2006年  第25卷  第5期

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Meso-scale available gravitational potential energy in the world oceans
FENG Yang, WANG Wei, HUANG Ruixin
2006, (5): 1-13.
摘要:
The pitfalls of applying the commonly used definition of available gravitational potential energy (AGPE) to the world oceans are re-examined.It is proposed that such definition should apply to the meso-scale problems in the oceans, not the global scale.Based on WOA98 climatological data, the meso-scale AGPE in the world oceans is estimated.Unlike previous results by Oort et al., the meso-scale AGPE is large wherever there is a strong horizontal density gradient.The distribution of meso-scale AGPE reveals the close connection between the baroclinic instability and the release of gravitational potential energy stored within the scale of Rossby deformation radius.
Impacts of TRMM SRR assimilation on the numerical prediction of tropical cyclone
MA Leiming, QIN Zenghao, DUAN Yihong, LIANG Xudong, WANG Dongliang
2006, (5): 14-26.
摘要:
Impacts of the four-dimensional variation (4DVAR) assimilation of Tropical Rainfall Measuring Mission (TRMM)/TMI surface rainfall rate (SRR) on the initialization and simulation of TC Danas in 2001 are studied.A number of sensitivity experiments are designed to evaluate the performance of assimilation during the particular stage when Danas developed from a tropical depression towards a typhoon, as well as an abrupt turning.Under the dynamic and thermodynamic constraints of meso-scale model and the 4DVAR, the TRMM SRR data are directly assimilated in high horizontal resolution (18 km).On the basis of the adjustment of initial model field, 4DVAR of TRMM SRR considerably improved the depiction of TC's structure and rainfall.The same explanation can also be given to the enhancement of simulation on TC's intensity and track.In comparison with the popular idea of twice steps of SRR assimilation, namely, 4DVAR plus 1DVAR, the retrieval error is expected to be avoided in the procedure of direct 4DVAR.In addition, the TRMM SRR 4DVAR within a high-resolution model can take into account as much information as observed and is expected to be performed in operational use if the observed rainfall data are routinely available.
Multifractal filtering method for extraction of ocean eddies from remotely sensed imagery
GE Yong, DU Yunyan, CHENG Qiuming, LI Ce
2006, (5): 27-38.
摘要:
Traditional methods of extracting the ocean wave eddy information from remotely sensed imagery mainly use the edge detection technology such as Canny and Hough operators.However, due to the complexities of ocean eddies and image itself, it is sometimes difficult to successfully detect ocean eddies using these methods.A multifractal filtering technology is proposed for extraction of ocean eddies and demonstrated using NASA MODIS, SeaWiFS and NOAA satellite data set in the typical area, such as ocean west boundary current.Results showed that the new method has a superior performance over the traditional methods.
Organic carbon and nitrogen isotopes in surface sediments from the western Arctic Ocean and their implications for sedimentary environments
CHEN Zhihua, SHI Xuefa, CAI Deling, HAN Yibing, YANG Zuosheng
2006, (5): 39-54.
摘要:
Surface sediments from the Chukchi Sea and adjacent arctic deep sea were investigated for organic carbon and nitrogen isotopes (in δ13Corg and δ15Norg) as well as biogenic silica (BSiO2).δ13Corg and δ15Norg values of surface sediments in the study area fall between the end-member values of marine and terrestrial organic matter from the surrounding lands and seas, their variations reflect the changes of marine productivity and terrestrial supply in the study area.BSiO2 shows a similar distribution pattern with δ13Corg and δ15Norg, and can be used as an indicator of marine productivity.In the central-west Chukchi Sea and the Chukchi Rise, sediments have higher δ13Corg, δ15Norg and BSiO2 values, indicating the region has high marine productivity influenced by the nutrient-rich branches of the Pacific waters.In the coastal zone off northwestern Alaska, δ13Corg and δ15Norg values become lighter, indicating a weakening marine productivity and an increasing terrigenous supply due to the effects of the least nutrient-rich branch of the Pacific waters.In the north and the northeast of the study area (including the Chukchi Plateau, the Canada Basin and the Beaufort shelf), δ13Corg, δ15Norg and BSiO2 have the lowest values, and the terrigenous organic matter becomes dominant in surface sediments because this region has the longest ice-covered duration, the least nutrient-rich seawater and the increasing supply of terrestrial materials from the Mackenzie River and the northern Alaska under the action of the clockwise Beaufort gyre.Because the subarctic Pacific waters are continuously discharged into the central basin of the Arctic Ocean through the study area, the nutrient pool in the Chukchi Sea can be considered as a typical open system, the ratio of δ15N to BSiO2 content show some tracers that the level of nutrient utilization is contrary to nutrient supply and marine productivity formed in seawater.
