2007 Vol. 26, No. 3

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Articles
Life cycle of intraseasonal oscillation of summer SST in the western South China Sea
XIE Qiang, WU Xiangyu, YUAN Wenya, WANG Dongxiao, XIE Shang-Ping
2007, (3): 1-8.
Abstract:
Intraseasonal oscillation (ISO,times-cales of 30~90 d) of summer sea surface temperature (SST) in the western South China Sea is studied using harmonic and empirical orthogonal function analyses of microwave observations by the tropical rainfall measuring mission satellite.Each summer from May to September,two or three ISO events occur off South Vietnam,with a typical period of approximately 50 d.The life cycle of these events from the initiation to decay of SST anomalies is described.
Effects of winds,tides and storm surges on ocean surface waves in the Sea of Japan
ZHAO Wei, TIAN Jiwei, LI Peiliang, HOU Yijun
2007, (3): 9-21.
Abstract:
Ocean surface waves are strongly forced by high wind conditions associated with winter storms in the Sea of Japan.They are also modulated by tides and storm surges.The effects of the variability in surface wind forcing,tides and storm surges on the waves are investigated using a wave model,a high-resolution atmospheric mesoscale model and a hydrodynamic ocean circulation model.Five month-long wave model simulations are inducted to examine the sensitivity of ocean waves to various wind forcing fields,tides and storm surges during January 1997.Compared with observed mean wave parameters,results indicate that the high frequency variability in the surface wind filed has very great effect on wave simulation.Tides and storm surges have a significant impact on the waves in nearshores of the Tsushima-kaihyō,but not for other regions in the Sea of Japan.High spatial and temporal resolution and good quality surface wind products will be crucial for the prediction of surface waves in the JES and other marginal seas,especially near the coastal regions.
Remote sensing of sea surface nutrient in the frontal zone of Changjiang diluted water and the Taiwan Warm Current
ZHANG Xiaoyu, LIN Yi'an, HE Xianqiang, WANG Difeng, GONG fang, ZHANG Wei
2007, (3): 22-32.
Abstract:
Field investigation was carried out during 4 to 15 April 2001 around the Changjiang River Estuary.The similar distribution of sea surface nutrients and suspended sediment (SS) concentration is attributed to the physical mixing of Changjiang diluted water (CDW) with the Taiwan Warm Current (TWC).On the basis of the observed positive relationship between total phosphorus (TP) and SS concentration,the sea surface TP is inversed from satellite SS data.SS is believed to be an ideal eutrophic state assessing index substitution for TP,the eutrophication classification critical value of SS adopted in this research was based on the linear model:cTP=0.000 6cSSsat+0.016 3,r2=0.564 5,n=32.Although lack of in-situ chromophoric dissolved organic matter (CDOM) measurement,a good relationship was observed between the in-situ DIN (dissolved inorganic nitrogen) concentration with near real time SeaWiFS absorption coefficient of CDOM (ACD) data:cDIN=1.406 5AACBsat-0.035 9,r2=0.741 5,n=16.This empirical regression algorithm was also utilized for inversing the DIN concentration from SeaWiFS ACD data,and for establishing the eutrophication classification critical value of satellite ACD data.The established remote eutrophication classification system was later used for seawater eutrophic state assessment.The evaluation suggested that the Zhoushan Fishing Ground especially the western border is affected seriously with the nutrient input.The nutrient is mainly from the terrestrial source transported by the Changjiang River runoff.The seawater quality classification precision was assessed by in-situ data,which suggested the seawater quality distribution is similar to the two classification systems,and the remote classification error is below 25%.
Seasonal and annual variations of marine sinking particulate flux during 1993~1996 in the central South China Sea
CHEN Ronghua, WIESNER M G, ZHENG Yulong, CHENG Xinrong, JIN Haiyan, ZHAO Qingying, ZHENG Lianfu
2007, (3): 33-43.
