2006 Vol. 25, No. 1

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Articles
Observation of ocean current response to 1998 Hurricane Georges in the Gulf of Mexico
ZHENG Quanan, LAI Ronald J, HUANG Norden E, PAN Jiayi, LIU W Timothy
2006, (1): 1-14.
Abstract:
The ocean current response to a hurricane on the shelf-break is examined.The study area is the DeSoto Canyon in the northeast Gulf of Mexico,and the event is the passage of 1998 Hurricane Georges with a maximum wind speed of 49 m/s.The data sets used for analysis consist of the mooring data taken by the Field Program of the DeSoto Canyon Eddy Intrusion Study,and simultaneous winds observed by NOAA (National Oceanic and Atmospheric Administration) Moored Buoy 42040.Time-depth ocean current energy density images derived from the observed data show that the ocean currents respond almost immediately to the hurricane with important differences on and offthe shelf.On the shelf,in the shallow water of 100 m,the disturbance penetrates rapidly downward to the bottom and forms two energy peaks,the major peak is located in the mixed layer and the secondary one in the lower layer.The response dissipates quickly after external forcing disappears.Off the shelf,in the deep water,the major disturbance energy seems to be trapped in the mixed layer with a trailing oscillation; although the disturbance signals may still be observed at the depths of 500 and 1 290 m.Vertical dispersion analysis reveals that the near-initial wave packet generated off the shelf consists of two modes.One is a barotropic wave mode characterized by a fast decay rate of velocity amplitude of 0.020 s-1,and the other is baroclinic wave mode characterized by a slow decay rate of 0.006 9 s-1.The band-pass-filtering and empirical function techniques are employed to the frequency analysis.The results indicate that all frequencies shift above the local inertial frequency.On the shelf,the average frequency is 1.04fin the mixed layer,close to the diagnosed frequency of the first baroclinic mode,and the average frequency increases to 1.07fin the thermocline.Off the shelf,all frequencies are a little smaller than the diagnosed frequency of the first mode.The average frequency decreases from 1.035fin the mixed layer to 1.02fin the thermocline,implying a trend for the shift in frequency of the oscillations towards f with the depth.
Second-order random interfacial wave solutions for two-layer fluid with a free surface
SONG Jinbao, SUN Qun
2006, (1): 15-20.
Abstract:
A previous study (Song.2004.Geophys Res Lett,31(15):L15302) of the second-order solutions for random interfacial waves is extended in a constant depth,two-layer fluid system with a rigid lid is extended into a more general case of two-layer fluid with a top free surface.The rigid boundary condition on the upper surface is replaced by the kinematical and dynamical boundary conditions of a free surface,and the equations describing the random displacements of free surface,density-interface and the associated velocity potentials in the two-layer fluid are solved to the second order using the same expansion technology as that of Song (2004.Geophys Res Lett,31 (15):L15302).The results show that the interface and the surface will oscillate synchronously,and the wave fields to the first-order both at the free surface and at the density-interface are made up of a linear superposition of many waves with different amplitudes,wave numbers and frequencies.The second-order solutions describe the second-order wave-wave interactions of the surface wave components,the interface wave components and among the surface and the interface wave components.The extended solutions also include special cases obtained by Thorpe for progressive interfacial waves (Thorpe.1968a.Trans R Soc London,263A:563~614) and standing interfacial waves (Thorpe.1968b.J Fluid Mech,32:489~528) for the two-layer fluid with a top free surface.Moreover,the solutions reduce to those derived for random surface waves by Sharma and Dean (1979.Ocean Engineering Rep 20) ifthe density of the upper layer is much smaller than that of the lower layer.
Inter-comparisons of thermodynamic sea-ice modeling results using various parameterizations of radiative flux
ZHANG Zhanhai, CHENG Bin, LAUNIAINEN Jouko, WU Huiding, LIU Yu
2006, (1): 21-31.
Abstract:
Radiative fluxes are of primary importance in the energy and mass balance of the sea-ice cover.Various parameterizations of the radiative fluxes are studied in a thermodynamic sea-ice model.Model outputs of the surface radiative and heat fluxes and mass balance are compared with observations.The contribution of short-wave radiation is limited to a long part of winter.Therefore,simple schemes are often sufficient.Errors in estimations of the short-wave radiation are due mainly to cloud effects and occasionally to multi-reflection between surface and ice crystals in the air.The long-wave radiation plays an important role in the ice surface heat and mass balance during most part of a winter.The effect of clouds on the accuracy of the simple radiative schemes is critical,which needs further attention.In general,the accuracy of an ice model depends on that of the radiative fluxes.
