective mixing by wind and surface heating/cooling is the primary force in driving the annual changes in SST and Chl_a in the open South China Sea (SCS), in which highly negative correlation coefficients between Chl_a and SST and moderately positive correlation coefficients between Chl_a and wind speed are found. Together, the seasonal variations in SST and wind speed account for about 80% of the seasonal variation in Chl_a. In the NoSoCS as a whole, however, the contribution is reduced to about 40%, primarily due to the effect of the Pearl River plume. A tongue of water extending eastward from the mouth of the River into the middle shelf with positive correlation coefficients between Chl_a and SST and around zero or slightly negative correlation coefficients between Chl_a and wind is the most striking feature in the NoSoCS. The westward and eastward propagations of the Pearl River plume are both very small during the northeast monsoonal season, driven primarily by the Coriolis effect. The abrupt increase in the areal coverage of the River plume, which is much more pronounced in the eastward propagation, between June and August can be attributed to the prevailing southwest monsoon as well as the annual peak of the river flow. Coastal upwelling is another sub-regional phenomenon in the NoSoCS. The upwelling at the shelf edge off the Taiwan Bank may be characterized by its elevated Chl_a. Its areal coverage and average Chl_a do not vary

  7. Origins of suspended particulate matter based on sterol distribution in low salinity water mass observed in the offshore East China Sea.

    PubMed

    Kim, Moonkoo; Jung, Jee-Hyun; Jin, Yongnu; Han, Gi Myeong; Lee, Taehee; Hong, Sang Hee; Yim, Un Hyuk; Shim, Won Joon; Choi, Dong-Lim; Kannan, Narayanan

    2016-07-15

    The molecular composition and distribution of sterols were investigated in the East China Sea to identify the origins of suspended particulate matter (SPM) in offshore waters influenced by Changjiang River Diluted Water (CRDW). Total sterol concentrations ranged from 3200 to 31,900pgL(-1) and 663 to 5690pgL(-1) in the particulate and dissolved phases, respectively. Marine sterols dominated representing 71% and 66% in the particulate and dissolved phases, respectively. Typical sewage markers, such as coprostanol, were usually absent at ~250km offshore. However, sterols from allochthonous terrestrial plants were still detected at these sites. A negative relationship was observed between salinity and concentrations of terrestrial sterols in SPM, suggesting that significant amounts of terrestrial particulate matter traveled long distance offshore in the East China Sea, and the Changjiang River Diluted Water (CRDW) was an effective carrier of land-derived particulate organic matter to the offshore East China Sea. PMID:27167134

  8. Tracing floating green algae blooms in the Yellow Sea and the East China Sea using Lagrangian transport simulations

    NASA Astrophysics Data System (ADS)

    Park, Young-Gyu; Son, Young Baek; Choi, Byoung-Ju; Kim, Yong Hoon

    2014-05-01

    Lagrangian particle tracking experiments were conducted to understand the pathway of the floating green algae patches observed in the Yellow Sea (YS) and East China Sea (ECS) in summer 2011. The numerical simulation results indicated that dominant southerly winds during June and July 2011 were related to offshore movement of the floating green algae, especially their eastward extension in the YS/ECS. An infrequent and unusual event occurred in June 2011: a severe Tropical Strom MEARI, caused the green algae to detach from the coast and initiated movement to the east. After the typhoon event, sea surface temperature recovered rapidly enough to grow the floating green algae, and wind and local current controlled the movement of the massive floating algae patches (coastal accumulation or offshore advection in the area). Analysis of the floating green algae movement using satellite images during passage of Typhoon MAON in July 2011 revealed that the floating green algae patches were significantly controlled by both ocean currents and enhanced winds. These findings suggest that the floating green algae bloom off Qingdao, China and in the middle of the YS and ECS in the summer of 2011 occurred due to the combined effects of recent rapid expansion of seaweed aquaculture, strong winds, and the wind patterns in blooming regions. Our combined approach, using satellite data and numerical simulations, provides a robust estimate for tracing and monitoring changes in green algae blooms on a regional scale.

  9. Retrieval of Secchi disk depth in the Yellow Sea and East China Sea using 8-day MODIS data

    NASA Astrophysics Data System (ADS)

    Yu, D. F.; Xing, Q. G.; Lou, M. J.; Shi, P.

    2014-03-01

    Secchi disk depth (SDD), is widely used as an indicator of water clarity. The traditional sampling method is not only time-consuming and labor-intensive but also limited in terms of temporal and spatial coverage. Remote sensing technology may deal with these limitations. In this paper, the applicability of 8-day MODIS-Aqua remote sensing reflectance data with 4 km spatial resolution for estimating water clarity in the Yellow Sea and the East China Sea was investigated. Field data such as Secchi depths were collected from two cruises conducted in the Yellow Sea and the East China Sea from 5 May to 7 June 2009. A three-band algorithm to retrieve SDD was developed based on remote sensing reflectance at bands of 488, 555, and 678 nm, which performed better than single-band model and band ratio algorithm, with a determination coefficient of 0.72 and a mean relative error of 19%. This suggests that 8-day MODIS-Aqua products of remote sensing reflectance could be used to assess water transparency in the study area.

  10. Sea-surface temperature fronts in the Yellow and East China Seas from TRMM microwave imager data

    NASA Astrophysics Data System (ADS)

    Huang, Daji; Zhang, Tao; Zhou, Feng

    2010-06-01

    Swath data from the Tropical Rainfall Measuring Mission microwave imager of sea-surface temperatures (SST) from 1998 to 2005 have been used to analyze the climatology and seasonal variability of the SST fronts in the Yellow and East China Seas (YES). Seven fronts have been identified and placed into three categories, namely, (1) the shelf-break front (Kuroshio Front), (2) the coastal fronts (Zhe-Min, Jiangsu, Shangdong Peninsula, Western Korean, and Western Chejudo Fronts), and (3) the shelf front (Western Yellow Sea Shelf Front). The Kuroshio Front exists from December through May, with the maximum SST gradient and highest frontal probability in April. The five coastal fronts exist year-round, all with their maximum SST gradient and highest frontal probability in February. The shelf front in the western Yellow Sea exists only from January to March. Frontogenesis in winter is due to effects of both air-sea heat exchange and advection by currents. The coastal fronts in the stratified months are expressed as tidal fronts. The coastal frontal zones coincide with the major spawning grounds of fish in the YES. The overwintering fishery ground in the Yellow Sea overlaps with the narrow band of favorable water temperature in the frontal zone. The overwintering grounds in the East China Sea are broad and bounded by fronts.

  11. [Characteristics of PM10 and PM2.5 concentrations in mountain background region of East China].

    PubMed

    Su, Bin-Bin; Liu, Xin-Dong; Tao, Jun

    2013-02-01

    The online PM10 and PM2.5 concentrations were measured from March 2011 'to February 2012 at the national atmospheric background monitoring station in Wuyishan of Fujian Province to discuss the characteristic of PM10 and PM2.5 concentrations and the impact factors in forest and mountain background region of East China. HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) Model was used to investigate the potential sources of particulates during the pollution episodes. The results showed that the background concentrations of PM10 and PM2.5 were (23 +/- 16) microg.m-3 and (18 +/- 12) microg.m-3, respectively. Seasonal variations of PMl0 and PM2.5 loadings were observed, and loadings decreased in the same order: spring > autumn > winter > summer. PM10 and PM2.5 concentrations were obviously higher in spring than in other seasons because of the transportation of dust storm. The fine particles were the dominant pollutant which accounted for 76% of PM10. The good correlation between PM10/PM2.5 and gas pollutants suggested that regional transportation and secondary aerosol were the major sources in the background station. One episode occurring in April 2011 was related with the transportation of dust storm. However, another episode occurring in September 2011 had close relationship with the transportation of higher pollutant loadings in East China. PMID:23668109

  12. River-derived sediment suspension and transport in the Bohai, Yellow, and East China Seas: A preliminary modeling study

    NASA Astrophysics Data System (ADS)

    Zeng, Xiangming; He, Ruoying; Xue, Zuo; Wang, Houjie; Wang, Yue; Yao, Zhigang; Guan, Weibing; Warrillow, Jennifer

    2015-12-01

    Coastal circulation and transport of sediment derived from the Huanghe and Changjiang Rivers in the Bohai, Yellow, and East China Seas (BYECS) over the past 48 years (1958-2005) were simulated and analyzed using the Coupled Ocean-Atmosphere-Wave-Sediment Transport modeling system. Model skill assessments against in situ wave and hydrographical observations indicate the model simulation can reasonably well reproduce the hydrodynamic environment of the BYECS. Model-simulated regions of high fine sediment accumulation rate correlate well with the observed regions, which are known as "muddy patches." Bottom stress analysis further indicates that the formation of muddy patches near river mouths is largely due to their proximity to the sediment source. Muddy patches formed in regions farther away from river mouths are results of local weak bottom stress and associated circulation pattern. Simulated seabed sediment distribution reveals that most of the Huanghe-derived sediment stays inside the Bohai Sea, whereas the Changjiang-derived sediment can spread into both the Yellow and East China Seas. Strong seasonal variations exist in the river-derived sediment transport with stronger (weaker) offshore sediment transport occurring in the winter (summer).

  13. Variations of surface ozone at Ieodo Ocean Research Station in the East China Sea and influence of Asian outflows

    NASA Astrophysics Data System (ADS)

    Han, J.; Shin, B.; Lee, M.; Hwang, G.; Kim, J.; Shim, J.; Lee, G.; Shim, C.

    2015-06-01

    Ieodo Ocean Research Station (IORS), a research tower (~ 40 m a.s.l.) for atmospheric and oceanographic observations, is located in the East China Sea (32.07° N, 125.10° E). The IORS is almost equidistant from South Korea, China, and Japan and, therefore, it is an ideal place to observe Asian outflows without local emission effects. The average ozone concentrations were 51.8 ± 15.9 ppbv during June 2003-December 2010. The seasonal variation of ozone was distinct, with a summer minimum (37.8 ppbv) and a spring maximum (61.1 ppbv), and was largely affected by seasonal wind pattern over East Asia. The fractional contribution of ozone at IORS could be attributed to six well distinguished air masses that were classified by the cluster analysis of backward trajectories. Marine air from the Pacific Ocean represents a relatively clean background air with a lowest ozone level of 32.2 ppbv in summer. In spring and winter the influence of Chinese outflows was dominant with higher ozone concentrations of 61.6 and 49.3 ppbv, respectively. This study confirms that the influence of Chinese outflows was the main factor determining O3 levels at IORS, of which extent was apt to be changed by meteorological state, particularly at a long-term scale.

  14. Variations of surface ozone at Ieodo Ocean Research Station in the East China Sea and the influence of Asian outflows

    NASA Astrophysics Data System (ADS)

    Han, J.; Shin, B.; Lee, M.; Hwang, G.; Kim, J.; Shim, J.; Lee, G.; Shim, C.

    2015-11-01

    Ieodo Ocean Research Station (IORS), a research tower (~ 40 m a.s.l.) for atmospheric and oceanographic observations, is located in the East China Sea (32.07° N, 125.10° E). The IORS is almost equidistant from South Korea, China, and Japan and, therefore, it is an ideal place to observe Asian outflows without local emission effects. The seasonal variation of ozone was distinct, with a minimum in August (37 ppbv) and two peaks in April and October (62 ppbv), and was largely affected by the seasonal wind pattern over east Asia. At IORS, six types of air masses were distinguished with different levels of O3 concentrations by the cluster analysis of backward trajectories. Marine air masses from the Pacific Ocean represent a relatively clean background air with a lowest ozone level of 32 ppbv, which was most frequently observed in summer (July-August). In spring (March-April) and winter (December-February), the influence of Chinese outflows was dominant with higher ozone concentrations of 62 and 49 ppbv, respectively. This study confirms that the influence of Chinese outflows was the main factor determining O3 levels at IORS and its extent was dependent on meteorological state, particularly at a long-term scale.

  15. Analysis of weather regime dependent wind biases over the east coast of China using 3 year WRF simulations

    NASA Astrophysics Data System (ADS)

    Lin, N.; Zhao, Y.; Xue, W.; Lin, Y.

    2015-12-01

    Reliable wind power resource estimates required by wind energy industry can be achieved by long term wind tower measurements or mesoscale model simulations. However, how to quantify and investigate the characteristics of wind bias of mesoscale modeling remain a challenge.Three-year simulations using WRF over the east coast of China have been conducted. A K-means cluster analysis is used to categorize the dominant weather regimes over this area.A systematic overestimate of wind speed over the coastal area is found during the daytime within the sea breeze dominant regime. Further analysis indicates that the positive bias is closely related to the strength of mixing within the boundary layer and land surface temperature bias. A typical sea breeze case is analyzed in terms of its evolution with a focus on the vertical and inland intrusion extent. A good simulation of local land sea breeze is critical for offshore and onshore wind farm design and operations over the east coast of China.

  16. The clinical management and outcome of term premature rupture of membrane in East China: results from a retrospective multicenter study.

    PubMed

    Xia, Hexia; Li, Xilian; Li, Xiaotian; Liang, Huan; Xu, Huan

    2015-01-01

    In this study, we investigated the management of term premature rupture of membranes (PROM) and maternal-fetal outcomes in East China. Between January and December 2012, the term delivery data for 111390 pregnant women was retrospectively analyzed. The subjects were divided into two groups: those women who had term PROM (PROM Group, n=13927) and those who did not (Control Group, n=94341). The general patient characteristics, the mode of delivery, and the maternal and fetal complications were recorded. Statistical analysis was completed using the Student's t-test and χ(2)-test. The incidence of term PROM in East China is approximately 12.5%. The maternal demographic and obstetric characteristics were similar between the two groups. Patients in the PROM group had a higher incidence of bacterial vaginitis (BV), chlamydia trachomatis (CT) infection, postpartum hemorrhage, and cesarean section deliveries. Infants in the PROM group experienced higher rates of infection, asphyxia, and jaundice. There was a high cesarean section rate, and further efforts are needed to increase the vaginal delivery rate for women with term PROM. PMID:26131227

  17. Concentrations and risk assessment of polychlorinated biphenyls and polybrominated diphenyl ethers in surface sediments from the East Lake, China.

    PubMed

    Yun, Xiaoyan; Yang, Yuyi; Liu, Minxia; Wang, Jun

    2015-01-01

    The concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in surface sediment samples collected from the East Lake, China in winter 2012 and summer 2013 were analyzed in this study. The total PCB and PBDE concentrations ranged from not detected to 107.1 ng g(-1) dw and from 9.7 to 151.3 ng g(-1) dw, respectively. PCB-28, 101 and 180 were dominant congeners in both winter and summer. BDE-28 (44 %) was the dominant congener in winter and summer, followed by BDE-99 (28 %) and BDE-47 (26 %). The concentrations of PCBs in the sediment samples collected in summer were higher than those in winter, while the concentrations of PBDEs did not show much seasonal variations. Source analysis showed that the PCBs probably originated from urban runoff, industrial pollution and atmospheric deposition, and the PBDEs probably originated from historical usage of penta-BDE mixtures. Potential eco-toxicological risks caused by PCBs were found in about 5 % of the sampling sites; PBDEs had moderate eco-toxicological risk in 80 % sampling sites in the East Lake, China. PMID:25336043

  18. Lateral variation in oxygen fugacity and halogen contents in early Cretaceous magmas in Jiaodong area, East China: Implication for triggers of the destruction of the North China Craton

    NASA Astrophysics Data System (ADS)

    Huang, Xiao-Long; He, Peng-Li; Wang, Xue; Zhong, Jun-Wei; Xu, Yi-Gang

    2016-04-01

    Pacific subduction has been suggested as the trigger of the destruction of the North China Craton, but evidence for it remains ambiguous. To further investigate this issue, we studied Wulian pyroxene monzonite (123 ± 1 Ma) in the west and Rushan gabbro-diorite (115 ± 1 Ma) in the east of the Sulu orogen, East China. The rocks of both locations are characterized by low TiO2 but high SiO2 and K2O, fractionated REE patterns with notable negative Ta-Nb-Ti anomalies, and by high initial 87Sr/86Sr ratios and strongly negative εNd (t) and εHf (t) values. These geochemical and isotopic characteristics can be interpreted to be formed by partial melting of enriched lithosphere mantle refertilized by recycled crustal materials that were associated with the Sulu orogeny. Oxygen fugacities of the Rushan gabbro-diorites, estimated based on magnetite-ilmenite equilibration, are significantly higher than those of Wulian pyroxene monzonite. This lateral difference is mirrored by lower F and F/Cl but higher Cl in biotite in the Rushan gabbro-diorite compared to Wulian pyroxene monzonite. All these data suggest a spatially heterogeneous Cretaceous mantle source in terms of halogens and water contents beneath the Sulu orogen, which was most likely caused by the subduction processes of the Pacific plate. H2O-rich fluid in the mantle beneath the east of the Sulu orogen closer to the mantle wedge was prominently from early dehydration of subducted slab at shallow depth, while F-bearing fluid to further west was released by dehydrated deeper slab or stagnant oceanic slab within the mantle transition zone.

  19. Molecular identification of Anisakis and Hysterothylacium larvae in marine fishes from the East China Sea and the Pacific coast of central Japan.

    PubMed

    Kong, Qingming; Fan, Lanfen; Zhang, Junhe; Akao, Nobuaki; Dong, Kewei; Lou, Di; Ding, Jianzu; Tong, Qunbo; Zheng, Bin; Chen, Rui; Ohta, Nobuo; Lu, Shaohong

    2015-04-16

    Anisakiasis is a human disease caused by the accidental ingestion of larvae belonging to the family Anisakidae. Three fish species, the small yellow croaker Pseudosciaena polyactis, the mackerel Pneumatophorus japonicus and the hairtail Trichiurus haumela are important source for food products in the East China Sea. The prevalence and the identification of Anisakidae larvae in these fishes will benefit the prevention and control of anisakiasis. In this study, fish samples were obtained from fish markers in the East China Sea and the Pacific coast of central Japan during April 2011 and July 2013. For species identification, the PCR-based restriction fragment length polymorphism (PCR-RFLP) analysis of the entire ITS region (ITS1, 5.8 S and ITS2) of nuclear ribosomal DNA (rDNA) was performed. In total, 2004 larvae were collected from 80 hairtail fish, 20 small yellow croaker, and 27 mackerel from the East China Sea and the Pacific coast of central Japan. High prevalence of Anisakidae larvae infection (116/122, 95.1%) was detected in the East China Sea. Seven species were identified belonging to the genera Anisakis (Nematoda: Anisakidae) and Hysterothylacium (Nematoda: Anisakidae). Anisakis pegreffii was the predominant species accounting for 84.8% of all larvae examined in East China Sea, while all Anisakidae larvae isolated from Japan were identified as Anisakis simplex sensu stricto (s.s.). In the East China Sea, A. simplex s.s. and Anisakis typica were 0.6% (4/619) and 1.5% (9/619) of the identified nematodes, respectively. Interestingly, one larva was identified as a recombinant genotype of A. simplex s.s. and A. pegreffii. In addition, four species of the genus Hysterothylacium, namely, Hysterothylacium amoyense (31/619, 5.0%), Hysterothylacium aduncum (10/619, 1.6%), Hysterothylacium fabri (21/619, 3.4%) and Hysterothylacium spp. (18/619, 2.9%) were also identified in the present study. This is a comprehensive epidemiological dataset for the family Anisakidae in

  20. A modelling study of inter-annual variation of Kuroshio intrusion on the shelf of East China Sea

    NASA Astrophysics Data System (ADS)

    Li, Jiaxing; Wei, Hao; Zhang, Zhihua; Lu, Youyu

    2013-12-01

    Inter-annual variability of the Kuroshio water intrusion on the shelf of East China Sea (ECS) was simulated with a nested global and Northwest Pacific ocean circulation model. The model analysis reveals the influence of the variability of Kuroshio transport east of Taiwan on the intrusion to the northeast of Taiwan: high correlation ( r = 0.92) with the on-shore volume flux in the lower layer (50-200 m); low correlation ( r = 0.50) with the on-shore flux in the upper layer (0-50 m). Spatial distribution of correlations between volume fluxes and sea surface height suggests that inter-annual variability of the Kuroshio flux east of Taiwan and its subsurface water intruding to the shelf lag behind the sea surface height anomalies in the central Pacific at 162°E by about 14 months, and could be related to wind-forced variation in the interior North Pacific that propagates westward as Rossby waves. The intrusion of Kuroshio surface water is also influenced by local winds. The intruding Kuroshio subsurface water causes variations of temperature and salinity of bottom waters on the southern ECS shelf. The influence of the intruding Kuroshio subsurface water extends widely from the shelf slope northeast of Taiwan northward to the central ECS near the 60 m isobath, and northeastward to the region near the 90 m isobath.

  1. Improving Seasonal Precipitation Predictions over the East River Basin, South China by Using Bias-corrected CFSv2 Forecasts

    NASA Astrophysics Data System (ADS)

    Wang, D.; Zhu, C.; Wu, Y.; Lin, K.; Liu, B.; Chen, Z.; Xinjun, T.; Huang, M.

    2015-12-01

    East River is one the major tributaries of Peal River, the third largest river over China. It is the most important water resource for agriculture, industry, and commerce in the Pearl River Delta. The water demand has dramatically increased with rapid population growth and booming economic development in this region. To meet the demand of water supply, the East River basin administration has conducted the water quantity operation over the basin since 2008. However, the operation target has been hardly achieved largely due to poor precipitation predictions. We try to improve seasonal precipitation predictions by correcting the bias of the NCEP CFSv2 forecasts. A variety of bias correction methods are applied to correct CFSv2 forecasts based on a long term datasets of gauge observations and CFSv2 reforecasts. The proper bias methods are selected for the flood and the dry season respectively based on evaluation results. The CFSv2 based predictions would help in making a reasonable water quantity operation plan and improving operational performance over the East River basin.

  2. Major mid-late Holocene cooling in the East China Sea revealed by an alkenone sea surface temperature record

    NASA Astrophysics Data System (ADS)

    Zhao, Meixun; Ding, Ling; Xing, Lei; Qiao, Shuqing; Yang, Zuosheng

    2014-12-01

    Although the mid-late Holocene cold and dry event about 4000 years ago (the 4 ka event) has been observed almost globally, it was most prominent in terrestrial climate proxies from the lower latitudes. Here we evaluate the oceanic response to this event in terms of a Holocene sea surface temperature (SST) record reconstructed using the U37K' index for Core B3 on the continental shelf of the East China Sea. The record reveals a large temperature drop of about 5°C from the mid-Holocene (24.7°C at 5.6 ka) to the 4 ka event (19.2°C at 3.8 ka). This mid-late Holocene cooling period in Core B3 correlated with (i) decreases in the East Asia summer monsoon intensity and (ii) the transition period with increased El Niño/Southern Oscillation activities in the Equatorial Pacific. Our SST record provides oceanic evidence for a more global nature of the mid-late Holocene climate change, which was most likely caused by a southward migration of the Intertropical Converge Zone in response to the decreasing summer solar insolation in the Northern Hemisphere. However, the large SST drop around Core B3 indicates that the mid-late Holocene cooling was regionally amplified by the initiation/strengthening of eddy circulation/cold front which caused upwelling and resulted in additional SST decrease. Upwelling during the mid-late Holocene also enhanced with surface productivity in the East China Sea as reflected by higher alkenone content around Core B3.

  3. Education Policy Borrowing in China: Has the West Wind Overpowered the East Wind?

    ERIC Educational Resources Information Center

    Tan, Charlene; Chua, Catherine S. K.

    2015-01-01

    Recent education reform in China reflects the global trend of education policy borrowing from Anglophone countries such as the USA. The reform in China essentially advocates shifting from knowledge reproduction and didacticism to knowledge construction by students through a learner-centredness approach. Aware of the trend of borrowing policy from…

  4. Enrichment of heavy metals in the inner shelf mud of the East China Sea and its indication to human activity

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Fan, Dejiang; Li, Weiran; Wang, Liang; Zhang, Xilin; Liu, Ming; Guo, Zhigang

    2014-11-01

    The Yangtze River Basin, which has a population of 0.4 billion and an economic output accounting for 50% of China's Gross Domestic Product (GDP), is one of the most developed regions in China. With dramatic developments in the economy, large quantities of pollutants have entered the Yangtze River and have eventually been discharged into the East China Sea (ECS), and then most of them were preserved in the inner shelf coastal mud areas of the ECS. The inner shelf costal mud areas of the ECS, with sedimentation rate ranging from 0.8 cm/a to 1.2 cm/a, are an ideal place to obtain the high-resolution heavy metal record. In this work, two sediment cores collected in the inner shelf of the coastal mud areas of the ECS in 2009 were used to reconstruct historical records of anthropogenic heavy metal input from the Yangtze River Basin. The temporal distribution of enrichment factors (EFs) is in good accordance with social development of Yangtze River Basin. Before the 1930s, the EFs of Pb and Zn are considered as the background level of study area, according to the agricultural country of China in that time. The much higher EFs of Pb and Zn from the 1930s to 1980s were associated with significant improvement of industry of the Yangtze River Basin. After 1983, the dramatical incensement of EFs of Pb and Zn responded to the remarkable economic development of the Yangtze River Basin. Of particular interest, the construction of the Three Gorges Dam (TGD) in 2003 possibly induced a significant increase in the heavy metal levels in the coastal ECS, and the ban on leaded gasoline in China induced a remarkable decrease in Pb levels. Although heavy metal levels have increased since the 1930s, the coastal mud area of the ECS remains under low ecological risk.