Abstract:
A total of 67 samples from the upper and lower sediment traps in the central South China Sea were analyzed,which were collected during 1993~1996.It is indicated that the distribution of stable isotope values,surface primary productivity,fluxes of total particulate matter,carbonate,biogenic opal,organic carbon,planktonic foraminiferal species and their total amount exhibit obviously seasonal and annual fluctuations.High values of the fluxes occurred in the prevailing periods of the northeastern and southwestern monsoons,and the low values occurred during the periods between the two monsoons.The fluxes of some planktonic foraminiferal species (Globigerinoides sacculifer,G.ruber,Globigerinita glutinata,Neogloboquadrina dutertrei) and their percentages also exhibit two prominent peaks during the prevailing periods of the northeastern and southwestern monsoons respectively,while those of Globigerina bulloides,Globorotalia menardii and Pulleniatina obliquiloculata only exhibit one peak in the prevailing periods of the northeastern monsoon.In addition,fluxes and percentages of Globigerinoides sacculifer and Globorotalia menardii as well as the fluxes of carbonate and total amount of planktonic foraminifera decrease gradually from 1993 to 1996,and those of Globigerina bulloides,Globigerinita glutinata and biogenic opal increase gradually from 1993 to 1996.The fluxes of carbonate and organic carbon in the upper trap are higher than those in the lower one.The study indicates that the seasonal and annual variations of the sediment fluxes and planktonic foraminiferal species are mainly controlled by the changes of surface primary productivity and hydrological conditions related to the East Asian monsoon.The lower carbonate and organic carbon fluxes in the lower trap are related to the dissolution.
Mineral provinces and matter provenance of the surficial sediments in the western Philippine Sea: implication for modern sedimentation in West Pacific marginal basin
REN Xiangwen, YAN Quanshu, SHI Xuefa, WANG Kunshan, JIANG Xiaoli
2007, (3): 44-55.
Abstract:
The characteristics and distribution patterns of detrital minerals (0.063~0.125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment.The detrital mineral composition of 219 surface sediment samples was analysed to identify the distribution of sediments within the western Philippine Sea.The area can be divided into three mineral provinces:(Ⅰ) province east of the Philippine Trench,the detrital minerals in this province are mainly composed of calcareous or siliceous organisms,with the addition of volcanogenic minerals from an adjacent island arc; (Ⅱ) middle mineral province,clastic minerals including feldspar,quartz and colorless volcanic glass,sourced from seamounts with intermediate-acid volcanic rock,or erupting intermediate-acid volcano; (Ⅲ) province west of the Palau-Kyūshū Ridge,the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate-acid composition,with a component of volcanic scoria sourced from a volcano erupting on the Palau-Kyūshū Ridge.it is suggested that,(1) Biogenic debris of the study area is closely related to water depth,with the amount of biogenic debris controlled by carbonate lysocline.(2) Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance.The weathering products of volcanic rocks of the submarine plateau (e.g.,Benham Plateau) and adjacent ridges provide an important source of detrital sedimentation,and the influence scope of them is constrained by the intensity of submarine weathering.(3) Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area,and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.
A preliminary study on thermoluminescence characteristics of sediments from the North Pacific
LV Huahua, SHI Xuefa, WU Yonghua, YANG Gang, WEI Jianwei, REN Xiangwen
2007, (3): 56-72.
