2004 Vol. 26, No. 2
Display Method:
2004, 26(2): 1-10.
Abstract:
On the basis of hydrographic data obtained in November 28-December 27, 1998 cruise, diagnostic calculation of the circulation in the South China Sea (SCS) is made by using the P vector method, in combination with SSH data from TOPEX/ERS-2 analysis.The following results have been obtained.(1) The main character istics of the circulation systems in the central SCS are as follows.A coastal southward jet in winter is present at the western boundary near the coast of Vietnam.There is a strong cyclonic circulation with a large horizontal scale east of this coastal southward jet and west of 114°E, and it is located about in the region from 10°N to 16°N.There is a weaker anticyclonic and warm eddy with a not large horizontal scale, and its center is located about at 14°N.There is a strong and nor theastward flow opposing the northeasterly monsoon between a strong cyclonic circulation and a weaker anticyclonic circulation above.The above distribution of circulation is the basic pattern of circulation in the central SCS, which agrees qualitatively with the horizontal distribution of temperature at 200 m level.
On the basis of hydrographic data obtained in November 28-December 27, 1998 cruise, diagnostic calculation of the circulation in the South China Sea (SCS) is made by using the P vector method, in combination with SSH data from TOPEX/ERS-2 analysis.The following results have been obtained.(1) The main character istics of the circulation systems in the central SCS are as follows.A coastal southward jet in winter is present at the western boundary near the coast of Vietnam.There is a strong cyclonic circulation with a large horizontal scale east of this coastal southward jet and west of 114°E, and it is located about in the region from 10°N to 16°N.There is a weaker anticyclonic and warm eddy with a not large horizontal scale, and its center is located about at 14°N.There is a strong and nor theastward flow opposing the northeasterly monsoon between a strong cyclonic circulation and a weaker anticyclonic circulation above.The above distribution of circulation is the basic pattern of circulation in the central SCS, which agrees qualitatively with the horizontal distribution of temperature at 200 m level.
2004, 26(2): 11-19.
Abstract:
Based on the data of sea ice grade in the Bohai Sea of China and the 74 factors of atmospheric circulation, the variation of sea ice conditions in decadal scale is studied by using the factors of atmospheric circulation in different time scale (year, half-year, season and month).The result shows that two period of sea ice conditions: the severe period (1932~1972) and the mild period (1973~2000) may be divided into by 1972 from 1932 to 2000 in the decadal variation, the most significant factor of atmospheric circulation influencing the sea ice conditions in the Bohai Sea is the subtropical high in the Pacific.
Based on the data of sea ice grade in the Bohai Sea of China and the 74 factors of atmospheric circulation, the variation of sea ice conditions in decadal scale is studied by using the factors of atmospheric circulation in different time scale (year, half-year, season and month).The result shows that two period of sea ice conditions: the severe period (1932~1972) and the mild period (1973~2000) may be divided into by 1972 from 1932 to 2000 in the decadal variation, the most significant factor of atmospheric circulation influencing the sea ice conditions in the Bohai Sea is the subtropical high in the Pacific.
2004, 26(2): 20-36.
Abstract:
Interannual variabilities of the temperature and circulation of global ocean, particularly of the tropical Pacific ocean, as well as the controlling mechanisms of ENSO evolution are investigated by a high resolution ocean general circulation model forced with COADS 1945~1993 monthly mean data.It was found that quite realistic interannual behaviors were reproduced well with the model.In the tropical Indian Ocean, the ENSO related basinwide warming/cooling mode and the dipole mode are successfully simulated.And the model also successfully simulates a ENSO-like mode of the SST variations in the tropical Atlantic on interannual time scale.In the tropical Pacific Ocean, the SST interannual variances are significantly dominated by ENSO variability, and the circulation also exhibits a mass cycle inter annual anomalies associated with ENSO, i.e., the mass cycle tends to weaken/intensify several months before a warm/cold event, among which the phase of SEC anomaly leads Nino 3 index to approx imate 5 months.The equatorial upwelling firstly appears on the surface 4 months before the mature phase of ENSO and subsequently spreads to the deep, an eastern propagation of EUC anomaly was found near 180° with its phase leads Nino3 index to 3 months.The eastern propagation of subsurface ocean temperature anomalies along equator was found closely related to the evolution of ENSO cycle, the "delayed oscillator" mode is the controlling mode of the model ENSO events.