  5. Spatial-temporal variations of dominant drought/flood modes and the associated atmospheric circulation and ocean events in rainy season over the east of China

    NASA Astrophysics Data System (ADS)

    Huang, Shaoni; Huang, Fei

    2012-06-01

    By using Season-reliant Empirical Orthogonal Function (S-EOF) analysis, three dominant modes of the spatial-temporal evolution of the drought/flood patterns in the rainy season over the east of China are revealed for the period of 1960-2004. The first two leading modes occur during the turnabout phase of El Niño-Southern Oscillation (ENSO) decaying year, but the drought/flood patterns in the rainy season over the east of China are different due to the role of the Indian Ocean (IO). The first leading mode appears closely correlated with the ENSO events. In the decaying year of El Niño, the associated western North Pacific (WNP) anticyclone located over the Philippine Sea persists from the previous winter to the next early summer, transports warm and moist air toward the southern Yangtze River in China, and leads to wet conditions over this entire region. Therefore, the precipitation anomaly in summer exhibits a `Southern Flood and Northern Drought' pattern over East China. On the other hand, the basin-wide Indian Ocean sea surface temperature anomaly (SSTA) plays a crucial role in prolonging the impact of ENSO on the second mode during the ENSO decaying summer. The Indian Ocean basin mode (IOBM) warming persists through summer and unleashes its influence, which forces a Matsuno-Gill pattern in the upper troposphere. Over the subtropical western North Pacific, an anomalous anticyclone forms in the lower troposphere. The southerlies on the northwest flank of this anticyclone increase the moisture transport onto central China, leading to abundant rainfall over the middle and lower reaches of the Yangtze River and Huaihe River valleys. The anomalous anticyclone causes dry conditions over South China and the South China Sea (SCS). The precipitation anomaly in summer exhibits a `Northern Flood and Southern Drought' pattern over East China. Therefore, besides the ENSO event the IOBM is an important factor to influence the drought/flood patterns in the rainy season over

  6. Bottom-up and top-down controls on picoplankton in the East China Sea

    NASA Astrophysics Data System (ADS)

    Guo, C.; Liu, H.; Zheng, L.; Song, S.; Chen, B.; Huang, B.

    2013-05-01

    Dynamics of picoplankton population distribution in the East China Sea (ECS), a marginal sea in the western North Pacific Ocean, were studied during two "CHOICE-C" cruises in August 2009 (summer) and January 2010 (winter). Dilution experiments were conducted during the two cruises to investigate the growth and grazing among picophytoplantkon populations. Picoplankton accounted for an average of ~29% (2% to 88%) of community carbon biomass in the ECS on average, with lower percentages in plume region than in shelf and kuroshio regions. Averaged growth rates (μ) for Prochlorococcus (Pro), Synechococcus (Syn) and picoeukaryotes (peuk) were 0.36, 0.89, 0.90 d-1, respectively, in summer, and 0.46, 0.58, 0.56 d-1, respectively, in winter. Seawater salinity and nutrient availability exerted significant controls on picoplankton growth rate. Averaged grazing mortality (m) were 0.46, 0.63, 0.68 d-1 in summer, and 0.22, 0.32, 0.22 d-1 in winter for Pro, Syn and peuk respectively. The three populations demonstrated very different distribution patterns regionally and seasonally affected by both bottom-up and top-down controls. In summer, Pro, Syn and peuk were dominant in Kuroshio, transitional and plume regions respectively. Protist grazing consumed 84%, 78%, 73% and 45%, 47%, 57% of production for Pro, Syn and peuk in summer and winter respectively, suggesting more significant top-down controls in summer. In winter, all three populations tended to distribute in offshore regions, although the area of coverage was different (peuk > Syn > Pro). Bottom-up factors can explain as much as 91.5%, 82% and 81.2% of Pro, Syn and peuk abundance variance in winter, while only 59.1% and 43.7% for Pro and peuk in summer. Regionally, Yangtze River discharge plays a significant role in affecting the intensity of top-down control, indicated by significant and negative association between salinity and grazing mortality of all three populations and higher grazing mortality to growth rate ratio

  7. Remote sensing observations and numerical studies of a super typhoon-induced suspended sediment concentration variation in the East China Sea

    NASA Astrophysics Data System (ADS)

    Li, Yangdong; Li, Xiaofeng

    2016-08-01

    By integrating remote sensing observations and a numerical modeling technique, we studied the influences of super Typhoon Saomai on the suspended sediment concentration (SSC) in the Yangtze River estuary and its adjacent coastal areas in the East China Sea. First, three consecutive Moderate Resolution Imaging Spectroradiometer (MODIS) images acquired during the post-typhoon stage were used to estimate the SSC. Then, we implemented a hydrodynamic model, including a sediment transport module, based on Delft3D to simulate the sediment erosion, re-suspension, transport and deposition processes in the study area during the passage of Typhoon Saomai. The model-simulated water level was validated against the in situ station data to show the feasibility of the model. The simulated SSC results agree reasonably well with the satellite observations. Time series of the simulation results showed that the model revealed the whole SSC variations during this extreme weather event and made up for the scarcity of in-situ and satellite observations. SSC significantly increased during the passage of the typhoon and decreased gradually during the post-typhoon stage. Modeled results also reveal that the spring-neap tidal effect significantly controlled the distribution and variation of SSC in the shallower coastal water (<20-30 m in depth) and the typhoon-induced re-suspension is evident in most of the study area, especially in the coastal waters near the Yangtze River estuary and Hangzhou Bay during the passage of the typhoon. Finally, based on the simulation results, we discuss the dynamic mechanisms including turbulent energy, bed shear stress and vertical mixing that caused the SSC variation.

  8. Distribution patters of mobile mud in the East China Sea: elucidated from particle size, radionuclides and magnetic analysis

    NASA Astrophysics Data System (ADS)

    Wang, J.; Du, J.; Zhang, W.; Zhang, J.

    2013-12-01

    Submarine surface sediments due to resuspension may return to water column followed by particles sedimentation on the seabed. Therefore, particulate material in estuarine and coastal environments would be typically deposited and resuspended several times before permanent accumulation or transport offshore. The suspension and mobile sediments, referred to be "mobile mud" definated by high water content(≥0.30) and no-decay 210Pbex vertical distribution, play an important role in the biogeochemical cycles in the estuarine/coastal area. In the present work, the spatial and temporal distribution of thickness, grain-size in the mobile mud of the East China Sea were conducted by May and August, 2011. Most mobile mud are distributed along the coast and north offshore, and the thick mud layer (≥2cm) is featured with fine grain size, high water content and TOC, exhibiting the activeness of mobile mud. The total amount of mobile mud in the East China Sea is ten times in comparison with annual sediment discharge from the Changjiang River. The maximum of mobile mud thickness and 7Be activity in May was distributed in the south coast, but that in August was distributed in the north coast. The mobile mud HIRM was relatively large both in May and August, but the north coast HIRM in August was larger than that in May. All these change of mobile mud thickness, nuclides and magnetic properties indicated that the mobile mud formation mechanism has the different patterns in the different region.The north coastal mobile mud formation is dominated by the Changjiang Diluted Water, and in the south is controlled by the monsoon-influenced Zhejiang-Fujian coastal current. The main source of mobile mud near the inshore is predominantly input from the Changjiang River. However, most mobile mud in the north offshore may be originally derived from the Changjiang River and old Huanghe River. Compared south offshore with thin layer of mobile mud, the north offshore mobile mud formation

  9. Health Status, Cognitive and Motor Development of Young Children Adopted from China, East Asia, and Russia across the First 6 Months after Adoption

    ERIC Educational Resources Information Center

    Pomerleau, Andree; Malcuit, Gerard; Chicoine, Jean-Francois; Seguin, Renee; Belhumeur, Celine; Germain, Patricia; Amyot, Isabelle; Jeliu, Gloria

    2005-01-01

    We compared health status, anthropometric and psychological development of 123 children adopted before 18 months of age from China, East Asia (Vietnam, Taiwan, Thailand, South Korea, Cambodia), and Eastern Europe (mostly Russia). Data were collected close to the time of arrival, and 3 and 6 months later. Anthropometric measures included weight,…

  10. Nonlinear effect on the East Asian summer monsoon due to two coexisting anthropogenic forcing factors in eastern China: an AGCM study

    NASA Astrophysics Data System (ADS)

    Deng, Jiechun; Xu, Haiming

    2016-06-01

    Two anthropogenic forcing factors dominate in eastern China: aerosols and urban land cover. Usually, aerosols induce surface cooling while urban land cover causes surface warming. It is important to explore whether or not a nonlinear effect may result from the coexistence of these two opposing effects, and to what extent such nonlinear effect may become significant in affecting the climate change in East Asia. In this study, the Community Atmosphere Model version 5.1 (CAM5.1) coupled with the Community Land Model version 4 (CLM4) is employed to investigate the nonlinear effect on the East Asian summer monsoon due to the coexistence of aerosols and urban land cover. The anthropogenic forcing can be studied by including only aerosol emissions, only urban land cover, or a combination of the two in eastern China. The nonlinear effect obtained in CAM5.1 is evident in eastern China to offset the urbanization effect. Large-scale atmospheric response produces anomalous upward motion and increases total cloud amount and precipitation. This increased total cloud amount and its associated negative shortwave cloud forcing in turn significantly decrease surface air temperature and cool the troposphere, especially in northern China, resulting in a reduced land-sea thermal contrast, which acts to weaken the prevailing southwesterly wind over the Yangtze River Valley and southwestern China and to enhance the wind over the northern South China Sea. The nonlinear effect also indirectly excites strong convection over southern China, leading to a pronounced increase in summer precipitation.

  11. Teaching East Asia: China, Japan, Korea. Lesson Plans for Middle School Teachers. Volume II.

    ERIC Educational Resources Information Center

    Beville, Francie; Boone, Mark; Chapman, Kelly; Crump, Claudia; Curtis, Lonnie; Erickson, Stacy; Kaiser-Polge, Tami; Klus, John A.; Luebbehusen, Mary Lou; Rea, Patrick S.; Ward, Mary E.

    This volume contains 23 lesson plans that were written for middle school teachers to help students learn about East Asia. The lessons are organized across six themes: (1) "People, Places & Environment"; (2) "Technology, Production, Distribution & Consumption"; (3) "Cultures, Continuity, and Change"; (4) "Aesthetics, Celebrations and Values"; (5)…

  12. Teaching East Asia: China, Japan, Korea. Lesson Plans for Middle School Teachers. Volume I.

    ERIC Educational Resources Information Center

    Aiken, Geoff; Benton, Susan; Duvall, James; Eltzroth, Diane; Hooyberg, Astrid; Keim, Marilee; Norris, Elizabeth; Smith, Peggy; Vogel, Kathy; Williams, Steven

    This volume contains 40 lesson plans that were written for middle school teachers to help students learn about East Asia. The lessons are organized across five themes: (1) "People, Places & Environment"; (2) "Technology, Production, Distribution & Consumption"; (3) "Cultures, Continuity, Change"; (4) Institutions, Power & Government"; and (5)…

  13. Application of CEDA and ASPIC computer packages to the hairtail ( Trichiurus japonicus) fishery in the East China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Liu, Qun

    2013-01-01

    Surplus-production models are widely used in fish stock assessment and fisheries management due to their simplicity and lower data demands than age-structured models such as Virtual Population Analysis. The CEDA (catch-effort data analysis) and ASPIC (a surplus-production model incorporating covariates) computer packages are data-fitting or parameter estimation tools that have been developed to analyze catch-and-effort data using non-equilibrium surplus production models. We applied CEDA and ASPIC to the hairtail ( Trichiurus japonicus) fishery in the East China Sea. Both packages produced robust results and yielded similar estimates. In CEDA, the Schaefer surplus production model with log-normal error assumption produced results close to those of ASPIC. CEDA is sensitive to the choice of initial proportion, while ASPIC is not. However, CEDA produced higher R 2 values than ASPIC.

  14. Reduction of primary production and changing of nutrient ratio in the East China Sea: Effect of the Three Gorges Dam?

    NASA Astrophysics Data System (ADS)

    Gong, Gwo-Ching; Chang, Jeng; Chiang, Kuo-Ping; Hsiung, Tung-Ming; Hung, Chin-Chang; Duan, Shui-Wang; Codispoti, L. A.

    2006-04-01

    It has been documented that the global proliferation of dam construction on the major river has reduced nutrient and sediment loading to coastal environments. As a consequence, dams can impact marine ecological systems by changing nutrient concentrations and ratios in the coastal zone. From 1998-2004, we conducted a high resolution oceanographic investigation of the East China Sea (ECS) before and after the first filling phase (June 2003) of the Three-Gorges Dam (TGD). We found that the Si:N ratio in the River affected region changed from 1.5 in 1998 to 0.4 in 2004 with sediment loading significantly reducing (about 55%) at the Datong station after June 2003. Most importantly, we found that the PP had declined by 86% between 1998 and 2003, both measured during the high flood season. The results suggest that the ECS ecosystem may respond sensitively to changes in the nutrient supply arising from the TGD project.

  15. Impact of monsoon-driven circulation on phytoplankton assemblages near fringing reefs along the east coast of Hainan Island, China

    NASA Astrophysics Data System (ADS)

    Li, Y.; Wang, D. R.; Su, J.; Zhang, J.

    2013-11-01

    taken into account in scientific management of fringing coral reefs health of the east coast of Hainan Island, especially during northeast monsoon season when blooming specie cells (such as N. scintillans) could be introduced from eutrophic South China mainland coast to the east coast of Hainan Island and piled to high-abundance at fringing reefs by monsoonal hydrodynamics.

  16. Seasonal circulation patterns of the Yellow and East China Seas derived from satellite-tracked drifter trajectories and hydrographic observations

    NASA Astrophysics Data System (ADS)

    Lie, Heung-Jae; Cho, Cheol-Ho

    2016-08-01

    We investigated seasonal circulation patterns of the Yellow and East China Seas (YECS), by reviewing previous works on the circulation and its dominant currents, and taking into account newly-compiled trajectories of satellite-tracked drifters collected between the 1980s and 2000s. The circulation patterns suggested before the 1990s can be categorized into two groups, depending on the identified origin of the Tsushima Warm Current in the Korea-Tsushima Straits: (i) branching from the Kuroshio southwest of Kyushu, or (ii) northeastward continuation of the Taiwan Strait throughflow. The branching of the Kuroshio southwest of Kyushu and northeast of Taiwan was clearly evidenced by current measurements and concurrent hydrographic surveys. However, there is still no clear evidence for the northeastward pathway of Taiwan Strait throughflow across the mid-shelf area of the East China Sea. Target-oriented surveys in the 1990s and 2000s employing advanced instruments, such as drifter tracking and acoustic Doppler current profiler measurements, now provide decisive proof of the clockwise rounding of the Cheju Warm Current around Jeju-do throughout the year, of the northeastward extension of Changjiang discharge in summer, and of the presence of the Yellow Sea Warm Current only in winter. Thus, both coastal currents in shallow water and secondary branch currents of the Kuroshio (such as the Yellow Sea Warm Current) are found to significantly change from winter to summer. To better present the basic pattern of YECS circulation and its seasonality, we have constructed seasonal circulations patterns, based on review results, on the newly-compiled drifter trajectories, and on hydrographic observations. Further investigations should be carried out in future, with support of comprehensive current measurements on shelf areas and through elaborate numerical modeling.

  17. Alongshore and cross-shore circulations and their response to winter monsoon in the western East China Sea

    NASA Astrophysics Data System (ADS)

    Huang, Daji; Zeng, Dingyong; Ni, Xiaobo; Zhang, Tao; Xuan, Jiliang; Zhou, Feng; Li, Jia; He, Shuangyan

    2016-02-01

    An array of four bottom-mounted acoustic Doppler current profilers (ADCPs) were deployed during the winter of 2008 (28 December 2008 to 12 March 2009) along a cross-shelf section in the western East China Sea to investigate the winter circulation and its response to wind. During the observation period, the observed subtidal currents exhibit coherent spatial structure and temporal variation in terms of their mean (seasonal), trend (intra-seasonal), and synoptic variability. The subtidal currents are polarized roughly in the alongshore direction parallel to local isobaths, and the weak cross-shore current is closely linked to the alongshore component. The temporal variation of the currents follows the rhythm of wind stress, sea level, and sea level difference at the synoptic scale. The mean currents are basically composed of two anti-parallel currents in the alongshore direction: the East China Sea coastal current (ECSCC) flows southwestward along the inner shelf and the Taiwan warm current (TWC) flows in the opposite direction along the outer-shelf. The strongest current occurs over the mid-shelf as a coastal jet. The intra-seasonal currents exhibit an expansion and intensification of the ECSCC along with shrinking and weakening the alongshore component of the TWC. There is a significant increase in onshore current particularly over the mid-shelf. The fluctuations of synoptic currents show a significant positive correlation with wind stress, and the fluctuations are negatively correlated with sea level and sea level difference. The coherent spatial structure of the currents indicates that the depth-independent column motion is related to the sea level difference through a barotropic pressure gradient. The vertical shear of currents is related to the density-related baroclinic pressure gradient in the whole water column and to the friction within the surface and bottom boundary layers.

  18. Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians

    PubMed Central

    Curnoe, Darren; Xueping, Ji; Herries, Andy I. R.; Kanning, Bai; Taçon, Paul S. C.; Zhende, Bao; Fink, David; Yunsheng, Zhu; Hellstrom, John; Yun, Luo; Cassis, Gerasimos; Bing, Su; Wroe, Stephen; Shi, Hong; Parr, William C. H.; Shengmin, Huang; Rogers, Natalie

    2012-01-01

    Background Later Pleistocene human evolution in East Asia remains poorly understood owing to a scarcity of well described, reliably classified and accurately dated fossils. Southwest China has been identified from genetic research as a hotspot of human diversity, containing ancient mtDNA and Y-DNA lineages, and has yielded a number of human remains thought to derive from Pleistocene deposits. We have prepared, reconstructed, described and dated a new partial skull from a consolidated sediment block collected in 1979 from the site of Longlin Cave (Guangxi Province). We also undertook new excavations at Maludong (Yunnan Province) to clarify the stratigraphy and dating of a large sample of mostly undescribed human remains from the site. Methodology/Principal Findings We undertook a detailed comparison of cranial, including a virtual endocast for the Maludong calotte, mandibular and dental remains from these two localities. Both samples probably derive from the same population, exhibiting an unusual mixture of modern human traits, characters probably plesiomorphic for later Homo, and some unusual features. We dated charcoal with AMS radiocarbon dating and speleothem with the Uranium-series technique and the results show both samples to be from the Pleistocene-Holocene transition: ∼14.3-11.5 ka. Conclusions/Significance Our analysis suggests two plausible explanations for the morphology sampled at Longlin Cave and Maludong. First, it may represent a late-surviving archaic population, perhaps paralleling the situation seen in North Africa as indicated by remains from Dar-es-Soltane and Temara, and maybe also in southern China at Zhirendong. Alternatively, East Asia may have been colonised during multiple waves during the Pleistocene, with the Longlin-Maludong morphology possibly reflecting deep population substructure in Africa prior to modern humans dispersing into Eurasia. PMID:22431968

  19. Cross-shelf variation in carbon-to-chlorophyll a ratios in the East China Sea, summer 1998

    NASA Astrophysics Data System (ADS)

    Chang, Jeng; Shiah, Fuh-Kwo; Gong, Gwo-Ching; Chiang, Kuo Ping

    2003-03-01

    Spatial variations of the phytoplankton carbon-to-chlorophyll a ratio (C:chl a) in the East China Sea were investigated during a June 1998 cruise. Based on a regression analysis between particulate organic carbon and chlorophyll a concentrations measured at 2-m depths, estimated values of C:chl a were 13.0 and 92.8 g g -1 for coastal and offshore waters, respectively. In addition, water samples were collected from 5-m depths at three stations with different hydrographic characteristics, and phytoplankton carbon biomass was estimated from microscope-measured cell volumes. At the coastal zone station, chlorophyll a concentration reached 7.9 mg m -3 with Skeletonema costatum as the dominant species. The total phytoplankton carbon was 142.8 mg m -3, and the estimated C:chl a was 18.0 g g -1. At the midshelf station, Synechococcus spp. and Pseudosolenia calcar-avis were the major contributors to phytoplankton carbon. The chlorophyll a concentration was 1.3 mg m -3, and C:chl a was 67.4 g g -1. In contrast, chlorophyll a concentration decreased to 0.1 mg m -3 at the Kuroshio station, where the filamentous cyanobacteria Trichodesmium spp., contributed to most of the phytoplankton carbon, and C:chl a was estimated to be 94.4 g g -1. The C:chl a ratios estimated by the two methods were in close agreement, and a linear relationship was established between the logarithm of chlorophyll a concentration and phytoplankton carbon. The estimated carbon biomass was used to calculate intrinsic growth rates of phytoplankton in the East China Sea. The results indicate that phytoplankton grow actively in the coastal zone, with growth rates often higher than 1.4 day -1, but much lower rates were observed near the margin of the continental shelf.

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

    SciTech Connect

    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.

  1. Formation of the modern current system in the East China Sea since the early Holocene and its relationship with sea level and the monsoon system

    NASA Astrophysics Data System (ADS)

    Zheng, Xufeng; Li, Anchun; Wan, Shiming; Jiang, Fuqing; Yin, Xueming; Lu, Jian

    2015-07-01

    The Okinawa Trough is a natural laboratory for the study of air-sea interaction and paleoenvironmental change. It has been demonstrated that present offshore export of particles in the bottom nepheloid layer occur primarily with downwelling from the northeast winter monsoon, which is inhibited by a transverse circulation pattern in summer. This current system was very different during the Last Glacial Maximum owing to low sea level (-120 m) and exposure of a large shelf area. We collected sediment core Oki01 from the middle Okinawa Trough during 2012 using R/V Kexue No. 1 to elucidate the timing and cause of the current system transition in the East China Sea. Clay mineral, dry density, and elemental (Ti, Ca) composition of core Oki01 was analyzed. The results indicate that clay minerals derived mainly from the Huanghe (Yellow) and the Changjiang (Yangtze) Rivers during 16.0-11.6 ka, and the modern current system in the East China Sea formed beginning in the early Holocene. Therefore, mixing of East China Sea continental shelf, Changjiang River and partially Taiwan Island sediment are the major contributors. The decrease of log(Ti/Ca) and alternating provenance since the early Holocene indicate less sediment from the East China in summer because of resistance of the modern current system, i.e., a "water barrier" and upwelling. Conversely, sediment delivery persists in winter and log(Ti/Ca) indicates the winter monsoon signal since the early Holocene. Our evidence also suggests that sediment from Taiwan Island could be transported by the Kuroshio Current to the middle Okinawa Trough, where it mingles with winter monsoon-induced export of sediment from the Changjiang River and East China Sea continental shelf. Although the present research advances understanding of the evolutionary history of paleoenvironmental change in the Okinawa Trough, more sediment cores should be retrieved over wide areas to construct a larger scenario.

  2. 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.

    PubMed

    Han, Zhi-Qiang; Han, Gang; Wang, Zhi-Yong; Gao, Tian-Xiang

    2015-01-01

    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. PMID:25654225

  3. 210Pb, 137Cs and 239,240Pu in East China Sea Sediments: Sources, Pathways and Budgets of Sediments and Radionuclides

    NASA Astrophysics Data System (ADS)

    Su, C.; Huh, C.

    2001-05-01

    Profiles of 210Pb, 137Cs and 239,240Pu measured in eighty-three sediment cores collected from various sedimentary regimes in the East China Sea were analyzed to elucidate the sources, routes and budgets of sediments as well as these radionuclides. Distributions of sedimentation rates and nuclide inventories reveal alongshore transport of sediments, 137Cs and 239,240Pu from the mouth of the Yangtze River toward the south, and it is largely confined to the inner-shelf area (water depth <70 m). Mass balance calculations of the budgets of nuclides suggest that the East China Sea is a sink for the particle-reactive 210Pb and 239,240Pu, with up to 20% of their sedimentary budgets supplied via boundary scavenging. In contrast, due to lower affinity of 137Cs for particles and rapid turnover of the shelf water, the East China Sea serves as a source for 137Cs. About two-thirds of the cumulative inputs of 137Cs have been transported out of the East China Sea, leaving the remaining one-third in sediments and the overlying water column. As for the sediment budget, mass balance can not be established due to a shortfall in sediment supply of more than 30% based on a comparison between input terms documented thus far and the sedimentation flux derived from this study. It could be that our sedimentation rates are overestimated, and/or that long-distance transport from the Yellow River's dispersal system to the ECS is underestimated previously. Alternatively, there is no reason to expect the attainment of equilibrium between sediment input and output in the East China Sea on decadal time scales.

  4. Observations of flow variability through the Kerama Gap between the East China Sea and the Northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Na, Hanna; Wimbush, Mark; Park, Jae-Hun; Nakamura, Hirohiko; Nishina, Ayako

    2014-02-01

    The Kerama Gap, near the middle of the Ryukyu Island chain, is the deepest channel with a sill depth of 1050 m connecting the East China Sea (ECS) to the Northwestern Pacific. We measured the flow through the Kerama Gap from June 2009 to June 2011. The 2 year mean transport, 2.0 ± 0.7 Sv, is into the ECS from the Northwestern Pacific; it contributes about 11% of the mean Kuroshio transport in the ECS at the PN line. Subtidal standard deviation of the transport through the Kerama Gap is 3.2 Sv, comparable to that of the PN-line Kuroshio transport (4.0 Sv), suggesting a significant effect of Kerama Gap transport on temporal variability of the Kuroshio transport in the ECS. Comparison with time series of satellite-measured sea surface height maps reveals that temporal variability of the Kerama Gap transport is related to the arrival of mesoscale eddies from the east: high (low) transport into the ECS is associated with the presence of a cyclonic (anticyclonic) eddy south of the Kerama Gap.

  5. Spatial and seasonal characteristics of dissolved heavy metals in the east and west Guangdong coastal waters, South China.

    PubMed

    Zhang, Ling; Shi, Zhen; Zhang, JingPing; Jiang, Zhijian; Wang, Fei; Huang, Xiaoping

    2015-06-15

    Heavy metal concentrations and physicochemical parameters in seawater were measured in Guangdong coastal waters, South China. Results showed that the concentrations and distribution of heavy metals varied spatially and seasonally. Generally, heavy metal concentrations in the east regions were higher than in the west. Concentrations of Pb, Zn, Cd and Cr in wet seasons were generally higher than in dry seasons owing to the seasonal differences of the river discharge, rainfall and seawater intrusion. Principal component (PC) analysis showed that PC1, PC2 and PC3 in the east were correlated to Pb+Cr+Zn+Cd, As+Cd and Cu, respectively, and they were correlated to Pb+Cr, Zn+Cu+Cd and As+Cu, respectively, in the west. That was maybe due to the differences of local heavy metal sources. The anthropogenic activities contributed more to the main sources of heavy metals, and contamination factors indicated that Zn and Pb pollution was serious in study area. PMID:25840866

  6. Lagrangian Coherent Structures (LCS) and the dispersion of algal bloom and marine debris in the Yellow and East China Sea

    NASA Astrophysics Data System (ADS)

    Kim, Y. H.; Choi, B.; Son, Y. B.; Shim, W. J.; Hwang, J. H.; Park, Y.