Bohai crude oil identification by gas chromatogram fingerprinting quantitative analysis coupled with cluster analysis
SUN Peiyan, BAO Mutai, GAO Zhenhui, LI Mei, ZHAO Yuhui, WANG Xinping, ZHOU Qing, WANG Xiulin
2006, (5): 55-62.
摘要:
By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corresponding normal paraffin hydrocarbon (including pristane and phytane) concentration was obtained by the internal standard method.The normal paraffin hydrocarbon distribution patterns of six crude oils were built and compared.The cluster analysis on the normal paraffin hydrocarbon concentration was conducted for classification and some ratios of oils were used for oils comparison.The results indicated:there was a clear difference within different crude oils in different oil fields and a small difference between the crude oils in the same oil platform.The normal paraffin hydrocarbon distribution pattern and ratios, as well as the cluster analysis on the normal paraffin hydrocarbon concentration can have a better differentiation result for the crude oils with small difference than the original gas chromatogram.
Inversion of teleseismic waves at Shidao Seismographic Station
RUAN Aiguo, LI Jiabiao, HAO Tianyao, WU Qingju, XU Yi
2006, (5): 63-73.
摘要:
Teleseismic datasets at the Shidao Seismographic Station, located in the northwestern South China Sea, are used to determine the earth anisotropy and the vertical distribution pattern of the shear wave velocity by inversion approaches.The rotated correction function is applied to analyzing high quality ScS records from five earthquakes at distance of 25°~35° to obtain shear wave splitting parameters of the lithosphere.The result from the deepest earthquake among the five events indicates that the polarization of the fast shear wave is N94°E, which means the direction of extensional stress or the moving of the upper mantle mass in Xisha Islands is nearly west to east and confirms that the crust in this region is a transitional one and the driving force beneath the crust is from the moving mass consistent with the Eurasian plate.The anisotropy effective thickness is estimated about 100 km based on the time delay of 1.3 s between the fast and slow shear waves.The receiver function is applied to analyzing high quality P wave records from nine earthquakes at distance of 20°~60° to obtain the vertical distribution pattern of shear wave velocity beneath the station.The result indicates that the crust could be divided into three layers:the uppermost crust (5 km above) is a velocity gradient zone consisting of several small layers, where the shear wave velocity increases from 1.5 to 3.5 km/s gradually; the 5~16 km depth interval also consiss of several small layers of which the mean velocity is about 3.8 km/s; and the lower crust (16.0~26.5 km) is an obvious low velocity layer with a velocity of about 3.6 km/s.The buried depth of the Moho discontinuity is 26.5 km, the mean velocity of the layers beneath the Moho is about 4.7 km/s and there is an obvious low velocity layer just beneath the Moho.Moreover, analysis of the arrival time of converted waves and the swinging variation of velocity around the initial model suggests that smaller layers in the model maybe are not reliable but the low velocity layer between 16 and 26.5 km maybe is the real one that implies the plasticity of the lower crust.
Model study on Bohai ecosystem 2.Annual cycle of nutrient-phytoplankton dynamics
LIU Hao, YIN Baoshu
2006, (5): 74-91.
摘要:
Using the coupled bio-physical model described in the first paper of this series of studies, the annual variations of algae biomass and nutrient concentration in the Bohai Sea are simulated.Modeled results show that the onset of spring bloom is induced by high nutrient stocks stored in winter, though the initial time is earlier in shallow waters than in deep waters, for which the evolution of the vertical stratification in deep waters plays an important role; on the other hand, newly added river-borne nutrients and resuspending sediment-borne nutrients are responsible for the outburst of autumn blooms.On the basis of modeled results, it is also found that the BS ecosystem, as a whole, is limited by nitrogen all the year round, though the phosphorus limitation is apparent in the Laizhou Bay where the ratio of nitrogen concentration to phosphorus concentration is higher than 16 due to the contribution of newly added nutrient species from Huanghe River discharges.
Taxonomic composition,abundance and biomass of mesozooplankton in the Zhelin Bay-an estuary with intensive aquaculture
DONG Qiaoxiang, LIN Xiaoping, HE Xin, KELSO W E, HUANG Changjiang
2006, (5): 92-111.