Interannual variabilities of the temperature and circulation of global ocean, particularly of the tropical Pacific ocean, as well as the controlling mechanisms of ENSO evolution are investigated by a high resolution ocean general circulation model forced with COADS 1945~1993 monthly mean data.It was found that quite realistic interannual behaviors were reproduced well with the model.In the tropical Indian Ocean, the ENSO related basinwide warming/cooling mode and the dipole mode are successfully simulated.And the model also successfully simulates a ENSO-like mode of the SST variations in the tropical Atlantic on interannual time scale.In the tropical Pacific Ocean, the SST interannual variances are significantly dominated by ENSO variability, and the circulation also exhibits a mass cycle inter annual anomalies associated with ENSO, i.e., the mass cycle tends to weaken/intensify several months before a warm/cold event, among which the phase of SEC anomaly leads Nino 3 index to approx imate 5 months.The equatorial upwelling firstly appears on the surface 4 months before the mature phase of ENSO and subsequently spreads to the deep, an eastern propagation of EUC anomaly was found near 180° with its phase leads Nino3 index to 3 months.The eastern propagation of subsurface ocean temperature anomalies along equator was found closely related to the evolution of ENSO cycle, the "delayed oscillator" mode is the controlling mode of the model ENSO events.
2004, 26(2): 37-44.
Abstract:
China has launched her first China's ocean clolor satellite HY-1A on May 15, 2003 since American ocean color satellite SeaStar was on the orbit in 1997.First, the properties and characteristics of HY-1A are briefly introduced; second, the quality and availability are evaluated by means of the complex signal noise ratio (CSNR) which is simulated theoretically; third, the received HY-1A data are compared with SeaStar data to understand the accuracy of the HY-1A; finally, the remote sensing products of ocean color and temperature are mapped by the HY-1A to study its application potentiality.The results show that the HY-1A has its latent capability for the application of marine environment detection, the management and protection of marine resources, and the national rights and interests.Meanwhile some suggestions are proposed to modify the next ocean satellite.
China has launched her first China's ocean clolor satellite HY-1A on May 15, 2003 since American ocean color satellite SeaStar was on the orbit in 1997.First, the properties and characteristics of HY-1A are briefly introduced; second, the quality and availability are evaluated by means of the complex signal noise ratio (CSNR) which is simulated theoretically; third, the received HY-1A data are compared with SeaStar data to understand the accuracy of the HY-1A; finally, the remote sensing products of ocean color and temperature are mapped by the HY-1A to study its application potentiality.The results show that the HY-1A has its latent capability for the application of marine environment detection, the management and protection of marine resources, and the national rights and interests.Meanwhile some suggestions are proposed to modify the next ocean satellite.
2004, 26(2): 45-51.
Abstract:
Based on the systematic analy tical data on the organic pollutants in seawater and surface sediments from Zhejiang coastal zone, the relationships between accumulation of the organic pollutants in surficial sediments and environment factors such as sedimentary environment, mineral composition and sources were studied.The results show that the main organic pollutants in the coastal water and surficial sediments are petroleum alkanes, o-benzenedicar-bonic acid ester, organic silicon chain, phenol-chloride, phenylether and amine.Their accumulative amount in surficial sediments has a tendency towards the estuary sedimentary environment bemg greater than coastal sedimentary environment bemg greater than stronger tidal river sedimentary environment.The differences of the organic pollutant accumulation in the sediments in same sedimentary environment were known, which indicates that the accumulation of organic pollutants in coastal sediments was related not only to sedimentary environment, but also to the regional sources of organic pollutants.
Based on the systematic analy tical data on the organic pollutants in seawater and surface sediments from Zhejiang coastal zone, the relationships between accumulation of the organic pollutants in surficial sediments and environment factors such as sedimentary environment, mineral composition and sources were studied.The results show that the main organic pollutants in the coastal water and surficial sediments are petroleum alkanes, o-benzenedicar-bonic acid ester, organic silicon chain, phenol-chloride, phenylether and amine.Their accumulative amount in surficial sediments has a tendency towards the estuary sedimentary environment bemg greater than coastal sedimentary environment bemg greater than stronger tidal river sedimentary environment.The differences of the organic pollutant accumulation in the sediments in same sedimentary environment were known, which indicates that the accumulation of organic pollutants in coastal sediments was related not only to sedimentary environment, but also to the regional sources of organic pollutants.
2004, 26(2): 52-60.