    2012-12-01

    Series of satellite images show that the development and migration of green macroalgal bloom (known as Ulva prolifera) in the Yellow Sea (YS) and Eastern China Sea (ECS). This presentation will utilize the Lagrangian Coherent Structures (LCS) analysis to demonstrate the dispersion pattern of algal bloom patches. Analyzing LCS such as stable and unstable manifolds is one of emerging technologies for characterizing Lagrangian pathways in aquatic environments. This approach is based on the assumption that unstable manifolds such as ridges (i.e., high values) in the finite-time Lyapunov exponent (FTLE) fields coincide with material transport barriers. In this study, the FTLE fields were computed from gridded trajectories using flow fields provided by Regional Ocean Modeling System (ROMS) in the YS/ECS during summer 2011. The results show that there exist two strong transport barriers that lie along the east-west direction, at least, for the simulation period; one is located from the north of Changjiang River mouth to the middle of the Yellow Sea and the other one is stretched from the south of Shandong Peninsular toward east/southeast. This LCS analysis suggests that patches of green algae developed in the coastal region of Jiangsu Province during summer may migrate toward east into the middle of the YS or even toward Korean coast rather than extending along the Jiangsu coast, which is consistent with the observation results derived from the satellite ocean color data. In the very same manner, the utilization of LCS results to evaluate the distribution/transport pattern of marine debris in the YS/ECS will also be discussed during the presentation.

  7. Mapping surface tidal currents and Changjiang plume in the East China Sea from Geostationary Ocean Color Imager

    NASA Astrophysics Data System (ADS)

    Hu, Zifeng; Wang, Dong-Ping; Pan, Delu; He, Xianqiang; Miyazawa, Yasumasa; Bai, Yan; Wang, Difeng; Gong, Fang

    2016-03-01

    The spatial pattern of the semidiurnal M2 tidal currents in the East China Sea (ECS) is mapped from the Geostationary Ocean Color Imager (GOCI), taking advantage of the satellite's unique 8 hourly local daytime sequential images. The GOCI-derived surface M2 tidal currents are validated with a comprehensive set of twenty-eight surface drifters and four mooring observations. The agreement is outstanding with the error variance less than 10% of the total variance. The gridded GOCI-derived tidal currents are also in good agreement with the Oregon State University (OSU) high-resolution regional tidal model of the China Seas. The detided mean flow shows a strong Changjiang plume extending hundreds of kilometers offshore, in agreement with the concurrent satellite sea surface temperature (SST) and sea surface salinity (SSS) distributions. The observed surface currents are compared with the daily mean flows derived from the Japan Coastal Ocean Predictability Experiment (JCOPE2). The model results are consistent with the observations, showing the sensitivity of Changjiang plume to wind forcing. The study clearly demonstrates the utility of geostationary satellite in mapping the surface currents over a wide (˜400 km), tidally dominated continental shelf.

  8. Impacts of wind forcing on sea level variations in the East China Sea: Local and remote effects

    NASA Astrophysics Data System (ADS)

    Li, Yanfang; Zuo, Juncheng; Lu, Qing; Zhang, Hua; Chen, Meixiang

    2016-02-01

    The regional sea level variation in the East China Sea (ECS) was influenced not only by local factors but also by remote wind from adjoining ocean with the oceanic connectivity influenced by upper-ocean circulation. The satellite altimeter observations showed that from 1993 to 2008, the inter-annual sea level variation in the ECS was negatively related to the strength of Kuroshio. To investigate the relative role of local and remote wind, two sensitive experiments were carried out using the POP model. Model experiments revealed that wind-induced redistributions of water played a significant role in the sea level variation of the ECS. The seasonal variations were induced by both local winds and remote Pacific wind stress with approximately equal contribution. However, on the inter-annual sea level variations, the remote wind forcing over the North Pacific could contribute substantially more than that of local wind which modulated sea level immediately. Remote wind influenced the China Sea in forms of changing of wind stress curl and ocean currents, which influenced the intensity of the Kuroshio, especially during El Nino episodes.

  9. Paroctonchus nanjiensis gen. nov., sp. nov. (Nematoda, Enoplida, Oncholaimidae) from intertidal sediments in the East China Sea.

    PubMed

    Shi, Benze; Xu, Kuidong

    2016-01-01

    Paroctonchus nanjiensis gen. nov., sp. nov. is described from a sand beach in the China Nanji Islands Natural Reserve in the East China Sea. Paroctonchus nanjiensis is distinct in the family Oncholaimidae in having more than three teeth, a character found otherwise only in the monotypic genera Octonchus and Patagonema. The new genus and species differs from Octonchus and Patagonema in the number and pattern of teeth, bearing three large teeth with the left ventrosublateral one the largest plus about 27 small teeth distributed on the wall of buccal cavity. By contrast, Octonchus possesses one large tooth plus eight small teeth, while Patagonema has three large teeth with the right ventrosublateral one the largest plus 12 small teeth on three mandibular ridges. Moreover, Paroctonchus nanjiensis differs from Octonchus also in position of the amphidial aperture (located in the middle portion of buccal cavity vs. at the base of buccal cavity), and from Patagonema in the absence of a demanian system (vs. present) and the presence of two subventral rows of wart-like precloacal supplements (vs. a ventral row of papillate supplements). We provide an improved diagnosis for the subfamily Octonchinae, and discuss the evolution of teeth in the family Oncholaimidae. PMID:27395574

  10. The intensification of the East Asian winter monsoon contributed to the disappearance of Cedrus (Pinaceae) in southwestern China

    NASA Astrophysics Data System (ADS)

    Su, Tao; Liu, Yu-Sheng (Christopher); Jacques, Frédéric M. B.; Huang, Yong-Jiang; Xing, Yao-Wu; Zhou, Zhe-Kun

    2013-09-01

    Climate change during the Quaternary played an important role in the distribution of extant plants. Herein, cone scales of Cedrus (Pinaceae) were uncovered from the Upper Pliocene Sanying Formation, Longmen Village, Yongping County of Yunnan Province in southwestern China. Detailed comparisons show that these fossils all belong to the genus Cedrus (Pinaceae), and a new species is proposed, Cedrus angusta sp. nov. This find expands the known distribution of Cedrus during the Late Pliocene to Yunnan, where the genus no longer exists in natural forests. Based on the analysis of reconstructed Neogene climate data, we suggest that the intensification of the East Asian winter monsoon during the Quaternary may have dramatically increased seasonality and given rise to a much drier winter in Yunnan. Combined with information on Cedrus fossil records and its seed physiology, we conclude that the intensification of a drier climate after the Late Pliocene may have prevented the survival of Cedrus seedlings, leading to the eventual disappearance of Cedrus in western Yunnan. This study indicates that the topography in southwestern China acted as a vital refuge for many plants during the Quaternary, but that other species gradually disappeared due to the intensification of the monsoonal climate.

  11. Impact of urban land-use change in eastern China on the East Asian subtropical monsoon: A numerical study

    NASA Astrophysics Data System (ADS)

    Yu, Rong; Jiang, Zhihong; Zhai, Panmao

    2016-04-01

    The effect of urban land-use change in eastern China on the East Asian subtropical monsoon (EASTM) is investigated by using the Community Atmosphere Model version 5.1. Comparison of the results between the urban expansion and reference experiments shows that with the urban expansion, the land surface energy balance alters: surface net radiation and sensible heat fluxes enhance while the latent heat fluxes reduce. As a result, a significant increase in surface air temperature over eastern China is detected. The urban land-use change contributes to a change in the zonal land-sea temperature difference (LSTD), leading to a delay in the time when LSTD changes from positive to negative, and vice versa. Additionally, the onset and retreat dates of the EASTM are also delayed. Meanwhile, the rise in surface air temperature leads to formation of abnormal northerly air flows, which may be the reason for the slower northward movement of the EASTM and a more southward location of its northern boundary.

  12. Three new and two known free-living marine nematode species of the family Ironidae from the East China Sea.

    PubMed

    Chen, Yu Zhen; Guo, Yu Qing

    2015-01-01

    Three new and two known species of free-living marine nematodes of the family Ironidae from the East China Sea are described and illustrated. Conilia sinensis sp. nov. is identified by the relatively large body size (1883-2399 µm); the well developed lips; the number, shape and length of spicule (single and striated, length 87-100 µm as arc); the shape of telamon; the number of supplements (1). Pheronous donghaiensis sp. nov. is characterized by its sharp tail point; caudal gland absent; buccal cavity armed with four big solid teeth and rows of minute denticles; spicules stout, with central septum at proximal end, male caudal region with two rows of small conical subventral papillae. Trissonchulus latispiculum sp. nov. can be distinguished by its head not set off from remaining body, tail short and blunt, buccal cavity with minute denticles, spinneret opening slightly ventrally, spicule broad and alate with central septum and head on proximal end. Trissonchulus benepapillosus (Schulz, 1935) and Trissonchulus oceanus Cobb 1920 which are first reported from China, are redescribed in detail with emphasis on new or hitherto poorly described morphological features. Types are deposited in the Institute of Oceanology, Chinese Academy of Sciences. PMID:26624035

  13. Learning Cities in East Asia: Japan, the Republic of Korea and China

    ERIC Educational Resources Information Center

    Han, SoongHee; Makino, Atsushi

    2013-01-01

    Lifelong learning cities emerged in Japan in the 1980s and 1990s; in the Republic of Korea in the 2000s and 2010s; and in China mostly from 2000 onwards. They were a countermeasure to the increasing challenges of global as well as post-industrial uncertainties at the turn of the century, when cities were trying to find governmental instruments to…

  14. High-quality heat flow determination from the crystalline basement of the south-east margin of North China Craton

    NASA Astrophysics Data System (ADS)

    Jiang, Guangzheng; Tang, Xiaoyin; Rao, Song; Gao, Peng; Zhang, Linyou; Zhao, Ping; Hu, Shengbiao

    2016-03-01

    Very few of heat flow data have come from the crystalline basement in the North China Craton but rather from boreholes in the sedimentary cover of oil-gas basins. Explorations for hot dry rock (HDR) geothermal resources and porphyry gold deposits in eastern China offer now valuable opportunities to study the terrestrial heat flow in the crystalline basement. In this study, we obtained continuous temperature logs from two boreholes (the LZ borehole with a depth of 3471 m and the DR borehole with a depth of 2179 m) located in the south-east margin of the North China Craton. The boreholes have experienced long shut-in times (442 days and 261 days for the LZ borehole and DR borehole, respectively); thus, it can be expected that the temperature conditions have re-equilibrated after drilling and drill-mud circulation. Rock thermal conductivity and radiogenic heat production were measured for 68 crystalline rock samples from these two boreholes. The measured heat-flow density was determined to be 71.8 ± 2.3 mW m-2 (for the LZ borehole) and 91.5 ± 1.2 mW m-2 (for the DR borehole). The heat flow for the LZ borehole is close to the value of 75 mW m-2 determined in the Chinese Continental Scientific Drilling main hole (CCSD MH), both being in the Sulu-Dabie orogenic belt and thus able to verify each other. The value for the DR borehole is higher than the above two values, which supports former high heat-flow values determined in the Bohai Bay Basin.

  15. Implications of East Asian summer and winter monsoons for interannual aerosol variations over central-eastern China

    NASA Astrophysics Data System (ADS)

    Cheng, Xugeng; Zhao, Tianliang; Gong, Sunling; Xu, Xiangde; Han, Yongxiang; Yin, Yan; Tang, Lili; He, Hongchang; He, Jinhai

    2016-03-01

    Air quality change is generally driven by two factors: pollutant emissions and meteorology, which are difficult to distinguish via observations. To identify the contribution of meteorological factor to air quality change, an aerosol simulation from 1995 to 2004 with the global air quality model GEM-AQ/EC was designed without year-to-year changes in the anthropogenic aerosol (including sulfate and organic and black carbon) emissions over the 10-year span. To assess the impact of interannual variations of East Asian monsoon (EAM) on air quality change in China, this modeling study focused on the region of central-eastern China (CEC), a typical East Asian monsoon (EAM) region with high anthropogenic aerosol emissions. The simulation analysis showed that the interannual variability in surface aerosols over CEC was driven by fluctuation in meteorological factors associated with EAM changes. Large amplitudes of interannual variability in surface aerosol concentrations reaching 20-30% relative to the 10-year averages were found over southern CEC in summer and over northern CEC in winter. The weakened near-surface winds of EAMs in both summer and winter were significantly correlated with aerosol increases over most areas of CEC. The summer and winter monsoon changes enhance the surface aerosol concentrations with increasing trend rates exceeding 30% and 40% over the southern and northern CEC region, respectively, during the 10 years. The composite analyses of aerosol concentrations in weak and strong monsoon years revealed that positive anomalies in surface aerosol concentrations during weak summer monsoon years were centered over the vast CEC region from the North China Plain to the Sichuan Basin, and the anomaly pattern with "northern higher" and "southern lower" surface aerosol levels was distributed over CEC in weak winter monsoon years. Aerosol washout by summer monsoon rainfall exerted an impact on CEC aerosol distribution in summer; aerosol dry depositions in

  16. Fractional iron solubility of aerosol particles enhanced by biomass burning and ship emission in Shanghai, East China.

    PubMed

    Fu, H B; Shang, G F; Lin, J; Hu, Y J; Hu, Q Q; Guo, L; Zhang, Y C; Chen, J M

    2014-05-15

    In terms of understanding Fe mobilization from aerosol particles in East China, the PM2.5 particles were collected in spring at Shanghai. Combined with the backtrajectory analysis, the PM2.5/PM10 and Ca/Al ratios, a serious dust-storm episode (DSE) during the sampling was identified. The single-particle analysis showed that the major iron-bearing class is the aluminosilicate dust during DSE, while the Fe-bearing aerosols are dominated by coal fly ash, followed by a minority of iron oxides during the non-dust storm days (NDS). Chemical analyses of samples showed that the fractional Fe solubility (%FeS) is much higher during NDS than that during DSE, and a strong inverse relationship of R(2)=0.967 between %FeS and total atmospheric iron loading were found, suggested that total Fe (FeT) is not controlling soluble Fe (FeS) during the sampling. Furthermore, no relationship between FeS and any of acidic species was established, suggesting that acidic process on aerosol surfaces are not involved in the trend of iron solubility. It was thus proposed that the source-dependent composition of aerosol particles is a primary determinant for %FeS. Specially, the Al/Fe ratio is poorly correlated (R(2)=0.113) with %FeS, while the apparent relationship between %FeS and the calculated KBB(+)/Fe ratio (R(2)=0.888) and the V/Fe ratio (R(2)=0.736) were observed, reflecting that %FeS could be controlled by both biomass burning and oil ash from ship emission, rather than mineral particles and coal fly ash, although the latter two are the main contributors to the atmospheric Fe loading during the sampling. Such information can be useful improving our understanding on iron solubility on East China, which may further correlate with iron bioavailability to the ocean, as well as human health effects associated with exposure to fine Fe-rich particles in densely populated metropolis in China. PMID:24607631

  17. Interdecadal Variations of East Asian Monsoon as Inferred by Tree-ring Data From Northeastern Qaidam Basin, Northwestern China

    NASA Astrophysics Data System (ADS)

    Shao, X.; Huang, L.; Yin, Z.; Guo, Q.

    2006-12-01

    East Asian monsoon is crucial for modulating the climate in China. Especially, the summer monsoon is closely related to the severe flood and drought events in eastern China. To study the characteristics of summer monsoon a long-term record is needed. In this study we attempted to examine the interdecadal variations of East Asian monsoon by using tree-ring data. The summer monsoon index (Ism) for the period of 1873- 2000 was calculated using sea level pressure data. Firstly, we calculated the difference (ΔP) of the sea level pressure between the land (110ºE) and sea (160ºE) from 10ºN to 50ºN with 5º intervals. Then the ΔP values that are smaller than or equal to -5 hPa in June, July and August were summed and defined as the Ism. By this definition Ism values greater than 1.0 represent strong monsoon conditions, and vice versa. Sea level pressure data prior to 1951 were obtained from the Meteorological Office of United Kingdom, and that afterwards were from the NCEP data set. The tree ring data of Qilian junipers (Sabina przewalskii Kom.) are from the northeastern part of the Qaidam Basin, located along the northeastern margin of the Qinghai-Tibetan Plateau. These tree-ring data have been used to reconstruct local precipitation and soil moisture conditions. Previous studies have revealed that there was a teleconnection in rainfall between eastern China and the Qinghai-Tibetan Plateau. We examined the relationships of the ring-width series with the Ism series over the common period of 1873-2000 AD. We found that the tree-ring widths were statistical significantly correlated with Ism. These negative correlations increased significantly after a low-pass filter was used for both data sets, indicating very good potential for reconstruction of low-frequency variations of Ism in the past. Variability of the Ism series and ring-width series were examined using power spectrum analysis and wavelet transformation. The reconstructed Ism values during the period 1440

  18. GIS/RS-based Integrated Eco-hydrologic Modeling in the East River Basin, South China

    NASA Astrophysics Data System (ADS)

    Wang, Kai

    Land use/cover change (LUCC) has significantly altered the hydrologic system in the East River (Dongjiang) Basin. Quantitative modeling of hydrologic impacts of LUCC is of great importance for water supply, drought monitoring and integrated water resources management. An integrated eco-hydrologic modeling system of Distributed Monthly Water Balance Model (DMWBM), Surface Energy Balance System (SEBS) was developed with aid of GIS/RS to quantify LUCC, to conduct physically-based ET (evapotranspiration) mapping and to predict hydrologic impacts of LUCC. To begin with, in order to evaluate LUCC, understand implications of LUCC and provide boundary condition for the integrated eco-hydrologic modeling, firstly the long-term vegetation dynamics was investigated based on Normalized Difference Vegetation Index (NDVI) data, and then LUCC was analyzed with post-classification methods and finally LUCC prediction was conducted based on Markov chain model. The results demonstrate that the vegetation activities decreased significantly in summer over the years. Moreover, there were significant changes in land use/cover over the past two decades. Particularly there was a sharp increase of urban and built-up area and a significant decrease of grassland and cropland. All these indicate that human activities are intensive in the East River Basin and provide valuable information for constructing scenarios for studying hydrologic impacts of LUCC. The physically-remote-sensing-based Surface Energy Balance System (SEBS) was employed to estimate areal actual ET for a large area rather than traditional point measurements . The SEBS was enhanced for application in complex vegetated area. Then the inter-comparison with complimentary ET model and distributed monthly water balance model was made to validate the enhanced SEBS (ESEBS). The application and test of ESEBS show that it has a good accuracy both monthly and annually and can be effectively applied in the East River Basin. The results of

  19. To promote peaceful and collaborative resolution of maritime territorial disputes in the South China Sea and its environs and other maritime areas adjacent to the East Asian mainland.

    THOMAS, 112th Congress

    Rep. Faleomavaega, Eni F. H. [D-AS-At Large

    2012-08-02

    09/12/2012 Committee Agreed to Seek Consideration Under Suspension of the Rules, (Amended) by Unanimous Consent. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  20. Atmospheric gaseous elemental mercury (GEM) over a coastal/rural site downwind of East China: Temporal variation and long-range transport

    NASA Astrophysics Data System (ADS)

    Ci, Zhijia; Zhang, Xiaoshan; Wang, Zhangwei; Niu, Zhenchuan

    2011-05-01

    Although much attention has been paid to the mercury pollution in China, limited field studies have been conducted to explore the atmospheric behavior of mercury. To investigate the temporal variation and long-range transport of atmospheric gaseous elemental mercury (GEM or Hg(0)), the GEM measurements covering four different seasons were performed at a coastal/rural site of the Yellow Sea downwind of East China. Hourly mean concentrations of GEM measured by RA-915+ mercury analyzer over the entire study (four different time periods between July 2007 and May 2009) were 2.31 ± 0.74 ng m -3 with a range of 1.12-7.01 ng m -3. The results showed moderate seasonal variations with high levels in cold seasons (winter: 2.53 ± 0.77 ng m -3 and spring: 2.34 ± 0.54 ng m -3) and low levels in warm seasons (summer: 2.28 ± 0.82 ng m -3 and fall: 2.16 ± 0.84 ng m -3). Over the each campaign a diurnal variation of GEM was observed consistently with peak levels in daytime and low levels in late night and early morning. The pollution rose and NOAA-HYSPLIT back-trajectory model analyses indicated that the elevated GEM was transported to the sampling site from the regional sources of East China and Korea peninsula-Japan. Air masses originated from the East China Sea and the regions of Continental East Asia with low emission strengths of atmospheric mercury (e.g., the east Russia, the north Inner Mongolia and the Bohai Sea) showed the decreased GEM levels.

  1. Identification and molecular characterization of two begomoviruses from Pouzolzia zeylanica (L.) Benn. exhibiting yellow mosaic symptoms in adjacent regions of China and Vietnam.

    PubMed

    Tang, Y F; Du, Z G; He, Z F; Brown, Judith K; She, X M

    2014-10-01

    Two monopartite begomoviruses were isolated from Pouzolzia zeylanica (L.) Benn. plants showing yellow mosaic symptoms in Gaoyao, Guangdong Province, China (GD1) and in Phu Tho, Vietnam (VN), respectively. A comparison of the complete genome sequence of GD1 (2,739 nucleotides [nt]) with VN (2,741 nt) indicated that they shared 86.2 % nt sequence identity. GD1 and VN shared the highest nucleotide sequence identity at 86.7 % and 91.4 % respectively, with isolate TY01 of pouzolzia golden mosaic virus (PGMV-TY01), another begomovirus isolated from P. zeylanica. Phylogenetic analysis revealed that GD1, VN, and PGMV-TY01 were members of a distinct begomovirus clade. Based on the ICTV guidelines for begomoviral species demarcation, GD1 belongs to a new begomovirus species, for which the name Pouzolzia yellow mosaic virus is proposed. Likewise, VN represents a previously unreported strain of PGMV. Recombination analysis predicted that VN was a recombinant between PGMV-TY01 and ageratum yellow vein China virus isolate G13 (AYVCNV-G13), and that PGMV-TY01 and VN were likely the parents of GD1 through recombination with allamanda leaf curl virus isolate G10 (AlLCV-G10), a begomovirus endemic to Guangdong Province of China. PMID:24838912

  2. Impact of the East Asian summer monsoon on long-term variations in the acidity of summer precipitation in Central China

    NASA Astrophysics Data System (ADS)

    Ge, B. Z.; Wang, Z. F.; Xu, X. B.; Tang, J.; He, Y. J.; Uno, I.; Ohara, T.

    2011-02-01

    The acidity of precipitation has been observed at stations of the Acid Rain Monitoring Network run by the China Meteorological Administration (CMA-ARMN) since 1992. Previous studies have shown that different long-term trends exist in different regions but detailed analysis of the causes of these is lacking. In this paper, we analyze summertime precipitation acidity data from the CMA-ARMN during 1992-2006 using EOFs and show that the summertime pH in China had different trends before and after 2000. The most significant decrease of pH is found in Central China. To investigate the causes of this decrease of pH in summer, we explore the relationship between changes in the pH value, the East Asian summer monsoon index, rainfall data, and pollutants emissions. We find that the East Asian summer monsoon can significantly affect the acidity of summer precipitation in Central China. In strong monsoon years, the pH in Central China is about 0.33 lower than that in weak monsoon years. Chemical transport model simulations using fixed emissions indicate that about 65% of the pH value difference (i.e., 0.22) is related to the summer monsoon, and constitutes 18-36% of the observed pH change (0.6∼1.2) in Central China during 1992-2006. Further studies reveal a relationship between the pH in Central China and the rainfall in the middle and lower reaches of the Yangtze River (MLYR), which can explain about 24% of the variance of pH in Central China. Simulations using an annually varying emission inventory show that at least 60% of the variation in precipitation acidity in Central China can be attributed to changes in pollutant emissions. Therefore, the increase in emissions of acidic species is the most important cause for the observed decrease of pH in Central China, and changes in meteorological factors, such as rainfall and other parameters related to the East Asian summer monsoon, play a less important but still significant role.

  3. Impact of the East Asian summer monsoon on long-term variations in the acidity of summer precipitation in Central China

    NASA Astrophysics Data System (ADS)

    Ge, B. Z.; Wang, Z. F.; Xu, X. B.; Tang, J.; He, Y. J.; Uno, I.; Ohara, T.

    2010-08-01

    The acidity of precipitation has been observed at stations of the Acid Rain Monitoring Network run by the China Meteorological Administration (CMA-ARMN) since 1992. Previous studies have shown that different long-term trends exist in different regions but detailed analysis of the causes of these is lacking. In this paper, we analyze summertime precipitation acidity data from the CMA-ARMN during 1992-2006 using EOFs and show that the summertime pH in China had different trends before and after 2000. The most significant decrease of pH is found in Central China. To investigate the causes of this decrease of pH in summer, we explore the relationship between changes in the pH value, the East Asian summer monsoon index, rainfall data, and pollutants emissions. We find that the East Asian summer monsoon can significantly affect the acidity of summer precipitation in Central China. In strong monsoon years, the pH in Central China is about 0.33 lower than that in weak monsoon years. Chemical transport model simulations using fixed emissions indicate that about 65% of the pH value difference (i.e., 0.22) is related to the summer monsoon, and constitutes 18-36% of the observed pH change (0.6-1.2) in Central China during 1992-2006. Further studies reveal a teleconnection between the pH in Central China and the rainfall in the middle and lower reaches of the Yangtze River (MLYR), which can explain about 24% of the variance of pH in Central China. Simulations using an annually varying emission inventory show that at least 60% of the variation in precipitation acidity in Central China can be attributed to changes in pollutant emissions. Therefore, the increase in emissions of acidic species is the most important cause for the observed decrease of pH in Central China, and changes in meteorological factors, such as rainfall and other parameters related to the East Asian summer monsoon, play a less important but still significant role.

