1998 Vol. 20, No. 5
Display Method:
1998, 20(5): 1-12.
Abstract:
The separation of the Kuroshio water in the northeastern East China Sea and its interaction with the shelf water are analysed on the basis of CTD data and the observations of 11 satellite-temperature traclred surface drifters conducted by the R/V Onnuri of Korea Ocean Research&Development Institute during August 25-September 7.1994 and then the formation process of the Tsushima Current in summer is also discussed.
The separation of the Kuroshio water in the northeastern East China Sea and its interaction with the shelf water are analysed on the basis of CTD data and the observations of 11 satellite-temperature traclred surface drifters conducted by the R/V Onnuri of Korea Ocean Research&Development Institute during August 25-September 7.1994 and then the formation process of the Tsushima Current in summer is also discussed.
1998, 20(5): 13-22.
Abstract:
A three-dimensional nonlinear baroclinic estuary and ocean model with primitive equation in σ-coordination system is developed to study the impacts of the factors of runoff, the Taiwan warm Current (TwC),the Huanghai Sea Cold water Mass (HSCWM)and wind field on the expansion of Changjiang diluted water(CDw). Numerical experiments show the northeast expansion of freshwater tongue of CDw and the circulation structure of the East China Sea. Runoff has an effect only on the trend of southeast expansion of CDw and the extent of expansion. As greatly affected by topography, TWC has a stable flow path that is independent of its strength. And also because of the long distance of TWC from the Changjiang Estuary, TWC has a very little effect on the expansion of CDw. The residual current induced by HSCWM blocks the CDw's southward expansion along the coast. In sea area far from the Changjiang Estuary, HSCwM induces the CDw expand southeast. The HSCWM has a significant influence on the northeast turning direction of the CDw. The stronger the HSCWM is, the greater the effect of the HSCwM's induced residual currents and the more obvious the northeast turning of the CDw.
A three-dimensional nonlinear baroclinic estuary and ocean model with primitive equation in σ-coordination system is developed to study the impacts of the factors of runoff, the Taiwan warm Current (TwC),the Huanghai Sea Cold water Mass (HSCWM)and wind field on the expansion of Changjiang diluted water(CDw). Numerical experiments show the northeast expansion of freshwater tongue of CDw and the circulation structure of the East China Sea. Runoff has an effect only on the trend of southeast expansion of CDw and the extent of expansion. As greatly affected by topography, TWC has a stable flow path that is independent of its strength. And also because of the long distance of TWC from the Changjiang Estuary, TWC has a very little effect on the expansion of CDw. The residual current induced by HSCWM blocks the CDw's southward expansion along the coast. In sea area far from the Changjiang Estuary, HSCwM induces the CDw expand southeast. The HSCWM has a significant influence on the northeast turning direction of the CDw. The stronger the HSCWM is, the greater the effect of the HSCwM's induced residual currents and the more obvious the northeast turning of the CDw.
1998, 20(5): 23-29.
Abstract:
Based on the nonlinear model of random sea waves which is exact to the second-order, the joint distribution of wave surface elevation and its first-and second-order derivatives with respect to time is derived by using the development of characteristic function and calculation directly each order moment. From the above joint distribution the statistical distribution of the maxima of sea wave surface is derived. The derived distribution is physically determined by both sea wave frequency spectra which is in the sense of linearity and the second-order wave-wave interaction. When nonlinear effect is neglected, the derived distribution of maxima of sea wove surface is reduced to that derived by Cartwright and Longuet-Higgins.
Based on the nonlinear model of random sea waves which is exact to the second-order, the joint distribution of wave surface elevation and its first-and second-order derivatives with respect to time is derived by using the development of characteristic function and calculation directly each order moment. From the above joint distribution the statistical distribution of the maxima of sea wave surface is derived. The derived distribution is physically determined by both sea wave frequency spectra which is in the sense of linearity and the second-order wave-wave interaction. When nonlinear effect is neglected, the derived distribution of maxima of sea wove surface is reduced to that derived by Cartwright and Longuet-Higgins.