ITF in a coupled GCM and its interannual variability related to ENSO and IOD
LI Wei, LI Zhaoxin, LIU Hailong
2006, (1): 32-47.
Abstract:
The interannual variability of the mass transport of the Indonesian Throughflow (ITF) is very possible to be connected with the El Niño-Southern Oscillation (ENSO) in the Pacific Ocean and/or the Indian Ocean Dipole (IOD).The IPSL (Institute Pierre-Simon Laplace) coupled general circulation model (CGCM) was employed to examine the interannual variability of the ITF and understand its relationship with the climatic variation in both the basins.A 1 000 a integration was conducted and an annual mean model output was utilized.The pathways of the simulated ITF are reasonable within the Indonesian seas.The major transport occurs in the upper 300 m,with an annual mean transport of 15.68×106 m3/s,among which the 13.83×106 m3/s through the Makassar Strait is the principal component.The interannual variability of the ITF transport is significant in a 2~4 a period.The relationship between sea level differences across the Indonesian seas (sites in the western Pacific north of the equator and south coast of Java,respectively) and the ITF transport is straightforward on the interannual time-scale with a simultaneous correlation of 0.82.Further investigation indicates that the preceding climatic variation in the tropical Pacific is related to the ITF transport anomaly.The ENSO-like pattern leads the extreme of ITF transport by 1 a,with the correlation between a Niño 3 SST index and the ITF transport of 0.37.It means that there tends to be an El Niño anomaly in the Pacific 1 a before a large ITF transport.The simultaneous correlation between the Niño 3 SST index and the ITF transport is -0.34.The patterns of sea surface temperature and sea surface height are,however,not the typical ENSO anomaly.The ITF transport is more related to the concurrent interannual variability over the Indian Ocean.The simultaneous correlation between the ITF transport and the dipole mode index is 0.46 and the pattern of upper layer anomaly is much like that of the IOD.
A general purpose exact Rayleigh scattering look-up table for ocean color remote sensing
HE Xianqiang, PAN Delu, BAI Yan, GONG Fang
2006, (1): 48-56.
Abstract:
The current exact Rayleigh scattering calculation of ocean color remote sensing uses the look-up table (LUT),which is usually created for a special remote sensor and cannot be applied to other sensors.For practical application,a general purpose Rayleigh scattering LUT which can be applied to all ocean color remote sensors is generated.An adding-doubling method to solve the vector radiative transfer equation in the plane-parallel atmosphere is deduced in detail.Compared with the exact Rayleigh scattering radiance derived from the MODIS exact Rayleigh scattering LUT,it is proved that the relative error of Rayleigh scattering calculation with the adding-doubling method is less than 0.25%,which meets the required accuracy of the atmospheric correction of ocean color remote sensing.Therefore,the adding-doubling method can be used to generate the exact Rayleigh scattering LUT for the ocean color remote sensors.Finally,the general purpose exact Rayleigh scattering LUT is generated using the adding-doubling method.On the basis of the general purpose LUT,the calculated Rayleigh scattering radiance is tested by comparing with the LUTs of MODIS,SeaWiFS and the other ocean color sensors,showing that the relative errors are all less than 0.5%,and this general purpose LUT can be applied to all ocean color remote sensors
Constructing a raster-based spatio-temporal hierarchical data model for marine fisheries application
SU Fenzhen, ZHOU Chenhu, ZHANG Tianyu
2006, (1): 57-63.
Abstract:
Marine information has been increasing quickly.The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time.Recently,greater emphasis has been placed on GIS (geographical information system)to deal with the marine information.The GIS has shown great success for terrestrial applications in the last decades,but its use in marine fields has been far more restricted.One of the main reasons is that most of the GIS systems or their data models are designed for land applications.They cannot do well with the nature of the marine environment and for the marine information.And this becomes a fundamental challenge to the traditional GIS and its data structure.This work designed a data model,the raster-based spatio-temporal hierarchical data model (RSHDM),for the marine information system,or for the knowledge discovery from spatio-temporal data,which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field.As an experiment,the marine fishery data warehouse (FDW) for marine fishery management was set up,which was based on the RSHDM.The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels
Study on copper complexing ligand concentrations in several China's coastal waters
GONG Haidong, ZHANG Zhengbin, LIU Chunying, LIU Liansheng
2006, (1): 64-77.