摘要:
The Zhelin Bay is an estuary that supports intensive aquaculture in South China.Aside from traditional nutrient inputs derived from waste water and agriculture, the increased intensification of aquaculture has accelerated eutrophication during the past decade, jeopardizing aquacultural production.Annual variations of mesozooplankton in the Zhelin Bay were described, providing baseline data for long-term ecological studies.The taxonomic composition, abundance and biomass of mesozooplankton were studied monthly from July 2001 to July 2002 at 19 stations.Collections yielded 73 taxa, including 60 species of copepods, three species of cladocerans, as well as tunicates, chaetognaths, polychaetes, medusae, ostracods, rotatori, amphipods, planktonic mollusks, pelagic larvae, and planktonic shrimps.The Zhelin Bay was dominated by small mesozooplankton, with 76% of the species smaller than 1.4 mm, and 97% of the individuals smaller than 1.0 mm.Dominant species (Paracalanus crassirostris, Oithona brevicornis, and Penilia avirostris) accounting for 60% of the total abundance were less than 0.6 mm in body length.Species diversity, biomass, and total abundance of mesozooplankton were greater in the samples collected outside the bay than inside the bay.Samples from the outer and eastern boundaries of the bay had greater biomass, diversity, and abundance than those from the inner and western boundaries.Total abundance and biomass had a unimodal annual pattern and were the greatest in August 2001 when water temperature was maximum, and the least in February 2002 when water temperature was minimum.Canonical correspondence analysis (CCA) revealed that temperature, turbidity, nutrients and salinity were the main determinants of spatial and temporal distributions of mesozooplankton in the Zhelin Bay, and six distinct zones were identified across the 19 sampling stations.
Distribution pattern of pelagic amphipods and its affecting facors in the East China Sea
XU Zhaoli, JIANG Mei
2006, (5): 112-119.
摘要:
On the basis of data from four seasonal cruises in the East China Sea (23°30'~33°N, 118°30'~128°E) from 1997 to 2000, horizontal distribution of amphipods, seasonal variations of abundance and their dynamic mechanisms were approached with quantitative and qualitative methods.Results showed that the average value of amphipod abundance in autumn was 115×10-2 ind./m3, the highest in four seasons.The second occurred in summer with a mean value of 44×10-2 ind./m3 and the lowest occurred in spring with a mean of 10×10-2 ind./m3.Amphipods were hardly observed in the north nearshore (29°30'~33°N and 122°30'~125°E) in winter and spring.In all seasons, except for the north of the sea in autumn and the south in summer, the abundance in the offshore area was higher than that nearshore.The major species influencing the amphipod abundance were Lestrigonus schizogeneios in spring, L.macrophthalmus and L.schizogeneios in summer, L.bengalensis and Hyperioides sibaginis in autumn and Gammarus sp.in winter.The amphipod abundance showed a prominent linear correlation with the surface water temperature, but no significant correlation with both other water temperatures and salinity in spring.It was found that water temperature and salinity were not significantly correlated with the variation of amphipod abundance in summer, autumn and winter.In addition, the amphipod abundance in all four seasons can be linearly correlated with the bottom water temperature.The highest abundance area was located in the mixture waters near the side of warm water current in summer.Peak of amphipod abundance in autumn, not in summer told a temporal process for amphipods to develop their populations.The continuance of warm current was beneficial to the development of amphipod abundance from summer to autumn.Amphipods are kinds of very important diets for fishes in the offshore East China Sea.
Meiofauna distributions at the oxygen minimum zone in Changjiang (Yangtze) River Estuary waters
HUA Er, ZHANG Zhinan, ZHANG Yan
2006, (5): 120-134.
摘要:
A quantitative study on meiofauna was carried out along a transect throughout the Changjiang Estuary's oxygen minimum zone (OMZ) in the East China Sea.There exist two distinct station groups in the OMZ:the fine-grained hypoxic area and the more fine-grained anoxic area.Meiofauna abundance ranged from (101.5±31.0) ind./cm2 (hypoxic area) to (369.9±123.9) ind./cm2 (anoxic area) along the transect.Free-living marine nematodes were the numerically dominant meiofauna at every station.The anoxic area differed significantly in meiofauna abundance and vertical distribution pattern from the hypoxic area.Within the anoxic area, nematodes abundance increased and amounted to over 90% of the total meiofauna; about 50% of nematodes were found in the 2~5 and 5~8 cm layers.At hypoxic stations, about over 85% were restricted to the top 2 cm.Benthic copepod abundance and dominance decreased consistently with the oxygen gradient.The pattern of meiofauna biomass was similar to that of abundance.The correlation analysis of the meiofauna numbers and environmental parameters indicated that abundance and biomass of total meiofauna and nematodes had significant or highly significant (P<0.05 or P<0.01) correlations with Chl a and Pha a, but no significant (P>0.05) correlations with bottom-water oxygen (BWO2).On the other hand, there was a highly significant positive correlation between benthic copepod abundance and bottom-water oxygen (P<0.05).The investigation on the nematode community structure indicated that two different nematode communities existed in hypoxic and anoxic areas.In certain way, the shift in nematode species composition distinguishes the anoxia to hypoxia.Nematode diversity was generally lower within the anoxic stations than the hypoxic ones, but the difference was not significant.Indices of the nematode community structure varied in relation to the bottom-water oxygen together with bottom-water temperature, Chl a concentration and median grain size of sediment.