1998, 20(5): 30-43.
Abstract:
A baroclinic typhoon mbdel with a moving triple-nested grid has been applied for marine environmental forecasts in the National Marine Environmental Forecasting Center of China. The governing equations of the model and the numerical methods have been described in the first part of this paper. An outline of the model grid,variational adjustment initialization and forecast experiments will be continued in the paper. The outmost region with coarse grids is fixed and the inner fine resolution regions follow the track of typhoon center. In the model,variables at the coarse and fine grids interact through two-way coupling. The equilibrium equation and the cu-equation, an idealized typhoon field and variational adjustment scheme are used for initialization of the typhoon model. Prediction results are improved by using a simple but effective data assimilation method in which the initial fields are adjusted by using a simple but effective data assimilation method in which the initial fields are adjusted by using the sixth hour's typhoon report and the week-constraint variational principle. Finally the results of the forecasts are shown in the paper. The statistics of the forecast errors show that the model has certain capability to predict typhoon tracks and gives good results for surface wind and pressure forecasts. And the typhoon model has been linked with a sea-wave model and satisfactory forecast for wave height has been gotten.
A baroclinic typhoon mbdel with a moving triple-nested grid has been applied for marine environmental forecasts in the National Marine Environmental Forecasting Center of China. The governing equations of the model and the numerical methods have been described in the first part of this paper. An outline of the model grid,variational adjustment initialization and forecast experiments will be continued in the paper. The outmost region with coarse grids is fixed and the inner fine resolution regions follow the track of typhoon center. In the model,variables at the coarse and fine grids interact through two-way coupling. The equilibrium equation and the cu-equation, an idealized typhoon field and variational adjustment scheme are used for initialization of the typhoon model. Prediction results are improved by using a simple but effective data assimilation method in which the initial fields are adjusted by using a simple but effective data assimilation method in which the initial fields are adjusted by using the sixth hour's typhoon report and the week-constraint variational principle. Finally the results of the forecasts are shown in the paper. The statistics of the forecast errors show that the model has certain capability to predict typhoon tracks and gives good results for surface wind and pressure forecasts. And the typhoon model has been linked with a sea-wave model and satisfactory forecast for wave height has been gotten.
1998, 20(5): 44-54.
Abstract:
Based on the reanalysis data of global 500 hPa geopotential height (NCEP-NCAR CDAS-1) and tropical Pacific SSTs, the characteristics of the global subtropical highs and their response to tropical eastern Pacific SST are investigated. Results show that the global subtropical highs respond to SST consistently. Subtropical high intensity correlates to the 3 months leading SST maximally. The relationships between SST and 500 hPa height stand out in low latitudes. The time for 500 hPa height reaching maximum correlation to SST is 2 months later in latitude of 100 and 9 months in latitude of 300 than equatorial zone. And the response of atmospheric circulation over extratropic performs as wave train, and the response is more significant in the condition of warmer SST. Persistence of SSTs and subtropical highs change obviously from season to season. Minimum persistence of subtrbpical highs in September and October may relate to the low persistence of SSTs in August and September.
Based on the reanalysis data of global 500 hPa geopotential height (NCEP-NCAR CDAS-1) and tropical Pacific SSTs, the characteristics of the global subtropical highs and their response to tropical eastern Pacific SST are investigated. Results show that the global subtropical highs respond to SST consistently. Subtropical high intensity correlates to the 3 months leading SST maximally. The relationships between SST and 500 hPa height stand out in low latitudes. The time for 500 hPa height reaching maximum correlation to SST is 2 months later in latitude of 100 and 9 months in latitude of 300 than equatorial zone. And the response of atmospheric circulation over extratropic performs as wave train, and the response is more significant in the condition of warmer SST. Persistence of SSTs and subtropical highs change obviously from season to season. Minimum persistence of subtrbpical highs in September and October may relate to the low persistence of SSTs in August and September.
1998, 20(5): 55-60.