Abstract:
Thirty-eight surficial deposit samples were collected from the equatorial North Pacific,and the natural thermoluminescence (TL) characteristics of both bulk and clay fraction samples (<2 μm fractions) were studied by the FJ427-A1 automatic TL Dosimeter for the first time.With the measurements of clay mineral composition,element composition by XRD and ICP,the correlations between TL intensity and sedimentary environment proxies were analyzed,such as water depth,ratio of FeO to Fe2O3 contents,LOI,and major clay mineral concentration,and it was found the bulk sample's TL signal was stronger than the clay ones.Usually,increase in the clay components may result in the decrease of TL intensity.From the shape of TL curves,the pelagic sediments can be divided into two groups:the majority group has two glow peaks,in general,the first peak is broad and flat,but the second narrow and sharp; the minority group only has a single peak because the first is absent.The peak centers of TL curves are almost fixed,falling in the temperature sections 230~260 and 390~405℃ respectively.Lorentz model packed in the Origin 7.5 was chosen to deal with the TL curves.From the processing results,three parameters (H,C and A),corresponding to the height,center,and kurtosis of TL curve,were obtained to describe the curve characteristics.The correlations between TL curve parameters and sedimentary environment proxies were also calculated.On the basis of the above work,the relationship between TL characteristics and sediment type,mineral composition,sedimentary environment of surface sediments was discussed in the study area,and a conclusion is:sediments from the environment of shallower water,higher organic contents and weaker reductivity have stronger TL signals.
An in-situ analysis and measurement of thorium-234, uranium isotopes in seawater
ZENG Xianzhang, QIU Manhua, YIN Mingduan, ZENG Wenyi, HE Jianhua, WAN Xueguo, CHEN Hengliang, LI Jing, TAN Baozeng
2007, (3): 73-83.
Abstract:
A low-level β counting-α spectrum apparatus used for the detection of the β radiation of thorium-234 and α spectrum of thorium-228 simultaneously and an easy operating procedure for the enrichment,radiochemical separating,sampling and measurement of thorium-234 and uranium-238 in the ocean are developed based on the requirements of analyzing export productivity in the euphotic zone via thorium-234-uranium-238 radioactivity disequilibrium.The detecting efficiency both of β and α radiation is higher than 20%.The background of β radiation is less than 0.5 min-1,and the energy resolution of α detector is better than 1%.Total recycle ratio of thorium-234 is about 75%.Using the above apparatus and procedure,the radioactivities of dissolved thorium-234 and uranium-238,particle thorium-234 and uranium-238 in seawater of the South China Sea,the Southern Ocean and the Arctic Ocean were analyzed.
One new species of free-living marine nematodes (Enoplida,Anticomidae, Cephalanticoma) from the Huanghai Sea
HUANG Yong, ZHANG Zhinan
2007, (3): 84-89.
Abstract:
One new species of free-living marine nematodes Cephalanticoma filicaudata sp.nov.from the Huanghai Sea,China is described and illustrated.Cephalanticoma filicaudata sp.nov.is characterized by well developed cephalic capsule,three teeth at the anterior of oesophagus,excretory pore opens posterior to cervical setae,only two cervical setae per file,body length longer than 5 200 μm,tail long and no ventral-lateral seta between the supplement and the cloacal opening.Types are deposited in the College of Marine Life Sciences,Ocean University of China.
The influence of main ecological and environmental factors on the energy budget of Schlegel's black rockfish Sebastes schlegeli
SUN Yao, ZHENG Bing, ZHANG Bo, TANG Qisheng
2007, (3): 90-100.
Abstract:
In the Maidao Ecological Laboratory of the Huanghai Sea Fisheries Research Institute in 1998~2000,the continuous flow-through method was adopted to determine the energy budget components and models of Schlegel's black rockfish under different ecological and environmental factors,such as temperature,food species,body mass and feeding level,etc.The body mass of test fish ranged from 21.2 to 224.5 g.The specific growth rate tended to invert "U" change with temperature increase.The ecological conversion efficiency showed the same trend as temperature and feeding level rise.Only the specific growth rate tended to decelerate the increment with the rise of feeding level.From the above quantitative relationships,the maximum and optimal growth temperatures could be obtained as 17.5 and 16.2℃,and the maintenance feeding rate and optimum feeding rate as 0.8% and 4.1% of the body mass.The specific growth rate and ecological conversion coefficient showed a decelerating decrease trend with body mass increment.The small-sized fish food was more advantageous to the feeding level increase in comparison with the small-sized shrimp food,which led to the increase of growth,metabolism and excretion,but had no significant influence on the ecological conversion coefficient.All of temperature,feeding level,body mass and food species can obviously change the energy budget models.The assigning rate of growth energy tended to change along the invert "U" curve with the increase of temperature and feeding level,and decrease with the body mass increase,but the assigning rates of metabolism energy and excretion energy were quite reverse.These relationships could be quantitatively described as quadratic or power function curve.If the above relationships proved true to other marine fish,the establishment of energy budget model of the same fish under different conditions can be largely simplified.