  4. Epidemiology and transmission characteristics of human adenovirus type 7 caused acute respiratory disease outbreak in military trainees in East China

    PubMed Central

    Cheng, Jun; Qi, Xiaoping; Chen, Dawei; Xu, Xujian; Wang, Guozheng; Dai, Yuzhu; Cui, Dawei; Chen, Qingyong; Fan, Ping; Ni, Liuda; Liu, Miao; Zhu, Feiyan; Yang, Mei; Wang, Changjun; Li, Yuexi; Sun, Changgui; Wang, Zhongyong

    2016-01-01

    Background: Human adenovirus type 7 (HAdV7) is globally attracting great concern as its high morbidity and severity in respiratory diseases, especially in Asia. Objective: To investigate the clinical and epidemiologic characteristics of HAdV7 infection outbreak in East China. Methods: The clinical samples were collected from the patients of an ARD outbreak in East Chinafor the detection of causative pathogens by multiplex PCR. The molecular type of human adenovirus isolates were identified by sequencing and homologous comparison based on their hexon genes. The spatiotemporal dynamics of global HAdV7 was investigated using the phylogenetic and phylogeographic analyses. Total 67 referenced HAdV7 hexon sequences (>800 bp) from GenBank were selected for constructing the maximum likelihood tree by MEGA 5.1.0, grouped according to the tree topology for the further migration analysis by PAUP* 4.0 and MigraPhyla 1.0 b to understand the transmission patterns of HAdV7 in global epidemics. Results: The results showed HAdV7 as the causative pathogen in this outbreak, and the outbreak strains had the hexon sequences highly identical with the isolates in Shaanxi (2012). The origin of HAdV7 was inferred as California, meanwhile a total of 21 migration routes were acquired. HAdV7 in this outbreak was statistically proven dispersed from Shaanxi province (2012). Conclusions: The analyses of epidemiology and transmission pattern of HAdV7 would not only enrich the molecular biological basic database but also provide theoretical basis for HAdV7 prevention and control strategy. PMID:27347341

  5. [Effect of stock abundance and environmental factors on the recruitment success of small yellow croaker in the East China Sea].

    PubMed

    Liu, Zun-lei; Yuan, Xing-wei; Yang, Lin-lin; Yan, Li-ping; Zhang, Hui; Cheng, Jia-hua

    2015-02-01

    Multiple hypotheses are available to explain recruitment rate. Model selection methods can be used to identify the best model that supports a particular hypothesis. However, using a single model for estimating recruitment success is often inadequate for overexploited population because of high model uncertainty. In this study, stock-recruitment data of small yellow croaker in the East China Sea collected from fishery dependent and independent surveys between 1992 and 2012 were used to examine density-dependent effects on recruitment success. Model selection methods based on frequentist (AIC, maximum adjusted R2 and P-values) and Bayesian (Bayesian model averaging, BMA) methods were applied to identify the relationship between recruitment and environment conditions. Interannual variability of the East China Sea environment was indicated by sea surface temperature ( SST) , meridional wind stress (MWS), zonal wind stress (ZWS), sea surface pressure (SPP) and runoff of Changjiang River ( RCR). Mean absolute error, mean squared predictive error and continuous ranked probability score were calculated to evaluate the predictive performance of recruitment success. The results showed that models structures were not consistent based on three kinds of model selection methods, predictive variables of models were spawning abundance and MWS by AIC, spawning abundance by P-values, spawning abundance, MWS and RCR by maximum adjusted R2. The recruitment success decreased linearly with stock abundance (P < 0.01), suggesting overcompensation effect in the recruitment success might be due to cannibalism or food competition. Meridional wind intensity showed marginally significant and positive effects on the recruitment success (P = 0.06), while runoff of Changjiang River showed a marginally negative effect (P = 0.07). Based on mean absolute error and continuous ranked probability score, predictive error associated with models obtained from BMA was the smallest amongst different

  6. Three Gorges Dam controls sediment coarsening of the mud patch on the inner East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Miao, Anyang; Chu, Zhongxin; Li, Yingkun

    2016-06-01

    The well-known Three Gorges Dam (TGD) within the Yangtze catchment launched its operation in 2003. The effect of the TGD operation on the sediment size on the East China Sea shelf is rarely known. High resolution (0.5 cm sampling) grain size analysis and 137Cs and 210Pb dating of the DH8-1 core were conducted with core collected from the distal part of a main sink for the modern Yangtze sediment entering the sea, the Min-Zhe Coastal Mud Deposits (MZCMD) on the inner East China Sea shelf. The 137Cs dating results show that the core DH8-1 formed during 1946-2012 with a mean deposition rate of 0.65 cm yr-1, indicating that the 0.5 cm sampling for grain size analysis in this local area could reflect environmental changes generally on a one-year time scale. The mean grain size of DH8-1 core sediment that deposited after 2003 is significantly larger than that deposited during 1988-2002. After ruling out other possible factors, we infer that the sediment coarsening of DH8-1 core after 2003 is attributed to the TGD operation which causes the erosion of the Yangtze subaqueous delta. Specifically, the TGD operation significantly intensifies the declining trend of the Yangtze sediment loads to the sea despite no decreased water discharge, which results in extensive erosion of the Yangtze subaqueous delta. The relatively coarse sediment of the subaqueous delta is eroded and resuspended by ocean dynamics and then transported by coastal current, finally depositing on the MZCMD area. In addition, the general sediment fining of core DH8-1 that deposited during 1988-2002, comparing with 1946-1987, is mainly caused by dam construction and soil and water conservation within the Yangtze catchment. Our findings are helpful for better understanding the effects of such a huge dam as the TGD on a sediment sink like the MZCMD of such a large river as the Yangtze River.

  7. Characterizing distributions, composition profiles, sources and potential health risk of polybrominated diphenyl ethers (PBDEs) in the coastal sediments from East China Sea.

    PubMed

    Wang, Guoguang; Peng, Jialin; Zhang, Dahai; Li, Xianguo

    2016-06-01

    Sediment samples (n = 20) were collected from Yangtze River Estuary (YRE) and the adjacent East China Sea (ECS) inner shelf to explore spatial and temporal distributions, environmental fate, sources and potential health risk of polybrominated diphenyl ethers (PBDEs). Concentrations of BDE-209 and total 7 PBDEs (without BDE-209; ∑7PBDEs) ranged from 62.3 to 1758 pg g(-1) and from 36.9 to 233.6 pg g(-1) dry weight, respectively; both of the highest values occurred near the city of Wenzhou. Concentrations of BDE-209 and ∑7PBDEs both indicated a decreasing trend from inshore areas toward outer shelf. Significantly positive linear correlations were only observed between logBDE-183 concentrations and TOC/grain size (r(2) = 0.6734 and 0.5977 for TOC and grain size, respectively) as well as BDE-209 and TOC/grain size (r(2) = 0.4137 and 0.5332 for TOC and grain size, respectively) in the north of 28(°)N, indicating that YR had significant influence on the distribution of higher brominated congeners only in the north part. Depth profiles of PBDEs in a sediment core P01 (n = 1, m = 11) collected from YRE showed that the input of BDE-209 gradually increased from 1930 to 2010, while the levels of ∑7PBDEs peaked in 1986 and obviously decreased in recent years. Partial Least-Squares Regression (PLSR) revealed that PBDEs in the coastal ECS were mainly from direct discharge of local anthropogenic activities (80.7%), followed by surface runoff of contaminated soils (15.1%), microbial degradation after sedimentation (2.6%) and photodegradation during atmospheric transportation (1.6%). The cancer risk of human exposure to BDE-209 at the 95% confidence level was 3.09 × 10(-7), 1.67 × 10(-7) and 8.86 × 10(-7) for children, teens and adults, respectively, significantly lower than the threshold level (10(-6)). Hazard index (HI) calculated for non-cancer risk was also far less than 1 for the three groups, suggesting no non-cancer risk. PMID:26970872

  8. Stable isotope ratios reveal food source of benthic fish and crustaceans along a gradient of trophic status in the East China Sea

    NASA Astrophysics Data System (ADS)

    Chang, Ni-Na; Shiao, Jen-Chieh; Gong, Gwo-Ching; Kao, Shuh-Ji; Hsieh, Chih-hao

    2014-08-01

    The East China Sea (ECS) receives large quantities of particulate organic matter (POM) and inorganic nutrients transported from the Changjiang (Yangtze River), which have produced high productivity in the northwestern ECS. This study evaluated potential contributions of terrigenous POM (allochthonous food source) and nutrient-induced marine production (autochthonous source) to the ECS benthic ecosystem by analyzing stable isotopic compositions of phytoplankton, zooplankton, benthic crustaceans and fish. Benthic consumers exhibited δ13C values similar to those of their autochthonous food sources (i.e., phytoplankton and zooplankton), revealing their major reliance on marine production. In contrast, the δ13C values of benthic fish (-19.6‰ to -13.5‰) and crustaceans (-18.9‰ to -15.0‰) were much higher than that of terrigenous POM (-25.7‰), which generally accounted for less than 20% of the most fish diet. Phytoplankton and zooplankton generally exhibited higher δ13C values at eutrophic and highly productive inshore sites than at oligotrophic offshore sites. This enrichment of inshore δ13C values was mainly attributed to lower photosynthetic fractionation during algal blooms, an effect that was further enhanced during flood period of the Changjiang. The δ13C values of demersal fish assemblages were also significantly higher at inshore sites and decreased seaward. However, fish δ15N values and their estimated trophic levels showed relatively small spatial variation. The disproportionate variations in δ13C and δ15N values suggested that the enriched C isotopic signatures derived from an elevated δ13C baseline of the inshore food web instead of trophic enrichment of the isotopic ratios. The significantly positive correlations between concentrations of chlorophyll a and nutrients versus fish δ13C provided further evidence for the use of pelagic algal bloom materials by inshore consumers. The isotopic and oceanographic survey data suggested that

  9. Chemical characterization of aerosols at the summit of Mountain Tai in Central East China

    NASA Astrophysics Data System (ADS)

    Deng, C.; Zhuang, G.; Huang, K.; Li, J.; Zhang, R.; Wang, Q.; Liu, T.; Sun, Y.; Guo, Z.; Fu, J. S.; Wang, Z.

    2011-07-01

    PM2.5 and TSP samples were collected at the summit of Mountain Tai (MT) (1534 m a.s.l.) in spring 2006/2007 and summer 2006 to investigate the characteristics of aerosols over central eastern China. For comparison, aerosol samples were also collected at Tazhong, Urumqi, and Tianchi in Xinjiang in northwestern China, Duolun and Yulin in northern China, and two urban sites in the megacities, Beijing and Shanghai, in 2007. Daily mass concentrations of TSP and PM2.5 ranged from 39.6-287.6 μg m-3 and 17.2-235.7 μg m-3 respectively at the summit of MT. Averaged concentrations of PM2.5 showed a pronounced seasonal variation with higher concentration in summer than spring. 17 water-soluble ions (SO42-, NO3-, Cl-, F-, PO43-, NO2-, CH3COO-, CH2C2O42-, C2H4C2O42-, HCOO-, MSA, C2O42-, NH4+, Ca2+, K+, Mg2+, Na+), and 19 elements of all samples were measured. SO42-, NO3-, and NH4+ were the major water-soluble species in PM2.5, accounting for 61.50 % and 72.65 % of the total measured ions in spring and summer, respectively. The average ratio of PM2.5/TSP was 0.37(2006) and 0.49(2007) in spring, while up to 0.91 in summer, suggesting that aerosol particles were primarily comprised of fine particles in summer and of considerable coarse particles in spring. Crustal elements (e.g., Ca, Mg, Al, Fe, etc.) showed higher concentration in spring than summer, while most of the pollution species (SO42-, NO3-, K+, NO2-, NH4+, Cl-, organic acids, Pb, Zn, Cd, and Cr) from local/regional anthropogenic emissions or secondary formation presented higher concentration in summer. The ratio of Ca/Al suggested the impact of Asian dust from the western deserts on the air quality in this region. The high concentration of K+ in PM2.5 (4.41 μg m-3) and its good correlation with black carbon (r = 0.90) and oxalic acid (r = 0.87) suggested the severe pollution from biomass burning, which was proved to be a main source of fine particles over central eastern China in summer. The contribution of biomass

  10. Development of a Plug-and-Play Monitoring System for Cabled Observatories in the East China Sea

    PubMed Central

    Yu, Yang; Xu, Huiping; Xu, Changwei

    2015-01-01

    Seafloor observatories enable long term, continuous and multidisciplinary observations, promising major breakthroughs in marine environment research. The effort to remotely control in situ multidisciplinary equipment performing individual and cooperative tasks is both a challenge and a guarantee for the stable operations of functional observatories. With China starting to establish ocean observatory sensor networks, in this study we describe a monitoring system for cabled observatories in the East China Sea (ESOMS) that enables this effort in a plug and play way. An information oriented monitoring architecture for ESOMS was first introduced, derived from a layered control model for ocean observatory sensor network. The architecture contained three components and enabled bidirectional information flow of observation data and commands, based on which architecture components were designed to enable plug-and-play control within related model layers. A control method enabled by general junction box (GJB) and ocean sensor markup language (OSML) was thus proposed as the plug-and-play solution for implementing ESOMS. The GJB-OSML enabled control method (GOE Control Method) mainly actualized two processes, one of which was that the in situ GJB interfaced and represented every attached sensor as a Sensing Endpoint in the cabled observatory network. The other process was that the remote ESOMS utilized the same IP/Port related information modeled by OSML to create/operate a Function Node acted as agent of the in situ sensor. A case study for using ESOMS in the Xiaoqushan Seafloor Observatory was finally presented to prove its performance and applicability. Given this successful engineering trial, the ESOMS design and implementation could be applicable and beneficial for similar efforts in future construction of seafloor observatory network both at home and abroad. PMID:26213931

  11. The effects of rapid urbanization on the levels in tropospheric nitrogen dioxide and ozone over East China

    NASA Astrophysics Data System (ADS)

    Huang, Jianping; Zhou, Chenhong; Lee, Xuhui; Bao, Yunxuan; Zhao, Xiaoyan; Fung, Jimmy; Richter, Andreas; Liu, Xiong; Zheng, Yiqi

    2013-10-01

    Over the past few decades, China has experienced a rapid increase in urbanization. The urban built-up areas (population) in Beijing, Shanghai, and Guangzhou increased by 197% (87%), 148% (65%), and 273% (25%), respectively, from 1996 to 2011. We use satellite retrieval data to quantify the effects of rapid urbanization on the yearly and seasonal changes in tropospheric nitrogen dioxide (NO2) over East China. The results show that rapid urbanization has a profound effect on tropospheric columns of NO2. During 1996-2011, the tropospheric columns of NO2 over the surrounding areas of Guangzhou, Shanghai, and Beijing increased by 82%, 292%, and 307%, respectively. The tropospheric columns of NO2 reach their maximum in winter and minimum in spring. The anthropogenic emissions related to urbanization are a dominant factor in the long-term changes in the yearly and seasonal mean tropospheric columns of NO2, whereas meteorological conditions such as the prevailing winds and precipitation account for the unique spatial patterns. Around the time of the 2008 Beijing Olympic Games, the tropospheric columns of NO2 over Beijing urban area significantly reduced by 48% in July, 35% in August, and 49% in September, relative to the same monthly averages over 2005-2007. However, this trend was reversed after the Games, and the increased rate was even larger than before. Our results show that the tropospheric NO2 above the three regions increased at rates 1.3-8 times faster than the rates in a recent inventory estimate of NOx emissions for 2000-2010. We also discuss the influence of urbanization on tropospheric ozone and find that the Ozone Monitoring Instrument (OMI) retrieval tropospheric column shows that ozone levels are relatively insensitive to urbanization and changes in tropospheric NO2.

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

    PubMed

    Cai, Deling; Li, Hongyan; Tang, Qisheng; Sun, Yao

    2005-12-01

    Stable carbon and nitrogen isotope ratios (delta (13)C and delta (15)N) 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. PMID:16483132

  13. ADV-based estimates of sediment settling velocity on the shelf of the Yellow and East China seas: evidence of marked seasonal and intra-tidal variations

    NASA Astrophysics Data System (ADS)

    Bian, Changwei; Mao, Xinyan; Jiang, Wensheng; Gu, Yanzhen

    2015-02-01

    Sediment settling velocity ( w s) patterns are well established at the Huanghe and Changjiang river mouths, but no w s results have been reported for the Yellow Sea and the East China Sea (YSECS) shelves due to the labor-intensive and time-consuming aspect of traditional w s measurement approaches (e.g., settling column method). This disadvantage can be overcome by the acoustic Doppler velocimeter (ADV). In this study, ten ADV-based field campaigns were conducted over various seasons of the years 2011 and 2013 at six YSECS sites, five on the East China Sea shelf (28 to 87 m depth) and one on the Yellow Sea shelf (74 m depth). The results demonstrate that ADV backscatter was a reliable proxy of suspended sediment concentration over a measurement range of 1 to 1,000 mg/L. The ADV-estimated w s was highest (1.43-1.88 mm/s) in summer in the southern East China Sea, and lowest (0.07 mm/s) in spring in the northern Yellow Sea. This can plausibly be explained by the hydrodynamic environment and bottom sediment type at the campaign sites. More importantly, the data reveal evidence of marked seasonal variations of w s in the middle sector of the East China Sea, as well as intra-tidal variations at all campaign sites. However, these variations of w s are not directly regulated by current velocity or suspended sediment concentration. This aspect represents a major challenge in future research in this shelf region and, for that matter, in similar settings worldwide. Evidently, expanding on the well-resolved continuous time series provided by the ADV approach is a key step in this direction.

  14. Spatio-temporal variability of satellite derived aerosol optical thickness and ground measurements over East China

    NASA Astrophysics Data System (ADS)

    Meng, Fei; Shi, Tongguang

    2016-04-01

    Two-year records of Visible Infrared Imaging Radiometer Suite (VIIRS) Intermediate Product (IP) data on the aerosol optical thickness (AOT) at 550 nm were evaluated by comparing them with sun-sky radiometer measurements from the Chinese sun hazemeter network (CSHNET) and the aerosol robotic network (AERONET). The monthly and seasonal variations in the aerosol optical properties over eastern China were then investigated using collocated VIIRS IP data and CSHNET and AERONET measurements.Results show that the performances of the current VIIRS IP AOT retrievals at the provisional stage were consistent with ground measurements. Similar characteristics of seasonal and monthly variations were found among the measurements, though the observational methodologies were different, showing maxima in the summer and spring and minima in the winter and autumn.

  15. The Time-lagged Impacts of Spring Sensible Heat over the Tibetan Plateau on the Summer Rainfall Anomaly in East China: Cases Study by Using WRF Model

    NASA Astrophysics Data System (ADS)

    Duan, A.

    2014-12-01

    This study explores the time-lagged impacts of the spring sensible heat (SH) source over the Tibetan Plateau (TP) on summer rainfall anomaly in east China by using the WRF model. Numerical experiments for the 2003 case indicates that spring SH anomaly over the TP can maintains its impact until summer and leads to the overall strong atmospheric heat source, which is characterized by the enhanced both SH over the western TP and condensation latent heat to the east. The wave activity diagnosis revealed that the enhanced TP heating forces a Rossby wave train to the downstream regions. The cyclonic response to the northeast TP brings about the low level northerly anomaly over the northern China, while the anticyclonic response over the western Pacific enhances the subtropical high and the low level southerly in its western flank. As a result, cold and dry airflows from mid-high latitudes and warm and wet airflows from tropical oceans converge around the Huaihe River basin. In addition, warm advection originated from the TP induces vigorous ascending motion over the convergence belt. With such a favourable circulation condition, the eastward propagating vortexes initiated over the TP intensify the torrential rainfall processes over the Huaihe River basin. Another case study of 2001 with weak spring SH over the TP and the overall southward retreat of summer rainfall belt in east China further demonstrates the role of spring SH over the TP in regulating the interannual variability of EASM in terms of wave activity and synoptic disturbance.

  16. Study on the seasonal variation of the suspended sediment distribution and transportation in the East China Seas based on SeaWiFS data

    NASA Astrophysics Data System (ADS)

    Wang, Wenjuan; Jiang, Wensheng

    2008-11-01

    The monthly mean suspended sediment concentration in the upper layer of the East China Seas was derived from the retrieval of the monthly binned SeaWiFS Level 3 data during 1998 to 2006. The seasonal variation and spatial distribution of the suspended sediment concentration in the study area were investigated. It was found that the suspended sediment distribution presents apparent spatial characteristics and seasonal variations, which are mainly affected by the resuspension and transportation of the suspended sediment in the study area. The concentration of suspended sediment is high inshore and low offshore, and river mouths are generally high concentration areas. The suspended sediment covers a much wider area in winter than in summer, and for the same site the concentration is generally higher in winter. In the Yellow and East China Seas the suspended sediment spreads farther to the open sea in winter than in summer, and May and October are the transitional periods of the extension. Winds, waves, currents, thermocline, halocline, pycnocline as well as bottom sediment feature and distribution in the study area are important influencing factors for the distribution pattern. If the 10 mg L-1 contour line is taken as an indicator, it appears that the transportation of suspended sediment 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 and the Kuroshio Current in the southern Yellow Sea and the East China Sea.

  17. Heavy metal enrichments in the Changjiang (Yangtze River) catchment and on the inner shelf of the East China Sea over the last 150 years.

    PubMed

    Guo, Yanwei; Yang, Shouye

    2016-02-01

    Compositions of heavy metals including Cu, Zn, Cr and Pb in three sediment cores recovered from the lower basin of the Changjiang (Yangtze River) and the inner shelf mud of the East China Sea were analyzed by traditional X-ray florescence (XRF) and XRF Core Scanner. This study aims to investigate the accumulation of heavy metals in the fluvial sediments and to decipher the influence of anthropogenic activities within the large catchment over the last 150 years. The data suggest that the heavy metals, especially Pb and Zn, show obvious enrichments in concentrations since 1950s, and the small and consistent variations of heavy metal concentrations before 1950s can represent geochemical background values. After removing the grain size effect on elemental concentrations, we infer that the sources of heavy metals predominantly come from natural weathering detritus, while human contamination has increased over the last half century. The calculations of both enrichment factor and geoaccumulation index, however, indicate that the pollution of these heavy metals in the fluvial and shelf environments is not significant. The rapid increase in human activities and fast socioeconomic development in the Changjiang catchment and East China over the last five decades accounts for the enrichments of heavy metals in the river and marine sediments. The inner shelf of the East China Sea, as the major sink of the Changjiang-derived fine sediments, provides a high-resolution sediment archive for tracing the anthropogenic impacts on the catchment. PMID:26580732

  18. Genetic differentiation of water buffalo (Bubalus bubalis) populations in China, Nepal and south-east Asia: inferences on the region of domestication of the swamp buffalo.

    PubMed

    Zhang, Y; Vankan, D; Zhang, Y; Barker, J S F

    2011-08-01

    Data from three published studies of genetic variation at 18 microsatellite loci in water buffalo populations in China (18 swamp type, two river type), Nepal (one wild, one domestic river, one hybrid) and south-east Asia (eight swamp, three river) were combined so as to gain a broader understanding of genetic relationships among the populations and their demographic history. Mean numbers of alleles and expected heterozygosities were significantly different among populations. Estimates of θ (a measure of population differentiation) were significant among the swamp populations for all loci and among the river populations for most loci. Differentiation among the Chinese swamp populations (which was due primarily to just one population) was much less than among the south-east Asian. The Nepal wild animals, phenotypically swamp type but genetically like river type, are significantly different from all the domestic river populations and presumably represent the ancestral Bubalus arnee (possibly with some river-type introgression). Relationships among the swamp populations (D(A) genetic distances, principal component analysis and structure analyses) show the south-east Asian populations separated into two groups by the Chinese populations. Given these relationships and the patterns of genetic variability, we postulate that the swamp buffalo was domesticated in the region of the far south of China, northern Thailand and Indochina. Following domestication, it spread south through peninsular Malaysia to Sumatra, Java and Sulawesi, and north through China, and then to Taiwan, the Philippines and Borneo. PMID:21749419

  19. An estimate of the cross-frontal transport at the shelf break of the East China Sea with the Finite Volume Coastal Ocean Model

    NASA Astrophysics Data System (ADS)

    Isobe, Atsuhiko; Beardsley, Robert C.

    2006-03-01

    The Finite Volume Coastal Ocean Model (FVCOM) is used to estimate the onshore cross-frontal transport at the shelf break of the East China Sea. Boundary conditions of FVCOM are provided by the Princeton Ocean Model simulating ocean currents in the Yellow Sea and East China Sea realistically. One advantage of this study is that the unstructured triangular cell grid of FVCOM resolves complex bottom topography that may trigger Kuroshio frontal waves. It is anticipated that these nonlinear frontal waves enhance the exchange of seawater between the Kuroshio and shelf regions. Kuroshio frontal waves in the model are excited around the location where the bottom slope changes abruptly, and have the phase speed and amplitude consistent with those observed in the East China Sea. In addition, the model reproduces the onshore transport associated with growing frontal waves in the upper and lower layers. On the basis of passive tracer experiments, the annually averaged onshore-transport integrated along the shelf break is estimated to be 0.85 × 106 m3/s.

  20. The Distribution of 18 Enterotoxin and Enterotoxin-Like Genes in Staphylococcus aureus Strains from Different Sources in East China.