Abstract:
The larvae of bay scallop Argopecten irradians were treated with catecholamines and metal canons, to test the ability of these compounds to induce metamorphosis. Epinephrine (10-4~10-6 mol/dm3),norepinephrine(10-5 mol/dm3)and L-DOPA(10-5 mol/dm3)could increase metamorphosis significantly; at long duration exposure to excess KCl and CaCl2,the metamorphosis of larvae was increased. When the larvae were induced with the optimum concentration of epinephrine, L-DOPA and KCl in a series time, they exhibited high sensitivity to epinephrine and L-DOPA, but the efficiency of K+ depended on time and dose. These suggest that epinephrine and L-DOPA appear to be via receptor-mediated pathway to trigger the process of metamorphosis; the elevated external concentration of K+ is to cause the depolarization of excitable cells and then enhance the larvae to metamorphose. The results of our study can offer an useful technique for inducing metamorphosis in spats commercial rearing of molluscs.
The larvae of bay scallop Argopecten irradians were treated with catecholamines and metal canons, to test the ability of these compounds to induce metamorphosis. Epinephrine (10-4~10-6 mol/dm3),norepinephrine(10-5 mol/dm3)and L-DOPA(10-5 mol/dm3)could increase metamorphosis significantly; at long duration exposure to excess KCl and CaCl2,the metamorphosis of larvae was increased. When the larvae were induced with the optimum concentration of epinephrine, L-DOPA and KCl in a series time, they exhibited high sensitivity to epinephrine and L-DOPA, but the efficiency of K+ depended on time and dose. These suggest that epinephrine and L-DOPA appear to be via receptor-mediated pathway to trigger the process of metamorphosis; the elevated external concentration of K+ is to cause the depolarization of excitable cells and then enhance the larvae to metamorphose. The results of our study can offer an useful technique for inducing metamorphosis in spats commercial rearing of molluscs.
1998, 20(5): 61-64.
Abstract:
All antifouling paints in use today are effective because toxic ingredients based on heavy metals are included in their formulation, the environmental effects of organotins in seawater have been a topic of much interest and concern in recent years. This study has found that the material of rich silicone rubber on coating surfacebased on the low dispersive component of surface energy makes barnacle settling on them unable to attach permanently and could be removed by moving water,the material permitted only small amounts of fouling to attach, such as algae, ciona intestinalis,because the high polar interaction of coating surface may be absorb water so that water film was formed in sea,and cause very low adhesion of the fouling species.
All antifouling paints in use today are effective because toxic ingredients based on heavy metals are included in their formulation, the environmental effects of organotins in seawater have been a topic of much interest and concern in recent years. This study has found that the material of rich silicone rubber on coating surfacebased on the low dispersive component of surface energy makes barnacle settling on them unable to attach permanently and could be removed by moving water,the material permitted only small amounts of fouling to attach, such as algae, ciona intestinalis,because the high polar interaction of coating surface may be absorb water so that water film was formed in sea,and cause very low adhesion of the fouling species.
1998, 20(5): 65-69.
Abstract:
The study on the effect of lanthanum-proline and lanthanum-phenylalanine complexes on Isochrysis galbana showed that these two complexes could distinctly enhance its cell reproduction and chlorophyll synthesis. When the concentrations of lanthanum-proline and lanthanum-phenylalanine were 5~20 mg/dm3, the cell numbers on the sixth day were increased by 10.8%~17.2% and 11.5%~20.5%,and the concentrations of chlorophyll by 31.7%~37.5% and 44.7%-48.4%,respectively (P<0.05),with an optimum concentration of 10 mg/dm3. The effect of lanthanum-proline and lanthanum-phenylalanine on Isochrysis galbans was the same as that of lanthanum.