Abstract:
Copper complexing ligand concentrations in the Daya Bay,Qingdao coast,Jiaozhou Bay,South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique.The distribution regularity and the relationship with other parameters were discussed.The results were as follows:Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas,and they were apparently higher than those of the ocean.Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon,of which the mechanism is similar to dissolved organic matter.The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest,then it decreased with depth accruing,and a higher value appeared at the bottom.Copper complexing ligand concentrations were higher than those of cadmium and lead.Ligands in each sea area exhibited a complicated property.In short,the distribution regularity of copper complexing ligand concentrations in China's coastal waters was consistent with that of other regions in the world.Meanwhile,the positive relationship between the copper complexing ligand concentrations and biological oxygen demand,chemical oxygen demand,dissolved organic carbon,and viscosity were found clearly.
Holocene tephra deposits in the northern Okinawa Trough
LIU Yanguang, OLE Bjφrslev Nielsen, ZHANG Deyu, DU Dewen, JAN Heinemeier, WU Yonghua
2006, (1): 78-89.
Abstract:
The mineralogical and geochemical characteristics of sediments of Core CSH1,which was collected from the northern Okinawa Trough,indicate that large amounts of volcanic materials have deposited in the northern Okinawa Trough during the Holocene.On the basis of down-core variations in mineral and element contents of sediments,two layers in the uppermost section of Core CSH1 characterized by high quartz,Na2O,MnO,K2O,uranium contents and low contents of clay minerals,volatiles,Fe2O3,MgO,CaO and strontium,have been identified as the tephra deposits.Systematic grain-size measurements also suggest that sediments from the northern Okinawa Trough are made up of terrigenous materials and volcanic ashes with different proportion during the Holocene.The sediments of tephra layers in Core CSH1 show bi-modal patterns in grain-size distribution with modal grain-sizes of 74.3 and 7.81 μm,respectively.According to the radiocarbon dating on shells of zooplankton foraminifera,two tephra layers in Core CSH1,formed at 7 250 and 10 870 a BP (cal),approximately correspond to the K-Ah tephra[7 300 a BP (cal)] and the eruption of Kuju Volcano (12~10 ka BP),respectively.
Pore-water distribution and quantification of diffusive benthic fluxes of nutrients in the Huanghai and East China Seas sediments
NI Jianyu, LIU Xiaoya, CHEN Qijiang, LIN Yian
2006, (1): 90-99.
Abstract:
The distribution of nitrate,nitrite,ammonia,phosphate and silicate in pore-water and their exchange between sediments and overlying waters (benthic flux) were determined at nine locations on the shelve of Huanghai and East China Seas.On the basis of the redox potential of sediments and nutrients distributions in the pore-waters,it is found that the benthic sediments are being in a suboxic to anoxic environment in the Huanghai and East China Seas.The nutrients distribution in the pore-waters is mainly controlled by the sediment environment,and ammonia is the major inorganic nitrogen in the pore-waters.On the basis of benthic fluxes of untrients calculated using Fick's first law,there is remarkable efflux of ammonia,dissolved inorganic nitrogen(DIN),phosphate and silicate from the sediments to the overlying waters in the study area,and their benthic fluxes are 299.3~2 214.8,404.4~2 159.5,5.5~18.8 and 541.3~1 781.6 μmol/(m2·d) respectively,and perhaps they are the major source of dissolved inorganic nitrogen,phosphate and cate for the overlying water.At most stations,the nitrate flux was from the overlying waters to the sediments,which suggests that suboxic organic matter decomposition via denitrification is dominated in the most area of Huanghai and East China Seas.High benthic fluxes appearing in the coastal area and relatively low benthic fluxes occurring in the shelf area are found and are consistent with primary productivity zoning in the study area.On the other hand,the ammonia flux displays an exponential decrease with water depth increase and an exponential increase with the bottom water temperature.However,others do not display this trend.
Study on abundance variation of pteropods in the East China Sea
XU Zhaoli, LI Chunju
2006, (1): 100-107.