    PubMed

    Cheng, Jinghua; Wang, Yan; Cao, Yongzhong; Yan, Wenguang; Niu, Xiaosai; Zhou, Liping; Chen, Jianhao; Sun, Ying; Li, Chenxi; Zhang, Xiaorong; Wu, Yantao

    2016-04-01

    The distribution of 18 staphylococcal enterotoxin (SE) or SE-like (SEl) genes in Staphylococcus aureus strains from different sources in east China was investigated. Among all 496 S. aureus strains, 291 strains carried one or more SE genes. The more frequently occurred genes were sea, seb, seg, selk, sell, selm, selo, and seq; the less frequent occurred genes were sec, selj, and ser. The classic SE genes and the enterotoxin gene cluster (egc) (seg, sei, selm, seln, selo, and/or selu) accounted for 25.67% and 61.68% of all detected genes, respectively. There were three gene clusters (egc, sea-sek-seq, and sed-sej-ser), of which the egc cluster was the important one that could generate novel complexes, and the sea-sek-seq cluster was a close relative to the hospital-acquired methicillin-resistant S. aureus. The SE gene distributions were different among strains of different sources and formed diverse toxin gene profiles. The human- and foodborne-origin strains harbored classic and novel SE and SEl genes, whereas animal-origin strains harbored egc and other novel SE and SEl genes mainly. The foodborne- and human-origin strains were the main dangerous factors of classic staphylococcal foodborne poisoning, whereas the strains (especially from animals) that carried egc and other novel genes mainly should be new potential dangerous factors for food safety. PMID:27074376

  1. Application of a sea surface temperature front composite algorithm in the Bohai, Yellow, and East China Seas

    NASA Astrophysics Data System (ADS)

    Ping, Bo; Su, Fenzhen; Meng, Yunshan; Du, Yunyan; Fang, Shenghui

    2016-05-01

    The oceanic front is a narrow zone in which water properties change abruptly within a short distance. The sea surface temperature (SST) front is an important type of oceanic front, which plays a signifi cant role in many fi elds including fi sheries, the military, and industry. Satellite-derived SST images have been used widely for front detection, although these data are susceptible to infl uence by many objective factors such as clouds, which can cause missing data and a reduction in front detection accuracy. However, front detection in a single SST image cannot fully refl ect its temporal variability and therefore, the long-term mean frequency of occurrence of SST fronts and their gradients are often used to analyze the variations of fronts over time. In this paper, an SST front composite algorithm is proposed that exploits the frontal average gradient and frequency more eff ectively. Through experiments based on MODIS Terra and Aqua data, we verifi ed that fronts could be distinguished better by using the proposed algorithm. Additionally through its use, we analyzed the monthly variations of fronts in the Bohai, Yellow, and East China Seas, based on Terra data from 2000 to 2013.

  2. Bacterial diversity in the surface sediments of the hypoxic zone near the Changjiang Estuary and in the East China Sea.

    PubMed

    Ye, Qi; Wu, Ying; Zhu, Zhuoyi; Wang, Xiaona; Li, Zhongqiao; Zhang, Jing

    2016-04-01

    Changjiang (Yangtze River) Estuary has experienced severe hypoxia since the 1950s. In order to investigate potential ecological functions of key microorganisms in relation to hypoxia, we performed 16S rRNA-based Illumina Miseq sequencing to explore the bacterial diversity in the surface sediments of the hypoxic zone near the Changjiang Estuary and in the East China Sea (ECS). The results showed that numerous Proteobacteria-affiliated sequences in the sediments of the inner continental shelf were related to both sulfate-reducing and sulfur-oxidizing bacteria, suggesting an active sulfur cycle in this area. Many sequences retrieved from the hypoxic zone were also related to Planctomycetes from two marine upwelling systems, which may be involved in the initial breakdown of sulfated heteropolysaccharides. Bacteroidetes, which is expected to degrade high-molecular-weight organic matter, was abundant in all the studied stations except for station A8, which was the deepest and possessed the largest grain size. In addition, dissolved organic carbon, water depth, percentage ratio of clay to silt, salinity, and sedimentary grain size were environmental effectors that shaped the sedimentary microbial community structure. Our results showed that putative Gammaproteobacteria-affiliated sulfur-oxidizing bacteria may not only detoxify hydrogen sulfide produced by sulfate-reducing prokaryotes, but also serve as the primary producers in the marine sediments. Specific groups of aerobic Bacteroidetes and Planctomycetes participated in degrading organic matter, which might contribute to the oxygen depletion in the hypoxic zones. PMID:26817579

  3. Multi-azimuth 3D Seismic Exploration and Processing in the Jeju Basin, the Northern East China Sea

    NASA Astrophysics Data System (ADS)

    Yoon, Youngho; Kang, Moohee; Kim, Jin-Ho; Kim, Kyong-O.

    2015-04-01

    Multi-azimuth(MAZ) 3D seismic exploration is one of the most advanced seismic survey methods to improve illumination and multiple attenuation for better image of the subsurface structures. 3D multi-channel seismic data were collected in two phases during 2012, 2013, and 2014 in Jeju Basin, the northern part of the East China Sea Basin where several oil and gas fields were discovered. Phase 1 data were acquired at 135° and 315° azimuths in 2012 and 2013 comprised a full 3D marine seismic coverage of 160 km2. In 2014, phase 2 data were acquired at the azimuths 45° and 225°, perpendicular to those of phase 1. These two datasets were processed through the same processing workflow prior to velocity analysis and merged to one MAZ dataset. We performed velocity analysis on the MAZ dataset as well as two phases data individually and then stacked these three datasets separately. We were able to pick more accurate velocities in the MAZ dataset compare to phase 1 and 2 data while velocity picking. Consequently, the MAZ seismic volume provide us better resolution and improved images since different shooting directions illuminate different parts of the structures and stratigraphic features.

  4. Alkylphenols in surface sediments of the Yellow Sea and East China Sea inner shelf: occurrence, distribution and fate.

    PubMed

    Duan, Xiao-yong; Li, Yan-xia; Li, Xian-guo; Zhang, Da-hai; Gao, Yi

    2014-07-01

    Alkylphenols (APs) have been found as ubiquitous environmental pollutants with reproductive and developmental toxicity. In this study, APs in surface sediments of the Yellow Sea (YS) and East China Sea (ECS) inner shelf were analyzed to assess influences of riverine and atmospheric inputs of pollutants on the marine environment. NP concentrations ranged from 349.5 to 1642.8 ng/g (average 890.1 ng/g) in the YS sediments and from 31.3 to 1423.7 ng/g (average 750.1 ng/g) in the ECS inner shelf sediments. NP distribution pattern was mainly controlled by the sedimentary environment. OP concentration was 0.8-9.3 ng/g (average 4.7 ng/g) in the YS sediments and 0.7-11.1 ng/g (average 5.1 ng/g) in the ECS sediments. Assessment of the influence of distances from land on OP concentrations provided evidence for the predominance of coastal riverine and/or atmospheric inputs rather than long-range transport. And the biological pump may play an important role for sequestration of OP in the nearshore area. PMID:24411839

  5. Seasonal response of the southern East China Sea shelf water to wind-modulated throughflow in the Taiwan Strait

    NASA Astrophysics Data System (ADS)

    Moon, Jae-Hong; Hirose, Naoki

    2014-02-01

    Seasonal change of the southern East China Sea (ECS) shelf water and its relation to the throughflow in the Taiwan Strait (TS) was examined based on comparative experiments with inserting passive tracers into a regional ocean model. Through analyzing the model output results, we found that from autumn to winter strong northeasterly wind over the TS significantly weakens the outflow from the TS (i.e., flowing into the ECS) and the Kuroshio water intrudes farther shoreward across the northern shelf of Taiwan in response to the weakened outflow. On the other hand, water flowing into the shelf from the TS extends further offshore from spring to summer when the TS throughflow is enhanced by a wind change from northeasterly to southwesterly and the Kuroshio water retreats seaward off the shelf due to the offshore extension of the shelf water. It suggests that the weakening (strengthening) of the TS throughflow could allow (inhibit) shelf-ward Kuroshio water onto the northeastern shelf of Taiwan, emphasizing that the throughflow modulated by a local wind can be an important factor controlling the seasonal variation of the southern ECS shelf water.

  6. Residues and Distribution of Organochlorine Pesticides in Water and Suspended Particulate Matter from Hangzhou Bay, East China Sea.

    PubMed

    Li, Weidong; Yang, Huayun; Jiang, Xia; Liu, Qi; Sun, Yan; Zhou, Jiazhong

    2016-03-01

    The concentrations, distribution, and possible sources of organochlorine pesticides (OCPs) in Hangzhou Bay, East China Sea, were studied by analyzing water column and suspended particulate matter (SPM) samples from 13 sites. The results showed that OCP contamination remains widespread in the area. The OCP concentrations were 2.52-27.99 ng/L in the SPM samples and 1.35-26.36 ng/L in the water column samples. Pattern analysis suggested that both fresh and weathered hexachlorocyclohexane (HCH) were present. Low α-HCH/γ-HCH ratios and high β-HCH and γ-HCH levels contributed to the total HCH concentrations in both the water column and SPM samples. High p,p'-dichlorodiphenyltrichloroethane (DDT)/o,p'-DDT ratios and low (dichlorodiphenyldichloroethylene + dichlorodiphenyldichloroethane)/DDT ratios were found, reflecting a "dicofol-type" DDT input pattern, This suggested that new DDT inputs are occurring because of dicofol still being used in the area. PMID:26825782

  7. Summer Surface Layer Thermal Response to Surface Gravity Waves in the Yellow Sea and the East China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Han, G.; Deng, Z.; Wang, X.

    2010-12-01

    A three-dimensional ocean model is applied to study the summer surface layer thermal response to surface gravity waves in the Yellow sea and the East China Sea(YES).The parameterization schemes of wave breaking developed by Mellor and Blumberg(2004) and Langmuir circulation developed by Kantha and Clayson(2004) are both included in the Mellor-Yamada turbulence closure model(Mellor and Yamada, 1982). Numerical results show that both surface wave breaking and Langmuir circulation determine the depth of surface boundary layer of temperature in the YES in summer. Langmuir circulation is able to obtain the turbulent kinetic energy injected by breaking waves near the surface and transport it downward to greater depths. A diagnostic analysis of the momentum balance shows that surface gravity waves can decrease the velocity near the surface and make the flow near the surface more homogeneous vertically in the YES. In addition, a diagnostic analysis of the temperature equation has been done for studying the heat budget. Diagnostic results show that more heat that is brought from surface in the YES can been transferred into the deeper layer owing to the surface gravity waves, which can induce local temperature there increase more rapidly. Besides, diagnostic results also suggest that surface gravity waves are likely to decrease upwelling near the bank in the region.

  8. Polycyclic aromatic hydrocarbons in the largest deepwater port of East China Sea: impact of port construction and operation.

    PubMed

    Li, Juan-Ying; Cui, Yu; Su, Lei; Chen, Yiqin; Jin, Ling

    2015-08-01

    PAHs were analyzed for samples of seawater, sediment, and oyster (Saccostrea cucullata) collected from Yangshan Port, East China between 2012 and 2013. Concentrations of ∑PAHs in seawater (180-7,700 ng/L) and oyster (1,100-29,000 ng/g dry weight (dw)) fell at the higher end of the global concentration range, while sediment concentrations (120-780 ng/g dw) were generally comparable to or lower than those reported elsewhere. PAHs in the particulate phase accounted for 85% (52-93%) of the total PAHs in seawater. Congener profile analysis revealed that PAHs in waters originate mainly from petrogenic sources, while high-temperature combustion processes are the predominant sources for sediment. ∑PAHs in oyster well correlated with ∑PAHs in the particulate phase, suggesting particle ingestion as an important pathway for bioaccumulation of PAHs. Cancer risk assessment of PAHs in oyster indicated high human health risks posed by these chemicals to the coastal population consuming this seafood. PMID:25903171

  9. The coupling of oligotrich ciliate populations and hydrography in the East China Sea: spatial and temporal variations

    NASA Astrophysics Data System (ADS)

    Chiang, Kuo-Ping; Lin, Chiu-Yi; Lee, Chung-Hsien; Shiah, Fuh-Kwo; Chang, Jeng

    2003-03-01

    Variations in the spatial and temporal distribution of oligotrich ciliate populations in the East China Sea were investigated during four cruises of the R/V Ocean Researcher I between December 1997 and October 1998. Over the entire continental shelf, a seasonal cycle was found with a distinct 3-5-fold increase in the abundance of oligotrich ciliates in summer. This increase appeared to be induced by the tremendous summertime runoff from the Changjiang. A radial-type spatial distribution pattern also was observed in summer, with population densities higher toward the Changjiang plume but highest of all in the margins of the plume. In spring and fall, the spatial distribution of the oligotrich ciliates was closely correlated to the abundance of cyanobacterium Synechococcus. In summer in the plume region, mixotrophic ciliates accounted for over 50% of the total ciliate population, compared to less than 30% outside the plume or that in other seasons. We propose a model in which these ciliates constitute part of the pathway through which the particulate and dissolved organic carbon in the runoff water is incorporated into the oceanic food web.

  10. Seasonal variation of polybrominated diphenyl ethers in PM2.5 aerosols over the East China Sea.

    PubMed

    Li, Yuanyuan; Lin, Tian; Wang, Fengwen; Ji, Tianyi; Guo, Zhigang

    2015-01-01

    PM2.5 aerosol samples were collected from a receptor site in the East China Sea (ECS) to explore the seasonal variation and sources of polybrominated diphenyl ethers (PBDEs). The concentrations of BDE-209 and total 11 PBDEs without BDE-209 (∑11PBDEs) were 7.1±6.8 and 0.97±0.52 pg m(-3), respectively. A distinct seasonal variation was observed for both BDE-209 and ∑11PBDEs, that higher concentrations in winter and spring dominated by the northwesterly winds while lower concentrations in autumn and summer when the southeasterly winds prevailed, suggesting a significant role of continental outflow on the elevated concentrations of PM2.5-bound PBDEs in winter and spring. Besides, the strong dust storm could increase the load of PBDEs in continental outflow to the atmosphere over ECS. Differently, due to the absence of continental outflow in autumn and summer, the good correlations between BDE-209 and ∑11PBDEs implied a potential contribution of the low brominated PBDEs from photoproducts of BDE-209 in high temperature circumstance, while the good correlations of OC with BDE-209 and BDE-99 suggested a significant role of OC in the occurrence of PM2.5-bound PBDEs over ECS. PMID:25150970

  11. Distribution and preservation of black carbon in the East China Sea sediments: Perspectives on carbon cycling at continental margins

    NASA Astrophysics Data System (ADS)

    Huang, Liang; Zhang, Jing; Wu, Ying; Wang, Jinlong

    2016-02-01

    We determined the concentrations and radiocarbon (14C) compositions of black carbon (BC) in the sediments of the East China Sea (ECS). The BC concentrations, which were in the range of 0.30-1.52 mg/g, accounted for 12-65% of the total organic carbon (TOC). The distribution of BC in ECS sediments was controlled by factors such as grain size, distance from the coast, and deposition rate. Radiocarbon measurements of BC yielded ages of 6350-10,440 years before present (BP), suggesting that the percentage of BC derived from biomass combustion was in the range of 29-48%. The BC burial flux in sediments of the ECS was estimated to be ∼1.39×106 t/yr, which was similar to burial fluxes reported for shelf sediments in other areas. However, the magnitude of the total BC sink was far greater than that of any other shelf regions studied to date, indicating the global importance of BC accumulation in the ECS, and the magnitude of BC input from large rivers (e.g., the Changjiang). The riverine delivery of BC to the ECS (73%) was far greater than that of atmospheric flux (27%). Further study of the BC cycle and the interactions of BC with other organic compounds in marginal seas was required to better understand the role of BC in the global carbon cycle.

  12. Comparison of wind data from ERA-Interim and buoys in the Yellow and East China Seas

    NASA Astrophysics Data System (ADS)

    Song, Lina; Liu, Zhiliang; Wang, Fan

    2014-09-01

    We compared data of sea surface wind from the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim) with that collected from eight buoys deployed in the Yellow and East China seas. The buoy data covered a period from 2010 to 2011, during which the longest time series without missing data extended for 329 days. Results show that the ERA-Interim wind data agree well with the buoy data. The regression coefficients between the ERA-Interim and observed wind speed and direction are greater than 0.7 and 0.79, respectively. However, the ERA-Interim wind data overestimate wind speed at most of the buoy stations, for which the largest bias is 1.8 m/s. Moreover, it is found from scatter plots of wind direction that about 13% of the ERA-Interim wind data can be classified as bad for wind speeds below 6 m/s. Overall, the ERA-Interim data forecast both the wind speed and direction well, although they are not very representative of our observations, especially those where the wind speed is below 6 m/s.

  13. Comparison of wind data from ERA-Interim and buoys in the Yellow and East China Seas

    NASA Astrophysics Data System (ADS)

    Song, Lina; Liu, Zhiliang; Wang, Fan

    2015-01-01

    We compared data of sea surface wind from the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim) with that collected from eight buoys deployed in the Yellow and East China seas. The buoy data covered a period from 2010 to 2011, during which the longest time series without missing data extended for 329 days. Results show that the ERA-Interim wind data agree well with the buoy data. The regression coefficients between the ERA-Interim and observed wind speed and direction are greater than 0.7 and 0.79, respectively. However, the ERA-Interim wind data overestimate wind speed at most of the buoy stations, for which the largest bias is 1.8 m/s. Moreover, it is found from scatter plots of wind direction that about 13% of the ERA-Interim wind data can be classified as bad for wind speeds below 6 m/s. Overall, the ERA-Interim data forecast both the wind speed and direction well, although they are not very representative of our observations, especially those where the wind speed is below 6 m/s.

  14. Effect of the mesoscale hydrographic features on larval fish distribution across the shelf break of East China Sea

    NASA Astrophysics Data System (ADS)

    Okazaki, Yuji; Nakata, Hideaki

    2007-06-01

    Surveys of fish larvae and oceanographic conditions were conducted along transects across the shelf break region in the East China Sea (ECS) in May 2001. The objective of this study was to investigate the distribution and assemblages of fish larvae across the shelf break region and their relationships to mesoscale hydrographic features. There was a warm surface streamer from the Kuroshio which extended toward the shelf region of the ECS; concurrently, we observed the intrusion of the less saline shelf water into the subsurface layer towards the offshore. In all 66 taxa (65 families and 1 order) of larvae were collected by oblique net tows using a bongo net, the larval fish density and number of families sampled were lower in the low-temperature area. Based on cluster analysis and environmental factor, two larval fish assemblages were identified: off-shelf/Kuroshio and shelf break. In shelf break assemblage, Auxis spp. and Diaphus spp. were abundant in the warm surface streamer. In contrast, Maurolicus japonicus, Synagrops spp., Bregmaceros sp. and Champsodon spp. were found in the off-shelf region where the offshore intrusion of less-saline water occurred. This different pattern of the horizontal distribution would reflect vertical distribution of the larvae in the water column. Moreover, copepod nauplii density was higher in the upper layer of the shelf region. Thus, dynamic interactions between the Kuroshio and shelf waters at the frontal boundary are concluded to potentially affect larval fish transport and prey availability.

  15. Major sources of MeO/OH-BDEs in the East China Sea elucidated from their records and phytoplankton biomarkers.

    PubMed

    Fan, Ying; Huh, Chih-An; Lan, Jing; Zhao, Meixun; Zhao, Zongshan; Li, Guoliang; Sun, Jianteng; Jiang, Guibin

    2014-09-01

    Hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have caused much concern because of their potential toxicity and worldwide distribution. These compounds are recently suggested to originate from the natural process in the ocean. However, their source remains highly controversial. In this study, we analyzed the contents of nine MeO-BDEs, ten OH-BDEs, and phytoplankton biomarkers (PBs) in two sediment cores collected from the East China Sea (ECS). The detection of 6-MeO-BDE-47, 2'-MeO-BDE-68, and 6-OH-BDE-47 have been reported since the 1920s, prior to the production of PBDEs. Significant relations were found between MeO/OH-BDEs and indicators of marine organic matters. The similar down-core variations and significant correlations between MeO/OH-BDEs and PBs suggest the possibility that phytoplankton produced these natural compounds. Laboratory incubation further demonstrates that phytoplankton can produce MeO-BDEs. Comparisons between the content ratios of 6-MeO-BDE-47/2'-MeO-BDE-68 and brassicasterol/dinosterol indicate that the signature of MeO-BDEs is controlled by the phytoplankton community structure. PMID:24874793

  16. [Responses of functional diversity of aquatic insect community to land use change in middle reach of Qiantang River, East China].

    PubMed

    Zhang, Lian-Bo; Liu, Dong-Xiao; Liu, Shuo-Ru; Zhang, Yong; Tong, Xiao-Li; Wang, Bei-Xin

    2013-10-01

    Based on the biological traits such as life history, resistance ability against environmental disturbance, and physiological characteristics of aquatic insects, and by using the fourth-corner statistical method, this paper studied the responses of the functional diversity of aquatic insect community to land use change in the middle reach of Qiantang River, Zhejiang Province of East China. For the test aquatic insect community, some of its biological traits were sensitive to land use change, and altered along human disturbance gradients as expected. With the increasing intensity of human disturbance, the maximal insect body length decreased gradually, the dominant respiration pattern evolved from gill respiration to tegument respiration, and the abundance of burrowers increased significantly. At the same time, the functional diversity measured as Rao's quadratic entropy was significantly higher in reference sites than in disturbed sites (P < 0.001), demonstrating that the changes in the functional diversity of the aquatic community were mainly induced by the land use change caused by human activities, which resulted in the decline of stream water quality and habitat quality and the variations of aquatic insect community composition and biological traits. The aquatic insect biological traits and functional diversity could be the potentially effective indicators in the stream health assessment in the future. PMID:24483092

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Biogeography of the Sediment Bacterial Community Responds to a Nitrogen Pollution Gradient in the East China Sea

    PubMed Central

    Xiong, Jinbo; Ye, Xiansen; Wang, Kai; Chen, Heping; Hu, Changju; Zhu, Jianlin

    2014-01-01

    Patterns of microbial distribution represent the integrated effects of historical and biological processes and are thus a central issue in ecology. However, there is still active debate on whether dispersal limitation contributes to microbial diversification in strongly connected systems. In this study, sediment samples were collected along a transect representing a variety of seawater pollution levels in the East China Sea. We investigated whether changes in sediment bacterial community structures would indicate the effects of the pollution gradient and of dispersal limitation. Our results showed consistent shifts in bacterial communities in response to pollution. More geographically distant sites had more dissimilar communities (r = −0.886, P < 0.001) in this strongly connected sediment ecosystem. A variance analysis based on partitioning by principal coordinates of neighbor matrices (PCNM) showed that spatial distance (dispersal limitation) contributed more to bacterial community variation (8.2%) than any other factor, although the environmental factors explained more variance when combined (11.2%). In addition, potential indicator taxa (primarily affiliated with Deltaproteobacteria and Gammaproteobacteria) were identified; these taxa characterized the pollution gradient. This study provides direct evidence that dispersal limitation exists in a strongly connected marine sediment ecosystem and that candidate indicator taxa can be applied to evaluate coastal pollution levels. PMID:24413606

  19. Modeling studies of the far-field effects of tidal flat reclamation on tidal dynamics in the East China Seas

    NASA Astrophysics Data System (ADS)

    Song, Dehai; Wang, Xiao Hua; Zhu, Xueming; Bao, Xianwen

    2013-11-01

    In recent decades, the reclamation of tidal flat carried out by the authorities around the Bohai Sea, Yellow Sea, and East China Sea (BYECS) has reached new heights as a consequence of significant economic expansion in the coastal areas. We are concerned that the tidal flat reclamation may have not only local but also far-field effects on tidal dynamics in the entire BYECS. Numerical study shows different tidal patterns due to tidal energy redistribution when tidal flats around the BYECS are removed, in which the tidal range and phase are changed, and the amphidromic points are displaced. Tidal flats provide storage and dissipation for tidal energy; the former is much more significant than the latter. Loss of these functions caused by tidal flat reclamation will induce a redistribution of the extra tidal energy. Furthermore, we show that far-field effects on tidal dynamics would be observed on the west coast of Korea following significant reclamation on the Chinese Jiangsu coast. In turn, reclamation on the west coast of Korea may generate the far-field effects on the Chinese coast. Reclamation in the BYECS can result in rise of tidal amplitude and onshore sediment transport. The former may enhance the coastal hazards such as storm surge, and the latter may result in severe siltation. Therefore, careful consideration must always be given to any proposed artificial changes to tidal flat, given the effects of these on both the local environment and further afield.

  20. Age and growth of chub mackerel ( Xcomber japonicus) in the East China and Yellow Seas using sectioned otolith samples

    NASA Astrophysics Data System (ADS)

    Li, Gang; Chen, Xinjun; Feng, Bo

    2008-11-01

    Although chub mackerel ( Scomber japonicus) is a primary pelagic fish species, we have only limited knowledge on its key life history processes. The present work studied the age and growth of chub mackerel in the East China and Yellow Seas. Age was determined by interpreting and counting growth rings on the sagitta otoliths of 252 adult fish caught by the Chinese commercial purse seine fleet during the period from November 2006 to January 2007 and 150 juveniles from bottom trawl surveys on the spawning ground in May 2006. The difference between the assumed birth date of 1st April and date of capture was used to adjust the age determined from counting the number of complete translucent rings. The parameters of three commonly used growth models, the von Bertalanffy, Logistic and Gompertz models, were estimated using the maximum likelihood method. Based on the Akaike Information Criterion ( AIC), the von Bertalanffy growth model was found to be the most appropriate model. The size-at-age and size-at-maturity values were also found to decrease greatly compared with the results achieved in the 1950s, which was caused by heavy exploitation over the last few decades.

  1. Geochemical behavior of dissolved manganese in the East China Sea: Seasonal variation, estuarine removal, and regeneration under suboxic conditions

    NASA Astrophysics Data System (ADS)

    Wang, Zhao-Wei; Ren, Jing-Ling; Jiang, Shuo; Liu, Su-Mei; Xuan, Ji-Liang; Zhang, Jing

    2016-02-01

    To better understand the geochemical cycle of dissolved manganese (Mn) in the East China Sea (ECS), the distribution of dissolved Mn across the ECS was investigated during three field studies in 2011 (May, August, and November). The concentration of dissolved Mn decreased across the ECS with distance from the coast. Mn-rich ECS shelf waters could export to the Kuroshio Waters, and had the potential to influence the northwest Pacific Ocean as well as the Japan Sea. The Kuroshio Waters were devoid of dissolved Mn, so its incursion could be tracked as it entered the ECS continental shelf region (approximately 50 m isobath). Seasonal variations of dissolved Mn in the ECS were significant, with the highest concentrations occurring in summer. Dissolved Mn in the Changjiang Estuary was nonconservative, and significant quantities were removed by net sorption onto suspended particulate matter. A model describing the sorption processes was applied to data for the Changjiang Estuary. Regeneration of dissolved Mn took place in near-bottom waters of the suboxic zone in August 2011, following extensive consumption of oxygen. The benthic flux of dissolved Mn was estimated based on Mn concentrations in the overlying waters and the near-bottom waters. A preliminary box model was established to develop a dissolved Mn budget for the ECS. Based on the dissolved Mn content in the ECS and the total input flux, a residence time of 76-350 days for dissolved Mn in the ECS was inferred.