The study on the effect of lanthanum-proline and lanthanum-phenylalanine complexes on Isochrysis galbana showed that these two complexes could distinctly enhance its cell reproduction and chlorophyll synthesis. When the concentrations of lanthanum-proline and lanthanum-phenylalanine were 5~20 mg/dm3, the cell numbers on the sixth day were increased by 10.8%~17.2% and 11.5%~20.5%,and the concentrations of chlorophyll by 31.7%~37.5% and 44.7%-48.4%,respectively (P<0.05),with an optimum concentration of 10 mg/dm3. The effect of lanthanum-proline and lanthanum-phenylalanine on Isochrysis galbans was the same as that of lanthanum.
1998, 20(5): 70-74.
Abstract:
A simple model is established to describe the fate of particle-reactive pollutants in the Xiamen Bay. Based on the conditional distribution coefficients (Kd) of chemicals and residence times of particle and waters, the model can be used to predict the fractions of pollutants which would be scavenged to sediments and would be escaped from the system. The model is calibrated using scavenging data derived from 234Th-238U disequilibria. The fate of a potential pollutant which will be scavenged is a function of the properties of the chemical, of the particle dynamics, and of the waters dynamics in the environment. It is inappropriate to overlook any factor.
A simple model is established to describe the fate of particle-reactive pollutants in the Xiamen Bay. Based on the conditional distribution coefficients (Kd) of chemicals and residence times of particle and waters, the model can be used to predict the fractions of pollutants which would be scavenged to sediments and would be escaped from the system. The model is calibrated using scavenging data derived from 234Th-238U disequilibria. The fate of a potential pollutant which will be scavenged is a function of the properties of the chemical, of the particle dynamics, and of the waters dynamics in the environment. It is inappropriate to overlook any factor.
1998, 20(5): 75-82.
Abstract:
Modern surface sediment samples collected from the tidal flats of the Jiangsu middle-south coast were quantitatively analysed. The results show the foraminiferal taphocoenoses are mixed from the indigenous with allochthonous compositions. The features of the taphoconoses are high in diversity, strongly variable in abundance, small in test size, rich in planktonic forms and common in mechanical destruction (test abrasion and brokenness). All these features are related tidal transport processes which are the dominant hydrodynamis conditions in the study area. During the transport, deposition processes, foraminiferal tests are well sorted, mixed and destructed. Therefore, the foraminiferal taphocoenoses in the study area are the combined product of ecoloeical and taphonomic factors of the environment.
Modern surface sediment samples collected from the tidal flats of the Jiangsu middle-south coast were quantitatively analysed. The results show the foraminiferal taphocoenoses are mixed from the indigenous with allochthonous compositions. The features of the taphoconoses are high in diversity, strongly variable in abundance, small in test size, rich in planktonic forms and common in mechanical destruction (test abrasion and brokenness). All these features are related tidal transport processes which are the dominant hydrodynamis conditions in the study area. During the transport, deposition processes, foraminiferal tests are well sorted, mixed and destructed. Therefore, the foraminiferal taphocoenoses in the study area are the combined product of ecoloeical and taphonomic factors of the environment.
1998, 20(5): 83-89.
Abstract:
An artificial neural network model is founded by analysing the background of the Pacific polymetallic nodules, that is used to study the relationship between geologic factors and distribution of polymetallic nodules in the area studied by BP method. In this paper, we advanced random BP method, and developed a software package of artificial neural network that can rapidly calculate abundance of polymetallic nodules in any site of the area studied.
An artificial neural network model is founded by analysing the background of the Pacific polymetallic nodules, that is used to study the relationship between geologic factors and distribution of polymetallic nodules in the area studied by BP method. In this paper, we advanced random BP method, and developed a software package of artificial neural network that can rapidly calculate abundance of polymetallic nodules in any site of the area studied.
1998, 20(5): 90-92.
Abstract:
Compared with the specific activity of protease, amylase and lipase in Pagrosomus major larva, juvenile and young fish in summer and winter, the result suggests that the changes of activity of the three enzymes were general similar. The activity of protease in winter was lower a grade of ten than that in summer; the activity of amylase in winter was.lower about twice than that in summer. This was possibly caused by temperature. The activity of lipase in winter was not only higher than that in summer, but kept in a relative stable level. It was suggested that the activity of lipase would make an important role in the growth and survival of the fish fry in winter.