In vitro acute cytotoxicity of the neonicotinoid insecticide acetamiprid to FG cells, the gill cell line of flounder Paralichthy olivaceus
SU Feng, ZHANG Shicui, YANG Ming, LI Hongyan
2006, (5): 135-140.
摘要:
The in vitro acute cytotoxicity of the neonicotinoid insecticide acetamiprid to FG cell line, derived from the gill of flounder Paralichthys olivaceus, was tested by the three widely used endpoint bioassays-neutral red (NR) assay, tetrazolium (MTT) assay and cell protein assay.It was found that acetamiprid was increasingly toxic to FG cells at concentrations of 1 μg/cm3 or above, and the inhibitory concentration 50% values for NR, MTT, and cell protein assays were 38.38, 36.27 and 32.03 μg/cm3, respectively.This appeared to be the first report on the in vitro cytotoxicity of acetamiprid to non-mammalian vertebrate cells.Ultrastructural examination revealed that for the cells exposed to 60 μg/cm3 acetamiprid for 48 h, their mitochondria were severely damaged with the cristae swelled up or disrupted, while their nuclei and rough endoplasmic reticlum (RER) appeared to be still normal.This suggests that mitochondria are possibly the primary target of acetamiprid.
Effects of dietary vitamin A on antioxidant responses of abalone Haliotis discus hannai Ino
FU Jinghua, ZHANG Wenbing, MAI Kangsen, FENG Xiuni, XU Wei, LIUFU Zhiguo, TAN Beiping
2006, (5): 141-150.
摘要:
A 240 d growth experiment was conducted in a re-circulated water system to investigate the effects of dietary vitamin A on growth and antioxidant responses of abalone Haliotis discus hannai Ino.Triplicate groups of juvenile abalone[initial mass was (0.96±0.02) g, shell length was (17.70±0.06) mm] were fed to satiation one of three semi-purified diets containing 0, 1×103, 1×106 IU vitamin A per kilogram diet, respectively.Results showed that the daily increment in shell length (DISL) of abalone in the treatment with 1×103 IU vitamin A per kilogram diet was significantly higher than that with 0 or 1×106 IU vitamin A per kilogram supplementation (P> 0.05).Vitamin A deficiency (0 IU/kg) significantly elevated the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione reductase (GR) in the viscera of abalone (P> 0.05).In muscle, the effects of vitamin A deficiency on SOD and GPX activities were the same as those in viscera, however, the activity of GR significantly decreased (P> 0.05).Vitamin A deficiency significantly decreased the ratio of CAT to SOD (catalase/superoxide dismutase) in viscera (P> 0.05).Nevertheless, it significantly decreased the ratio of GR to GPX in muscle (P> 0.05).Compared with the supplement of 1×103 IU vitamin A per kilogram, excessive vitamin A (1×106 IU/kg) had no significant effects on the activities of CAT, SOD and glutathione-S-transferase (GST) (P> 0.05), but significantly elevated GPX and GR activities in viscera (P> 0.05).In muscle, the activities of CAT, SOD, GPX, GST and GR were significantly decreased by the excessive dietary vitamin A supplement (P> 0.05).Compared with the supplement of 1×103 IU vitamin A per kilogram, vitamin A-excessive had no significant effect on the value of ratio of CAT to SOD either in viscera or in muscle (P>0.05).The ratio of GR to GPX was significantly decreased in viscera, but significantly elevated in muscle in the vitamin A-excessive group (P> 0.05).In conclusion, optimum supplement of vitamin A (1×103 IU/kg) was beneficial for abalone to maintain maximum growth and antioxidant system.Hypo-or hyper-vitaminosis A would decrease growth and the efficiency of scavenging reactive oxygen species (ROS) of abalone.
Pedigree tracing of Fenneropenaeus chinensis by microsatellite DNA markers genotyping
DONG Shirui, KONG Jie, ZHANG Qingwen, LIU Ping, MENG Xianhong, WANG Rucai
2006, (5): 151-157.
摘要:
Two microsatellite DNA loci were used to trace the pedigree structure of six families in the shrimp Fenneropenaeus chinensis.Four of the families were natural mating, and the others were mated by artificial insemination.Eleven alleles were acquired at two microsatellite DNA loci (locus RS0622 and locus EN0033) by investigating 145 offsprings and 11 parents.Five alleles were acquired from locus RS0622 and six from locus EN0033.As analyzed, the gene frequencies were between 0.024 1 and 0.493 1, the heterozygosity was 0.652 2 and 0.688 8, and the polymorphism information content (PIC) was 0.585 7 and 0.652 9 for the locus RS0622 and the locus EN0033, respectively.Twenty-three genotypes were detected and the genotypes of the losing parents were also inferred.The pedigrees of three F1 and three F2 generations were determined by matching the genotype at each locus.