  2. Compound-specific isotopes of fatty acids as indicators of trophic interactions in the East China Sea ecosystem

    NASA Astrophysics Data System (ADS)

    Wu, Ying; Wang, Na; Zhang, Jing; Wan, Ruijing; Dai, Fangqun; Jin, Xianshi

    2016-09-01

    The composition and compound-specific isotopes of fatty acids were studied within food webs in the East China Sea. Lipid-normalized stable carbon isotopes of total organic carbon had a good correlation with trophic level. Variations in fatty acid compositions among diff erent species were observed but were unclear. Diff erent dietary structures could be traced from molecular isotopes of selected fatty acids in the Shiba shrimp ( Matapenaeus joyneri), the coastal mud shrimp ( Solenocera crassicornis) and the northern Maoxia shrimp ( Acetes chinensis). Both M. joyneri and S. crassicornis are mainly benthos feeders, while A. chinensis is a pelagic species, although they have a similar fatty acid composition. There was a good correlation for isotopes of arachidonic acid (C20:4n6; ARA) and docosahexaenoic acid (C22:6n3; DHA) among pelagic species from higher trophic levels. The isotopic compositions of DHA in benthic species were more negative than those of pelagic species at the same trophic level. The fact that the diet of benthic species contains more degraded items, the carbon isotopes of which are derived from a large biochemical fraction, may be the reason for this variation. A comparative study of benthic and pelagic species demonstrated the diff erent carbon sources in potential food items and the presence of a more complex system at the water-sediment interface.

  3. Compound-specific isotopes of fatty acids as indicators of trophic interactions in the East China Sea ecosystem

    NASA Astrophysics Data System (ADS)

    Wu, Ying; Wang, Na; Zhang, Jing; Wan, Ruijing; Dai, Fangqun; Jin, Xianshi

    2016-01-01

    The composition and compound-specific isotopes of fatty acids were studied within food webs in the East China Sea. Lipid-normalized stable carbon isotopes of total organic carbon had a good correlation with trophic level. Variations in fatty acid compositions among diff erent species were observed but were unclear. Diff erent dietary structures could be traced from molecular isotopes of selected fatty acids in the Shiba shrimp (Matapenaeus joyneri), the coastal mud shrimp (Solenocera crassicornis) and the northern Maoxia shrimp (Acetes chinensis). Both M. joyneri and S. crassicornis are mainly benthos feeders, while A. chinensis is a pelagic species, although they have a similar fatty acid composition. There was a good correlation for isotopes of arachidonic acid (C20:4n6; ARA) and docosahexaenoic acid (C22:6n3; DHA) among pelagic species from higher trophic levels. The isotopic compositions of DHA in benthic species were more negative than those of pelagic species at the same trophic level. The fact that the diet of benthic species contains more degraded items, the carbon isotopes of which are derived from a large biochemical fraction, may be the reason for this variation. A comparative study of benthic and pelagic species demonstrated the diff erent carbon sources in potential food items and the presence of a more complex system at the water-sediment interface.

  4. [Abundance and biomass of planktonic ciliates in the shelf of East China Sea in spring and autumn].

    PubMed

    Yu, Ying; Zhang, Wu-chang; Zhou, Feng; Liu, Cheng-gang; Feng, Mei-ping; Li, Hai-bo; Zhao, Yuan; Xiao, Tian

    2013-08-01

    An investigation was made on the abundance and biomass of planktonic ciliates in the shelf of East China Sea in May (spring) and November (autumn), 2011. The abundance of the ciliates in spring and autumn was averagely (614 +/- 861) and (934 +/- 809) ind x L(-1), and the biomass was averagely (1.70 +/- 3.91) and (0.93 +/- 0.99) microg C x L(-1), respectively. The high abundance and biomass in spring were found in coastal and offshore areas, and those in autumn were in offshore only. In the two seasons, the ciliates tended to accumulate in the waters upper layer, and sometimes flocked in the bottom. In the spring, aloricate ciliate species were larger than those in the autumn. Tintinnids occupied (26.9% +/- 34.3)% and (44.9% +/- 25.2)% of the total ciliates abundance in spring and autumn, respectively. In taxonomy, 52 tintinnid species of 27 genera were identified. The most dominant species were Tintinnidium primitivum, Stenosemella oliva, and Tintinnopsis tubulosoides in spring, and Tintinnidium primitivum, Stenosemella parvicollis, and Tintinnopsis nana in autumn. The ciliates abundance showed significant positive correlations with water temperature and Chl a concentration, the tintinnids abundance showed significant negative correlation with water salinity, and the tintinnids community was significantly related to water temperature. PMID:24380353

  5. Feifantangia zhejiangensis gen. nov., sp. nov., a marine bacterium isolated from seawater of the East China Sea.

    PubMed

    Zheng, Gang; Chen, Zuo-Guo; Jiang, Ri-Jin; Yang, Zhi-Jian

    2015-12-01

    A marine bacterium, NMD7(T), was isolated from seawater of the East China Sea. The cells were found to be aerobic, Gram-stain negative, non-motile rods. Growth of strain NMD7(T) could be observed in the medium without Na(+). Flexirubin-type pigments were observed to be produced. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NMD7(T) is an authentic member of the Cytophaga-Flavobacterium-Bacteroides phylum, forming a monophyletic clade as retrieved in neighbor-joining, maximum-likelihood and maximum-parsimony phylogenetic trees, and is closely related to Formosa spongicola A2(T) (96.0 %). The predominant respiratory quinone was determined to be MK-6. Major cellular fatty acids were identified as iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH. The main polar lipids were found to consist of phosphatidylethanolamine, one aminophospholipid, three aminolipids and five unidentified lipids. Based on phenotypic, chemotaxonomic and phylogenetic characteristics, it is proposed that strain NMD7(T) be classified as representing a new genus, Feifantangia gen. nov. and a new species, Feifantangia zhejiangensis sp. nov. The type strain is NMD7(T) (=KCTC 42445T =MCCC 1K00458T). PMID:26410371

  6. Geochemistry of river-borne clays entering the East China Sea indicates two contrasting types of weathering and sediment transport processes

    NASA Astrophysics Data System (ADS)

    Bi, Lei; Yang, Shouye; Li, Chao; Guo, Yulong; Wang, Quan; Liu, James T.; Yin, Ping

    2015-09-01

    The East China Sea is characterized by wide continental shelf receiving a huge input of terrigenous matter from both large rivers and mountainous rivers, which makes it an ideal natural laboratory for studying sediment source-to-sink transport processes. This paper presents mineralogical and geochemical data of the clays and bulk sediments from the rivers entering the East China Sea, aiming to investigate the general driving mechanism of silicate weathering and sediment transport processes in East Asian continental margin. Two types of river systems, tectonically stable continental rivers and tectonically active mountainous rivers, coexist in East Asia. As the direct weathering products, clays can better reflect the silicate weathering regimes within the two river systems. Provenance rock types are not the dominant factor causing silicate weathering intensity difference existed in the East Asian rivers. The silicate weathering intensity of tectonically stable river basins is primarily driven by monsoon climate, and the sediment transfer is relatively slow because of natural trapping process and increasing damming effect. The geochemistry of these river-borne sediments can thus indicate paleo-weathering intensities in East Asian continent. In contrast, silicate weathering intensity in tectonically active mountainous rivers is greatly limited by strong physical erosion despite the high temperature and highest monsoon rainfall. The factors controlling silicate weathering in tectonically active catchments are complex and thus, it should be prudent to use river sediment records to decipher paleoclimate change. These two different silicate weathering regimes and sediment transport processes are manifestations of the landscape evolution and overall dominate the sedimentation in Asian continental margin.

  7. VIEW OF CONCRETE CHANNEL ADJACENT TO TUMALO FEED CANAL INTAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF CONCRETE CHANNEL ADJACENT TO TUMALO FEED CANAL INTAKE STRUCTURE (DOWNSTREAM SIDE). LOOKING EAST/NORTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  8. Probabilistic Quantitative Precipitation Forecasting over East China using Bayesian Model Averaging

    NASA Astrophysics Data System (ADS)

    Yang, Ai; Yuan, Huiling

    2014-05-01

    The Bayesian model averaging (BMA) is a post-processing method that weights the predictive probability density functions (PDFs) of individual ensemble members. This study investigates the BMA method for calibrating quantitative precipitation forecasts (QPFs) from The Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) database. The QPFs over East Asia during summer (June-August) 2008-2011 are generated from six operational ensemble prediction systems (EPSs), including ECMWF, UKMO, NCEP, CMC, JMA, CMA, and multi-center ensembles of their combinations. The satellite-based precipitation estimate product TRMM 3B42 V7 is used as the verification dataset. In the BMA post-processing for precipitation forecasts, the PDF matching method is first applied to bias-correct systematic errors in each forecast member, by adjusting PDFs of forecasts to match PDFs of observations. Next, a logistic regression and two-parameter gamma distribution are used to fit the probability of rainfall occurrence and precipitation distribution. Through these two steps, the BMA post-processing bias-corrects ensemble forecasts systematically. The 60-70% cumulative density function (CDF) predictions well estimate moderate precipitation compared to raw ensemble mean, while the 90% upper boundary of BMA CDF predictions can be set as a threshold of extreme precipitation alarm. In general, the BMA method is more capable of multi-center ensemble post-processing, which improves probabilistic QPFs (PQPFs) with better ensemble spread and reliability. KEYWORDS: Bayesian model averaging (BMA); post-processing; ensemble forecast; TIGGE

  9. Extraction of palaeochannel information from remote sensing imagery in the east of Chaohu Lake, China

    NASA Astrophysics Data System (ADS)

    Wang, Xinyuan; Guo, Zhenya; Wu, Li; Zhu, Cheng; He, Hui

    2012-03-01

    Palaeochannels are deposits of unconsolidated sediments or semi-consolidated sedimentary rocks deposited in ancient, currently inactive river and stream channel systems. It is distinct from the overbank deposits of currently active river channels, including ephemeral water courses which do not regularly flow. We have introduced a spectral characteristics-based palaeochannel information extraction model from SPOT-5 imagery with special time phase, which has been built by virtue of an analysis of remote sensing mechanism and spectral characteristics of the palaeochannel, combined with its distinction from the spatial distribution and spectral features of currently active river channels, also with the establishment of remote sensing judging features of the palaeochannel in remote sensing image. This model follows the process of supervised classification → farmland masking and primary component analysis → underground palaeochannel information extraction → information combination → palaeochannel system image. The Zhegao River Valley in the east of Chaohu Lake was selected as a study area, and SPOT-5 imagery was used as a source of data. The result was satisfactory when this method has been successfully applied to extract the palaeochannel information, which can provide good reference for regional remote sensing archeology and neotectonic research. However, the applicability of this method needs to be tested further in other areas as the spatial characteristics and spectral response of palaeochannel might be different.

  10. Ontogenetic changes in isotopic signatures of an omnivorous fish Cultrichthys erythropterus in East Lake Taihu, China

    NASA Astrophysics Data System (ADS)

    Li, Yunkai; Zhang, Miao

    2015-05-01

    The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter ( Cultrichthys erythropterus), commonly found in East Lake Taihu, was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature (δ13C) in this study, in which δ13C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model, the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However, the stable nitrogen isotopic signature (δ15N) exhibited an unusual pattern compared with previous studies. The δ15N of C. erythropterus showed no relationship with body size, even though dietary changes were observed. This indicated that δ15N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events, such as estimating the trophic positions of fish species.

  11. Editorial: Eutrophication and hypoxia and their impacts on the ecosystem of the Changjiang Estuary and adjacent coastal environment

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Xiao, Tian; Huang, Daji; Liu, Su Mei; Fang, Jianguang

    2016-02-01

    The Changjiang (Yangtze River) Estuary plays an important role in the land-ocean interactions of East Asia, particularly in regard to the fate of land-derived materials and their impact on marine ecosystems in the Northwest Pacific Ocean. The 12 papers included in this special issue describe results from the MEcoPAM Study, an IMBER-China project, which occurred in 2011-2015. This project used a multi-disciplinary approach to understand ecosystem function of the Changjiang Estuary in response to multiple stressors (i.e. combined external forcings). The results presented here show that human activities in the watersheds have greatly changed the flux and variation of dissolved and particulate materials from the river. Further interactions between the Changjiang Watersheds and the East China Sea can dramatically modify the pathways of biogeochemistry and food web dynamics of the estuary and adjacent coastal environment at seasonal and inter-annual scales.

  12. Distribution and accumulation of hexachlorobutadiene in soils and terrestrial organisms from an agricultural area, East China.

    PubMed

    Tang, Zhenwu; Huang, Qifei; Cheng, Jiali; Qu, Dan; Yang, Yufei; Guo, Wei

    2014-10-01

    Hexachlorobutadiene (HCBD) is a potential persistent organic pollutant that has been found in abiotic environments and organisms. However, information on HCBD in soils and its accumulation in terrestrial food chains is scarce. This study investigated the accumulation of HCBD in soils, plants, and terrestrial fauna in a typical agricultural area in Eastern China, and drew comparisons with organochlorine pesticides (OCPs). The HCBD concentrations in soils were <0.02-3.1ng/g dry weight, which were similar to α-endosulfan concentrations but much lower than the concentrations of some other OCPs. The HCBD soil-plant accumulation factors, 8.5-38.1, were similar to those of o,p'-DDT and higher than those of HCHs and p,p'-DDT, indicating that HCBD is strongly bioaccumulated by rice and vegetables. HCBD concentrations of 1.3-8.2ng/g lipid weight were found in herbivorous insects, earthworms, and Chinese toads. The biomagnification factor, the ratio between the lipid-normalized concentrations in the predator and the prey, was found to be 0.16-0.64 for different food chains of Chinese toads, so HCBD was found not to biomagnify, which is in contrast with OCPs. Further research into whether HCBD is biomagnified in high trophic level organisms or through the entire terrestrial food web is required. PMID:25124679

  13. Risk factors for sporadic Vibrio parahaemolyticus gastroenteritis in east China: a matched case-control study.

    PubMed

    Yan, W X; Dai, Y; Zhou, Y J; Liu, H; Duan, S G; Han, H H; Chen, Y

    2015-04-01

    SUMMARY To determine risk factors for sporadic Vibrio parahaemolyticus gastroenteritis, we conducted a population-based case-control study in sentinel hospital surveillance areas of Shanghai and Jiangsu province, China. Seventy-one patients with diarrhoea and confirmed V. parahaemolyticus infections were enrolled, and they were matched with 142 controls for gender, age and residential area. From the multivariable analysis, V. parahaemolyticus infections were associated with antibiotics taken during the 4 weeks prior to illness [odds ratio (OR) 7·6, 95% confidence interval (CI) 1·1–54·4)], frequent eating out (OR 3·3, 95% CI 1·0–10·4), and shellfish consumption (OR 3·4, 95% CI 1·0–11·1), with population-attributable fractions of 0·09, 0·24, and 0·14, respectively. Protective factors included keeping the aquatic products refrigerated (OR 0·4, 95% CI 0·2–1·0) and pork consumption (OR 0·2, 95% CI 0·1–0·9) [corrected] . PMID:24992005

  14. Methylmercury and trace elements in the marine fish from coasts of East China.

    PubMed

    Xia, Chonghuan; Wu, Xiaoguo; Lam, James C W; Xie, Zhouqing; Lam, Paul K S

    2013-01-01

    Fish consumption is an important source of human exposure to heavy metals. To determine the health risks for metals by consumption of marine fish in China, three species of fish, namely large yellow croaker (Pseudosciaena crocea), small yellow croaker (Pseudosciaena polyactis) and silver pomfret (Pampus argenteus) were collected and analyzed for methylmercury (MeHg), total mercury (T-Hg), selenium, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, strontium and zinc. The large yellow croakers had the highest concentrations of mercury, lead, nickel and zinc, and the levels of MeHg were positively correlated to T-Hg. The ratios of MeHg to T-Hg in yellow croakers were significantly higher than those in silver pomfret, indicating differences in accumulation and magnification of MeHg in these two types of fish. The concentration of T-Hg was found to decrease as the Se level in fish tissues increased. Cadmium levels in 16% of the samples were higher than the criterion recommended by the European Commission Regulation. The concentrations of other metals were well below international standards. A human health risk assessment showed that the estimated daily intake of these metals did not exceed the reference dose established by the US Environmental Protection Agency. The hazard quotients (HQs) were all less than 1, indicating a situation of no risk for consumption of these fish. PMID:23802158

  15. Land-sea interactions at the east coast of Hainan Island, South China Sea: A synthesis

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Wang, Dao Ru; Jennerjahn, Tim; Dsikowitzky, Larissa

    2013-04-01

    The structure and function of coastal ecosystems is affected by land-based human activities, including changes in water, sediment and pollutant input, as well as land reclamation in coastal areas. Many coastal areas can be considered over-stressed systems as a whole, the ecosystem services of which are strongly impaired. This is particularly important in tropical regions, where the coastal zone is under the influence of a strong climate variability including monsoons and frequent extreme weather events, such as typhoons. During the past decades the continuous development of Hainan's coastal zone and its hinterland, in combination with episodic natural events (e.g., typhoons), caused environmental changes in its coastal ecosystems. However, little is known on the consequences of environmental changes for the biogeochemistry and ecology and, hence, the natural resources of the Hainan coastal ecosystems. The Sino-German inter-disciplinary LANCET (land-sea interactions along coastal ecosystems of tropical China: Hainan) project was designed to address these issues on a local to regional scale and at the same time, to contribute to the global data base in which this type of information from tropical regions is still under-represented. The results obtained from LANCET have been delivered to the local government for an adaptive management at the ecosystem level, and the knowledge is believed to be relevant to other studies of tropical and coastal regions.

  16. Application of MODIS time series data for drought assessment in East China

    NASA Astrophysics Data System (ADS)

    Liu, Chaoshun; Shi, Runhe; Gao, Wei; Gao, Zhiqiang

    2010-08-01

    Drought is one of the major environmental disasters in China, so it is very important to detect and monitor drought periodically at large scale for decision making. This study focuses on combining information from visible, near infrared, and short wave infrared channels of MODIS to improve sensitivity to drought severity. Significant correlations have been found between NDVI/NMDI values and precipitation/soil moisture data in individual stations. It was confirmed that both NDVI and NMDI indices could be used to monitor drought in the study area at a regional scale. However, NMDI had a slightly higher correlation with soil moisture or precipitation than NDVI, which suggests that NMDI variations can be a good indicator of water changes and in turn, the drought conditions in individual stations in the study area. Results from analysis of time series NDVI and NDWI data over the study area also indicate that NMDI was more sensitive than NDVI to drought conditions. Future efforts are being need to more fully exploit the potential of NMDI as an active drought-monitoring tool for different geographic regions, climates, and multiple spatial scales.

  17. The absence of human papillomavirus in esophageal squamous cell carcinoma in East China

    PubMed Central

    Teng, Haohua; Li, Xiaojing; Liu, Xiuping; Wu, Jie; Zhang, Jie

    2014-01-01

    Esophageal squamous cell carcinoma (ESCC) is one of the most common types of tumors worldwide, particularly in China, and human papillomavirus (HPV) is thought to be a potential risk factor for this cancer. To determine whether this is true, we collected 177 formalin-fixed and paraffin-embedded ESCC samples from two hospitals. We screened for 23 different HPV genotypes using a human papillomavirus genotyping kit, which allowed us to amplify the L1 gene by polymerase chain reaction (PCR) and test for 23 HPV subtypes by reverse dot blot (RDB) on a single membrane. We also used immunohistochemistry (IHC) to detect the P16INK4a protein, the expression of which is linked to HPV E7 activity and which is used to diagnose cervical intraepithelial neoplasia. The genotyping results showed that only six samples were weakly positive for HPV: two for HPV16, two for HPV11 and two for HPV35, with no samples showing strong positive signals. The IHC results showed only five samples with diffuse positive staining, with the other samples being completely negative or having only focal positive signals, which were considered as negative. This study demonstrates that the HPV infection rate in ESCC samples is very low, suggesting that HPV is not the etiological cause of ESCC. PMID:25120798

  18. Adjacent segment disease.

    PubMed

    Virk, Sohrab S; Niedermeier, Steven; Yu, Elizabeth; Khan, Safdar N

    2014-08-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Understand the forces that predispose adjacent cervical segments to degeneration. 2. Understand the challenges of radiographic evaluation in the diagnosis of cervical and lumbar adjacent segment disease. 3. Describe the changes in biomechanical forces applied to adjacent segments of lumbar vertebrae with fusion. 4. Know the risk factors for adjacent segment disease in spinal fusion. Adjacent segment disease (ASD) is a broad term encompassing many complications of spinal fusion, including listhesis, instability, herniated nucleus pulposus, stenosis, hypertrophic facet arthritis, scoliosis, and vertebral compression fracture. The area of the cervical spine where most fusions occur (C3-C7) is adjacent to a highly mobile upper cervical region, and this contributes to the biomechanical stress put on the adjacent cervical segments postfusion. Studies have shown that after fusion surgery, there is increased load on adjacent segments. Definitive treatment of ASD is a topic of continuing research, but in general, treatment choices are dictated by patient age and degree of debilitation. Investigators have also studied the risk factors associated with spinal fusion that may predispose certain patients to ASD postfusion, and these data are invaluable for properly counseling patients considering spinal fusion surgery. Biomechanical studies have confirmed the added stress on adjacent segments in the cervical and lumbar spine. The diagnosis of cervical ASD is complicated given the imprecise correlation of radiographic and clinical findings. Although radiological and clinical diagnoses do not always correlate, radiographs and clinical examination dictate how a patient with prolonged pain is treated. Options for both cervical and lumbar spine ASD include fusion and/or decompression. Current studies are encouraging regarding the adoption of arthroplasty in spinal surgery, but more long

  19. Two tales of the continental lithospheric mantle prior to the destruction of the North China Craton: Insights from Early Cretaceous mafic intrusions in western Shandong, East China

    NASA Astrophysics Data System (ADS)

    Huang, Xiao-Long; Zhong, Jun-Wei; Xu, Yi-Gang

    2012-11-01

    Weakened lithospheric zones such as the Dabie-Sulu orogenic belt and Tan-Lu fault zone played important roles in the destruction of the North China Craton (NCC) during the late Mesozoic. Early Cretaceous mafic intrusions in western Shandong, contemporary with extensive magmatism during the destruction of the NCC, delineate two spatially distinct mantle domains (EM1- and EM2-like) beneath the craton’s interior and weakened lithospheric zones, respectively. The Jinan and Zouping gabbros from the craton interior (∼128 Ma) show fractionated LREE and nearly flat HREE patterns ([La/Yb]N = 2.94-8.95; [Dy/Yb]N = 1.23-1.69) with notable negative Ta, Nb and Ti anomalies. They have strong negative εNd(t) (-15.7 to -7.1), low initial 87Sr/86Sr (0.7039-0.7060) and negative zircon εHf(t) of -20.0 to -6.2. These “crustal fingerprints” cannot be explained by crustal contamination, but were likely derived from a hybrid mantle source. Crustal delamination or detachment during the Early Paleoproterozoic might be responsible for the involvement of Early Precambrian crustal materials in the Mesozoic mantle source beneath the southeastern NCC. In comparison, the Early Cretaceous mafic igneous rocks from regions (e.g., Yinan, Mengyin and Fangcheng) adjacent to the Dabie-Sulu orogenic belt and Tan-Lu fault zone have higher 87Sr/86Sr ratios (0.7059-0.7119), suggesting modification of the lithospheric mantle by melts/fluids derived from the Yangtze crust. The Mesozoic crustal delamination may have triggered the destruction of the lithospheric root beneath the Dabie-Sulu orogenic belt, whereas the lithospheric thinning beneath the interior of the southeastern NCC is attributed to the thermo-mechanical erosion by lateral convective asthenosphere.

  20. A strong ‘filter’ effect of the East China Sea land bridge for East Asia’s temperate plant species: inferences from molecular phylogeography and ecological niche modelling of Platycrater arguta (Hydrangeaceae)

    PubMed Central

    2014-01-01

    Background In East Asia, an increasing number of studies on temperate forest tree species find evidence for migration and gene exchange across the East China Sea (ECS) land bridge up until the last glacial maximum (LGM). However, it is less clear when and how lineages diverged in this region, whether in full isolation or in the face of post-divergence gene flow. Here, we investigate the effects of Quaternary changes in climate and sea level on the evolutionary and demographic history of Platycrater arguta, a rare temperate understorey shrub with disjunct distributions in East China (var. sinensis) and South Japan (var. arguta). Molecular data were obtained from 14 P. arguta populations to infer current patterns of molecular structure and diversity in relation to past (Last Interglacial and Last Glacial Maximum) and present distributions based on ecological niche modelling (ENM). A coalescent-based isolation-with-migration (IM) model was used to estimate lineage divergence times and population demographic parameters. Results Combining information from nuclear/chloroplast sequence data with nuclear microsatellites, our IM analyses identify the two varieties as genetically distinct units that evolved in strict allopatry since the mid-Pleistocene, c. 0.89 (0.51–1.2) Ma. Together with Bayesian Skyeline Plots, our data further suggest that both lineages experienced post-divergence demographic growth, followed by refugial isolation, divergence, and in the case of var. arguta post-glacial admixture. However, past species distribution modelling indicates that the species’ overall distribution has not greatly changed over the last glacial cycles. Conclusions Our findings highlight the important influence of ancient sea-level changes on the diversification of East Asia’s temperate flora. Implicitly, they challenge the notion of general temperate forest expansion across the ECS land bridge, demonstrating instead its ‘filter’ effect owing to an unsuitable environment

  1. Using Bayesian optimization method and FLEXPART dispersion model to evaluate CO emission in East China based on three-year measurements at high altitude mountain site

    NASA Astrophysics Data System (ADS)

    Xiaole, P.; Kanaya, Y.; Wang, Z.