Abstract:
Based on XRD results of clay mineral components with high resolution sampled sediments from two gravity cores with a sedimentary history about 130 000 a in the southern part of South China Sea, it is recognized that the clay minerals are mainly of terrigenous rather than authigenic origin.The differences in geologic condition, weathering environment and transport route in the lands around the study area, such as Kalimantan Island in the east, control the spatio temporal variation of component distribution of clay minerals along the sedimentary core.It is inter esting to discover that high concentration of smectite corresponds to the warm or interg lacial period, and low concentration of smectite to the cold or glacial period.The behavior and paleoceanographic indication of illite are opposite to those of smectite.As a research method, the high resolution study of clay components in the sediment cores will be helpful to explaining the source characteristics, transport path and paleoclimatic evolution since the late Quaternary in the South China Sea.
Based on XRD results of clay mineral components with high resolution sampled sediments from two gravity cores with a sedimentary history about 130 000 a in the southern part of South China Sea, it is recognized that the clay minerals are mainly of terrigenous rather than authigenic origin.The differences in geologic condition, weathering environment and transport route in the lands around the study area, such as Kalimantan Island in the east, control the spatio temporal variation of component distribution of clay minerals along the sedimentary core.It is inter esting to discover that high concentration of smectite corresponds to the warm or interg lacial period, and low concentration of smectite to the cold or glacial period.The behavior and paleoceanographic indication of illite are opposite to those of smectite.As a research method, the high resolution study of clay components in the sediment cores will be helpful to explaining the source characteristics, transport path and paleoclimatic evolution since the late Quaternary in the South China Sea.
2004, 26(2): 61-71.
Abstract:
After using ICP-AES to analyze clay fraction of the samples of Croe DGKS9603 which was taken from the middle Okinawa Trough, the conclusions are obtained as follows: the down variation of the element contents is caused by the paleoclimate and paleoenvironmental evolution; its material source varies clearly, biogenic source is the major source during 45~43 and 11.2~0 ka BP respectively; volcanic source is dominant during 43~41 ka BP and epicontinental source is the most important provenance during 41~11.2 ka BP.Additionally, the seven cold events E3, YD, H1, LGM, H2, H3, H5 are recorded clearly in Core DGKS9603, and the core is probably influenced by three volcanic events A, B, C.
After using ICP-AES to analyze clay fraction of the samples of Croe DGKS9603 which was taken from the middle Okinawa Trough, the conclusions are obtained as follows: the down variation of the element contents is caused by the paleoclimate and paleoenvironmental evolution; its material source varies clearly, biogenic source is the major source during 45~43 and 11.2~0 ka BP respectively; volcanic source is dominant during 43~41 ka BP and epicontinental source is the most important provenance during 41~11.2 ka BP.Additionally, the seven cold events E3, YD, H1, LGM, H2, H3, H5 are recorded clearly in Core DGKS9603, and the core is probably influenced by three volcanic events A, B, C.
2004, 26(2): 72-80.
Abstract:
Based on the clastic mineralogical and geochemical characteristics, it is indicated that the core 69 with a length of 560 cm (20°07.10"N, 118°49.0'E; 2 971 m water depth) sampled by gravity piston corer from the north-eastern South China Sea could be divided into the late Pleistocene last glacial period and the Holocene epoch with a boundary at about 165 cm.This result consists with that of the oxygen and carbon stable isotopic analyses of planktonic foraminifers.During the last glacial period, there was a relatively closed anoxic environment, dry and cold climate, weak chemical weathering conditions which were suggested by the characteristics of higher content of heavy mineral with abundant authigenic pyrite, higher SiO2 and S contents, and lower CaCO3 content, as well as higher ratios of Na to Al, Mg to Al and Na to K in sedimentary samples.The sediments are composed mainly of siliceous deposits.The lower CaCO3 contents of sediments might caused by the dilution of terrigenous components.In turn, during the postglacial period, the CaCO3 and Al2O3 contents became higher, and the ratios of Na to Al, Mg to Al and Na to K decreased, which reflected that the sedimentary environment became an open oxidation environment, the climate became humid and hot with a stronger condition of chemical weathering.The sediments are composed mainly of aluminosilicate deposits.Furthermore, the maximum carbonate content occurs in the deglaciation period.