Compared with the specific activity of protease, amylase and lipase in Pagrosomus major larva, juvenile and young fish in summer and winter, the result suggests that the changes of activity of the three enzymes were general similar. The activity of protease in winter was lower a grade of ten than that in summer; the activity of amylase in winter was.lower about twice than that in summer. This was possibly caused by temperature. The activity of lipase in winter was not only higher than that in summer, but kept in a relative stable level. It was suggested that the activity of lipase would make an important role in the growth and survival of the fish fry in winter.
1998, 20(5): 93-100.
Abstract:
This study is based on the quantitative analysis on 805 net samples of 69 stations (28°～34°N, 120°30'～127°E),hauled vertically (from bottom to surface layers) with a small plankton net (76 pm in mesh diameter) by State Oceanic Administration during the monthly cruises between December 1977 and November 1978, approaches the characteristics of Trichodesmium distribution in a year round in the waters and the relationship of Trichodessnium with some environmental factors (including temperature, salinity and current systerns such as Kuroshio and so on).
This study is based on the quantitative analysis on 805 net samples of 69 stations (28°～34°N, 120°30'～127°E),hauled vertically (from bottom to surface layers) with a small plankton net (76 pm in mesh diameter) by State Oceanic Administration during the monthly cruises between December 1977 and November 1978, approaches the characteristics of Trichodesmium distribution in a year round in the waters and the relationship of Trichodessnium with some environmental factors (including temperature, salinity and current systerns such as Kuroshio and so on).
1998, 20(5): 101-108.
Abstract:
Abstract-Under different UV light conditions,the cells growth rate,Chl a,dimethylsulfoniopropionat (DMSP)content and dimethysulfide(DMS)releases of Phaeocystis antarctica were determined and showed that ultraviolet (UV-B) inhibit cells growth rate and Chl a. The high capability of cleaved DMSP to DMS and acrylic acid may be caused by UV-B radiation,UV-A inhibits DMSP synthesis. Phaeocystis antarctica is widely distribution in polar water and forms massive near surface blooms in the marginal ice edge zone around Antarctica during spring and summer. A large amount of DMS was released during Phaeocystis antarctica bloom. It is likely significantly that the masses of DMS released in polar water could be relative to the effect of UV-B irradiation from stratospheric ozone depletion.
Abstract-Under different UV light conditions,the cells growth rate,Chl a,dimethylsulfoniopropionat (DMSP)content and dimethysulfide(DMS)releases of Phaeocystis antarctica were determined and showed that ultraviolet (UV-B) inhibit cells growth rate and Chl a. The high capability of cleaved DMSP to DMS and acrylic acid may be caused by UV-B radiation,UV-A inhibits DMSP synthesis. Phaeocystis antarctica is widely distribution in polar water and forms massive near surface blooms in the marginal ice edge zone around Antarctica during spring and summer. A large amount of DMS was released during Phaeocystis antarctica bloom. It is likely significantly that the masses of DMS released in polar water could be relative to the effect of UV-B irradiation from stratospheric ozone depletion.
1998, 20(5): 109-113.
Abstract:
Seasonal differences were analysed comprehensively based on the informations with obvious difference between summer and winter on the effect of Kuroshio, South China Sea Warm Current, Huanghai Sea Cold Water Mass, Tsushima Warm Current,coastal current in Fujian and Zhejiang, coastal current in East Guangdong, seasonal wind and runoff to near seas of China. It is shown that the difference brings about the seasonal changes of geographic location on community habitat of Ostracoda.
Seasonal differences were analysed comprehensively based on the informations with obvious difference between summer and winter on the effect of Kuroshio, South China Sea Warm Current, Huanghai Sea Cold Water Mass, Tsushima Warm Current,coastal current in Fujian and Zhejiang, coastal current in East Guangdong, seasonal wind and runoff to near seas of China. It is shown that the difference brings about the seasonal changes of geographic location on community habitat of Ostracoda.
1998, 20(5): 114-119.