    2012-12-01

    The rapid economic growth and energy consumption in East China has resulted in serious regional-scale and trans-boundary air pollutions. Variation of carbon monoxide (CO) is of great interest as a restriction factor for pollutants related with incomplete combustion processes. This study attempted to evaluate CO emission in East China using analytical inverse modeling and nearly three-year measurements (2005-2007) at Mt. Huashan (34°28'52"N, 110°04'36"E, a.s.l.1577 m). Inversion methodology combined FLEXPART_WRF (Version 6.2) with Bayesian optimization iterative algorithm. Regarding calculations, five days backward simulations of air mass movement were used to determine the Source-Receptor Relationship (SRR) between emissions at the source regions and observation at receptor. And then SRR, a priori CO emission (INTEX-B) and corresponding uncertainties (70%) were fed into inversion algorithm to optimize the CO emission by minimizing the mismatch between simulated and observed CO concentrations. To reduce the number of unknowns (a posterior), we used variable-resolution grid setting with high spatial resolution in the vicinity of observation site and coarse resolution for the regions some distance away due to decrease of SRR values. Inversion result showed that simulation of CO mixing ratio with the a posterior information was evidently improved, reducing root-mean square (RMS) of differences between observation and simulation by 30%. A posterior indicated that CO emission in East China was probably 10%, 25% and 6% of underestimated by emission inventory for spring, autumn and winter time. Spatial distribution of a posterior indicated that North China Plain (30°N-40°N, 110°E-120°E) significantly accounted for the total increase of CO emission in the East China; Nevertheless, the CO emission from South China region (20°N-30°N, 100°E-120°E) might be overestimated ~10% annually. Uncertainties analysis with repeated random samplings approach demonstrated that

  2. Tree diversity promotes insect herbivory in subtropical forests of south-east China

    PubMed Central

    Schuldt, Andreas; Baruffol, Martin; Böhnke, Martin; Bruelheide, Helge; Härdtle, Werner; Lang, Anne C; Nadrowski, Karin; von Oheimb, Goddert; Voigt, Winfried; Zhou, Hongzhang; Assmann, Thorsten; Fridley, Jason

    2010-01-01

    1.Insect herbivory can strongly affect ecosystem processes, and its relationship with plant diversity is a central topic in biodiversity–functioning research. However, very little is known about this relationship from complex ecosystems dominated by long-lived individuals, such as forests, especially over gradients of high plant diversity. 2.We analysed insect herbivory on saplings of 10 tree and shrub species across 27 forest stands differing in age and tree species richness in an extraordinarily diverse subtropical forest ecosystem in China. We tested whether plant species richness significantly influences folivory in these highly diverse forests or whether other factors play a more important role at such high levels of phytodiversity. 3.Leaf damage was assessed on 58 297 leaves of 1284 saplings at the end of the rainy season in 2008, together with structural and abiotic stand characteristics. 4.Species-specific mean damage of leaf area ranged from 3% to 16%. Herbivory increased with plant species richness even after accounting for potentially confounding effects of stand characteristics, of which stand age-related aspects most clearly covaried with herbivory. Intraspecific density dependence or other abiotic factors did not significantly influence overall herbivory across forest stands. 5.Synthesis.The positive herbivory–plant diversity relationship indicates that effects related to hypotheses of resource concentration, according to which a reduction in damage by specialized herbivores might be expected as host plant concentration decreases with increasing plant diversity, do not seem to be major determinants for overall herbivory levels in our phytodiverse subtropical forest ecosystem. We discuss the potential role of host specificity of dominant herbivores, which are often expected to show a high degree of specialization in many (sub)tropical forests. In the forest system we studied, a much higher impact of polyphagous species than traditionally assumed

  3. New perspective of Earthquake generation in the east margins of Tibet, China

    NASA Astrophysics Data System (ADS)

    Wang, Zhi; Wang, Xuben

    2016-04-01

    Global seismic waveform inversion can reveal where rupture initiated and how it expanded for the 2013 Ms 7.0 Lushan earthquake, Sichuan province of China. To investigate the generation mechanism of the Lushan earthquake and its relation to the 2008 Wenchuan earthquake (Ms 8.0), we installed 50 temporal seismic stations at the source area following the Lushan earthquake. We also collected crustal stress data along the Longmen-Shan fault zone (LMFZ) to reveal its influence on the Lushan earthquake generation. Our seismic imaging and crustal stress analysis indicates that the Lushan earthquake occurred in a distinct area with high-velocity (Vp, Vs), low-Poisson's ratio (σp and high crustal stress. The high velocity zone at the Lushan source may reflect the metamafic seismogenic layer that enables the accumulation of high crustal stress for large earthquake generation. However, a sharp contrast gap zone with low velocity and high-gσ anomalies is clearly imaged in the upper crust under the conjunction area between the Lushan and Wenchuan earthquakes. Our seismic images indicate that the slow velocity gap zone is associated with fluid-bearing ductile flow from the lower crustal materials of Tibet being pushed into the weakened segment of the LMFZ. Our study suggests that the 2013 Lushan earthquake may have been triggered by the high crustal stress accumulation together with the high coseismic stress increased by the Wenchuan Earthquake in the metamafic seismogenic layer. The contrasting rheological variation in the crust and crustal stress change along the LMFZ controls the rupture processes of the Lushan and Wenchuan earthquakes, as well as the generation of new earthquakes in the future.

  4. Microphysical characteristics of sea fog over the east coast of Leizhou Peninsula, China

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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 μm. 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.

  5. Spatial distributions of polyunsaturated aldehydes and their biogeochemical implications in the Pearl River Estuary and the adjacent northern South China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Zhengchao; Li, Qian P.

    2016-09-01

    This study reports the first comprehensive exploration of the spatial patterns of dissolved and particulate polyunsaturated aldehydes (PUAs), their physical and biological controlling factors, and their potential biogeochemical influences in the Pearl River Estuary (PRE) of the northern South China Sea (NSCS). High levels of total particulate PUAs (0-41 nM) and dissolved PUAs (0.10-0.37 nM) were observed with substantial spatial variation during an intense summer phytoplankton bloom outside the PRE mouth. We found the particulate PUAs strongly correlated with temperature within the high chlorophyll bloom, while showing a generally positive correlation with chlorophyll-a for the entire region. Additionally, the Si/N ratio significantly correlated with the particulate PUAs along the estuary suggesting the important role of silica on PUA production in this region. The dissolved PUAs counterparts exhibited a positive correlation with chlorophyll-a within the high chlorophyll bloom, but a negatively one with temperature outside, reflecting the essential bio-physical coupling effects on the dissolved PUAs distributions in the ocean. Biogeochemical implications of PUAs on the coastal ecosystem include not only the deleterious restriction of high PUAs-producing diatom bloom on copepod population, but also the profound influence of particulate PUAs on the microbial cycling of organic carbon in the NSCS.

  6. Tracking Monsoon Related Provenance Changes in Continental Margin Sediments of the East China Sea: Preliminary Results from IODP Expedition 346.

    NASA Astrophysics Data System (ADS)

    Anderson, C. H.; Dunlea, A. G.; Murray, R. W.; Kinsley, C. W.; McGee, D.; Giosan, L.; Zheng, H.; Tada, R.; Alvarez Zarikian, C. A.

    2014-12-01

    Sedimentation in the East China Sea (ECS) is driven largely by fluvial and eolian fluxes that are likely influenced by the East Asian Monsoon (EAM). Terrigenous matter from the Yangtze River is transported into the ECS and is also carried by winds of the Westerly Jet. Seasonal and long term shifts in the atmospheric and precipitation regimes over Asia are recorded in the inorganic chemistry of the sediment of the ECS and other Asian coastal seas. For example, changes in intensity and timing of the EAM over short and long term time scales likely impact the relative proportion of fluvial and eolian inputs to the region, and perhaps their individual sources. Bulk sediment was recovered from IODP Sites U1428 and U1429 in the ECS during Expedition 346. T these sites are separated by 7.4 km, located in the northernmost portion of the ECS in the Danjo Basin, and are generally characterized by two sedimentary units. Unit A is largely nannofossil-rich calcareous ooze and calcareous-rich clays, punctuated with smaller tephra layers throughout. Unit B is composed of fine- to medium-grained, rounded sands. Here we present major, trace and rare earth element (REE) data for 54 bulk sediment samples analyzed via ICP-ES and ICP-MS. We trace downhole fluctuations in the geochemical data in order to investigate the provenance of terrigenous material during the Pleistocene. Preliminary major element concentration data indicate the presence of distinct continental sediment and carbonates at both sites. Average downhole major element ratios exhibit limited variation at both sites. For example, Ti/Al (g/g) is tightly constrained with values of 0.05 /- 0.003, Fe/Al 0.5 /- 0.05, and Si/Al 3.3 /- 0.3. In addition to standard geochemical techniques to assess provenance, we are using multivariate statistics (e.g., Q-Mode Factor Analyses, Multiple Linear Regressions) to examine this large dataset. We focus on a smaller suite of elements that are exclusively associated with the terrigenous

  7. Temporal and spatial distributions of dominant shrimp stocks and their relationship with the hydrological environment in the East China Sea

    NASA Astrophysics Data System (ADS)

    Lü, Huaqing; Song, Haitang; Bayly, Chris

    2007-10-01

    To provide a scientific and technological base for fishery administration, holding a moratorium on fishing, and combating habitat degradation, a shrimp stock survey was carried out in May, August, and November 1998 and in February 1999. The study was conducted in the area between 26°00' N and 33°00' N and to the west of 127°00' E in the East China Sea using a multi-sac trawl-net, with 115 stations being sampled. Up to 2001, we had found 121 species, which belong to 63 genera under 22 families, and 41 species are of high economic value and in great abundance. Nine shrimp species were of great economic importance, whose stock accounted for 76.8% of the demersal total. They were Parapenaeus fissuroides, Metapenaeopsis philippi, Palaemon gravieri, Metapenaeopsis barbata, Solenocera koelbeli, Solenocera crassicornis, Trachypenaeus curvirostris, Solenocera melantho and Parapenaeopsis hardwickii (listed in stock order). The nine species belong to the curythermal and eurysaline community and high thermal and high saline community, had different migration patterns and stocks, and their distribution patterns could be generally classified into three types: (1) dominating in the north or the south; (2) dominating to the north of and in the coast to the south of 30°00' N; and (3) dominating to the east of 60 m isobath, which were related to six water masses in the ECS near two lines, i.e., the 60 m isobath and 30°00'N latitudinal lines. Densely habited shrimps were found in all four seasons due to temperature and salinity frontiers and upwelling. The general stock density index was relatively higher in spring, summer, and autumn, when it surpassed 10 kg/h, while in winter, it was only 6.8 kg/h which might be caused by overfishing. According to the spawning areas of the nine species and their distribution patterns, to attain sustainable development of the shrimp fishery in the ECS, it is imperative to protect fishing areas and to hold a moratorium on catching to the west of

  8. Digital reconstruction on geographical environment of Neolithic human activities in the Lingjiatan site of Chaohu City, East China

    NASA Astrophysics Data System (ADS)

    Wang, Xinyuan; Zhang, Jie; Wu, Li; Zhou, Kunshu; Mo, Duowen

    2010-11-01

    The Chaohu Lake Basin is an important area for ancient human activities in East China. The Lingjiatan site, which is located at the southeast of Chaohu City, Anhui Province, and 35 km north to the Yangtze River and 5 km south to the Taihu Mountain, is the most representative Neolithic Age site with advanced jade-carving techniques in this area. The 14C date of Lingjiatan Site is about 5600~5300aBP, the same time as the Hongshan culture and earlier than the Liangzhu culture, which falls into the Mid-Holocene epoch. Based on mid-high resolution remote sensing images and former archaeological materials, combined with field investigations and sampling analysis of the archaeological site profile of Lingjiatan Site as well as core drillings in the Chaohu Lake, the paper reconstructs the climate environment of the Lingjiatan site and the environmental background of ancient human activities during Mid-Holocene. The research results show that: (1) The ancients in Lingjiatan lived in the Holocene Optimum, its culture development was during the interim phase when the climate transformed from warm and wet to cool and dry. (2) The ground surface deposited in the last phase of late Pleistocene epoch (OSL dating is 11.6 +/-1.0 ka BP) was the living ground for Lingjiatan ancient humans. The sedimentary discontinuous surface may be caused by strong fluvial erosion under the warm and humid climatic conditions of the Mid-Holocene. (3) Originally, paleo-geomorphic surface was a level shallow mesa foreside southern part of Taihu Mountain, but was cut by fluvial waters and the geomorphologic configuration formed "finger-like" features alternately with strip hillocks and rivers. These features can be seen on the Landsat ETM+ remote sensing image, especially the depression area. This depression is now cropland, and was interpreted as the palaeochannels. (4) Based on the remote sensing image interpretation, the site was in a "peninsula shape" environment which had rivers flowing around the

  9. Digital reconstruction on geographical environment of Neolithic human activities in the Lingjiatan site of Chaohu City, East China

    NASA Astrophysics Data System (ADS)

    Wang, Xinyuan; Zhang, Jie; Wu, Li; Zhou, Kunshu; Mo, Duowen

    2009-09-01

    The Chaohu Lake Basin is an important area for ancient human activities in East China. The Lingjiatan site, which is located at the southeast of Chaohu City, Anhui Province, and 35 km north to the Yangtze River and 5 km south to the Taihu Mountain, is the most representative Neolithic Age site with advanced jade-carving techniques in this area. The 14C date of Lingjiatan Site is about 5600~5300aBP, the same time as the Hongshan culture and earlier than the Liangzhu culture, which falls into the Mid-Holocene epoch. Based on mid-high resolution remote sensing images and former archaeological materials, combined with field investigations and sampling analysis of the archaeological site profile of Lingjiatan Site as well as core drillings in the Chaohu Lake, the paper reconstructs the climate environment of the Lingjiatan site and the environmental background of ancient human activities during Mid-Holocene. The research results show that: (1) The ancients in Lingjiatan lived in the Holocene Optimum, its culture development was during the interim phase when the climate transformed from warm and wet to cool and dry. (2) The ground surface deposited in the last phase of late Pleistocene epoch (OSL dating is 11.6 +/-1.0 ka BP) was the living ground for Lingjiatan ancient humans. The sedimentary discontinuous surface may be caused by strong fluvial erosion under the warm and humid climatic conditions of the Mid-Holocene. (3) Originally, paleo-geomorphic surface was a level shallow mesa foreside southern part of Taihu Mountain, but was cut by fluvial waters and the geomorphologic configuration formed "finger-like" features alternately with strip hillocks and rivers. These features can be seen on the Landsat ETM+ remote sensing image, especially the depression area. This depression is now cropland, and was interpreted as the palaeochannels. (4) Based on the remote sensing image interpretation, the site was in a "peninsula shape" environment which had rivers flowing around the

  10. 50. View looking east. East bay is on the left. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. View looking east. East bay is on the left. The dismantling of the last crib. Note the identifying tags nailed to the crib sidewalls. Foundation timbers and the outline of the crib structure are visible in the foreground. - Wabash & Erie Canal, Lock No. 2, 8 miles east of Fort Wayne, adjacent to U.S. Route 24, New Haven, Allen County, IN

  11. Acidifying intermediate water accelerates the acidification of seawater on shelves: An example of the East China Sea

    NASA Astrophysics Data System (ADS)

    Lui, Hon-Kit; Chen, Chen-Tung Arthur; Lee, Jay; Wang, Shu-Lun; Gong, Gwo-Ching; Bai, Yan; He, Xianqiang

    2015-12-01

    This study is the first to present observed acidification rates at the shelf break of the East China Sea (ECS) and in the Okinawa Trough between 1982 and 2007. The use of apparent oxygen utilization (AOU) data to quantify the change in pH due to physical changes and changes in biological activities is demonstrated. The results thus obtained reveal that the drop in pH of the Kuroshio Intermediate Water (KIW) in the ECS is a result of not only the intrusion of atmospheric CO2, but also an increase in AOU concentration. The acidification rates caused by the increasing AOU concentration could contribute up to -0.00086±0.00017 pH unit yr-1 at 900 m in the Okinawa Trough and -0.00082±0.00057 pH unit yr-1 on the shelf break of the ECS. These values are equivalent to 54% and 51%, respectively, of the acidification rate of -0.0016 pH unit yr-1 based on an assumption of the air-sea CO2 equilibrium. When the effects of changing AOU and θ are eliminated, the acidification rate in the basin of the ECS captures the rate of change that is caused by an increase in anthropogenic CO2 concentration. In contrast, when the effects of changing AOU and θ are eliminated, the acidification rate at the shelf break is 69% higher than the rate based on an assumption of the air-sea CO2 equilibrium. Since the seawater on the shelf contains a higher proportion of the South China Sea (SCS) seawater and coastal water than does that in the Okinawa Trough, the result herein may imply that the SCS seawater, coastal water, or a combination of them suffered a higher acidification rate during the studied period. This study, to the best of the authors' knowledge, is the first to demonstrate that changing the carbonate chemistry of both incoming offshore intermediate seawater and coastal water results in the acidification of seawater on a continental shelf. The results herein reveal a situation in which the acidification of coastal seawater may be faster than expected when the reduction of pH of the

  12. New production in the East China Sea, comparison between well-mixed winter and stratified summer conditions

    NASA Astrophysics Data System (ADS)

    Chen, Yuh-ling Lee; Chen, Houng-Yung; Lee, Wen-Huei; Hung, Chin-Chang; Wong, George T. F.; Kanda, Jota

    2001-04-01

    This paper compares the variations of nitrate-based "new" production (NP) in the continental shelf of the East China Sea (ECS) between summer, when seawater stratification was strong, and winter when seawater was well mixed. New production and f-ratio (ratio of nitrate-based new production to primary production) showed no obvious seasonality and were generally low with two exceptions: one in the coastal upwelling off China in summer, and the other in the Kuroshio upwelling off northeastern Taiwan in winter. When not counting the two exceptional areas which were relatively small area-wise, integrated nitrate-based new production (INP) ranged 0.06-0.41 g C m -2 d -1 in summer and 0.08-0.27 g C m -2 d -1 in winter with f-ratios of 0.25-0.42 and 0.18-0.35. In summer, NP in the Changjiang-influenced coastal waters was significantly correlated to a high ambient nitrate concentration, which originated from the Changjiang discharge or from the coastal upwelling. Phosphate from the coastal upwelling alleviated the phosphorus deficiency caused by the river mixing, and the nitrate to phosphate ratio was near the Redfield ratio. Nitrate was readily consumed and converted into phytoplankton biomass. This leads to a low surface nitrate concentration (mostly below the detectable limit of 0.1 μM) and thus resulting in low NP in the surrounding shelf waters. NP in winter, in contrast, was not correlated to the nitrate concentration. Despite the abundant nitrate on the continental shelf (ranging between 0.52 and 14.24 μM), INP remained relatively low (0.01-0.55 g C m -2 d -1). Light limitation hampered nitrate utilization. The deep mixing layer (>euphotic depth), low photosynthesis available radiation, and a significant correlation between new production and stratification index indicated that NP in winter was controlled by irradiation intensity rather than nutrient concentration. The present results strongly suggest that production in the ECS was limited by N deficiency in summer

  13. Temporal evolution of granitic magmas in the Luanchuan metallogenic belt, east Qinling Orogen, central China: Implications for Mo metallogenesis

    NASA Astrophysics Data System (ADS)

    Li, Dong; Han, Jiangwei; Zhang, Shouting; Yan, Changhai; Cao, Huawen; Song, Yaowu

    2015-11-01

    The Luanchuan metallogenic belt, located within the eastern part of the Qinling Orogen, central China, hosts a number of world-class Mo deposits that are closely related to small late Mesozoic granitic plutons. Zircon U-Pb dating of distinct plutons in the Luanchuan metallogenic belt has yielded ages of 153 ± 1, 154 ± 2, 152 ± 2, and 148 ± 1 Ma. Molybdenite Re-Os isotopic compositions of Yuku ore district in the southern part of Luanchuan metallogenic belt has yielded an isochron age of 146 ± 1 Ma, which is consistent with the large-scale mineralization ages in the northern part of the Luanchuan metallogenic belt. A combination of previous studies and new geochronological and isotopic data show a concordant temporal and genetic link between granitic magmatism and Mo mineralization in the Luanchuan metallogenic belt, suggesting that this mineralization episode formed the most extensive Mo mineralization belt in the east Qinling Orogen. Zircon grains from Mo-related granitic plutons show similar trace element distributions. High-precision Multi Collector-Inductively Coupled Plasma-Mass Spectrometry (MC-ICP-MS) Pb isotope analysis of K-feldspar megacrysts from mineralization-related granites suggest that they were derived from the lower crust. Similarly, the Pb isotopic compositions of pyrite coprecipitated with molybdenite also suggest that the metals were derived form the lower crust, with probably minor mantle contribution. A continuum mineralization model that describes the sourcing of Mo from an evolving granitic magma over successive differentiation events, possibly in separate but connected magma chambers, could explain the remarkable Mo enrichment in the Luanchuan metallogenic belt. The volatile- and Mo-bearing granitic magmas ascended as diapirs from the deep crust, and were emplaced as dikes in the upper crust. Lithological differences between these Mo-bearing granites may relate to different stages in the evolution of individual magmas. Finally, ore

  14. Chemical composition and mass size distribution of PM1.0 at an elevated site in central east China

    NASA Astrophysics Data System (ADS)

    Zhang, Y. M.; Zhang, X. Y.; Sun, J. Y.; Hu, G. Y.; Shen, X. J.; Wang, Y. Q.; Wang, T. T.; Wang, D. Z.; Zhao, Y.

    2014-06-01

    Size-resolved aerosol chemical compositions were measured continuously for one and half years with an aerosol mass spectrometer (AMS) to characterize the mass and size distributions (MSDs) of each component in bulk, fresh and aged submicron particles (approximately PM1.0) at Mountain Tai, an elevated site in Central East China (CEC) from June 2010 to January 2012. The majority of the regionally-dispersed aerosols were found to be contributed from short distance mixed aerosol, mostly from its south with organics and sulfate as the major components. The annual mean mass concentrations of organics, sulfate, nitrate, ammonium and chloride were 11.2, 9.2, 7.2, 5.8 and 0.95 μg m-3, respectively, which are much lower for organics and sulfate, and slightly lower for nitrate, ammonium and chloride than those at the nearby surface rural sites. High organics were observed for all four seasons, and the relatively fresh organic aerosol (OA) containing high proportion of less-photo chemically OA, were found from long-range transported aerosol from northwest. Semi-volatile and low-volatile oxidized OAs together contributed approximately 49%, 55% in spring and 72% and 51% in winter of total OA, showing at least 50% of OA can be attributable to SOA. Seasonally, the chemical components at the elevated site showed a "winter high and autumn low" pattern, with organics, sulfate and ammonium peaking in summer. Though no obvious differences of MSDs were seen for various chemical components in the planetary boundary layer (PBL) and free troposphere (FT), the concentrations were a factor of 5-7 higher in PBL than in FT. The averaged MSDs of particles between 30-1000 nm for organics, sulfate, nitrate, and ammonium are approximately log-normal with similar mass median diameters (MMDs) of 539, 585, 542, and 545 nm, respectively, which were slightly larger than those in ground sites within North China Plain (NCP). Obvious differences in MMDs were found between fresh and aged aerosols for

  15. Distinct groundwater recharge sources and geochemical evolution of two adjacent sub-basins in the lower Shule River Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Wang, Liheng; Dong, Yanhui; Xie, Yueqing; Song, Fan; Wei, Yaqiang; Zhang, Jiangyi

    2016-08-01

    Based on analysis of groundwater hydrogeochemical and isotopic data, this study aims to identify the recharge sources and understand geochemical evolution of groundwater along the downstream section of the Shule River, northwest China, including two sub-basins. Groundwater samples from the Tashi sub-basin show markedly depleted stable isotopes compared to those in the Guazhou sub-basin. This difference suggests that groundwater in the Tashi sub-basin mainly originates from meltwater in the Qilian Mountains, while the groundwater in the Guazhou sub-basin may be recharged by seepage of the Shule River water. During the groundwater flow process in the Tashi sub-basin, minerals within the aquifer material (e.g., halite, calcite, dolomite, gypsum) dissolve in groundwater. Mineral dissolution leads to strongly linear relationships between Na+ and Cl- and between Mg2++ Ca2+ and SO4 2- + HCO3 -, with stoichiometry ratios of approximately 1:1 in both cases. The ion-exchange reaction plays a dominant role in hydrogeochemical evolution of groundwater in the Guazhou sub-basin and causes a good linear relationship between (Mg2++ Ca2+)-(SO4 2- + HCO3 -) and (Na++ K+)-Cl- with a slope of -0.89 and also results in positive chloroalkaline indices CAI 1 and CAI 2. The scientific results have implications for groundwater management in the downstream section of Shule River. As an important irrigation district in Hexi Corridor, groundwater in the Guazhou sub-basin should be used sustainably and rationally because its recharge source is not as abundant as expected. It is recommended that the surface water should be used efficiently and routinely, while groundwater exploitation should be limited as much as possible.