Adhesion of pathogenic Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea
CHEN Qiang, YAN Qingpi, MA Shen, ZHUANG Zhixia, WANG Xiaoru
2007, (3): 101-109.
Abstract:
Adhesion of Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea has been investigated using[methyl-3H] thymidine as isotope tracer.The results showed that:the adhesive quantity of V.alginolyticus increased with bacterial concentrations and reached equilibrium after incubated for 180 min; the higher adhesive quantity was obtained at 15~30℃ and sourish conditions; adhesion of V.alginolyticus could not achieved without Na+,and Ca2+ played an auxiliary role in the bacterial adhesion; adhesion of V.alginolyticus was inhibited remarkably by starvation,heat treatment and periodic acid treatment; all of the eight kinds of carbohydrates investigated enhanced the adhesion of V.alginolyticus to the gill mucus of P.crocea,among them,glucose,mannose,fructose and maltose showed the specially enhanced adhesion.The results indicated that V.alginolyticus could adhere to the gill mucus of P.crocea facilely in seawater,and this bacterial adhesion was influenced by environmental factors and closely related to superficial carbohydrate structures and some heat-sensitive structures.
Preliminary study on different nutrient pools supplies for the phytoplankton growth in the Jiaozhou Bay in China in the fall of 2004
WANG Dan, SUN Jun, SONG Shuqun, LUAN Qingshan, Joey McMurdie
2007, (3): 110-120.
Abstract:
The source and significance of two nutrients,nitrogen and phosphorous,were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay,in autumn 2004.This modified dilution method accounted for the phytoplankton growth rate,microzooplankton grazing mortality rate,the internal and external nutrient pools,as well as nutrient supplied through remineralization by microzooplankton.The results indicated that the phytoplankton net growth rate increased in turn from inside the bay,to outside the bay,to in the Xiaogang Harbor.The phytoplankton maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d-1 outside the bay,0.42 and 0.32 d-1 inside the bay and 0.98 and 0.62 d-1 in the harbor respectively.Outside the bay,the remineralized nitrogen (Kr=24.49) had heavy influence on the growth of the phytoplankton.Inside the bay,the remineralized phosphorus(Kr=3.49) strongly affected the phytoplankton growth.In the harbor,the remineralized phosphorus (Kr=3.73) was in larger demand by phytoplankton growth.The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure,microzooplankton grazing mortality rates and environmental conditions.It is revealed that nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed.
Numerical simulation of solitary wave propagation based on MPS method
LI Shaowu, YU Zhi'an, XIONG Zan
2007, (3): 121-128.
Abstract:
The concept of candidate particle set is introduced in the MPS gridless numerical method to generate neighboring particle setmatrix,which can reduce the CPU time to 1/11 of that before introduction.The Bi-CGSTAB (bi-conjugate gradient stabilized) algorithm is applied to solving the Poisson pressure equation,by which the solving speed is significantly accelerated.The process of solitary waves propagating over a numerical flume and interacting with a vertical wall is simulated.The simulated results of water surface elevation are in good agreement with the analytical solution as well as the measured data.The predicted maximum values of the run-up of solitary waves with various relative incident wave heights agree well with the measured results.
Reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core
LIU Yong, LI Yucheng, TENG Bin, MA Baolian
2007, (3): 129-141.