Abstract:
An acoustic suspended sediment monitor(ASSM)has been developed for the observations of suspended sediment concentration profilers in water, monitoring pollutants in water and for the studies of coastal sediment transportation and deposition. The determination of main technical parameters and the methodology of resolving key techniques are reviewed. The ASSM was applied to observe the suspended sediment in the Changjiang River Estuary, typical suspended sediment concentration profilers are obtained.
An acoustic suspended sediment monitor(ASSM)has been developed for the observations of suspended sediment concentration profilers in water, monitoring pollutants in water and for the studies of coastal sediment transportation and deposition. The determination of main technical parameters and the methodology of resolving key techniques are reviewed. The ASSM was applied to observe the suspended sediment in the Changjiang River Estuary, typical suspended sediment concentration profilers are obtained.
1998, 20(5): 120-125.
Abstract:
The key to the problem of probing the concentration of suspended sediment in water and its variation with acoustic equipment is how to calibrate the obtained data. Combining the acoustic backscatter intensity data with the real concentration of suspended sediment from water samples collected from the Changjiang River Estuary. three in-situ calibration methods for transforming measured sediment are induced. Results show that the discrepancies between calibrated values given by characteristic times calibration and real ones are less than the values given by single shot method, and the statistical error is 20% approximately. Calibration on characteristic times can be more simple and practice than synchronic calibration.
The key to the problem of probing the concentration of suspended sediment in water and its variation with acoustic equipment is how to calibrate the obtained data. Combining the acoustic backscatter intensity data with the real concentration of suspended sediment from water samples collected from the Changjiang River Estuary. three in-situ calibration methods for transforming measured sediment are induced. Results show that the discrepancies between calibrated values given by characteristic times calibration and real ones are less than the values given by single shot method, and the statistical error is 20% approximately. Calibration on characteristic times can be more simple and practice than synchronic calibration.
1998, 20(5): 126-135.
Abstract:
Based on Navier-Stokes equation, the model equation has been deduced through algebraic coordinate transformation, then under this coordinate, the three-dimensional flow field is split into many layers along its depth and the model equation in each layer is integrated. As to numerical solving method, split step characteristic difference approximation and Galerkin lumping coefficient matrix definite element method are utilized. In a practical application,three-dimensional calculation to the tide current in the Lianzhou Bay, Zhuang Autonomous Region of Guangxi is done.
Based on Navier-Stokes equation, the model equation has been deduced through algebraic coordinate transformation, then under this coordinate, the three-dimensional flow field is split into many layers along its depth and the model equation in each layer is integrated. As to numerical solving method, split step characteristic difference approximation and Galerkin lumping coefficient matrix definite element method are utilized. In a practical application,three-dimensional calculation to the tide current in the Lianzhou Bay, Zhuang Autonomous Region of Guangxi is done.
1998, 20(5): 136-141.
Abstract:
The scour in front of vertical breakwater under the action of irregular waves was studied by the method of combined theoretical and experimental work. Basic conclusions of this study can be given as follows; (I)The maximum depth of scouring trough can be detemined by Eq.(6),when the bottom surface is horizontal and the foundation of breakwater is under the cover of the bottom surface. (2) In case hc/h<0.4, the effect of hc on the scouring patterns is not obvious. (3) The effect of the slope of the bottom surface on the scouring patterns is obvious. (4) As for the depths of scouring troughs, the more far from the breakwater, the more small.
The scour in front of vertical breakwater under the action of irregular waves was studied by the method of combined theoretical and experimental work. Basic conclusions of this study can be given as follows; (I)The maximum depth of scouring trough can be detemined by Eq.(6),when the bottom surface is horizontal and the foundation of breakwater is under the cover of the bottom surface. (2) In case hc/h<0.4, the effect of hc on the scouring patterns is not obvious. (3) The effect of the slope of the bottom surface on the scouring patterns is obvious. (4) As for the depths of scouring troughs, the more far from the breakwater, the more small.
1998, 20(5): 142-146.
Abstract:
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