  16. Detail of north intermediate abutment pylon showing proximity of adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of north intermediate abutment pylon showing proximity of adjacent 1001-1007 East First Street (James K. Hill and Sons Pickle Works Building), facing east - First Street Bridge, Spanning Los Angeles River at First Street, Los Angeles, Los Angeles County, CA

  17. Comparison of buried sand ridges and regressive sand ridges on the outer shelf of the East China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Ziyin; Jin, Xianglong; Zhou, Jieqiong; Zhao, Dineng; Shang, Jihong; Li, Shoujun; Cao, Zhenyi; Liang, Yuyang

    2016-06-01

    Based on multi-beam echo soundings and high-resolution single-channel seismic profiles, linear sand ridges in U14 and U2 on the East China Sea (ECS) shelf are identified and compared in detail. Linear sand ridges in U14 are buried sand ridges, which are 90 m below the seafloor. It is presumed that these buried sand ridges belong to the transgressive systems tract (TST) formed 320-200 ka ago and that their top interface is the maximal flooding surface (MFS). Linear sand ridges in U2 are regressive sand ridges. It is presumed that these buried sand ridges belong to the TST of the last glacial maximum (LGM) and that their top interface is the MFS of the LGM. Four sub-stage sand ridges of U2 are discerned from the high-resolution single-channel seismic profile and four strikes of regressive sand ridges are distinguished from the submarine topographic map based on the multi-beam echo soundings. These multi-stage and multi-strike linear sand ridges are the response of, and evidence for, the evolution of submarine topography with respect to sea-level fluctuations since the LGM. Although the difference in the age of formation between U14 and U2 is 200 ka and their sequences are 90 m apart, the general strikes of the sand ridges are similar. This indicates that the basic configuration of tidal waves on the ECS shelf has been stable for the last 200 ka. A basic evolutionary model of the strata of the ECS shelf is proposed, in which sea-level change is the controlling factor. During the sea-level change of about 100 ka, five to six strata are developed and the sand ridges develop in the TST. A similar story of the evolution of paleo-topography on the ECS shelf has been repeated during the last 300 ka.

  18. A unique Fe-rich carbonate chimney associated with cold seeps in the Northern Okinawa Trough, East China Sea

    NASA Astrophysics Data System (ADS)

    Sun, Zhilei; Wei, Helong; Zhang, Xunhua; Shang, Luning; Yin, Xijie; Sun, Yunbao; Xu, Lei; Huang, Wei; Zhang, Xianrong

    2015-01-01

    The East China Sea is an important marginal sea of the Western Pacific Ocean, from which natural gas hydrate sample has not been acquired so far. Recently, copious carbonate chimneys have been discovered in turbidite deposits in the olistostrome zone located on the west slope of the northern section of Okinawa Trough. Here, the petrology, geochemistry and chronology of an iron-rich carbonate chimney were characterized, confirming a close relationship between its formation and the dissociation of natural gas hydrate beneath the chimney in OT. A distinctive relationship has been observed between goethite and total carbonate contents along with a negative correlation between Fe and Ca contents. Conversely, abundant Fe accumulated on carbonate substrate by mineralized microorganisms. The δ13C values of the chimney wall were from -27.56 to -43.66‰ (average: -37.18‰, V-PDB), implying anaerobic oxidation of methane (AOM) as a predominant controlling factor on carbonate precipitation. As no pyrite and organic residues were identified in the iron-rich chimney, it was assumed that AOM was coupled to the iron reduction reaction at least to some extent during the chimney growth owing to the local deficiency of sulfate supply. The δ56Fe values of bulk chimney wall (ranging from -0.316‰ to -0.023‰, average -0.134‰) suggest mass and isotope exchanges between the chimney and ambient environment during its growth history, whereas the enrichment of δ18O of the carbonate implies these carbonate sourcing from hydrate dissociation underlying our sampling site. This assumption has been supported by a distinct bottom simulation reflector (BSR) and a well-developed fault system beneath the sampling site. This is the first report of cold seepage inside the OT and the identified iron-dependent AOM has shed a new light to the Carbon cycle related to the marine methane oxidation, particularly before the Great Oxidation Event ~2.45 Ga ago.

  19. Enhancement of Eddy Heat Transport due to the Anticyclonic Submesoscale Eddies around Ryukyu Islands near Kuroshio in East China Sea

    NASA Astrophysics Data System (ADS)

    Kamidaira, Y.; Uchiyama, Y.; Mitarai, S.; Miyazawa, Y.

    2014-12-01

    A synoptic, regional downscaling experiment of Kuroshio off Ryukyu Islands, Japan, exhibits the evident predominance of submesoscale anticyclonic eddies over cyclones in the narrow strip between Kuroshio and the islands (Uchiyama et al., 2013). In the present study, the mechanism and impacts of the anticyclone dominance are examined with a detailed oceanic downscaling model in a double nested ROMS configuration at the horizontal resolution of 3km (ROMS-L1) and 1km (ROMS-L2), forced by the assimilative JCOPE2 oceanic reanalysis and the JMA GPV-MSM atmospheric hindcast. The model results are extensively validated against a variety of data including shipboard hydrography and satellite altimetry and temperature data to show a good agreement. An alternative ROMS-L2 experiment is also conducted to examine topographic effects on the anticyclones around the Ryukyu Islands by eliminating all the island topography above z > -1000 m, while the other configurations are held unchanged. If the islands are removed, the submesoscale negative vortices on the eastern side of the Kuroshio become much weaker than those of the original case with the islands. The experiment clearly demonstrates that dominance of the negative vorticity between Kuroshio and the Ryukyu Islands is caused by enhanced lateral shear due to the concentrated Kuroshio mean current associated with appropriate formation of the eastern branch, the northward-drifting Ryuku Current, and resultant eddy shedding in the narrow channel between the continental shelf of the East China Sea and the Okinawan ridge. A diagnostic eddy heat flux analysis illustrates that the submesoscale anticyclonic eddies play a crucial role in enhancing the eddy heat transport and thus the lateral mixing between Kuroshio and the islands as compared to those in the coarser resolution models (L1 and JCOPE2), resulting in promoting regional larval and material transport from Kuroshio to the islands.

  20. Effect of model error representation in the Yellow and East China Sea modeling system based on the ensemble Kalman filter

    NASA Astrophysics Data System (ADS)

    Kwon, Kyung Man; Choi, Byoung-Ju; Lee, Sang-Ho; Kim, Young Ho; Seo, Gwang-Ho; Cho, Yang-Ki

    2016-02-01

    To increase the accuracy of ocean predictions in the Yellow and East China Sea (YES), the satellite-borne sea surface temperature (SST) data have been assimilated to an operational ocean modeling system by applying an ensemble Kalman filter (EnKF). As the observed SST was assimilated continuously into the model with time, the ensemble spread decreased and the efficiency of data assimilation degenerated. To increase liability of the system and the ensemble spread, model uncertainties were represented stochastically by perturbing the model tendency parameters such as eddy viscosity, bottom drag coefficient, light attenuation depth, as well as atmospheric forcing. Data assimilation experiments were performed with forcing from a regional atmospheric model from September 2011 to February 2012. The assimilation results with and without the stochastically perturbed model parameters and atmospheric forcing were compared. The ensemble with the perturbations has larger spread and smaller root-mean-square deviation (RMSD) in temperature compared with the ensemble without the perturbations. The SST RMSD relative to anther supplementary SST dataset was reduced from 0.91 to 0.81 °C over the YES. The assimilation of the SST data improved the simulated SST compared with the observation at the ocean buoy stations, and also made the subsurface temperature profiles closer to the observed ones. The assimilation experiments showed that a stochastic representation of the model errors by the perturbations of the model parameters and atmospheric forcing increases the spread of the ensemble and improves the structure of background error covariance, which enhances the performance of the ensemble modeling system in the YES.

  1. Daily anomalous high flow (DAHF) of a headwater catchment over the East River basin in South China

    NASA Astrophysics Data System (ADS)

    Chen, Ji; Niu, Jun; Sivakumar, Bellie

    2014-11-01

    This study develops a new method for analyzing the terrestrial hydrologic responses to precipitation through using level-based daily anomalous high flow (DAHF) occurrence in a catchment. The objectives of this study are twofold: (1) to explore the DAHF features over a headwater catchment; and (2) to evaluate the performance of a hydrologic model for DAHF simulation. In this study, DAHF is defined as the daily streamflow on a given day, whose deseasonalised daily streamflow is larger than a given multiplier of the standard deviation (STD) of the long-term deseasonalised streamflow series. Streamflow observations of a headwater catchment over the period of 1952-1972 (i.e., before reservoir operation) at the Longchuan station in the East River basin in South China are studied. The macro-scale Variable Infiltration Capacity (VIC) model is used for streamflow simulation in the catchment, and wavelet analysis is performed to explore the DAHF variability. The study reveals that the percentages of the number of days with the first and second levels of DAHFs are 4.2% and 1%, respectively, for the observed streamflows, while the corresponding percentages for the VIC model-simulated streamflow are 5% and 1.3%, respectively. Application of the Kolmogorov-Smirnov goodness-of-fit test indicates that these two levels of DAHFs can be described by two probability distribution functions, namely the Lognormal distribution and Generalized Extreme Value Type II distribution, respectively. The variability spectrum of the first level DAHF is basically consistent with that of antecedent precipitation, but not for the second level DAHF, as revealed by the wavelet analysis. The VIC model has better performance on the variability simulation of the first level of DAHF.

  2. Reductive Reactivity of Iron(III) Oxides in the East China Sea Sediments: Characterization by Selective Extraction and Kinetic Dissolution

    PubMed Central

    Chen, Liang-Jin; Zhu, Mao-Xu; Yang, Gui-Peng; Huang, Xiang-Li

    2013-01-01

    Reactive Fe(III) oxides in gravity-core sediments collected from the East China Sea inner shelf were quantified by using three selective extractions (acidic hydroxylamine, acidic oxalate, bicarbonate-citrate buffered sodium dithionite). Also the reactivity of Fe(III) oxides in the sediments was characterized by kinetic dissolution using ascorbic acid as reductant at pH 3.0 and 7.5 in combination with the reactive continuum model. Three parameters derived from the kinetic method: m0 (theoretical initial amount of ascorbate-reducible Fe(III) oxides), k′ (rate constant) and γ (heterogeneity of reactivity), enable a quantitative characterization of Fe(III) oxide reactivity in a standardized way. Amorphous Fe(III) oxides quantified by acidic hydroxylamine extraction were quickly consumed in the uppermost layer during early diagenesis but were not depleted over the upper 100 cm depth. The total amounts of amorphous and poorly crystalline Fe(III) oxides are highly available for efficient buffering of dissolved sulfide. As indicated by the m0, k′ and γ, the surface sediments always have the maximum content, reactivity and heterogeneity of reactive Fe(III) oxides, while the three parameters simultaneously downcore decrease, much more quickly in the upper layer than at depth. Albeit being within a small range (within one order of magnitude) of the initial rates among sediments at different depths, incongruent dissolution could result in huge discrepancies of the later dissolution rates due to differentiating heterogeneity, which cannot be revealed by selective extraction. A strong linear correlation of the m0 at pH 3.0 with the dithionite-extractable Fe(III) suggests that the m0 may represent Fe(III) oxide assemblages spanning amorphous and crystalline Fe(III) oxides. Maximum microbially available Fe(III) predicted by the m0 at pH 7.5 may include both amorphous and a fraction of other less reactive Fe(III) phases. PMID:24260377

  3. Reductive reactivity of iron(III) oxides in the east china sea sediments: characterization by selective extraction and kinetic dissolution.

    PubMed

    Chen, Liang-Jin; Zhu, Mao-Xu; Yang, Gui-Peng; Huang, Xiang-Li

    2013-01-01

    Reactive Fe(III) oxides in gravity-core sediments collected from the East China Sea inner shelf were quantified by using three selective extractions (acidic hydroxylamine, acidic oxalate, bicarbonate-citrate buffered sodium dithionite). Also the reactivity of Fe(III) oxides in the sediments was characterized by kinetic dissolution using ascorbic acid as reductant at pH 3.0 and 7.5 in combination with the reactive continuum model. Three parameters derived from the kinetic method: m 0 (theoretical initial amount of ascorbate-reducible Fe(III) oxides), k' (rate constant) and γ (heterogeneity of reactivity), enable a quantitative characterization of Fe(III) oxide reactivity in a standardized way. Amorphous Fe(III) oxides quantified by acidic hydroxylamine extraction were quickly consumed in the uppermost layer during early diagenesis but were not depleted over the upper 100 cm depth. The total amounts of amorphous and poorly crystalline Fe(III) oxides are highly available for efficient buffering of dissolved sulfide. As indicated by the m 0, k' and γ, the surface sediments always have the maximum content, reactivity and heterogeneity of reactive Fe(III) oxides, while the three parameters simultaneously downcore decrease, much more quickly in the upper layer than at depth. Albeit being within a small range (within one order of magnitude) of the initial rates among sediments at different depths, incongruent dissolution could result in huge discrepancies of the later dissolution rates due to differentiating heterogeneity, which cannot be revealed by selective extraction. A strong linear correlation of the m 0 at pH 3.0 with the dithionite-extractable Fe(III) suggests that the m 0 may represent Fe(III) oxide assemblages spanning amorphous and crystalline Fe(III) oxides. Maximum microbially available Fe(III) predicted by the m 0 at pH 7.5 may include both amorphous and a fraction of other less reactive Fe(III) phases. PMID:24260377

  4. A numerical study on the seasonal variability of polychlorinated biphenyls from the atmosphere in the East China Sea.

    PubMed

    Ono, Jun; Takahashi, Daisuke; Guo, Xinyu; Takahashi, Shin; Takeoka, Hidetaka

    2012-10-01

    A three-dimensional/high-resolution transport model for persistent organic pollutants (POPs) has been developed for the East China Sea (ECS). The POPs model has four compartments (gaseous, dissolved, phytoplankton-bound, and detritus-bound phases) and includes processes for diffusive air-water exchange, phytoplankton uptake/depuration to POPs, decomposition of dissolved phase, vertical sinking of phytoplankton, detritus production by phytoplankton mortality, and vertical sinking and decomposition of detritus. The POPs model is coupled with an ocean circulation model that can reproduce the seasonal variation in physical variables to represent the advection and diffusion of POPs. We applied the POPs model to the polychlorinated biphenyl congener 153 (PCB 153) from the atmosphere and examined the behavior of PCB 153 in the ocean. The model showed a remarkable seasonal variability of PCB 153. Concentrations in the dissolved and particulate phases are high in winter (January-March) and low in summer (July-September). In coastal regions, where chlorophyll a concentration is high, horizontal and vertical distributions in the dissolved and particulate PCB 153 concentrations are strongly affected by phytoplankton uptake. The sensitivity experiments on the dynamics of PCB 153 suggested that a change of Henry's law constant associated with water temperature is the major factor controlling the seasonal variability of PCB 153. The model-based yearly mass balance of PCB 153 in the ECS indicated that most of the atmospheric input (35.5 kg year(-1)) is removed by the horizontal advection outside the ECS (19.0 kg year(-1)) and accumulates to the sea bottom by vertical sinking (15.7 kg year(-1)). For comparison with PCB 153, we also conducted simulations for PCB 52, 101, and 180. The seasonal variations are similar to that of PCB 153. The mass balance of PCB 52 that has short half-life time and less hydrophobic property shows the different results compared with PCB 101, 153, and 180

  5. Variation of levels and distribution of N-nitrosamines in different seasons in drinking waters of East China.

    PubMed

    Li, Ting; Yu, Dian; Xian, Qiming; Li, Aimin; Sun, Cheng

    2015-08-01

    We surveyed the occurrence of nine N-nitrosamine species in ten bottled drinking waters from supermarket and other water samples including raw waters, finished waters, and distribution system waters from nine municipal drinking water treatment plants in eight cities of Jiangsu Province, East China. N-nitrosodimethylamine (NDMA) was detected in one of ten bottled drinking water samples at concentration of 4.8 ng/L and N-nitrosomorpholine (NMor) was detected in four of the ten bottles with an average concentration and a standard deviation of 16 ± 15 ng/L. The levels of nitrosamines in the distribution system water samples collected during summer season ranged from below detection limit (BDL) to 5.4 ng/L for NDMA, BDL to 9.5 ng/L for N-nitrosomethylethylamine (NMEA), BDL to 2.7 ng/L for N-nitrosodiethylamine (NDEA) and BDL to 8.5 ng/L for N-nitrosopyrrolidine (NPyr). Samples of distribution system waters collected in winter season had levels of nitrosamines ranged from BDL to 45 ng/L for NDMA, BDL to 5.2 ng/L for NPyr, and BDL to 309 ng/L for N-nitrosopiperidine (NPip). A positive correlation of the concentration of NDMA as well as the total nine N-nitrosamines between finished waters and distribution system waters was observed. Both dissolved organic carbon and nitrite were found to correlate linearly with N-nitrosamine levels in raw waters. PMID:25860554

  6. Mesozooplankton and copepod community structures in the southern East China Sea: the status during the monsoonal transition period in September

    NASA Astrophysics Data System (ADS)

    Tseng, Li-Chun; Dahms, Hans-Uwe; Chen, Qing-Chao; Hwang, Jiang-Shiou

    2012-12-01

    A field sampling was conducted before the onset of the northeasterly monsoon to investigate the copepod community composition during the monsoon transition period at the northern coast of Taiwan (East China Sea). In total, 22 major mesozooplankton taxa were found, with the Calanoida (relative abundance: 66.36%) and Chaetognatha (9.44%) being the most abundant. Mesozooplankton densities ranged between 226.91 and 2162.84 individuals m-3 (mean ± SD: 744.01 ± 631.5 individuals m-3). A total of 49 copepod species were identified, belonging to 4 orders, 19 families, and 30 genera. The most abundant species were: Temora turbinata (23.50%), Undinula vulgaris (17.92%), and Acrocalanus gibber (14.73%). The chaetognath Flaccisagitta enflata occurred at all 8 sampling stations, providing a 95% portion of the overall chaetognath contribution. Amphipoda were abundant at stations 4 and 5, with Hyperioides sibaginis and Lestigonus bengalensis being dominant, and comprising about 50% of all amphipods. Chaetognath abundance showed a significantly negative correlation with salinity ( r = 0.77, p = 0.027), whereas mesozooplankton group numbers had a significantly positive correlation with salinity ( r = 0.71, p = 0.048). Densities of four copepod species ( Calanus sinicus, Calocalanus pavo, Calanopia elliptica and Labidocera acuta) showed a significantly negative correlation with seawater temperature. Communities of mesozooplankton and copepods of northern Taiwan varied spatially with the distance to land. The results of this study provide evidence for the presence of C. sinicus in the coastal area of northern Taiwan during the early northeast monsoon transition period in September.

  7. Fine processing and analysis of seabed topographic features in the outer shelf of the north of the East China Sea

    NASA Astrophysics Data System (ADS)

    Tang, Q.; Zhou, X.; Ding, J.; Chen, Y.

    2015-12-01

    On the outer shelf of the north of the East China Sea, seabed ridges and troughs are widely distributed consecutively. The seabed bedforms are in the area where Yellow Sea Trough extends to the Okinawa Trough and lies in the entrance channel of Yellow Sea Warm Current (YSWC), one branch of the Kuroshio Current. The fine post-processing and characteristic analysis for seabed bedforms data will contribute to an overall understanding of seabed topographic features and distribution of the ridges and troughs. Based on the high-precision multi-beam echo sounder (MBES) data, we create a high-precision seabed Digital Terrain Model (DTM) and sonar mosaic images to generate high-resolution 3D seabed maps, as well as seabed slope, aspect maps and other special terrain profiles. From those maps, we can measure height, width, length, direction and other characteristic parameters of the seabed Rippled Scour Depressions (RSDs) and sand ridges. We find a deep seabed gully with the water depth of 153.2 m in the northeast corner of the study area. The relative height difference is up to 32 m indicates strong erosion with dramatic changes in seabed topography. There are also more than 10 large-scale straight RSDs and sand ridges, all NW-SE direction, in length from a few kilometers to 40 km. The general height difference is about 5 m and the maximum height difference can reach up to 10 m. In the study area we find out a great quantity of seabed sand ridges and erode RSDs, which form ridges-troughs and erosion-deposition special seabed topographic features.

  8. Comparative reproductive biology of three dominant myctophids of the genus Diaphus on the slope region of the East China Sea

    NASA Astrophysics Data System (ADS)

    Sassa, Chiyuki; Tanaka, Hiroshige; Ohshimo, Seiji

    2016-09-01

    We examined the reproductive biology of three dominant pseudoceanic myctophids, Diaphus garmani, D. chrysorhynchus, and D. watasei, on the slope region of the East China Sea. Overall, females were more abundant in D. garmani and D. chrysorhynchus, while males were more abundant in D. watasei. The gonadosomatic index (GSI) at 50% sexual maturity of females of D. garmani, D. chrysorhynchus, and D. watasei was 3.65, 3.92, and 6.27, respectively. Based on these criteria, females of each species can mature at sizes larger than 42, 71, and 120 mm standard length (SL), respectively. In all three species, GSI of females showed high values during summer, i.e. the primary spawning season, and occurrence of females with hydrated ovaries was restricted to the daytime (0600-1530 h) in the mesopelagic layer of 270-450 m depth. Oocytes at various sizes were found in mature ovaries, indicating that they are multiple spawners. Spawning frequencies were estimated to be approximately 3-9 days. Mean egg size at hydration and batch fecundity was respectively smallest and lowest in D. garmani (0.60 mm and 612-2200 eggs) and largest and highest in D. watasei (0.65 mm and 10,356-44,879 eggs). Batch fecundity increased linearly with SL in all species, with a steeper slope in D. watasei. Diaphus garmani is characterized by early maturation at a smaller size, while D. watasei channels a larger part of the energy budget into somatic growth during the juvenile and later immature stages (<120 mm SL) than the other two species and subsequently reproduces at a larger size as mature adults.

  9. Spatial distributions of methoxylated and hydroxylated polybrominated diphenyl ethers in the East China Sea--a seaward increasing trend.

    PubMed

    Fan, Ying; Lan, Jing; Li, Huijuan; Li, Guoliang; Cao, Yali; Zhao, Zongshan; Zhao, Meixun; Jiang, Guibin

    2014-11-01

    Methoxylated (MeO-) and hydroxylated (OH-) polybrominated diphenyl ethers (PBDEs) in marine environments have been of increasing concern due to their potential ecological toxicities and worldwide occurrence. However, few reports have been referred to their occurrence and distributions in marine sediments despite large numbers of studies on marine organisms have been reported. In the present paper, nine MeO-BDEs, ten OH-BDEs and three phytoplankton biomarkers (PBs) of brassicasterol, dinosterol and alkenones have been measured in surface sediments from the East China Sea. 6-MeO-BDE47, 2'-MeO-BDE68 and 6-OH-BDE47 were predominant congeners, ranging from 5.2 to 599.5 pg g(-1)dw, 5.2 to 562.4 pg g(-1)dw, and 11.4 to 129.1 pg g(-1)dw, respectively. Their spatial patterns all presented a seaward increasing trend and higher levels of these compounds were mainly concentrated in the outer shelf influenced by the Kuroshio Current. The patterns further prove that these ortho-substituted MeO-BDEs and OH-BDEs in marine sediments are natural compounds. Furthermore, alkenones also presented a seaward increasing trend. Statistical analysis shows that there are significant correlations between MeO-BDEs, OH-BDEs and alkenones, impling the potential of coccolithophorids for producing these natural compounds and their global distribution, especially in open oceans. Comparison between TOC and the ratio of 6-MeO-BDE47/6-OH-BDE47 suggests that TOC should be a potential controlling factor of the conversion between MeO-BDE and OH-BDE pairs. PMID:25113209

  10. Levels of flame retardants HBCD, TBBPA and TBC in surface soils from an industrialized region of East China.

    PubMed

    Tang, Jianfeng; Feng, Jiayong; Li, Xinhu; Li, Gang

    2014-05-01

    Hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) are of increasing concern because of their potential environmental persistence, bioaccumulation and toxicity. Tris-(2,3-dibromopropyl)isocyanurate (TBC) is another brominated flame retardant (BFR) which has recently been found in the environment and begun to attract attention. The objective of this study is to determine the concentration of these three BFRs in surface soil samples collected from a heavily industrialized and urbanized region in East China. Levels of ∑HBCDs ranged from below detection limits (0.020 ng g(-1)) to 102.6 ng g(-1) on a dry weight basis (dw) with a median level of 15.8 ng g(-1) dw. For TBBPA, the concentration ranged from below detection limits (0.025 ng g(-1)) to 78.6 ng g(-1) dw with a median level of 9.17 ng g(-1) dw. TBC was found at relatively lower concentrations ranging from below detection limits (0.024 ng g(-1)) to 16.4 ng g(-1) dw with a median level of 0.95 ng g(-1) dw. The concentrations of these three BFRs are significantly positively correlated, indicating a common source. Variable BFRs levels were found in different types of soils, with significantly higher concentrations observed at waste dumping sites and industrial areas. The diastereoisomer profiles of HBCDs in most of the soil samples differed from those of the commercial products. The mass inventories of HBCDs, TBBPA and TBC in this region gave preliminarily estimates of 6.68, 2.67 and 0.85 kg, respectively. Therefore, the ubiquitous contamination of soils by these BFRs may well reflect their widespread usage in the study area. PMID:24599331

  11. SAR observation and numerical modeling of tidal current wakes at the East China Sea offshore wind farm

    NASA Astrophysics Data System (ADS)

    Li, XiaoMing; Chi, Lequan; Chen, Xueen; Ren, YongZheng; Lehner, Susanne

    2014-08-01

    A TerraSAR-X (TS-X) Synthetic Aperture Radar (SAR) image acquired at the East China Sea offshore wind farm presents distinct wakes at a kilometer scale on the lee of the wind turbines. The presumption was that these wakes were caused by wind movement around turbine blades. However, wind analysis using spaceborne radiometer data, numerical weather prediction, and in situ measurements suggest that the prevailing wind direction did not align with the wakes. By analyzing measurement at the tidal gauge station and modeling of the tidal current field, these trailing wakes are interpreted to have formed when a strong tidal current impinged on the cylindrical monopiles of the wind turbines. A numerical simulation was further conducted to reproduce the tidal current wake under such conditions. Comparison of the simulated surface velocity in the wake region with the TS-X sea surface backscatter intensity shows a similar trend. Consequently, turbulence intensity (T.I.) of the tidal current wakes over multiple piles is studied using the TS-X observation. It is found that the T.I. has a logarithmic relation with distance. Furthermore, another case study showing wakes due to wind movement around turbine blades is presented to discuss the differences in the tidal current wakes and wind turbine wakes. The conclusion is drawn that small-scale wakes formed by interaction of the tidal c