Abstract:
On the basis of the census in four seasons from 1997 to 2000 in the East China Sea (23° 30'~33° N,118° 30'~128° E),the horizontal distribution of pteropods,the seasonal variations of their abundance and dynamic mechanisms of these variations were approached with quantitative and qualitative methods.Results showed that the total abundance of pteropods varied clearly with the seasons in an order of decrease of autumn (108×l0-2 ind./m3),summer (33×10-2 ind./m3),winter(28×10-2 ind./m3) and spring (10×l0-2 ind./m3).Pteropods were not observed in the north nearshore of the East China Sea (29° 30'~33° N,122° 30'~125° E)in winter and spring.In all seasons,the peteropod abundance was higher in the south than that in the north and higher in the offshore than that in the nearshore.The major species influencing the peteropod abundance were Creseis acicula in spring,Creseis virgula in summer,Desmopterus papilio in autumn and Limacina trochiformis in winter.The variation ofpteropod abundance showed a prominent linear correlation with the surface water temperature and 10 m water temperature,but no significant correlation with both the bottom water temperature and salinity.In summer,the high-abundance distribution area of pteropods was located in the place where the Taiwan Warm Current branched from the Kuroshio.Inautumn,the distribution area with an abundance higher than 250×10-2ind./m3 expanded northward along with the Taiwan Warm Current within the mixing area where the Changjiang freshwater,the Fujian-Zhejiang coastal water and the Huanghai Sea Cold Water met together.Water temperature and warm currents were the most important environmental factors that influenced the changes ofpteropod abundance in the East China Sea.
Pigment signatures of some diatoms isolated from China seas
YAO Peng, YU Zhigang, DENG Chunmei
2006, (1): 108-118.
Abstract:
The photosynthetic pigments of 12 species (14 strains) of cultured diatoms from six genera under specific conditions were examined by the HPLC.The diatom genera were Skeletonema,Thalassiosira,Chaetoceros,Nitzschia,Phaeodactylum and Meuniera.All strains were isolated from China seas and most of them were from the Jiaozhou Bay,China.Fifteen pigments were identified and eight of them were various chlorophyll a derivatives.Chlorophyll a,c2 and c1 and the carotenoids fucoxanthin,diadinoxanthin,diatoxanthin and β,β-carotene existed in all species.The ratios of each pigment to chlorophyll a were compared with the results in literatures.The pigment ratios of this study generally fall within the ranges reported by the literatures although the maximum ratio of fucoxanthin to chlorophyll a was higher and the ratios of chlorophyll c and diatoxanthin to chlorophyll a were low.The pigment ratios are useful to understanding the pigment signatures of diatoms in the Jiaozhou Bay,China,and to setting up the chemotaxonomic method ofphytoplankton in these sea areas.
Phylogenetic position of Dysteria derouxi (Ciliophora: Phyllo-pharyngea: Dysteriida) inferred from the small subunit ribosomal RNA gene sequence
LI Lifang, SONG Weibo
2006, (1): 119-126.
Abstract:
The complete small subunit rRNA (SSrRNA) gene sequence of a marine ciliate,Dysteria derouxi Gong and Song,2004,was determined to be of 1 708 nucleotides.The phylogenetic position of this species within the class Phyllopharyngea was deduced using distance matrix,maximum parsimony and maximum likelihood methods.Dysteria derouxi,together with other available ciliates of the class Phyllopharyngea,forms a monophyletic clade with strong bootstrap support in the distance matrix,maximum parsimony and likelihood tree construction methods,while the dysterids are,as a monophyletic group,phylogenetically close to the clade of chlamydodontids[values of 100% LS(least-squares),100% NJ(neighbor-joining)].In addition,the trees indicate that dysteriids may be a higher or specialized group within the class,which corresponds well to the morphology and infraciliature.
Molecular cloning and expression analysis of interleukin-1β from Japanese sea perch (Lateolabrax japonicus)
QIU Lihua, SONG Linsheng, WU Longtao, CAI Zhonghua, JIANG Shigui
2006, (1): 127-136.
Abstract:
The technology of homology cloning and anchored PCR was used to clone the IL-1 β gene from the Japanese sea perch (Lateolabrax japonicus).The full-length cDNA of sea perch IL-1β was 1 310 bp,including a 5' untranslated region (UTR) of 136 bp,a 3' UTR of 430 bp,and an ORF of 774 bp encoding a polypeptide of 258 amino acids with an estimated molecular mass of 29.31 kDa.The searches for nucleotides and protein sequence similarities with the BLAST analysis indicated that the deduced amino acid sequence of sea perch IL-1 β was homological to the IL-1 β in other fish species and even the mammalian.Conserved signature sequences of the IL-1 β gene family were found in the sea perch IL-1β deduced amino acid sequence.Temporal expressions of the IL-1β gene in LPS or iridovirus challenged group and in control group were measured by the semi-quantitative RT-PCR.The mRNA transcripts of IL-1β could be detected in head-kidney,spleen,liver,gill and heart of the healthy individuals,and the expression level of IL-1 β in head-kidney,spleen and gill was higher than that in liver and heart,but it was hard to be detected in the brain.After being stimulated by the LPS or iridovirus,the IL-1 β expression in most of examined tissues was up-regulated,and also could be detected in the brain.These results indicated that the expression of sea perch IL-1 β was constitutive and could be up-regulated by immune effector stimulation.Therefore the sea perch IL-1 β could play a critical role in the host-pathogen interaction.