Abstract:
The reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core is examined.The present mathematical model is developed by means of the matched eigenfunction method.Numerical results of the present model are compared with the experimental data of different researchers.Numerical examples are given to examine the effect of rock fill on the reflection coefficient.The differences between regular and irregular waves are also investigated by means of theoretical and experimental results.It is found that the minimum reflection coefficient of irregular waves is larger than that of corresponding regular waves,but the contrary is the case for the maximum reflection coefficient.
Applications of sediment sudden deposition model based on the third-generation numerical model for shallow water wave
BAI Yuchuan, ZHANG Yinqi, ZHANG Bin
2007, (3): 142-149.
Abstract:
The existing numerical models for nearshore waves are briefly introduced,and the third-generation numerical model for shallow water wave,which makes use of the most advanced productions of wave research and has been adapted well to be used in the environment of seacoast,lake and estuary area,is particularly discussed.The applied model realizes the significant wave height distribution at different wind directions.To integrate the model into the coastal area sediment,sudden deposition mechanism,the distribution of average silt content and the change of sediment sudden deposition thickness over time in the nearshore area are simulated.The academic productions can give some theoretical guidance to the applications of sediment sudden deposition mechanism for stormy waves in the coastal area.And the advancing directions of sediment sudden deposition model are prospected.
Research Notes
Seasonal distribution of Calanus sinicus (Copepoda, Crustacea) in the East China Sea
XU Zhaoli, CHEN Bijuan
2007, (3): 150-159.
Abstract:
On the basis of the four-season investigation in 23°30'~33°N and 118°30'~128°E of the East China Sea from 1997 to 2000,the seasonal distribution of Calanus sinicus was studied with aggregation intensity,regression contribution and other statistical methods.It was inferred that C.sinicus's predominance presented from winter to summer,especially in spring and summer,because its dominance amounted to 0.62 and 0.29 respectively.The percent of its abundance in copepod abundance was 76.71% in summer,greater than 66.60% in spring,greater than 19.02% in winter,greater than 4.02% in autumn.The occurrence frequency in winter and spring was 83.08% and 93.89%,higher than that in summer and autumn,76.71% and 73.87%.Compared with other dominant species of copepods,C.sinicus's contribution to the copepod abundance was obviously greater than that of the other species in winter,summer and spring,but smaller in autumn.C.sinicus tended to have an aggregated distribution.The clumping index peaked in summer (50.19),followed in spring (19.60),declined in autumn (13.18) and was the lowest in winter (3.04).The abundance changed in different seasons and areas,relating to temperature but not salinity in spring and autumn,to salinity but not temperature in summer; to neither temperature nor salinity in winter.In spring and summer,its high abundance area was often located in the mixed water mass formed by the Taiwan Warm Current,the Huanghai Sea Cold Water Mass,the coastal water masses and the Changjiang Dilute Water.In spring and autumn,its abundance was affected by the warm current,as well as the runoff from continental rivers affected it in summer.It can be inferred that C.sinicus was adapted to wide salinity and temperature,as a euryhalinous and eurythermous species in the East China Sea.
A method of determining dominant wave direction from multiparameter hydrological gauge measurements and its application
WANG Sheng'an, LONG Xiaomin, ZHANG Keben, CHEN Junchang, ZHANG Wenjing, CAI Shuqun
2007, (3): 160-166.
Abstract:
Multi-parameter hydrological gauge is an instrument developed by the South China Sea Institute of Oceanology,the Chinese Academy of Sciences to make simultaneous observation of current,wave,tide,water temperature and conductivity.By using the well-known "PUV method",the directional wave spectrum can be calculated and the dominant wave direction is then obtained.The comparison of the dominant wave directions derived from the measurements using both the multi-parameter hydrological gauge and the MARK Ⅱ "Wave-Rider" directional buoy shows that the dominant wave directions derived from the two kinds of measurements are in good agreement.