Based on the clastic mineralogical and geochemical characteristics, it is indicated that the core 69 with a length of 560 cm (20°07.10"N, 118°49.0'E; 2 971 m water depth) sampled by gravity piston corer from the north-eastern South China Sea could be divided into the late Pleistocene last glacial period and the Holocene epoch with a boundary at about 165 cm.This result consists with that of the oxygen and carbon stable isotopic analyses of planktonic foraminifers.During the last glacial period, there was a relatively closed anoxic environment, dry and cold climate, weak chemical weathering conditions which were suggested by the characteristics of higher content of heavy mineral with abundant authigenic pyrite, higher SiO2 and S contents, and lower CaCO3 content, as well as higher ratios of Na to Al, Mg to Al and Na to K in sedimentary samples.The sediments are composed mainly of siliceous deposits.The lower CaCO3 contents of sediments might caused by the dilution of terrigenous components.In turn, during the postglacial period, the CaCO3 and Al2O3 contents became higher, and the ratios of Na to Al, Mg to Al and Na to K decreased, which reflected that the sedimentary environment became an open oxidation environment, the climate became humid and hot with a stronger condition of chemical weathering.The sediments are composed mainly of aluminosilicate deposits.Furthermore, the maximum carbonate content occurs in the deglaciation period.
2004, 26(2): 81-86.
Abstract:
The effects of a PSP producing dinoflag ellate Alexandrium tamarense on marine bivalves at their several important life stages: egg, S-shape larva, eyespot larva, juvenile and adult, are studied.The results show that the hatching, survival, activity, filtration and growth are adversely affected by the alga and the impact is significant with the increased algal density.The inhibitory effect on egg hatching is most significant, which the hatching rate is only 30% of the control when exposed to the alga at 100 cells/cm3 after 36 h.Fur ther experiment shows that the algal culture, cells and cell fragments have the inhibitory effect, but no effect from the cell-free medium, cell contents and standard STX.The results indicate that the alga can produce unknown toxins, rather than PSP, associated with the cell surface.
The effects of a PSP producing dinoflag ellate Alexandrium tamarense on marine bivalves at their several important life stages: egg, S-shape larva, eyespot larva, juvenile and adult, are studied.The results show that the hatching, survival, activity, filtration and growth are adversely affected by the alga and the impact is significant with the increased algal density.The inhibitory effect on egg hatching is most significant, which the hatching rate is only 30% of the control when exposed to the alga at 100 cells/cm3 after 36 h.Fur ther experiment shows that the algal culture, cells and cell fragments have the inhibitory effect, but no effect from the cell-free medium, cell contents and standard STX.The results indicate that the alga can produce unknown toxins, rather than PSP, associated with the cell surface.
2004, 26(2): 87-94.
Abstract:
Fifteen rare earth elements (REEs) in benthic seaweeds, molluscs and arthropods(mainly crustaceans) from the Xiamen Bay and adjacent waters w ere determined with an inductively coupled plasma mass spectrometer (ICPMS) in order to study the REE distribution and their environmental implications.The results show that the total REE contents in seaweeds vary between 0.780~49.1μg/g and the highest REE content is found in green seaweeds with an average of 24.3μg/g.The contents of REE in molluscs are between 0.365~21.6μg/g and the bivalves show the higher REE content than gastropods, with an average of 12.9μg/g.The contents of REE in art hropods are relatively low and range from 0.154 to 0.807μg/g.Enrichment of light REE (LREE) over heavy REEs (HREE) was observed for all benthic or ganisms, which suggested higher biological effects of LREE than those of heavy REEs.The NASC-normalized distribution pattern of REE for most benthic or ganisms showed a W-type tetrad effect, while small differences were observed for different biological groups.The significance of taxonomic and geographic variation in contents and distribution patterns of REE in benthic or ganisms for ecological environmental monitoring was discussed.
Fifteen rare earth elements (REEs) in benthic seaweeds, molluscs and arthropods(mainly crustaceans) from the Xiamen Bay and adjacent waters w ere determined with an inductively coupled plasma mass spectrometer (ICPMS) in order to study the REE distribution and their environmental implications.The results show that the total REE contents in seaweeds vary between 0.780~49.1μg/g and the highest REE content is found in green seaweeds with an average of 24.3μg/g.The contents of REE in molluscs are between 0.365~21.6μg/g and the bivalves show the higher REE content than gastropods, with an average of 12.9μg/g.The contents of REE in art hropods are relatively low and range from 0.154 to 0.807μg/g.Enrichment of light REE (LREE) over heavy REEs (HREE) was observed for all benthic or ganisms, which suggested higher biological effects of LREE than those of heavy REEs.The NASC-normalized distribution pattern of REE for most benthic or ganisms showed a W-type tetrad effect, while small differences were observed for different biological groups.The significance of taxonomic and geographic variation in contents and distribution patterns of REE in benthic or ganisms for ecological environmental monitoring was discussed.