The effects of enriched CO2 and enhanced UV-B radiation on ultra-structure of Dunaliella salina, singly and in combination
YU Juan, XIAO Hui, TIAN Jiyuan, ZHANG Peiyu, DONG Shuanglin, TANG Xuexi
2006, (1): 137-146.
Abstract:
The effects of ambient CO2/ambient UV-B,enriched CO2/ambient UV-B,ambient CO2/enhanced UV-B,and enriched CO2/enhanced UV-B on the ultrastructure of Dunaliella salina were investigated.(1) The ultrastructure of D.salina cell in the control experiment showed that the arrangement of thylakoid lamellae was regular,and there were many large starch grains among the thylakoid lamellae.A prominent well-developed pyrenoid was found in the middle of the chloroplast.Nucleus envelope and nucleolus were clearly observed.The Golgi apparatus accompanied by numerous vesicles with a compact arrangement of cisternae and the peripheral tips of the cisternae were swollen to a size comparable to that of some of the associated vesicles.(2) The ultrastructure of D.salina cell in enriched CO2 showed that the arrangement ofthylakoid was regular and the lamellae were vivid.Developed pyrenoids were found in the low-CO2-grown cells,but not in the high-CO2-grown cells.The mitochondria cristae were vivid.The arrangement of Golgi apparatus was compact.(3) The ultrastructure of D.salina cell in enhanced UV-B showed that the thylakoid was dissolved and the cells had a less developed pyrenoid or no detectable pyrenoid.Part of the nucleus envelope was dissolved.The number ofmitochondria was increased and some mitochondria cristae were disintegrated.The starch grains were broken apart into many small starch grains.The Golgi apparatus with a loose arrangement of cisternae and the peripheral tips of the Golgi cisternae were not especially swollen,with several large associated vesicles.(4) The ultrastructure of D.salina cell in the enriched CO2/enhanced UV-B showed that part of the thylakoid and nucleus envelopes of some cells were dissolved.The pyrenoid was larger than that of the enhanced UV-B.There were many mitochondria between stroma and chloroplast membrane,but mitochondria cristae were partly dissolved.Many small starch grains were accumulated in cells.The starch sheath was broken into several discontinuous starch grains with different sizes.The arrangement of Golgi apparatus was loose.Above all,although the enriched CO2 can alleviate the damage induced by the UV-B radiation,the effects of experimental UV-B radiation were larger than the effects of actual UV-B radiation,the damage induced by the UV-B radiation was so severe,therefore,CO2 enrichment could not restore the ultrastructure to the control level.
Three-dimensional numerical simulation of oblique wave action on vertical walls
LI Benxia, YU Xiping, YU Yuxiu
2006, (1): 147-153.
Abstract:
A three-dimensional numerical model based on the potential theory was developed to study the oblique wave action on vertical walls.A source term inside the domain was used to generate incident waves and outgoing waves were dissipated by sponge layers and transmitted by radiation boundaries.The finite difference method was used to solve the governing equations and boundary conditions in the regular transformed domain in σ-coordinate.Satisfactory agreements between the numerical predictions and experimental results of wave force were obtained.It is concluded that the maximum wave force acting on the vertical walls is induced by the obliquely incident waves rather than the normally incident waves.
Research Notes
Studies on the pathogenic bacterium of ulcer disease in Epinephelus awoara
QIN Yingxue, WANG Jun, SU Yongquan, WANG Dexiang, CHEN Xinzhong
2006, (1): 154-159.
Abstract:
Studies were conducted to determine the cause of the acute mortality of cage-cultured Epinephelus awoara in the Tong'an Bay of Xiamen,China during the summer of 2002.Predominant bacteria strain TS-628 was isolated from the diseased grouper.The virulence test confirmed that TS-628 was the pathogenic bacterium.Biochemical characteristics of the isolates were determined using the automatic bacterial identification system and standard tube tests.To further confirm the identification,a 1 121 bp 16S rRNA gene sequence of the isolate was amplified by PCR,which had been deposited into Genbank (accession number:AY747308).According to the biochemical characteristics and by comparing the 16S rRNA gene homology of the isolate,the pathogenic bacterium was identified as Vibrio harveyi.Drug sensitivity tests showed that this pathogenic bacterium was sensitive to 16 antibacterials,especially to chloramphenicol and actinospectacin,but completely resistant to antibacterials likes vancomycin,penicillin,lincomycin,and so on.