2004, 26(2): 95-103.
Abstract:
Nonlinear time courses of NH4+ depletion from the mediumimply that the rate limiting step for ammonium uptake changes over time.NH4+ uptake by the starved macroalgae Gracilaria tenuistipitata var.liui and Ulva pertusa were studied from the depletion of NH4+ after single additions of NH4+ to cultures.The experiments were carried out by the combination of two different experimental setups——the "multiple flask" and the "perturbation" technologies.Uptake rate was nonlinear with time and decreased in Vm as incubation time increased (i.e., Vmax0~15, Vmax15~30, Vmax30~60, Vmax90~120 and Vmax120~240).The corresponding maximum uptake rates, the half saturation constants and the Vmax/Ks (a) ratios (the affinity for ammonium uptake at low substrate concentrations) in U.pertusa were all higher than those of in G.tenuistipitata.Three distinct succeeding phases of NH4+ uptake were identified: (1) Surge uptake phase, (2) internally controlled uptake phase, and (3) externally controlled uptake phase.The nature of NH4+ uptake rate of decline is species specific and may be due to feedback inhibition from the filling of an internal pool.
Nonlinear time courses of NH4+ depletion from the mediumimply that the rate limiting step for ammonium uptake changes over time.NH4+ uptake by the starved macroalgae Gracilaria tenuistipitata var.liui and Ulva pertusa were studied from the depletion of NH4+ after single additions of NH4+ to cultures.The experiments were carried out by the combination of two different experimental setups——the "multiple flask" and the "perturbation" technologies.Uptake rate was nonlinear with time and decreased in Vm as incubation time increased (i.e., Vmax0~15, Vmax15~30, Vmax30~60, Vmax90~120 and Vmax120~240).The corresponding maximum uptake rates, the half saturation constants and the Vmax/Ks (a) ratios (the affinity for ammonium uptake at low substrate concentrations) in U.pertusa were all higher than those of in G.tenuistipitata.Three distinct succeeding phases of NH4+ uptake were identified: (1) Surge uptake phase, (2) internally controlled uptake phase, and (3) externally controlled uptake phase.The nature of NH4+ uptake rate of decline is species specific and may be due to feedback inhibition from the filling of an internal pool.
2004, 26(2): 104-117.
Abstract:
A two-dimensional time-domain coupled numerical model is developed in order to obtain efficient method for nonlinear wave forces acted on moored ship in harbor.The fluid domain is divided into an inner domain and an outer domain.The inner domain is the area under the ship section, which is governed by Euler equations.The outer domain is the area outside the two sides of ship hull, which is governed by Boussinesq equations.Matching conditions on the interface boundaries between the inner domain and the outer domain are the continuation of volume flux and the equality of pressures.In addition, the boundary element method in complex is adopted to verify the coupled model.Relevant physical experiment is conducted to validate the two numerical models, and it is shown that the numerical results agree with experimental results, but the computational efficiency of the boundary element method is much lower than that of the coupled model.In addition, the numerical computations of the coupled model are simple, which can be used to compute the nonlinear wave forces acted on moored ship in harbor.
A two-dimensional time-domain coupled numerical model is developed in order to obtain efficient method for nonlinear wave forces acted on moored ship in harbor.The fluid domain is divided into an inner domain and an outer domain.The inner domain is the area under the ship section, which is governed by Euler equations.The outer domain is the area outside the two sides of ship hull, which is governed by Boussinesq equations.Matching conditions on the interface boundaries between the inner domain and the outer domain are the continuation of volume flux and the equality of pressures.In addition, the boundary element method in complex is adopted to verify the coupled model.Relevant physical experiment is conducted to validate the two numerical models, and it is shown that the numerical results agree with experimental results, but the computational efficiency of the boundary element method is much lower than that of the coupled model.In addition, the numerical computations of the coupled model are simple, which can be used to compute the nonlinear wave forces acted on moored ship in harbor.
2004, 26(2): 118-124.
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2004, 26(2): 125-131.
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2004, 26(2): 132-139.
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2004, 26(2): 140-148.
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